WO2024155720A1

WO2024155720A1 - Medical system

Info

Publication number: WO2024155720A1
Application number: PCT/US2024/011849
Authority: WO
Inventors: Brad Matthew Kellerman; Christopher Dean CHAPEK; Joseph Rodgers STEELE JR.; John Frederick PONTIUS; Jeffrey E. Hull; Jill SOMMERSET; J. Christopher Flaherty
Original assignee: Aveera Medical, Inc.
Priority date: 2023-01-18
Filing date: 2024-01-17
Publication date: 2024-07-25

Abstract

Provided herein are systems and methods for performing a medical procedure. The system can include a channel creation device for forming a flow pathway between two blood vessels. Flow of oxygenated blood through the flow pathway can treat or at least improve one or more medical conditions of the patient.

Description

MEDICAL SYSTEM

DESCRIPTION

RELATED APPLICATIONS

[001] This application claims benefit of United States Provisional Application Serial Number 63/439,760, titled “Medical System”, filed January 18, 2023, the content of which is incorporated by reference in its entirety for all purposes.

[002] This application claims benefit of United States Provisional Application Serial Number 63/535,206, titled “Medical System”, filed August 30, 2023, the content of which is incorporated by reference in its entirety for all purposes.

TECHNICAL FIELD

[003] The present invention relates generally to medical systems, and in particular, systems for performing a revascularization procedure.

BACKGROUND

[004] Numerous surgical, laparoscopic, and interventional procedures are used to perform a revascularization procedure in mammalian patients. There is a need for improved procedures which have improved safety and/or efficacy.

BRIEF SUMMARY

[005] According to an aspect of the present inventive concepts, a method of treating a medical condition of a patient comprises: selecting a patient for treatment; performing an identification procedure comprising: identifying a source vessel; identifying a perfusion vessel; and identifying an anatomical location for a channel; providing vascular access comprising: providing venous access; and/or providing arterial access; and creating the channel between the source vessel and the perfusion vessel at an intended channel location (also referred to as “target channel location”, “proposed channel location”, or simply “channel location”). Blood flow through the channel delivers oxygenated blood to target tissue which treats the medical condition of the patient.

[006] In some embodiments, the medical condition treated comprises ischemia. The ischemia can comprise critical limb ischemia. The critical limb ischemia can comprise ischemia of the foot.

[007] In some embodiments, the medical condition comprises end-stage plantar disease.

[008] In some embodiments, the patient selected for treatment exhibits a criteria selected from the group consisting of: source vessel diameter of at least 1.2mm, 1.5mm, 1.7mm and/or 2.0mm; perfusion vessel diameter of at least 1.2mm, 1.5mm, and/or 2.0mm; patient has Rutherford Category 5/6 Ischemia with ulceration; patient has Small arterial disease (SAD); patient has slow pedal acceleration time (PAT), such as slow PAT in the lateral plantar artery, dorsalis pedis artery, distal tibial artery, arcuate artery, and/or peroneal vessel artery, such as when the PAT has a value of at least 225ms; a resistive index that exceeds a threshold; and combinations thereof.

[009] In some embodiments, the patient is selected for treatment if one or more pedal arteries are not patent and/or if one or more tibial arteries are not patent.

[010] In some embodiments, the patient is selected for treatment if a previous arterial revascularization procedure has failed.

[011] In some embodiments, the patient is selected for treatment if diffuse calcium is present in one or more pedal arteries.

[012] In some embodiments, the patient is selected for treatment if the patient’s MAC score is 4 or 5.

[013] In some embodiments, the patient is selected for treatment if the patient exhibits small artery disease (SAD).

[014] In some embodiments, the patient is selected for treatment if the patient exhibits an ankle-brachial index (AB I) of no more than 0.39.

[015] In some embodiments, the patient is selected for treatment if the patient exhibits an absolute ankle pressure of no more than 50mmHg.

[016] In some embodiments, the patient is selected for treatment if the patient exhibits a peak pressure of no more than 30mmHg. [017] In some embodiments, the patient is selected for treatment if the patient exhibits a Rutherford Category of 5 or 6.

[018] In some embodiments, the patient is excluded from treatment if the ratio of the diameter of the source vessel at the channel location to the diameter of the perfusion vessel at the channel location is below a threshold. The threshold can comprise a ratio of 3 : 1, 2.5: 1, and/or 2: 1.

[019] In some embodiments, the patient is excluded from treatment if the patient has a source vessel with a stenosis above a threshold. The threshold can comprise a stenosis percentage of 20%, 30%, and/or 40%.

[020] In some embodiments, the patient is excluded from treatment if the patient has a quantity of digit wounds above a threshold. The threshold can be two digit wounds or three digit wounds.

[021] In some embodiments, the method can further comprise amputating one or more digits of the patient, and the creation of the channel is configured to promote healing of the amputation site. The amputating of the one or more digits can be performed at least 1 week, 3 weeks, and/or 5 weeks after the creation of the channel. The amputating of the one or more digits can be performed at least 5 weeks after the creation of the channel.

[022] In some embodiments, the patient is excluded from treatment if the patient has a wound surface area above a threshold in the area to be treated. The patient can be excluded from treatment if the patient has digit wounds that prevent healing or prevent successful amputation of tissue after creation of the channel. The patient can be excluded from treatment if the patient has digit wounds covering more than 50% of a digit of the patient. The patient can be excluded from treatment if the patient has a wound that covers or penetrates more than 50% of a metatarsal length.

[023] In some embodiments, the method can further comprise performing an imaging procedure of a portion of the patient’s anatomy to gather information related to inclusion or exclusion of the patient for treatment. The imaging procedure can comprise a procedure selected from the group consisting of: contrast-based imaging such as angiography and/or CT angiography; ultrasound; magnetic resonance angiography or venography; and combinations thereof. The imaging procedure can comprise obtaining retrograde access of a lateral plantar vein, median marginal vein and/or other veins of the foot, and then performing an angiogram to map the venous anatomy of the foot. The method can further comprise dilating one or more blood vessels prior to performing the angiogram. The dilating can comprise a procedure selected from the group consisting of: warming of a leg, foot, or other tissue such as via a warming blanket; application of nitroglycerin gel; applying a tourniquet on the venous outflow; systemically inject nitro infused saline, such as via an IV line; and combinations thereof. The patient can be excluded from treatment if a communicating vein in a diseased area to be treated can be not present. The imaging procedure determines the diameter of one or more blood vessels of the patient, and the patient can be excluded from treatment if at least one of the determined diameters can be not above a threshold. The patient can be excluded from treatment if the diameter of a source vessel or perfusion vessel at the channel location can be not above a threshold. The patient can be excluded from treatment if the patient has a source vessel with a diameter at the channel location that can be not above a threshold. The threshold can comprise a diameter of at least 2.0mm, 2.5mm, and/or 3.0mm. The patient can be excluded from treatment if the diameter of a downstream vein that receives blood via the channel can be not above a threshold. The downstream vein can comprise the lateral plantar vein, and the threshold can comprise a diameter of at least 1.0mm, 1.2mm, and/or 1.5mm. The patient can be excluded from treatment if the patient’s anatomy can be missing the pedal loop and/or missing one or more segments of the pedal loop.

[024] In some embodiments, the method can further comprise performing a treatment procedure on the source vessel and/or a vessel in fluid communication with the source vessel. The treatment procedure can comprise a treatment procedure selected from the group consisting of: a vessel dilation procedure; an atherectomy procedure; a stenting procedure; intravascular lithrotripsy (IVL) procedure; and combinations thereof.

[025] In some embodiments, the source vessel comprises an artery selected from the group consisting of: femoral artery; popliteal artery; tibial artery; anterior tibial artery; posterior tibial artery; tibioperoneal (TP) trunk artery; peroneal artery; brachial artery; radial artery; ulnar artery; a cardiac artery; and combinations thereof.

[026] In some embodiments, the perfusion vessel comprises a vein selected from the group consisting of: femoral vein; popliteal vein; tibial vein; anterior tibial vein; posterior tibial vein; tibioperoneal (TP) trunk vein; brachial vein; radial vein; ulnar vein; a cardiac vein; and combinations thereof. [027] In some embodiments, the source vessel comprises a popliteal artery, tibial artery and/or peroneal artery. The tibial artery can comprise a posterior tibial artery and/or anterior tibial artery.

[028] In some embodiments, the perfusion vessel comprises a native in-situ vein. The in- situ vein can be comprised of a tibial vein and/or peroneal vein. The tibial vein can comprise a posterior tibial vein and/or anterior tibial vein.

[029] In some embodiments, the identification procedure comprises performing an identification using x-ray imaging such as fluoroscopy or computed tomography (CT) scan.

[030] In some embodiments, the identification procedure comprises performing an identification using ultrasound imaging. The ultrasound imaging can comprise intravascular ultrasound.

[031] In some embodiments, the identification procedure comprises performing an identification using x-ray imaging and ultrasound imaging.

[032] In some embodiments, the identification procedure comprises performing an identification using an endovascular non-radiating imaging device.

[033] In some embodiments, the channel location is at least 5mm, 10mm, and/or 15mm proximal to a calcified and/or partially occluded portion of the source vessel.

[034] In some embodiments, the identification procedure identifies a location for the channel at an anatomical location in which the source vessel and the perfusion vessel are separated by no more than a maximum threshold distance. The maximum threshold distance can comprise a distance of no more than 1.5mm.

[035] In some embodiments, the identification procedure identifies a location for the channel at an anatomical location in which the source vessel has a diameter of at least 2.0mm.

[036] In some embodiments, the identification procedure identifies a location for the channel at an anatomical location in which the source vessel has a diameter of less than 2.0mm, and wherein the source vessel is dilated to achieve a diameter of at least 2.0mm at the channel location. The source vessel can be dilated at least 25%, no more than 50%, or both.

[037] In some embodiments, the identification procedure identifies a location for the channel at an anatomical location in which the perfusion vessel has a diameter of at least 2.0mm. [038] In some embodiments, venous access is provided into a vein selected from the group consisting of: lateral plantar vein; posterior tibial vein; anterior tibial vein; peroneal vein; medial marginal vein; a perforator vein; arcuate vein; and combinations thereof.

[039] In some embodiments, the providing venous access comprises providing pedal access. The providing pedal access can comprise providing access to the lateral plantar vein and/or the arcuate vein.

[040] In some embodiments, venous access is provided using image guidance, image assistance, or both. The image guidance and/or image assistance can be performed using ultrasound, a venogram, and/or a vein finder.

[041] In some embodiments, providing venous access comprises using a vein finder to access a superficial vein; performing a venography via the superficial vein to find a deep vein; and accessing the deep vein using fluoroscopy and/or ultrasound imaging.

[042] In some embodiments, providing venous access comprises finding a vein with image assistance and performing a surgical cutdown.

[043] In some embodiments, the providing venous access comprises placing a guidewire into one or more veins under image guidance. The image guidance can comprise ultrasound image guidance, x-ray image guidance, or both. The placing a guidewire can comprise advancing the guidewire to a perforating vein. The guidewire can be placed directly into a perforating vein, such as a perforating vein that connects the dorsal and plantar veins. The guidewire can be advanced through the lateral plantar vein into the posterior tibial vein. The guidewire can be advanced into the tibioperoneal trunk. The providing venous access can comprise placing a guide catheter with a diameter less than or equal to a threshold diameter. The threshold diameter can equal 6Fr. The guide catheter can be configured to allow injection of visualizable material when a guidewire can be positioned within the guide catheter. The guide catheter can comprise a tapered lumen and a distal portion including fluid delivery ports for delivery of the visualizable material. The guidewire can comprise a lumen through which visualizable material can be delivered. The guidewire can comprise a proximal end with a rotating connector and an atraumatic distal portion including fluid delivery ports. The guidewire can comprise a hypotube with a laser cut pattern. [044] In some embodiments, arterial access is provided into an artery selected from the group consisting of: femoral artery; common femoral artery; superficial femoral artery; popliteal artery; and combinations thereof.

[045] In some embodiments, providing arterial access comprises placement of a sheath in a femoral artery, such as a sheath with a diameter of at least 4Fr and/or no more than lOFr, such as an 8cm or 10cm sheath.

[046] In some embodiments, the providing arterial access comprises placing a guidewire into one or more arteries under image guidance. The guidewire can comprise a lumen through which visualizable material can be delivered. The guidewire can comprise a proximal end with a rotating connector and an atraumatic distal portion including fluid delivery ports.

[047] In some embodiments, the channel is void of an implanted device.

[048] In some embodiments, a stent, a covered stent, and/or another scaffolding device is implanted within or at least proximate the channel, wherein the scaffolding device remains in place for a limited time period, such as a time period of no more than 1 week, 1 month, and/or 3 months. The scaffolding device can be configured to be removed and/or bioabsorbed within the limited time period.

[049] In some embodiments, creating the channel comprises placing a guidewire between the source vessel and the perfusion vessel. The guidewire can be placed with a device similar to an Outback Elite re-entry catheter. The guidewire can be placed from artery to vein. The guidewire can be placed from vein to artery. The guidewire can be placed by advancing the needle from a starting vessel to a target vessel, and then advancing the guidewire through a hole created by the needle. The guidewire can be advanced through the hole via a lumen of the needle. The method can further comprise performing an ultrasound imaging procedure to determine the angle of the source vessel and the perfusion vessel relative to each other and setting a fluoroscopy angle such that the source vessel and the perfusion vessel overlap and/or can be side-by-side in the fluoroscopy image. The method can further comprise performing simultaneous contrast injections and/or roadmap contrast injections to align and/or target the source vessel and the perfusion vessel. A target can be placed in the target vessel. The target can comprise an expandable funnel that slidingly receives the guidewire. The method can further comprise positioning a vascular occlusion element in the perfusion vessel (e.g., the target vessel) proximate to a proposed channel location and prior to releasing the vascular occlusion element performing a venogram to confirm proper positioning of the vascular occlusion element. The method can further comprise repositioning the vascular occlusion elements to occlude one or more side-branches and/or adjusting the channel location, such as a repositioning and/or an adjustment performed based on the venogram. The guidewire can be placed from the source vessel to the perfusion vessel after the performance of the venogram. The method can further comprise rotating an imaging device to provide an image in which the source vessel and perfusion vessel can be shown on top of each other. The method can further comprise deploying one or more stabilizing elements to assist in advancing the needle. A first stabilizing element can be positioned in the starting vessel. A first stabilizing element can be positioned in the target vessel. The method can further comprise positioning a target in the target vessel. The method can further comprise snaring the guidewire using a snare device. The snare device can comprise a device similar to the EN Snare 6- 10mm device. The snare device can be configured to provide a target during the placement of the guidewire into the target vessel. The channel creation procedure can include performing the VAST technique. The method can further comprise: deploying a first device comprising a basket device or snare device in the source vessel; deploying a second device comprising a basket device or a snare device in the perfusion vessel; advancing a needle through both the first device and the second device; advancing the guidewire through the needle and retracting the needle; capturing a distal portion of the guidewire with the second device and bringing a distal end of the guidewire outside of the patient via retraction of the second device; and capturing a proximal portion of the guidewire with the first device and bringing a proximal end of the guidewire outside of the patient via retraction of the first device. The guidewire can comprise a double floppy wire. The method can further comprise dilating the source vessel with the first device; dilating the perfusion vessel with the second device; or both. Once the guidewire can be placed between the source vessel and the perfusion vessel, an elongate tube can be advanced over the wire such that it can be positioned in each vessel. A distal venous sheath can be advanced. The elongate tube can provide a conduit to the source vessel.

[050] In some embodiments, the creating of a channel is performed using a catheter that applies energy to create a fused anastomosis. The catheter can further apply pressure to create the fused anastomosis. The energy can comprise energy in a form selected from the group consisting of electromagnetic energy such as radiofrequency energy; sound energy such as ultrasound energy; light energy such as laser light energy; mechanical energy; thermal energy such as Joule heating and/or other heat energy and/or cryogenic energy; chemical energy; and combinations thereof. The energy delivery can comprise closed loop energy delivery. The energy can be delivered between distal and proximal heating elements, and the energy can be focused on vessel walls captured between the distal and proximal heating elements. The energy can be delivered via an energy delivery element with low thermal mass, and/or and the energy can be delivered at a minimum of 500°F/s, a maximum of 700°F/s, or both, such as to ablate tissue captured between the heating elements and minimize undesired heating of non-target tissue outside the heating elements. The ablation of the tissue can result in a channel with a noncircular cross section. The non-circular cross section can have an aspect ratio of at least 2: 1. The energy can be delivered in durations of no more than 1 second, such as to minimize undesired heating of non-target tissue. The method can further comprise dilating the channel location prior to the application of the energy. The channel can be created using a Boomerang catheter and/or a catheter similar to the Boomerang catheter. The catheter includes a pair of markers that can be parallel with an angled surface of a heating element of the catheter. An imaging device can be oriented such that the imaged vessels can be shown in a parallel arrangement and the catheter can be oriented such that the pair of markers overlap in the image of the parallel vessels.

[051] In some embodiments, the creation of the channel comprises: inserting a channel creation device from a first vessel into a second vessel such that one or more markers of the channel creation device are positioned in the second vessel; and applying tension to the channel creation device to cause a hook or other engagement mechanism of the channel creation device to engage a wall of the second vessel.

[052] In some embodiments, the method can further comprise modifying the created channel. The channel modification can be performed based on a change in flow rate of the source vessel. The channel modification can be performed if the flow rate through the channel can be below a threshold. The threshold can comprise a flow rate of at least 150ml/min, 175ml/min, and/or 200ml/min. The channel modification can be performed if the flow rate through the channel is above a threshold, and wherein the threshold comprises a flow rate of no more than 175ml/min, 200ml/min, and/or 250ml/min. The channel modification can be performed via a device placed over the same guidewire that can be used to create the channel. The channel modification can cause an increase in flow through the channel. The channel modification can comprise a dilation of the channel. The dilation can be performed via expansion of a balloon and/or other expandable component within the channel. The channel can be dilated to a diameter of at least 2mm and/or no more than 4mm. The modification can cause a reduction of flow through the channel. The flow reduction can be performed to prevent or at least reduce cardiac complications and/or to prevent or at least reduce steal of arterial blood flow. The flow reduction can be performed if the flow through the channel can be above a threshold. The threshold can comprise a flow rate of at least lOOOml/min; 1250ml/min; 1500ml/min; 1750ml/min; and/or 2000ml/min. The flow reduction can be achieved via banding of the channel and/or banding of the source vessel. The channel modification procedure can comprise a procedure selected from the group consisting of: implanting a stent; implanting a stent graft; implanting of a closure device; implanting of an occlusion device; and combinations thereof The modification can be performed via a device that can be introduced from a first artery, into the channel, and into a first vein. The modification can be performed via a device that can be introduced from a first vein, into the channel, and into a first artery.

[053] In some embodiments, the method can further comprise determining whether a flow modification procedure should be performed. The method can further comprise measuring at least one resistive index in one or more blood vessels, and the determining of whether a flow modification procedure should be performed can be based on one or more of the at least one resistive index measurements. The resistive index can comprise the following calculation: (PSV - EDV) / PSV; where the PSV can be the peak systolic velocity, and the EDV can be the end diastolic velocity, in a blood vessel to be measured. The resistive index can be measured in a source vessel, and a flow modification procedure can be performed if the measured resistive index can be above a threshold. The threshold can comprise a value of at least 0.6, a value of no more than 0.85, or both. The resistive index can be measured in a location in a proximal perfusion conduit, such as a location in the mid-calf region, and a flow modification procedure can be performed if the measured resistive index can be above a threshold. The threshold can comprise a value of at least 0.5, a value of no more than 0.8 or both. The resistive index can be measured in location in a distal perfusion conduit, such as a location proximate the ankle, and a flow modification procedure can be performed if the measured resistive index can be above a threshold. The threshold can comprise a value of at least 0.5, a value of no more than 0.7 or both. The method can further comprise assessing perfusion of the target tissue, and the determining of whether a flow modification procedure should be performed can be based on the perfusion assessment. The perfusion assessment can comprise a measurement of vPAT in a vein providing oxygenated blood to the target tissue, and a flow modification procedure can be performed if the measured vPAT can be above 180. VPAT can be measured in the plantar vein. VPAT can be measured in a vein distal to the plantar vein.

[054] In some embodiments, the flow rate through the channel comprises a flow rate of at least lOOml/min, 125ml/min, 150ml/min, 175ml/min, and/or 200ml/min.

[055] In some embodiments, the flow rate through the channel comprises a flow rate of no more than 250ml/min.

[056] In some embodiments, the flow rate through the channel comprises a flow rate configured to cause minimal and/or no swelling and/or to cause minimal and/or no edema.

[057] In some embodiments, the channel is created to have a flow rate configured to preserve patency and/or provide for wound healing, and then modified such as to increase the flow to an increased level.

[058] In some embodiments, if the flow rate through the channel is below a threshold and/or the flow rate through the perfusion vessel is below a threshold, then an additional procedure is performed to increase the flow rate through the channel and/or the perfusion vessel. [059] In some embodiments, the flow rate through the channel is selected based on the anatomical location of the channel.

[060] In some embodiments, the flow rate through the channel comprises a flow rate of no more than lOOOml/min, 1250ml/min, 1500ml/min, 1750ml/min, and/or 2000ml/min.

[061] In some embodiments, if the flow rate through the channel is above a threshold and/or the flow rate through the perfusion vessel is above a threshold, then an additional procedure is performed to decrease the flow rate through the channel and/or the perfusion vessel.

[062] In some embodiments, the channel is created without blocking flow in the source vessel distal to the channel.

[063] In some embodiments, the method avoids a significant reduction in arterial flow that was present before the creation of the channel. The method can avoid significant reduction in antegrade flow in the source vessel distal to the channel. The method avoids significant reduction in flow in one or more arteries that can be proximate the channel. The one or more arteries can comprise the peroneal artery and/or collaterals of the peroneal artery. The method can avoid (e.g., the method can be configured to avoid) significantly reducing arterial flow distal to the channel and avoids steal of arterial flow.

[064] In some embodiments, the method can further comprise treating the source vessel at an anatomical location proximal to the channel. The treating of the source vessel can be performed prior to the creation of the channel. The treating of the source vessel can comprise a treatment selected from the group consisting of: angioplasty; angioplasty with a drug-coated balloon; stenting; stenting with a drug-coated balloon; intravascular lithotripsy; valve or other tissue scoring; and combinations thereof.

[065] In some embodiments, the method can further comprise performing a venous treatment procedure that is configured to improve venous retrograde flow. The venous treatment procedure can comprise a procedure that treats one or more venous valves. The venous treatment procedure can disrupt each of the one or more venous valves, such as to disrupt the leaflet of the valve and/or the annulus of the valve. The venous treatment procedure can remove at least a portion of each of the one or more venous valves. The venous treatment procedure can be performed with the same device that creates the channel. The venous treatment procedure can include application of Joule heating, heat energy, cryogenic energy, and/or other thermal energy. The venous treatment procedure can include providing retrograde catheter access with fluid distention of a vein; puncturing of a leaflet of a venous valve; and advancing of a balloon or other vessel dilator to tear the venous valve. The venous treatment procedure can comprise placing a stent at a location of a first venous valve. The stent can be placed using a device similar to the Phillips Tack Stent device. The venous treatment procedure can comprise scoring the first venous valve prior to placing the stent, such as when the annulus of the first venous valve can be scored. The venous treatment procedure can be performed using a valvulotome. The venous treatment procedure can be performed under image guidance. The image guidance can comprise fluoroscopic and/or ultrasound image guidance. The image guidance can comprise performing intermittent venograms to position the valvulotome. The venous treatment procedure can be performed using one or more of: a sharp cutting element; a hole punch; a spiralized ribbon cutter; and/or a thermal energy delivery device, such as a device comprising plates and/or wires configured to deliver thermal energy. The venous treatment procedure can be performed using a cutting balloon and/or a cutting sheath. The venous treatment procedure can comprise a first treatment in which a valve annulus can be treated and a second procedure in which one or more valve leaflets can be treated. The venous treatment procedure can comprise a procedure that reduces venous shunting. The venous treatment procedure can comprise at least partially occluding a vein segment to prevent shunting of arterial blood to the heart and/or to prevent competing flow through bridging and/or collateral veins. The vein can be at least partially occluded at a location within 5cm, 4cm, 3cm, 2.5cm, and/or 1cm of the location of the channel. The method can further comprise performing an imaging procedure to locate one or more collateral venous branches, and the location of the at least partial occlusion of the vein can be selected based on the location of the collateral venous branches. The at least partial occlusion of the vein can be performed to increase flow of oxygenated blood to the foot of the patient. The venous treatment procedure can comprise at least partially occluding a venous side-branch, such as a venous side-branch of the perfusion vessel. The venous treatment procedure can be performed at least one day after the creation of the channel. The venous shunting can be reduced via implantation of: a coil; adhesive; a gel; a vascular plug; and/or an end-covered stent. The venous shunting can be reduced via closing of a vein segment via application of suture, clips, and/or heat. The venous shunting can be reduced by placing a covered stent in a vein, and the covered stent covers the ostium of a venous side-branch. The venous treatment procedure can comprise imaging one or more veins and based on the imaging determining the size and/or implant locations of one or more occlusion devices to be implanted in the one or more veins.

The implanting of the one or more occlusion device can prevent flow of blood back to the heart and/or modifies or prevents competing flow of blood through bridging and/or collateral veins. [066] In some embodiments, the method can further comprise performing a flow modification procedure configured to modify flow through the source vessel, the channel, and/or the perfusion vessel. The flow modification procedure can comprise dilating the channel. The flow modification procedure can comprise dilating a segment of the source vessel at a location proximate the channel. The flow modification procedure can comprise dilating a segment of the perfusion vessel at a location in or otherwise proximate the channel. The flow modification procedure can comprise at least partially occluding the source vessel at a location distal to the channel. The flow modification procedure can be performed at least one day after the creation of the channel. [067] In some embodiments, the method can further comprise placing a scaffold in the channel. The scaffold can comprise a covering configured to at least reduce undesired venous shunting. The scaffold can include a porous covering. The scaffold can comprise a drug-coated scaffold.

[068] In some embodiments, the method can further comprise administering drug therapy to the patient.

[069] In some embodiments, the method can further comprise creating a second channel between a first blood vessel and a second blood vessel. The second channel can be configured to increase venous retroperfusion. The second channel can be configured to divert blood flow back into the source vessel at a location distal to a fully occluded or at least partially occluded segment of the source vessel. The second channel can be created by introducing a channel creation device from the source vessel to a second vein, and the second vein does not comprise the perfusion vessel. The second channel can be created by introducing a channel creation device from the perfusion vessel to a second vein.

[070] In some embodiments, the method can further comprise performing a non-invasive blood vessel dilation procedure. The non-invasive blood dilation procedure can be performed prior to the providing vascular access and/or prior to the channel creation. The non-invasive blood dilation procedure can comprise applying nitroglycerin gel and a wrapping to a limb of the patient. The non-invasive blood vessel dilation procedure can include a procedure selected from the group consisting of delivery of an intravascular vasodilator; application of a tourniquet; application of manual compression; application of a nerve block; application of a femoral or popliteal nerve block; and combinations thereof.

[071] In some embodiments, the method can further comprise performing a non-invasive venous outflow limiting procedure. The non-invasive venous outflow limiting procedure can comprise applying a constricting device to a limb of the patient. The constricting device can comprise a tourniquet or pressure cuff. The constricting device can be configured to apply a varied constriction in a closed-loop arrangement.

[072] In some embodiments, the method can further comprise performing a flow measuring and/or assessing procedure. The flow measuring and/or assessing procedure can comprise providing an estimation of flow through the channel by subtracting an estimation of blood flow in the source vessel prior to channel creation from an estimation of blood flow in the source vessel distal to the channel after channel creation. The flow measuring and/or assessing procedure can be configured to measure flow through the channel. The flow measuring and/or assessing procedure can be configured to measure flow through a vein segment carrying retrograde flow. The method can further comprise performing a channel flow modification procedure and/or other flow modification procedure if the measured flow can be below a threshold. The flow modification procedure performed can comprise a venous segment flow modification procedure if the measured flow can be below a threshold, where the flow measuring and/or assessing procedure can comprise performing real-time flow measurements using ultrasound or other flow measurement devices and, based on the flow measurement and/or assessment, modifying at least one of: the source vessel; the channel; and/or the perfusion vessel. The modifying can comprise performing a procedure selected from the group consisting of: angioplasty; stenting; and/or embolization.

[073] In some embodiments, the method can further comprise performing a second clinical procedure. The second clinical procedure can comprise treating the source vessel at an anatomical location upstream of the channel. The second clinical procedure can be performed prior to the creation of the channel. The second clinical procedure can be performed at least one day prior to the creation of the channel. The second clinical procedure can comprise treating at least one lesion of the patient. The second clinical procedure can comprise percutaneous transluminal angioplasty (PTA); implantation of a stent; and/or atherectomy. The second clinical procedure can comprise causing the artery to achieve a diameter of at least 3mm proximal the channel. The second clinical procedure can comprise creation of a second channel between two blood vessels of the patient. The second channel can be created at least eight hours after the creation of the first channel.

[074] In some embodiments, the method can further comprise performing a reversing procedure in which flow through the channel is stopped.

[075] In some embodiments, the method achieves one, two, or more efficacy endpoints selected from the group consisting of: reversal of flow within a native vein; flow of oxygenated blood in one or more veins below the level of the ankle and into the foot; retrograde flow rate in a vein above a threshold; flow of oxygenated blood to a diseased area of the foot and/or diseased area of other tissue; antegrade flow of oxygenated blood beyond the channel in a native vessel; redder and/or warmer foot tissue and/or other tissue at one week or one month after creation of the channel; wound healing such as wound healing comprising at least 25% of skin growth; transmetatarsal amputation, other mid foot amputation, and/or other tissue amputation that is free of vascular complications and/or achieves accelerated healing; and combinations of these.

[076] In some embodiments, the creation of the channel results in: an increase in venous pressure; and/or the primary vein loop and small tributary veins surrounding the wound having a distinct systolic and diastolic velocity waveform with a venous pedal acceleration time (vPAT) that is less than 180ms. The increase in venous pressure can cause one or more venous valves to become incompetent. The increase in venous pressure can cause arterialization of both a primary vein loop and of one or more small tributary veins. The method can be configured such that the small tributary veins provide oxygenated blood to tissue after the primary vein loop becomes at least partially occluded.

[077] In some embodiments, the method comprises determining a procedural parameter. The procedural parameter can be determined by an algorithm. The algorithm can comprise an artificial intelligence algorithm. The algorithm can analyze data selected from the group consisting of: images of the patient’s anatomy; vessel diameter data; lesion data; blood flow data; diagnostic data; and combinations thereof. The procedural parameter determined can comprise one or more proposed channel locations. The one or more proposed channel locations can be determined based on one, two, three, or more parameters selected from the group consisting of: diameter of one or more vessels at anatomical locations proximate the proposed channel location; distance of the proposed channel location to a bifurcation; location of a calcified segment of a blood vessel; tortuosity of one or more vessels at anatomical locations proximate the proposed channel location; proximity of one or more side-branches to the proposed channel location; proximity of the source and perfusion vessels to each other at the proposed channel location; desired flow rate through the channel; location and/or quantity of collateral arterial vessels proximate the proposed channel location; location and/or quantity of collateral venous vessels proximate the proposed channel location; location of a previous surgery or intervention; and combinations thereof. The procedural parameter determined can comprise a channel flow parameter. The procedural parameter determined can comprise a channel size parameter. The procedural parameter determined can comprise a channel modification procedure to be performed. The procedural parameter determined can comprise one or more proposed anatomical locations for embolization to be performed. The proposed anatomical locations can be chosen to optimize flow of oxygenated blood to the pedal loop of the foot. The procedural parameter determined can comprise a valve treatment procedure to be performed.

[078] According to another aspect of the present inventive concepts, a system for treating a patient comprises: a channel creation device configured to create a channel between a source vessel and a perfusion vessel, and the system is configured to treat a medical condition of the patient.

[079] In some embodiments, the system can further comprise a venous access device through which the channel creation device is inserted, and the channel creation device comprises a shaft that is at least 2cm, 4cm, and/or 5cm longer than the shaft of the venous access device. [080] In some embodiments, the channel creation device comprises a shaft that comprises a length of at least 47cm, 49cm, and/or 50cm.

[081] In some embodiments, the channel creation device is configured to deliver energy to tissue during the creation of the channel. The channel creation device can be configured to apply a heat gradient in which a center portion of the channel can be heated to a higher temperature than one or more edge portions of the channel. The channel creation device can be configured to ablate tissue of the center portion and to denature and/or fuse tissue of the one or more edge portions.

[082] In some embodiments, the system can further comprise a console that operably attaches to the channel creation device.

[083] In some embodiments, the system can further comprise a guidewire that is delivered across the channel location, and the channel creation device is introduced over the guidewire. The guidewire can comprise a 0.014” guidewire. The guidewire can comprise a proximal end portion, a mid portion, and a distal end portion, and the proximal end portion can be more flexible than the mid portion, and the distal end portion can be more flexible than the mid portion.

[084] In some embodiments, the system can further comprise a guidewire placement device. The guidewire placement device can comprise a curved needle. The guidewire placement device can comprise a side-access needle. The guidewire placement device can comprise one or more stabilization elements.

[085] In some embodiments, the system can further comprise a venous access device.

[086] In some embodiments, the system can further comprise an arterial access device. [087] In some embodiments, the system can further comprise an embolization device. The embolization device can be configured to prevent or at least limit flow in a blood vessel by delivery of one or more of: a coil; glue; a gel; a vascular plug; and/or an end-covered stent.

[088] In some embodiments, the system can further comprise a valve treatment device that is configured to improve continuous flow through a vein at a location proximate a valve. The valve treatment device can be configured to apply heat to at least a portion of a valve, cut a portion of a valve, and/or score a portion of a valve. The valve treatment device can comprise a first valve treatment device, and the system can comprise a second valve treatment device that can be configured to improve continuous flow through a vein at a location proximate a valve, and the second valve treatment device can be of different construction and arrangement as compared to the first valve treatment device. The first valve treatment device can comprise a first radially expandable assembly with a first expanded diameter, and the second valve treatment device can comprise a second expandable assembly with a second expanded diameter that can be different than the first expanded diameter. The first valve treatment device can comprise a first offset tip, and the second valve treatment device can comprise a second offset tip, and the first offset tip and the second offset tip comprise different amounts of offset. The first valve treatment device can comprise a first recess, and the second valve treatment device can comprise a second recess, and the first recess and the second recess comprise different depths. The valve treatment device can comprise a radially expandable assembly comprising one or more cutting elements that are configured to treat the valve. The radially expandable assembly can comprise a cage that can be resiliently biased in a radially expanded geometry. The valve treatment device can further comprise a sheath that can be configured to capture and radially compress the cage. The valve treatment device can comprise a first shaft and a second shaft, and the first shaft can be configured to translate relative to the second shaft, and the translation causes the expandable assembly to radially expand and/or radially contract. The expandable assembly can comprise a distal end that is free-floating and does not attach to the first shaft. The radially expandable assembly can comprise a cage with an expanded diameter of at least 2mm, 3mm, or 4mm, and/or an expanded diameter of no more than 8mm, 9mm, or 10mm. The radially expandable assembly can comprise a cage including at least three flexible struts, and the at least three flexible struts can each include a cutting element of the one or more cutting elements. The radially expandable assembly can comprise a cage with at least one strut, the at least one strut can comprise at least one cutting element of the one or more cutting elements, and the at least one strut can be configured in a z-shaped or an s-shaped geometry. The z-shaped or s-shaped geometry can be configured to allow a venous valve leaflet to collapse to a smaller diameter than the diameter of the radially expandable assembly such that the one or more cutting elements are prevented from cutting the wall of the vein in which the venous valve leaflet is located. The radially expandable assembly can comprise a cage including at least one strut, and the at least one strut can comprise a cutting element. The cutting element can comprise a hook -like geometry. The cutting element can comprise a cutting surface. The cutting element can comprise a recess configured to capture tissue of the valve to be treated. The recess can comprise a depth of at least 0.0150”, of no more than 0.150”, or both. The valve treatment device can comprise an offset tip. The offset tip can comprise an offset of at least 0.006”, at most 0.060”, or both. The cutting element can comprise a distal-facing cutting element. The cutting element can comprise a proximal-facing cutting element. The cage can comprise a minimum bend radius of 5mm. The valve treatment device can comprise a guidewire lumen. The valve treatment device can further comprise an expandable cage and at least one shaft, and the guidewire lumen can comprise a split lumen and/or an otherwise non-contiguous lumen that allows the distal end of the expandable cage to translate relative to the at least one shaft as the diameter of the expandable cage changes.

[089] In some embodiments, the system can further comprise a flow reducing device configured to reduce flow through a blood vessel and/or the channel created by the channel creation device. The flow reducing device can be configured to reduce flow in a blood vessel and/or the channel by delivering: a coil; glue; a gel; and/or an end-covered stent.

[090] In some embodiments, the system can further comprise at least one imaging device. The at least one imaging device can comprise: an x-ray device such as a fluoroscope or CT scanner; an ultrasound imaging device; and/or an MRI.

[091] In some embodiments, the system can further comprise a flow sensing device. The flow sensing device can comprise a device selected from the group consisting of: a flow wire; a doppler ultrasound device; and combinations thereof.

[092] In some embodiments, the system can further comprise at least one sensor configured to produce a signal. The system can be configured to perform closed loop energy delivery during channel creation, and the energy can be delivered based on the signal produced by the at least one sensor. The at least one sensor can comprise a flow sensor. [093] In some embodiments, the system can further comprise a processor and a memory module that stores instructions, and the system is configured to perform one or more algorithms based on the instructions.

[094] The technology described herein, along with the attributes and attendant advantages thereof, will best be appreciated and understood in view of the following detailed description taken in conjunction with the accompanying drawings in which representative embodiments are described by way of example.

INCORPORATION BY REFERENCE

[095] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. The content of all publications, patents, and patent applications mentioned in this specification are herein incorporated by reference in their entirety for all purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

[096] Fig. 1 illustrates a schematic view of a medical system comprising a channel creation device and other components, consistent with the present inventive concepts.

[097] Fig. 1A illustrates a flow chart of a method of performing a revascularization procedure, consistent with the present inventive concepts.

[098] Fig. 2 is a flow chart of a method of determining if a flow modification procedure should be performed, consistent with the present inventive concepts.

[099] Figs. 2A-B are images provided on a screen of a doppler ultrasound imaging device, consistent with the present inventive concepts.

[100] Figs. 3A-C illustrate perspective and two sectional side views of a valve treatment device, consistent with the present inventive concepts.

DETAILED DESCRIPTION OF THE DRAWINGS

[101] Reference will now be made in detail to the present embodiments of the technology, examples of which are illustrated in the accompanying drawings. Similar reference numbers may be used to refer to similar components. However, the description is not intended to limit the present disclosure to particular embodiments, and it should be construed as including various modifications, equivalents, and/or alternatives of the embodiments described herein.

[102] It will be understood that the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[103] It will be further understood that, although the terms first, second, third, etc. may be used herein to describe various limitations, elements, components, regions, layers and/or sections, these limitations, elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one limitation, element, component, region, layer or section from another limitation, element, component, region, layer or section. Thus, a first limitation, element, component, region, layer or section discussed below could be termed a second limitation, element, component, region, layer or section without departing from the teachings of the present application.

[104] It will be further understood that when an element is referred to as being “on”, “attached”, “connected” or “coupled” to another element, it can be directly on or above, or connected or coupled to, the other element, or one or more intervening elements can be present. In contrast, when an element is referred to as being “directly on”, “directly attached”, “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc ).

[105] As used herein, the terms “operably attached”, “operably connected”, “operatively coupled” and similar terms related to attachment of components shall refer to attachment of two or more components that results in one, two, or more of: electrical attachment; fluid attachment; magnetic attachment; mechanical attachment; optical attachment; sonic attachment; and/or other operable attachment arrangements. The operable attachment of two or more components can facilitate the transmission between the two or more components of: power; signals; electrical energy; fluids or other flowable materials; magnetism; mechanical linkages; light; sound such as ultrasound; and/or other materials and/or components.

[106] It will be further understood that when a first element is referred to as being “in”, “on” and/or “within” a second element, the first element can be positioned: within an internal space of the second element, within a portion of the second element (e.g., within a wall of the second element); positioned on an external and/or internal surface of the second element; and combinations of one or more of these.

[107] As used herein, the term “proximate”, when used to describe proximity of a first component or location to a second component or location, is to be taken to include one or more locations near to the second component or location, as well as locations in, on and/or within the second component or location. For example, a component positioned proximate an anatomical site (e.g., a target tissue location), shall include components positioned near to the anatomical site, as well as components positioned in, on and/or within the anatomical site.

[108] Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like may be used to describe an element and/or feature’s relationship to another element(s) and/or feature(s) as, for example, illustrated in the figures. It will be further understood that the spatially relative terms are intended to encompass different orientations of the device in use and/or operation in addition to the orientation depicted in the figures. For example, if the device in a figure is turned over, elements described as “below” and/or “beneath” other elements or features would then be oriented “above” the other elements or features. The device can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[109] The terms “reduce”, “reducing”, “reduction” and the like, where used herein, are to include a reduction in a quantity, including a reduction to zero. Reducing the likelihood of an occurrence shall include prevention of the occurrence. Correspondingly, the terms “prevent”, “preventing”, and “prevention” shall include the acts of “reduce”, “reducing”, and “reduction”, respectively.

[110] The term “and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example “A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein. [1 11] The term “one or more”, where used herein can mean one, two, three, four, five, six, seven, eight, nine, ten, or more, up to any number.

[112] The terms “and combinations thereof’ and “and combinations of these” can each be used herein after a list of items that are to be included singly or collectively. For example, a component, process, and/or other item selected from the group consisting of: A; B; C; and combinations thereof, shall include a set of one or more components that comprise: one, two, three or more of item A; one, two, three or more of item B; and/or one, two, three, or more of item C.

[113] In this specification, unless explicitly stated otherwise, “and” can mean “or”, and “or” can mean “and”. For example, if a feature is described as having A, B, or C, the feature can have A, B, and C, or any combination of A, B, and C. Similarly, if a feature is described as having A, B, and C, the feature can have only one or two of A, B, or C.

[114] As used herein, when a quantifiable parameter is described as having a value “between” a first value X and a second value Y, it shall include the parameter having a value of: at least X, no more than Y, and/or at least X and no more than Y. For example, a length of between 1 and 10 shall include a length of at least 1 (including values greater than 10), a length of less than 10 (including values less than 1), and/or values greater than 1 and less than 10.

[115] The expression “configured (or set) to” used in the present disclosure may be used interchangeably with, for example, the expressions “suitable for”, “having the capacity to”, “designed to”, “adapted to”, “made to” and “capable of’ according to a situation. The expression “configured (or set) to” does not mean only “specifically designed to” in hardware.

Alternatively, in some situations, the expression “a device configured to” may mean that the device “can” operate together with another device or component.

[116] As used herein, the terms “about” or “approximately” shall refer to ±20% of a stated value.

[117] As used herein, the term “threshold” refers to a maximum level, a minimum level, and/or range of values correlating to a desired or undesired state. In some embodiments, a system parameter is maintained above a minimum threshold, below a maximum threshold, within a threshold range of values, and/or outside a threshold range of values, such as to cause a desired effect (e.g., efficacious therapy) and/or to prevent or otherwise reduce (hereinafter “prevent”) an undesired event (e.g., a device and/or clinical adverse event). In some embodiments, a system parameter is maintained above a first threshold (e.g., above a first temperature threshold to cause a desired therapeutic effect to tissue) and below a second threshold (e.g., below a second temperature threshold to prevent undesired tissue damage). In some embodiments, a threshold value is determined to include a safety margin, such as to account for patient variability, system variability, tolerances, and the like. As used herein, “exceeding a threshold”, “exceeds a threshold”, and the like, relates to a parameter going above a maximum threshold, below a minimum threshold, within a range of threshold values and/or outside of a range of threshold values.

[118] As described herein, “room pressure” shall mean pressure of the environment surrounding the systems and devices of the present inventive concepts. Positive pressure includes pressure above room pressure or simply a pressure that is greater than another pressure, such as a positive differential pressure across a fluid pathway component such as a valve. Negative pressure includes pressure below room pressure or a pressure that is less than another pressure, such as a negative differential pressure across a fluid component pathway such as a valve. Negative pressure can include a vacuum but does not imply a pressure below a vacuum. As used herein, the term “vacuum” can be used to refer to a full or partial vacuum, or any negative pressure as described hereabove.

[119] The term “diameter” where used herein to describe a non-circular geometry is to be taken as the diameter of a hypothetical circle approximating the geometry being described. For example, when describing a cross section, such as the cross section of a component, the term “diameter” shall be taken to represent the diameter of a hypothetical circle with the same cross- sectional area as the cross section of the component being described.

[120] The terms “major axis” and “minor axis” of a component where used herein are the length and diameter, respectively, of the smallest volume hypothetical cylinder which can completely surround the component.

[121] As used herein, the term “functional element” is to be taken to include one or more elements constructed and arranged to perform a function. A functional element can comprise a sensor, a transducer, or both. In some embodiments, a functional element is configured to deliver energy, deliver a therapeutic treatment, and/or otherwise perform a function.

Alternatively or additionally, a functional element (e.g., a functional element comprising a sensor) can be configured to record one or more parameters, such as a patient physiologic parameter; a patient anatomical parameter (e.g., a tissue geometry parameter); a patient environment parameter; and/or a system parameter. In some embodiments, a sensor or other functional element is configured to perform a diagnostic function (e.g., to gather data used to perform a diagnosis). In some embodiments, a functional element is configured to perform a therapeutic function (e.g., to deliver therapeutic energy and/or a therapeutic agent). In some embodiments, a functional element comprises one or more elements constructed and arranged to perform a function selected from the group consisting of: deliver energy; extract energy (e.g., to cool a component); deliver a drug or other agent; manipulate a system component or patient tissue; record or otherwise sense a parameter such as a patient physiologic parameter or a system parameter; and combinations of one or more of these. A functional element can comprise a fluid and/or a fluid delivery system. A functional element can comprise a reservoir, such as an expandable balloon or other fluid-maintaining reservoir. A “functional assembly” can comprise an assembly constructed and arranged to perform a function, such as a diagnostic and/or therapeutic function. A functional assembly can comprise an expandable assembly. A functional assembly can comprise one or more functional elements.

[122] The term “transducer” where used herein is to be taken to include any component or combination of components that receives energy or any input, and produces an output. For example, a transducer can include an electrode that receives electrical energy, and distributes the electrical energy to tissue (e.g., based on the size of the electrode). In some configurations, a transducer converts an electrical signal into any output, such as: light (e.g., a transducer comprising a light emitting diode or light bulb), sound (e.g., a transducer comprising a piezo crystal configured to deliver ultrasound energy); pressure (e.g., an applied pressure or force); heat energy; cryogenic energy; chemical energy; mechanical energy (e.g., a transducer comprising a motor or a solenoid); magnetic energy; and/or a different electrical signal (e g., different than the input signal to the transducer). Alternatively or additionally, a transducer can convert a physical quantity (e.g., variations in a physical quantity) into an electrical signal. A transducer can include any component that delivers energy and/or an agent to tissue, such as a transducer configured to deliver one or more of: electrical energy to tissue (e.g., a transducer comprising one or more electrodes); light energy to tissue (e.g., a transducer comprising a laser, light emitting diode and/or optical component such as a lens or prism); mechanical energy to tissue (e.g., a transducer comprising a tissue manipulating element); sound energy to tissue (e.g., a transducer comprising a piezo crystal); chemical energy; electromagnetic energy; magnetic energy; and combinations of one or more of these.

[123] As used herein, the term “fluid” can refer to a liquid, gas, gel, or any flowable material, such as a material which can be propelled through a lumen and/or opening.

[124] As used herein, the term “material” can refer to a single material, or a combination of two, three, four, or more materials.

[125] It is appreciated that certain features of the inventive concepts, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the inventive concepts which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub -combi nation. For example, it will be appreciated that all features set out in any of the claims (whether independent or dependent) can be combined in any given way.

[126] It is to be understood that at least some of the figures and descriptions of the inventive concepts have been simplified to focus on elements that are relevant for a clear understanding of the inventive concepts, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the inventive concepts. However, because such elements are well known in the art, and because they do not necessarily facilitate a better understanding of the inventive concepts, a description of such elements is not provided herein.

[127] Terms defined in the present disclosure are only used for describing specific embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. Terms provided in singular forms are intended to include plural forms as well, unless the context clearly indicates otherwise. All of the terms used herein, including technical or scientific terms, have the same meanings as those generally understood by an ordinary person skilled in the related art, unless otherwise defined herein. Terms defined in a generally used dictionary should be interpreted as having meanings that are the same as or similar to the contextual meanings of the relevant technology and should not be interpreted as having ideal or exaggerated meanings, unless expressly so defined herein. In some cases, terms defined in the present disclosure should not be interpreted to exclude the embodiments of the present disclosure. [128] Provided herein are systems for performing a medical procedure, such as a procedure comprising a diagnostic procedure, a therapeutic procedure (also referred to as a “treatment procedure”), or both. The systems of the present inventive concepts comprise a channel creation device for creating one or more flow pathways between a source vessel such as one or more arteries, and a perfusion vessel such as one or more veins. The one or more flow pathways can be created as part of a revascularization procedure, such as a procedure that causes an increase of oxygenated blood being provided to tissue to be treated, “target tissue” herein, such as oxygenated blood that is provided to the capillary bed of the target tissue. The oxygenated blood that results from the creation of the one or more flow pathways can be delivered to the capillary bed via retrograde flow of the oxygenated blood through one or more veins, through antegrade flow through one or more arteries, or both. In use of the system of the present invention, a patient is selected for treatment. An “identification procedure” can be performed comprising identifying a source vessel; identifying a perfusion vessel; and identifying an anatomical location for a flow pathway (also referred to as “channel” herein). The identification procedure can further comprise identifying one or more medical procedure parameters, such as to identify the parameters of one or more diagnostic steps (e.g., flow measurement and/or vessel measurements performed) and/or to identify the parameters of one or more treatment steps (e.g., a dilation parameter, an embolization parameter, and/or a flow pathway parameter). Vascular access can be performed comprising providing venous access; and/or providing arterial access. A “channel creation procedure” can be performed comprising creating a flow pathway (also referred to as a “channel”) between the source vessel and the perfusion vessel at the channel location. Blood flow through the channel treats the medical condition of the patient. In some embodiments, a “flow modification procedure” can be performed, such as to modify the flow of blood through one or more of: a source vessel and/or a vessel supplying blood and/or otherwise fluidly connected to a source vessel; the channel; and/or to a perfusion vessel and/or a vessel receiving blood from and/or otherwise fluidly connected to a perfusion vessel.

[129] Referring now to Fig. 1, a system for performing a medical procedure is illustrated, consistent with the present inventive concepts. System 10 comprises channel creation device 100, which can comprise one, two, or more devices configured to create a “channel” comprising a flow passageway between two blood vessels of a patient. The channel can be created to treat ischemia and/or other undesired medical condition of a patient. The channel can be created by device 100 between a “source vessel”, for example an artery or other vessel containing oxygenated blood, and a “perfusion vessel”, for example a vein or other vessel through which oxygenated blood received from the source vessel can be routed (e.g., in a retrograde direction) to perfuse otherwise oxygen- starved tissue of the patient (“target tissue”). System 10, via channel creation device 100, can be configured to perform a revascularization procedure on a patient in which oxygenated blood from a first blood vessel is diverted into a second blood vessel via a channel created by device 100.

[130] Channel creation device 100 can comprise one, two, or more catheters and/or other devices, such as one or more catheters or other devices configured to be used in an interventional procedure. In some embodiments, device 100 comprises one, two, or more devices selected from the group consisting of a catheter; a surgical device; a device inserted through a laparoscopic port; a device inserted through an endoscope; and combinations of these.

[131] Channel creation device 100 can comprise a shaft that is at least 2cm, 4cm, and/or 5cm longer than the shaft of the venous access device 440 through which device 100 is inserted. In some embodiments, channel creation device 100 comprises a length of at least 47cm, 49cm, and/or 50cm (e.g., when device 100 is configured to create a channel in the lateral plantar vein and/or when venous access device 440 comprises a length of approximately 45cm).

[132] Channel creation device 100 can comprise one or more needles, needle 150 shown, such as one, two, or more needles that can be advanced from a “starting vessel” to a “target vessel”, after which a guidewire can be advanced through the needle 150 and into the target vessel. In some embodiments, a starting vessel comprises a source vessel (e.g., an artery), and the target vessel comprises a perfusion vessel (e.g., a vein). In some embodiments, a starting vessel comprises a perfusion vessel (e.g., a vein), and a target vessel comprises a source vessel (e.g., an artery).

[133] Channel creation device 100 can comprise energy delivery element 160 shown, such as one, two or more components configured to deliver energy to tissue (e.g., to tissue of a channel as described herein). Energy delivery element 160, also referred to as EDE 160, can be configured to deliver one, two, or more forms of energy selected from the group consisting of: radiofrequency, electroporation, microwave, and/or other electromagnetic energy; ultrasound and/or other sound energy; light energy such as laser light energy; thermal energy such as heat energy and/or cryogenic energy; mechanical energy; chemical energy; and combinations of these. Channel creation device 100 can be configured to deliver energy (e.g., via EDE 160) to tissue during the creation of the channel. Device 100 can be configured to apply a heat gradient in which a center portion of the channel is heated to a higher temperature than one or more edge portions of the channel. Device 100 can be configured to ablate tissue of the center portion of the channel, and to denature and/or fuse tissue of the one or more edge portions of the channel.

[134] Channel creation device 100 can comprise one, two, or more markers, marker 198 shown. Marker 198 can comprise one, two, or more markers selected from the group consisting of: standard light visible marker; radiographically visible marker; ultrasonically visible marker; magnetically visible marker; chemically-activated marker; light-activated marker; and combinations of these; In some embodiments, marker 198 comprises two or more markers in a particular geometric arrangement (e g., a parallel arrangement) that is used to orient device 100 in an image (e.g., a fluoroscopic image, ultrasound image, and/or other image provided by an imaging device 50 described herein).

[135] Channel creation device 100 can comprise functional element 199, as shown. Functional element 199 can comprise one or more sensors, and/or one or more transducers, as described herein. In some embodiments, functional element 199 comprises a vacuum element configured to intermittently (e.g., on demand) secure one or more portions of channel creation device 100 to tissue. In some embodiments, functional element 199 comprises a vibrational element configured to cause one or more portions of channel creation device 100 to vibrate (e.g., to function as a tactile alert to an operator during a warning or other state in which operator attention or notification is desired).

[136] In some embodiments, system 10 comprises console 200, as shown. Console 200 can comprise a device which operatively attaches to channel creation device 100 and/or another component of system 10. Console 200 can comprise one or more sensors, transducers, and/or other functional elements, functional element 299, also as shown. Functional element 299 can comprise a controller (e.g., an electronic controller), as described herein.

[137] In some embodiments, system 10 comprises guidewire placement device 300, as shown. Device 300 can comprise a catheter or other device which is configured to place a guidewire between a first blood vessel (e.g., a starting vessel) and a second blood vessel (e.g., a target vessel), such as a catheter configured to be inserted in a starting vessel and into which an advanceable needle can be advanced into the target vessel (after which a guidewire can be advanced into the target vessel). In some embodiments, guidewire placement device 300 comprises a standard needle (e.g., a straight or curved needle which can be advanced through a starting vessel and into a target vessel, and through which a guidewire 420 (e.g., a double floppy wire as described herein) can be advanced. Device 300 can comprise one or more sensors, transducers, and/or other functional elements, functional element 399, also as shown.

Functional element 399 can comprise a controller (e.g., an electronic controller), as described herein.

[138] In some embodiments, system 10 comprises guidewire 420 as shown, which can comprise one, two, three, or more similar and/or dissimilar guidewires. Guidewire 420 can comprise a guidewire (e.g., a 0.014” guidewire) that is placed across a channel location, such as by using a guidewire placement device 300. In some embodiments, guidewire 420 comprises a “double floppy wire”, guidewire 420DF that can be used to obtain “through and through access”. Both a proximal portion and distal portion of the guidewire 420DF are flexible (e.g., similarly or dissimilarly flexible, but more flexible than the mid portion of guidewire 420DF), such that each end portion can be easily grasped, and can be safely (e.g., atraumatically) and easily advanced in either the source vessel or the perfusion vessel. In some embodiments, the guidewire 420DF is passed through both walls of a starting vessel and into the lumen of a target vessel, such as when advanced through a needle or other delivery component of guidewire placement device 300, as described herein. The guidewire 420DF can be advanced in the target vessel until at least a portion of the flexible proximal portion of the guidewire 420DF is located between the walls of the starting vessel (e.g., at least a portion of the flexible proximal portion of guidewire 420DF is located within the lumen of the starting vessel). The flexible proximal section of guidewire 420DF being located in the starting vessel allows the guidewire 420DF to prolapse and track within the lumen of the starting vessel (e.g., when advanced from the target vessel via a grasping device). In some embodiments a snare (e.g., snare 940 described herein) can be used to grasp a flexible end portion of the guidewire 420DF such as to: advance the guidewire 420DF in either the starting vessel or the target vessel; and/or externalize (i.e. bring outside the body) the guidewire 420DF via one end portion passing through either arterial access device 460 or venous access device 440. In some embodiments, guidewire 420DF comprises a flexible proximal section, and/or a flexible distal section, that each comprise a length of at least 2cm and/or a length of no more than 10cm.

[139] In some embodiments, system 10 comprises venous access device 440 as shown, which can comprise one, two, or more devices for accessing a vein of a patient.

[140] In some embodiments, system 10 comprises arterial access device 460 as shown, which can comprise one, two, or more devices for accessing an artery of a patient.

[141] In some embodiments, system 10 comprises embolization device 500 as shown, which can comprise one, two, or more devices for occluding one, two, or more segments of a blood vessel. Embolization device 500 can be configured to prevent or at least limit flow in a blood vessel (e.g., to cause blood flow to preferentially flow in another direction) by delivery of one or more of: a coil; glue; a gel; a vascular plug; and/or an end-covered stent. Embolization device 500 can comprise one or more or more vascular occlusion elements, occlusion element 510 shown. Occlusion element 510 can comprise one, two, or more elements such as: a vascular plug; occlusion coil; and/or other occlusion element. Occlusion element 510 can be configured to be positioned in a perfusion vessel, proximate to (e.g., central to) a channel location, such as to prevent undesired shunting in the perfusion vessel, as described herein. Embolization device 500 can further comprise a delivery device (e.g., a delivery catheter), delivery device 520 shown, which can be configured to deliver (e.g., implant) one or more occlusion elements 510.

[142] In some embodiments, system 10 comprises valve treatment device 600 as shown, which can comprise one, two, or more devices for treating (e.g., disrupting) one, two, or more venous valves. Valve treatment device 600 can be configured to improve continuous flow through a vein proximate a valve (e.g., a vein used to provide oxygenated blood to target tissue). Valve treatment device 600 can be configured to apply heat to at least a portion of a valve, cut a portion of a valve, and/or score a portion of a valve. In some embodiments, valve treatment device 600 is constructed and arranged as described in reference to Figs. 3A-C herein. In some embodiments valve treatment device 600 is configured to expand and disrupt the annulus of the valve rather than cutting and/or scoring the valve leaflet. Disruption of the annulus can be achieved by over dilating (at least 30% larger) the annulus which causes the leaflets to not close and seal effectively, allowing retrograde flow through the associated vein. In some embodiments valve treatment device 600 comprises a standard percutaneous transluminal angioplasty (PTA) balloon catheter that is used to disrupt the annulus. Alternatively or additionally, valve treatment device 600 can comprise a catheter including force applier 650 shown, such as a projection, rigid portion, cutting element (e.g., cutter 612 described herein), and/or other feature that focalizes pressure and/or scores the circumference of the annulus of the valve during treatment. Force applier 650 can be configured to stretch and/or tear (e.g., evenly tear) the valve annulus around its circumference and can reduce the likelihood of the annulus rupturing at a single location. A single large rupture or tear is more likely to cause thrombosis formation due to exposure of blood to non-vascular tissue, and should be avoided. In some embodiments, a minimum of three semilongitudinal scores are created (e g., via a force applier 650 comprising three force appliers, and/or via multiple applications of one or more force appliers). The scores can be created by a force applier 650 comprising focal ribs located on the outside of a balloon. In some embodiments, valve treatment device 600 comprises a sheath in which an inflatable balloon is positioned, and force applier 650 (e.g. sharp struts or other force appliers) are positioned on the outer surface of the sheath. Inflation of the balloon within the sheath is used to treat valves. In some embodiments, valve treatment device 600 comprises an expandable basket, and force applier 650 comprises one or more sharp or other valve disrupting projections or other features positioned on struts of the basket.

[143] In some embodiments, system 10 comprises flow reducing device 700 as shown, which can comprise one, two, or more devices for reducing the flow within a blood vessel and/or to reduce flow within a channel created by channel creation device 100. Flow reducing device 700 can be configured to reduce flow in a blood vessel and/or the channel by delivering (e.g., implanting) a component of device 700 comprising: a coil; glue; a gel; and/or an end-covered stent. In some embodiments, flow reducing device 700 is configured to stop the flow within a blood vessel (e.g., to increase flow through another flow conduit of the patient). In some embodiments, flow reducing device 700 is configured to stop the flow within a channel created by channel creation device 100 (e.g., to reverse a previously performed channel creation procedure). In some embodiments, flow reducing device 700 comprises one or more components, flow reducer 710 shown, which can be configured to be delivered into the patient to reduce or otherwise modify flow within one or more locations within the patient (e.g., a blood vessel and/or the channel). Flow reducer 710 can comprise: a coil; adhesive; a gel; a vascular plug; an end-covered stent; and/or another component configured to reduce and/or otherwise modify flow of fluid. [144] In some embodiments, system 10 comprises vessel treatment device 800 as shown, which can comprise one, two, or more devices for modifying and/or otherwise treating a segment of a blood vessel, such as an artery or vein. In some embodiments, vessel treatment device 800 is configured to treat a lesion of a blood vessel, such as when device 800 comprises a device selected from the group consisting of: an angioplasty catheter; an angioplasty catheter including a drug-coated balloon; a stent and/or stent delivery catheter; a stent with a drug-coated balloon delivery catheter; an intravascular lithotripsy device; an atherectomy device; and combinations of these.

[145] In some embodiments, system 10 comprises target 910 as shown, which can comprise one, two, or more elongate filaments or other components that include at least a portion (e.g., a distal portion) that can be positioned in a segment of a blood vessel and used as an imageable target (e g., a target used to direct a needle (e g., needle 150), guidewire (e.g., guidewire 420), and/or other advanceable component toward the location in which the target is placed). Target 910 can comprise a portion that is configured to grasp a previously advanced component (e.g., capture a guidewire 420 that has been advanced from one vessel to another, such as to maintain the position of that guidewire 420).

[146] In some embodiments, system 10 comprises flow sensing device 920 as shown, which can comprise one, two, or more devices for sensing flow (e.g., sensing and/or estimating flow rate) through a segment of a blood vessel. Flow sensing device 920 can comprise one, two, or more devices selected from the group consisting of: a flow wire; a doppler ultrasound device; and combinations thereof. Flow sensing device 920 can comprise one or more flow sensing portions (e.g., blood flow sensing portions) that are positioned within the patient (e.g., positioned intravascularly), and/or one or more flow sensing portions positioned external to the patient (e.g., positioned on the skin of the patient). Flow sensing device 920 can comprise a Logiq Ultrasound system of GE healthcare and/or other flow sensing device configured to both measure flow and produce images of the patient. Flow sensing device 920 can be used to measure arterial flow, venous flow, or both. The flow measurements can be performed prior to, during, and/or after channel creation, such as to adjust flow in an artery, the channel, and/or a vein, prior to, during, and/or after channel creation, as described herein.

[147] In some embodiments, system 10 comprises stabilizer 930 as shown, which can comprise one, two, or more components that include at least a portion (e.g., a distal portion) that can be positioned in a segment of a blood vessel to provide stability to the tissue of the blood vessel in that segment. In some embodiments, stabilizer 930 comprises a device with a balloon, cage, unfurlable sheet, and/or other expandable element on its distal portion. In some embodiments, stabilizer 930 comprises an expandable element configured to allow a needle to be advanced into a portion of the expandable element without damaging the expandable element and/or other portion of stabilizer 930.

[148] In some embodiments, system 10 comprises snare 940 as shown, which can comprise one, two, or more components configured to snare and/or otherwise capture a guidewire (e.g., guidewire 420) and/or other elongate component that can be translated within a blood vessel.

[149] In some embodiments, system 10 comprises channel modifier 950 as shown, which can comprise one, two or more components configured to modify a channel (e.g., a channel created between a source vessel and a perfusion vessel as described herein). In some embodiments, channel modifier 950 comprises one or more catheters and/or other devices that include a dilating element (e.g., a balloon and/or other expandable element) that can be positioned in a channel to dilate the channel (e.g., to increase flow through the channel). In some embodiments, channel modifier 950 comprises implant 951 as shown. Implant 951 can comprise a stent, clip, and/or other component, and/or one or more materials (e.g., an adhesive) that can be positioned in a channel, such as to dilate the channel (e.g., to increase flow through the channel), to partially occlude the channel (e.g., to decrease flow through the channel), and/or to modify the direction of flow through the channel.

[150] In some embodiments, system 10 comprises vessel dilator 960 as shown, which can comprise one, two, or more devices for modifying and/or otherwise treating a segment of a blood vessel, such as an artery or vein. In some embodiments, vessel dilator 960 is configured to dilate a blood vessel. For example, vessel dilator 960 can be configured to non-invasively dilate a blood vessel, such as when dilator 960 comprises a device selected from the group consisting of: a warming blanket or other warming device (e.g., a device configured to warm a leg, foot, or other tissue); nitroglycerin, such as nitroglycerin-infused saline (e.g., to be infused systemically, such as through an intravenous line) and/or nitroglycerin gel (e.g., to be topically applied); a tourniquet (e.g., a tourniquet applied to the venous outflow); and combinations of these.

[151] In some embodiments, system 10 comprises one, two, or more imaging devices, imaging device 50 shown. Imaging device 50 can comprise one, two, or more imaging devices selected from the group consisting of: fluoroscope and/or other X-ray imaging device; an ultrasound imaging device; a CT-scan imaging device; a magnetic resonance imager (MRI); a PET scanner; an optical coherence tomography (OCT) imaging device; and combinations of these.

[152] In some embodiments, system 10 comprises agent 60 shown, such as when agent 60 comprises one or more pharmaceutical drugs or other agents that can be administered to the patient and/or otherwise used by system 10 in the treating of the patient.

[153] In some embodiments, system 10 comprises algorithm assembly 80 as shown. Algorithm assembly 80 can comprise controller 81, memory module 82, and algorithm 85. Controller 81 can comprise one or more electronic elements, electronic assemblies, and/or other electronic components, such as components selected from the group consisting of: microprocessors; microcontrollers; state machines; memory storage components; analog-to- digital converters; rectification circuitry; filters and other signal conditioners; sensor interface circuitry; transducer interface circuitry; and combinations of one, two, or more of these. Memory module 82 can be coupled to controller 81, and memory module 82 can store instructions used by controller 81 to perform one or more algorithms of system 10, algorithm 85. All or a portion of algorithm 85 can be integrated into (e.g., stored in the memory of) one, two, or more of the various components of system 10, such as a server (e.g., server 90 described herein), a device or other component of system 10 comprising a processor (e.g., channel creation device 100, guidewire placement device 300, and/or imaging device 50), and/or a console of system 10 (e.g., console 200). Algorithm 85 can comprise one or more machine learning, neural net, and/or other artificial intelligence algorithms (“Al algorithm” herein)

[154] System 10 can comprise one, two, or more sensors, such as sensor 90 shown. Sensor 90 can comprise one, two or more sensors configured to produce a signal that corresponds to a measured parameter. In some embodiments, sensor 90 comprises one, two, or more flow sensors (e.g., one, two, or more sensors to produce a signal that corresponds to the level of blood flow in a blood vessel and/or the channel). In some embodiments, system 10 is configured to perform closed-loop energy delivery (e.g., energy delivered via EDE 160) in a closed loop arrangement, such as when a channel is created via energy delivered in a closed loop arrangement, and sensor 90 provides a signal used by system 10 to change an energy delivery parameter (e.g., amplitude, frequency, pulse width, temperature, and/or other energy delivery parameter) in the closed loop arrangement.

[155] System 10 can comprise one, two, or more functional elements, such as functional element 99 shown. Functional element 99 can comprise one, two, or more sensors, transducers, and/or other functional elements. In some embodiments, functional element 99 comprises a sheath.

[156] Referring additionally to Fig. 1A, a method of performing a medical procedure is illustrated, consistent with the present inventive concepts. Method 1000 of Fig. 1A can comprise a revascularization procedure in which oxygenated blood from a first blood vessel (e.g., an artery) is diverted into a second blood vessel (e.g., a vein) such that oxygenated blood can perfuse target tissue via the venous system. System 10 and/or method 1000 can be configured to treat ischemia (e.g., critical limb ischemia) of the patient, such as ischemia of the foot. In some embodiments, end-stage plantar disease is treated.

[157] In STEP 1100, a patient is selected for treatment using the systems and methods of the present inventive concepts. In some embodiments, a patient is selected based on one or more arteries being patent, such as when one or more pedal arteries of a patient are not patent. In some embodiments, a patient is selected based on having failed a previously performed arterial revascularization procedure (e.g., a procedure in which compromised arterial flow was not able to be significantly improved). In some embodiments, a patient is selected if diffuse calcium is present in one or more arteries (e.g., one or more pedal arteries).

[158] In STEP 1200, an “identification procedure” is performed. The identification procedure can comprise an analysis of the patient’s anatomy and/or circulation such as to determine one, two, or more parameters selected from the group consisting of: location of a channel; and combinations of these. The identification procedure can comprise selecting a “source vessel”, selecting a “perfusion vessel”, and/or selecting a “channel location”.

[159] In STEP 1300, a “vascular access procedure” is performed, such as a procedure in which a venous introducer is placed (e g., a venous introducer of venous access device 440) to provide access to the venous vasculature of the patient, and an arterial introducer is placed (e.g., an arterial introducer of arterial access device 460) to provide access to the arterial vasculature of the patient. [160] In STEP 1400, a “channel creation procedure” is performed, such as a procedure in which a “channel” (flow pathway) is created at the channel location, wherein the channel fluidly connects the source vessel (e.g., an artery) and the perfusion vessel (e.g., a vein). In some embodiments, the channel creation procedure comprises creation of multiple channels, each channel fluidly connecting two blood vessels of the patient. Each channel can be created using channel creation device 100 described herein. In some embodiments, channel creation device 100 is inserted over a guidewire (e.g., guidewire 420) that has been placed between the two blood vessels (e.g., placed using guidewire placement device 300).

[161] Method 1000 can comprise additional procedures, such as one, two, or more procedures selected from the group consisting of: placement of a guidewire between two blood vessels (e.g., using guidewire placement device 300); occlusion of one or more segments of one or more veins or other blood vessels (e.g., using embolization device 500); disruption, removal, and/or other treatment of one or more venous valves (e.g., using valve treatment device 600); reducing flow within one or more blood vessels (e.g., using flow reducing device 700); determining the flow rate within one or more segments of one or more blood vessels (e.g., using flow sensing device 920); and combinations of these.

[162] As described herein, system 10 can be configured to treat one or more medical conditions of a patient. After a patient is selected for treatment, an identification procedure can be performed (e.g., using imaging device 50), such as an identification procedure comprising: identifying a source vessel; identifying a perfusion vessel; and identifying an anatomical location for a channel. Vascular access can be provided, such as vascular access comprising providing venous access (e.g., using venous access device 440); and/or providing arterial access (e.g., using arterial access device 460). A channel can be created between the source vessel and the perfusion vessel at the channel location (e.g., a channel created using channel creation device 100). Blood flow through the channel treats ischemia, end-stage plantar disease, and/or one or more other medical conditions of the patient. In some embodiments, blood flow through the channel treats critical limb ischemia, such as ischemia of the foot.

[163] The patient that is selected for treatment can comprise a patient that exhibits one, two, or more criteria selected from the group consisting of: source vessel diameter of at least 1.2mm, 1.5mm, 1.7mm and/or 2.0mm; perfusion vessel diameter of at least 1.2mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, and/or 4.0mm; patient has Rutherford Category 5/6 Ischemia with ulceration; patient has Small arterial disease (SAD); patient has slow arterial pedal acceleration time (PAT), such as a slow PAT in the lateral plantar artery, dorsalis pedis artery, distal tibial artery, and/or peroneal vessel artery, for example a PAT of at least 225ms; a resistive index that exceeds a threshold (e.g., as described herein); and combinations of these. The patient that is selected for treatment can comprise a patient selected from the group consisting of: a patient with one or more pedal arteries that are not patent; a patient with or one or more tibial arteries that are not patent; a patient that received a previous arterial revascularization procedure that has failed; a patient with diffuse calcium being present in one or more pedal arteries; a patient with a MAC score is 4 or 5; a patient exhibiting small artery disease (SAD); a patient exhibiting an ankle- brachial index (AB I) of no more than 0.39; a patient exhibiting an absolute ankle pressure of no more than 50mmHg; a patient exhibiting a peak pressure of no more than 30mmHg; a patient exhibiting a Rutherford Category of 5 or 6.

[164] In some embodiments, a patient is excluded from treatment if one or more particular exclusion criteria is present, such as an exclusion criterion selected from the group consisting of: the diameter of the perfusion vessel at a proposed channel location is not at least as large as the diameter of the source vessel at the channel location; a ratio of source vessel diameter to perfusion vessel diameter above a threshold, such as a threshold of 3: 1, 2.5: 1, and/or 2: 1; a source vessel with a stenosis above a threshold, such as a threshold comprising a stenosis percentage of 20%, 30%, and/or 40%; a quantity of digit wounds above a threshold, such as a quantity of at least 2 digit wounds or 3 digit wounds; a wound surface area above a threshold in the area to be treated (e.g., the patient has digit wounds that prevent healing or prevent successful amputation of tissue after creation of the channel; the patient has digit wounds covering more than 50% of a digit of the patient; and/or the patient has a wound that covers or penetrates more than 50% of a metatarsal length); and/or lack of a communicating vein in a diseased area to be treated. The patient can be excluded: if the patient has digit wounds that prevent healing or successful trans metatarsal amputation (TMA) after creation of the channel; if the patient has digit wounds covering more than 50% of a digit of the patient; and/or if the patient has a wound that covers or penetrates more than 50% of the metatarsal length. The patient can be excluded if the diameter of a source vessel or perfusion vessel at a proposed channel location is not above a threshold. The patient can be excluded from treatment if the patient has a source vessel with a diameter at a proposed channel location that is not above a threshold. The threshold can comprise a diameter of at least 2.0mm, 2.5mm, and/or 3.0mm. The patient can be excluded from treatment if the diameter of a downstream vein that would receive blood via the creation of a channel is not above a threshold. The downstream vein can comprise the tibial vein, peroneal vein, median marginal vein, or lateral plantar vein, and the threshold can comprise a diameter of at least 1.0mm, 1.2mm, 1.5mm, 2mm, and/or 3mm. The patient can be excluded from treatment if the patient has a non-patent saphenous vein (lessor or greater) or if the patient’s vasculature is missing the pedal loop and/or missing one or more segments of the pedal loop.

[165] In some embodiments, a patient is selected for treatment despite the diameter of the source vessel at the channel location is less than 2.0mm. In these embodiments, the source vessel can be dilated to achieve a diameter of at least 2.0mm at the channel location, such as when the dilation comprises a dilation of at least 25%, of no more than 50%, or both (e.g., a dilation that avoids undesired subsequent vessel occlusion due to the flow through the channel).

[166] In some embodiments, amputation of one or more digits or other patient tissue is performed after creation of the channel, such as when the channel is created to promote healing of the amputation sites, as described herein.

[167] In some embodiments, system 10 comprises one or more devices (e.g., vessel treatment device 800) that are configured to perform a preliminary treatment procedure on the source vessel and/or a vessel in fluid communication with the source vessel. In these embodiments, the treatment procedure can be performed to change a patient parameter such that the patient meets one or more inclusion criteria associated with the channel creation procedure to be performed using system 10. The preliminary treatment procedure can comprise a treatment procedure selected from the group consisting of: a vessel dilation procedure; an atherectomy procedure; a stenting procedure; an intravascular lithotripsy (IVL) procedure; and combinations of these.

[168] In some embodiments, system 10 is used to perform an imaging procedure configured to gather information related to inclusion and/or exclusion criteria of the patient, such as for determining acceptability of a treatment (e.g., channel creation) to be performed using system 10. The imaging procedure can be performed using imaging device 50, and can comprise a procedure selected from the group consisting of: contrast-based imaging, such as angiography and/or CT angiography; ultrasound; magnetic resonance angiography or venography; and combinations of these. The imaging procedure can comprise obtaining retrograde access of a median marginal vein and/or other veins of the foot, and then performing an angiogram to map the venous anatomy of the foot. System 10 can be used to dilate one or more blood vessels prior to performing an angiogram (e.g., an angiogram performed using imaging device 50). The dilating can be performed using vessel dilator 960 described herein and can comprise a procedure selected from the group consisting of: warming of a leg, foot, or other tissue, such as via a warming blanket; application of nitroglycerin gel; applying a tourniquet on the venous outflow; systemic injection of nitro infused saline, such as via an IV line; and combinations thereof. The patient’s limb can be positioned such that the foot is externally rotated between 0 and 45 degrees, and supported at the knee and ankle (e.g., allowing the calf to hang unsupported). This position prevents compression of the venous anatomy in the lower limb. The imaging procedure can determine if a communicating vein in a diseased area to be treated is present (e.g., when the patient is excluded if a communicating vein is not present). The imaging procedure can determine the diameter of one or more blood vessels of the patient, such as when the patient is excluded if at least one of the determined diameters is not above a threshold.

In some embodiments, the vessel selected to be a source vessel comprises an artery selected from the group consisting of: femoral artery; popliteal artery; tibial artery; anterior tibial artery; posterior tibial artery; tibioperoneal (TP) trunk artery; peroneal artery; brachial artery; radial artery; ulnar artery; a cardiac artery; and combinations thereof. In some embodiments, the source vessel comprises a tibial artery and/or peroneal artery. The tibial artery selected as a source vessel can comprise a posterior tibial artery and/or an anterior tibial artery.

[169] In some embodiments, the vessel selected to be the perfusion vessel comprises a vein selected from the group consisting of: native in-situ vein; femoral vein; popliteal vein; tibial vein; anterior tibial vein; posterior tibial vein; tibioperoneal (TP) trunk vein; brachial vein; radial vein; ulnar vein; a cardiac vein; and combinations thereof. In some embodiments, the perfusion vessel comprises a tibial vein and/or peroneal vein. The tibial vein selected as a perfusion vessel can comprise a posterior tibial vein and/or an anterior tibial vein.

[170] In some embodiments, an identification procedure comprises an identification of one or more vessels using an imaging device 50 that comprises an x-ray imaging device, such as fluoroscopy or computed tomography (CT) scan. Alternatively or additionally, an identification procedure comprises identification of one or more vessels using an imaging device 50 that comprises an ultrasound imaging device. The ultrasound imaging device can comprise an intravascular ultrasound (IVUS) device. In some embodiments, the identification procedure comprises an identification procedure that is performed using an imaging device 50 that comprises both an x-ray imaging device and an ultrasound imaging device. In some embodiments, the identification procedure comprises an identification performed using an endovascular non-radiating imaging device (e.g., an IVUS and/or other non-radiating imaging device).

[171] In some embodiments, the channel created using system 10 (e.g., using channel creation device 100) has a channel location (e g., as determined in an identification procedure) that is at least 1mm, 5mm, 10mm, and/or 15mm proximal to a calcified and/or partially occluded portion of the source vessel. In some embodiments, the identification procedure identifies a location for the channel at an anatomical location in which the source vessel and the perfusion vessel are separated by no more than a maximum threshold distance, such as a distance of no more than 1.5mm.

[172] In some embodiments, the identification procedure performed using system 10 identifies a location for the channel at an anatomical location in which the source vessel has a diameter of at least 2.0mm, a location in which the perfusion vessel has a diameter of at least 2.0mm, or both.

[173] In some embodiments, venous access is provided via venous access device 440 into a vein selected from the group consisting of: lateral plantar vein; posterior tibial vein; anterior tibial vein; peroneal vein; medial marginal vein; a perforator vein; arcuate vein; and combinations thereof. In some embodiments, the providing venous access comprises providing pedal access. The providing pedal access can comprise providing access to the lateral plantar vein and/or the arcuate vein.

[174] In some embodiments, providing venous access comprises using image guidance, image assistance, or both, for example using imaging device 50 (e.g., an ultrasound device and/or a vein finder). A venogram can be performed in the providing of the venous access. A vein finder can be used to access a superficial vein; venography via the superficial vein can be used to find (e.g., image) a deep vein; and the deep vein can then be accessed (e.g., using an imaging device comprising a fluoroscope and/or an ultrasound imaging device). In some embodiments, venous access is provided by finding a vein with image assistance, and then performing a surgical cutdown to the vein. [175] In some embodiments, the providing venous access comprises placing a guidewire 420 into one or more veins under image guidance provided by imaging device 50. The image guidance can comprise ultrasound image guidance, x-ray image guidance, or both. The placing of guidewire 420 can comprise advancing the guidewire to a perforating vein. The guidewire 420 can be placed directly into a perforating vein, such as a perforating vein that connects the dorsal and plantar veins. The guidewire 420 can be advanced through the lateral plantar vein into the posterior tibial vein. The guidewire 420 can be advanced into the tibioperoneal trunk. In some embodiments, a vein such as the lateral plantar vein and/or a tibial vein is directly accessed (e.g., via venous access device 440). In some embodiments, the vein accessed (e.g., directly or otherwise) comprises a vein selected from the group consisting of: dorsalis pedis vein; medial plantar vein; lateral plantar vein; marginal vein; medial marginal vein; deep foot perforating vein; a perforating vein that connects the dorsal and plantar veins; and combinations of one or more of these.

[176] In some embodiments, venous access device 440 can include a guide catheter with a diameter less than or equal to a threshold diameter, such as a threshold diameter of 6Fr. The guide catheter can be configured to allow injection of visualizable material when a guidewire (e.g., guidewire 420) is positioned within the guide catheter. The guide catheter can comprise a tapered lumen and/or a distal portion including fluid delivery ports for delivery of the visualizable material. A guidewire 420 can comprise a lumen, such as a lumen through which visualizable material (e.g., radiographic and/or ultrasonically reflective material) can be delivered. The guidewire 420 can comprise a proximal end with a rotating connector and an atraumatic distal portion including fluid delivery ports. The guidewire can comprise a hypotube with a laser cut pattern.

[177] In some embodiments, arterial access device 460 provides access into an artery selected from the group consisting of: femoral artery; common femoral artery; superficial femoral artery; popliteal artery; and combinations thereof. Arterial access device 460 can comprise a 4Fr to lOFr 10cm sheath (e.g., a 6Fr 10cm sheath), such as when placed in a femoral artery.

[178] In some embodiments, system 10 is configured to provide arterial access by placing a guidewire 420 into one or more arteries under image guidance provided by imaging device 50. [179] In some embodiments, system 10 is configured to create a channel that is void of any implanted device (e.g., void of any implanted device when the procedure is complete).

Alternatively, a stent, covered stent, and/or other scaffolding device can be implanted within or at least proximate the channel, and remain in place for a limited time period, such as a time period of no more than 1 week, 1 month, or 3 months. For example, the implanted scaffolding device can be removed and/or it can be configured to be bioabsorbed.

[180] In some embodiments, system 10 is configured to create a channel via the placement of a guidewire 420 between the source vessel and the perfusion vessel. The guidewire 420 can be placed with guidewire placement device 300, such as a device 300 that is similar to an Outback Elite re-entry catheter. Guidewire placement device 300 can include a needle 150 that can be advanced from a starting vessel to a target vessel, after which a guidewire 420 can be advanced into the target vessel (e.g., through the needle 150 and/or a hole created by the needle 150). The guidewire 420 can be placed from an artery to a vein, and/or from a vein to an artery.

[181] In some embodiments, imaging device 50 (e.g., an ultrasound imaging device) is used to perform an imaging procedure in order to determine the angle of the source vessel and the perfusion vessel relative to each other. In these embodiments, imaging device 50 can further comprise a fluoroscope, and the determined angle can be used to set an angle of the fluoroscope, such that the source vessel and the perfusion vessel overlap and/or are side-by-side in the fluoroscopy image.

[182] In some embodiments, system 10 is configured to perform (e g., automatically perform and/or allow a clinician or other operator to perform) simultaneous contrast injections and/or roadmap contrast injections to align and/or target the source vessel and the perfusion vessel (e.g., in a fluoroscopic image). A target, such as target 910 described herein, can be placed in the target vessel. Target 910 can comprise an expandable funnel that slidingly receives (e.g., and captures) the guidewire.

[183] In some embodiments, system 10 includes one, two, or more vascular occlusion elements (e.g., an occlusion element 510 comprising: a vascular plug, occlusion coil, and/or other occlusion element), such as a vascular occlusion element configured to be positioned in a perfusion vessel (e.g., a target vessel or starting vessel), proximate to (e.g., central to) a channel location. In some embodiments, prior to releasing the vascular occlusion element (e.g., releasing the occlusion element 510 from a delivery device, such as device 520), an imaging procedure, such as a venogram or other imaging procedure performed using imaging device 50, can be performed to confirm proper positioning of the vascular occlusion element. In some embodiments, one or more vascular occlusion elements (e.g., elements 510) can be positioned (e.g., repositioned) to block one or more side-branches of the target vessel, for example one or more side-branches proximate the target location that are identified during the imaging procedure. The position of the vascular occlusion elements can be adjusted after the imaging procedure, after which each vascular occlusion element can be released (e.g., released from a delivery device, such as delivery device 520 described herein). The channel location can be adjusted as well. In some embodiments, guidewire 420 is advanced from the source vessel to the perfusion vessel after the venogram is completed (e.g., and elements 510 are potentially repositioned).

[184] In some embodiments, a source vessel, a perfusion vessel, or both, are modified to have a minimum diameter (e.g., a diameter of at least 2.0mm) at a channel location (e.g., a proposed channel location), such as a channel location in which the source vessel and the perfusion vessel are within 1.5mm of each other. An occlusion element 510 can be delivered into the perfusion vessel (e.g., the target vessel in an artery-to-vein approach), and an angiogram can be performed to determine if there are any large side branches in the perfusion vessel. If large side branches are identified, the occlusion element 510 can be repositioned, and/or one or more additional occlusion elements 510 can be delivered (e.g., to prevent any undesired shunting). Subsequently, guidewire 420 can be advanced from the source vessel to the perfusion vessel.

[185] In some embodiments, imaging device 50 comprises an imaging device that is configured to rotate (e.g., a fluoroscope with a rotating imaging unit), such as to provide an image in which the source vessel and perfusion vessel can be shown on top of each other via rotation of the imaging device.

[186] In some embodiments, system 10 comprises one or more stabilizing elements, such as stabilizer 930 described herein, such as to assist in advancing needle 150 of channel creation device 100. Stabilizer 930 can comprise: a stabilizing element that can be positioned in the starting vessel (e.g., to stabilize a segment of the starting vessel); a stabilizing element that can be positioned in the target vessel (e.g., to stabilize a segment of the target vessel); or both. [187] In some embodiments, system 10 comprises snare 940 described herein, such as to snare a guidewire 420 that has been advanced from a starting vessel to a target vessel using guidewire placement device 300. Snare 940 can comprise a device similar to the EN Snare 6- 10mm device. Snare 940 can be configured to provide a target during the placement of the guidewire into the target vessel (e.g., snare 940 comprises target 910 or vice versa).

[188] In some embodiments, system 10 is configured to allow an operator (e.g., a clinician) to perform a procedure similar to a venous arterialization simplified technique (VAST) as known to those of skill in the art. In this technique a first device comprising a snare 940 or a target 910 can be advanced through arterial access device 460, and a second device comprising a snare 940 or a target 910 can be advanced through venous access device 440, and each can be positioned at the desired channel creation location. In some embodiments, the first device or the second device is configured to dilate the source vessel, and/or the perfusion vessel, respectively (e.g., either or both devices comprise a balloon or other expandable element configured to dilate a blood vessel). The imaging device 50 can be positioned such that the arterial and venous targets overlap. A needle (e.g., needle 150 of device 100, a straight vascular access needle, or other needle) can be advanced through the skin, and through both walls of the first vessel and into the second vessel (e.g., also passing through a snaring or other distal portion of the first device and the second device). Proper placement in both vessels can be confirmed by verifying the needle is captured by the target 910 or snare 940 in each vessel. A guidewire 420 comprising a double ended floppy guidewire, guidewire 420DF described herein can be inserted through the needle and captured with the snare 940 in the second vessel. The guidewire 420DF can be retracted through the second vessel until the proximal tip of the guidewire 420DF is proximate the initial skin puncture site (e.g., within 1cm to 5cm of the initial skin puncture site). The proximal floppy end of the guidewire 420DF can be captured in the first vessel with the snare 940 and the tip of the guidewire 420DF can be retracted through the skin and into the first vessel. The flexible portions on both ends of the guidewire 420DF allow the guidewire 420DF to prolapse when captured by the snare 940, and further allow the guidewire 420DF to be retracted without injuring the vessel walls. It should be noted that either the perfusion vessel or the source vessel can be configured to be either the first vessel or the second vessel described herein, depending on anatomical orientation of the vessels. In some cases, a sheath (e.g., a functional element 99 comprising a sheath) can be advanced over the guidewire 420DF, crossing from the perfusion vessel into the source vessel, thus providing access to the source vessel through the sheath.

[189] In some embodiments, channel creation device 100 is configured to apply energy (e.g., via EDE 160) to the channel creation, such as to create a “fused anastomosis” between the two vessels. In these embodiments, device 100 can be further configured to apply pressure to tissue of the channel to create the fused anastomosis. The energy provided by channel creation device 100 (e.g., as provided by console 200) can comprise energy in a form selected from the group consisting of: electromagnetic energy such as radiofrequency energy; sound energy such as ultrasound energy; light energy such as laser light energy; mechanical energy; thermal energy such as Joule heating, other heat energy, and/or cryogenic energy; chemical energy; and combinations thereof. System 10 (e.g., via console 200 and device 100) can be configured to deliver energy via EDE 160 in a closed loop delivery arrangement (e g., based on a signal provided by one or more sensors of system 10 as described herein). Energy can be delivered between distal and proximal heating elements of an EDE 160. EDE 160 can comprise an energy delivery element with low thermal mass. EDE 160 can be configured to deliver energy at a minimum of 500°F/s, a maximum of 700°F/s, or both, such as to minimize undesired heating of non-target tissue. The heating can be applied in short pulses, such as to minimize the thermal spread to adjacent tissues and/or to prevent the shaft of the delivery device from getting undesirably hot. For example, heat pulses can comprise a duration of less than 1 second, with a cooling time equal to or greater than the heat pulse duration, or both. The ablation of the tissue results in a channel with a non-circular cross section, such as a cross section with an aspect ratio of at least 2:1.

[190] In some embodiments, system 10 (e.g., via channel creation device 100 or other device) is configured to dilate the channel location, such as via an expandable balloon and/or other expandable portion of a catheter of channel creation device 100 and/or channel modifier 950. The dilation of the channel can be performed prior to, during, and/or after the application of energy to the channel (e.g., via EDE 160 of device 100). In some embodiments, channel creation device 100 comprises a Boomerang™ catheter and/or a catheter similar to the Boomerang catheter. Device 100 can comprise a catheter that includes one or more markers, marker 198 described herein, such as a pair of markers that are parallel with an angled surface of an EDE 160 (e.g., a heating element) of device 100. Imaging device 50 can be oriented such that the imaged vessels are shown in a parallel arrangement and the catheter of device 100 can be oriented such that the pair of markers overlap in the image of the parallel vessels. In some embodiments, device 100 comprises a heating element surface that is at a shallow angle relative to the axis of the shaft of device 100, for example such that the length of the heating element surface is at least 25% or at least 50% longer than the diameter of the shaft.

[191] In some embodiments, channel creation device 100 (e.g., a catheter) is inserted from a first vessel into a second vessel, such as is described herein. Device 100 can comprise one or more markers 198 that are positioned on the distal portion of device 100. Device 100 can be advanced into the second vessel until one or more of the markers 198 are positioned in the second vessel (e.g., as determined via an imaging procedure, such as when the markers 198 comprise radiopaque markers that are visible in the second vessel under fluoroscopic imaging performed using imaging device 50). In some embodiments, the position of device 100 can be confirmed with an injection of contrast into the first and/or second vessel, such as an arterial contrast injection. In some embodiments, device 100 can be advanced to a location in the second vessel distal to a desired placement location, and device 100 can subsequently be retracted until one or more of the markers 198 are properly positioned within the second vessel (e.g., such that device 100 is properly positioned). In some embodiments, once device 100 is properly positioned, tension can be applied to device 100 to cause a functional element 199 comprising an engagement mechanism (e.g., a hook, barb, and/or other engagement mechanism), positioned on the distal portion of the catheter, to engage the wall of the second vessel.

[192] In some embodiments, system 10 comprises channel modifier 950 for modifying a channel created using channel creation device 100. The channel modification can be performed based on a change in flow rate of the source vessel (e.g., an undesired change in flow rate that occurs in the source vessel), and/or otherwise when the flow rate of the source vessel is not at a desired level. The channel modification can be performed if the flow rate through the channel is below a threshold, such as when a channel modification (e.g., a channel dilation and/or other flow rate increasing procedure) is performed when the flow rate is below a minimum, such as a minimum flow rate of at least 150ml/min, 175ml/min, and/or 200ml/min. The channel modification can be performed if the flow rate through the channel is above a threshold, such as when a channel modification (e.g., a flow rate decreasing procedure) is performed when the flow rate is above a maximum, such as a flow rate of no more than 175ml/min, 200ml/min, and/or 250ml/min. The channel modification can be performed via a channel modifier 950 that is placed over the same guidewire 420 that is used to create the channel (e.g., the same guidewire 420 over which channel creation device 100 is placed). Channel modifier 950 can be configured to cause an increase in flow through the channel, such as when modifier 950 comprises a balloon or other expandable component configured to be positioned within the channel to dilate the channel (e.g., expand tissue of the channel to increase the cross-sectional area of the channel at one or more locations). In some embodiments, the channel is dilated by channel modifier 950 to a diameter of at least 2mm, to a diameter of no more than 4mm, or both. In some embodiments, channel modifier 950 can be configured to cause a reduction of flow through the channel, such as a flow reduction performed to prevent or at least reduce cardiac complications and/or to prevent or at least reduce undesired steal of arterial blood flow. The flow reduction can be performed using modifier 950 if the flow through the channel is above a threshold, such as when the flow rate is at least lOOOml/min; 1250ml/min; 1500ml/min; 1750ml/min; and/or 2000ml/min.

Channel modifier 950 can be configured to band the channel and/or band the source vessel (e.g., when modifier 950 comprises a band and/or a device configured to deploy a band). Channel modifier 950 can comprise a device (e.g., a delivery device and an implant) such as a device selected from the group consisting of a stent and/or a stent delivery device; a stent graft and/or a stent graft delivery device; a closure device; an occlusion device and/or an occlusion device delivery device; and combinations of these. A channel modification can be performed via introduction of channel modifier 950 from an artery, into the channel, and into a vein.

Alternatively, the modification can be performed via introduction of channel modifier 950 from a vein, into the channel, and into an artery.

[193] In some embodiments, a patient is excluded from receiving a channel creation procedure of the present inventive concepts if a source artery is occluded or severely diseased. However in alternative embodiments, the source artery can be treated (e.g., via angioplasty, stenting, atherectomy and/or the like via vessel treatment device 800), and a channel creation procedure can be performed using that artery as a source artery.

[194] Referring now to Fig. 2, a flow chart of a method for determining whether a flow modification procedure should be performed is illustrated, consistent with the present inventive concepts. In some embodiments, a flow modification procedure is performed based upon a measurement of the resistive index (RI) in a blood vessel, such as in one or more source vessels (e.g. the artery in which the channel is created and/or an artery in fluid communication with that artery), in one or more perfusion conduit vessels (e.g., veins receiving the oxygenated blood via the channel), and/or in one or more vessels downstream of the perfusion conduit (e.g., small veins proximate the target tissue, or veins proximate but upstream of those small veins), as described in reference to method 2000 of Fig. 2. The resistive index is defined herein as: (PSV - EDV) / PSV; where the PSV is the peak systolic velocity, and the EDV is the end diastolic velocity, in a blood vessel to be measured. Resistive index can be determined using flow sensing device 920 and/or one or more other components of system 10, such as when the flow measurements are performed using imaging via imaging device 50. One or more flow modification procedures can be performed using embolization device 500, valve treatment device 600, flow reducing device 700, vessel treatment device 800, channel modifier 950, vessel dilator 960, and/or other system 10 device, such as when the flow modification is performed using imaging via imaging device 50.

[195] In STEP 2100, the RI of a source vessel is measured.

[196] In STEP 2150, if the RI measured in STEP 2100 is above a threshold (e.g., a threshold of at least 0.6, and/or a threshold of no more than 0.85), STEP 2200 is performed, otherwise STEP 2300 is performed.

[197] In STEP 2200, a flow modification procedure (e.g., one or more flow modification procedures as described herein) is performed to the source vessel (e g., to one or more segments of the source vessel and/or an artery in fluid communication with the source vessel) and/or to a segment of the “perfusion conduit” (e.g., a segment of the perfusion vessel and/or a segment of a vein downstream of the perfusion vessel), to reduce the associated RI. Subsequently STEP 2300 is performed.

[198] In STEP 2300, the RI of the “proximal perfusion conduit” (a proximal portion of the perfusion conduit) is measured. For example, in treatments of target tissue located in the foot of the patient, the proximal perfusion conduit can comprise one or more veins in the mid-calf region.

[199] In STEP 2350, if the RI measured in STEP 2300 is above a threshold (e.g., a threshold of at least 0.5 and/or a threshold of no more than 0.8), STEP 2400 is performed, otherwise STEP 2500 is performed. [200] In STEP 2400, a flow modification procedure (e.g., one or more flow modification procedures as described herein) is performed to the perfusion conduit (e.g., to one or more segments of the proximal and/or distal perfusion conduit), to reduce the associated RI. Subsequently STEP 2500 is performed.

[201] In STEP 2500, the RI of the “distal perfusion conduit” (a distal portion of the perfusion conduit) is measured. For example, in treatments of target tissue located in the foot of the patient, the distal perfusion conduit can comprise one or more veins in the ankle.

[202] In STEP 2550, if the RI measured in STEP 2500 is above a threshold (e.g., a threshold of at least 0.5 and/or a threshold of no more than 0.7), STEP 2700 is performed, otherwise STEP 2600 is performed.

[203] In STEP 2700, vPAT is measured in a small vein proximate the target tissue being treated, after which STEP 2750 is performed.

[204] In STEP 2750, if the vPAT measured in STEP 2700 is below a threshold (e.g., a threshold of 180, indicating adequate perfusion of target tissue is present), STEP 2800 is performed, otherwise STEP 2900 is performed.

[205] In STEP 2900, a flow modification procedure (e.g., one or more flow modification procedures as described herein) is performed to increase flow to target tissue. Subsequently STEP 2800 is performed.

[206] In STEP 2600, vPAT is measured in a vein distal to the distal perfusion conduit, but proximal to the small veins proximate the target tissue (e.g. upstream of the vPAT measurement location of STEP 2700), after which STEP 2650 is performed. In some embodiments, the segment of the perfusion conduit in which the vPAT is measured in STEP 2600 is a segment of the plantar vein.

[207] In STEP 2650, if the vPAT measured in STEP 2600 is below a threshold (e.g., a threshold of 180, indicating adequate perfusion of target tissue is present), STEP 2800 is performed, otherwise STEP 2700 is performed.

[208] In STEP 2800, a monitoring of perfusion and wound healing is performed (e.g., at a time period of between two and four weeks from a previous step). If undesired results are achieved, one or more additional treatments can be performed, as described herein, such as a treatment configured to increase flow in the conduit vessel or redirect flow to the diseased area. [209] Flow modifications (e.g., flow modifications as described herein, and as determined using method 2000 of Fig. 2) can be performed at a time proximate the time of channel creation, or at any time thereafter. Flow modifications include but are not limited to: flow modifications to increase and/or otherwise improve flow such as valvulotomy, angioplasty, and/or stent placement; a flow modification to reroute and/or redirect flow such as branch embolization; and combinations of these.

[210] In some embodiments, the resistive index is measured (e.g., using flow sensing device 920) in one, two, or all of the source vessel, proximal perfusion conduit vessel, and distal perfusion conduit vessel, such as to determine if there is an undesired flow restriction in the pathway of oxygenated blood to be delivered to target tissue. A high RI can be associated with a restriction distal to the measured location, and the associated restriction may prevent sufficient blood flow to adequately perfuse the target tissue (e.g., target tissue comprising tissue of the foot). In some embodiments, a sufficient restriction can ultimately lead to thrombosing of the channel or the perfusion conduit vessel. The maximum resistive index threshold is different for different anatomical locations (e.g., as there are more side branches proximally). The RI at the source vessel should be less than 0.6, and/or no more than 0.85; the RI at the proximal perfusion conduit vessel should be less than 0.5, and/or no more than 0.8; and the RI at the distal perfusion conduit vessel should be less than 0.5, and/or no more than 0.7. If RI measurements exceed these thresholds, a flow modification procedure should be performed.

[211] As described herein, one or more flow measurements can be performed, such as using flow sensing device 920. Referring to Figs. 2A-2B, images produced in a flow sensing device 920 comprising the Logiq Ultrasound system of GE Healthcare are shown. In Fig. 2A, an image of flow in a human patient is shown in which inflow and outflow are each determined to be at an acceptable range (e.g., no flow modification procedure is indicated). In Fig. 2B, an image of flow in another human patient is shown in which while outflow is acceptable, inflow is below an acceptable level and a flow modification of the associated source vessel (e.g., an associated artery) should be performed.

[212] In some embodiments, the venous pedal acceleration time (vPAT) can be used to determine if a flow modification procedure needs to be performed (e.g., a flow modification procedure performed proximate the time of channel creation, or any time thereafter). The vPAT is an objective measurement to determine if there are inflow restrictions from the source vessel into the perfusion conduit vessel, and/or to determine if flow is being directed into a collateral vessel prior to where the measurement is taken. The vPAT measurement can be conducted by measuring the time it takes for blood to accelerate from the onset of systole to peak systole (reference Figs. 2A-B) in a vein with arterialized flow (e.g. a vein proximate the target tissue, and/or distal to the distal perfusion conduit). The measured venous flow can be split into three vPAT classifications: Class I, less than 180ms; Class II, between 180ms and 225ms; and Class III, greater than 225ms. In some embodiments, if the vPAT is Class II or greater, a modification procedure is performed to: increase the flow through the channel, direct (e.g., efficiently direct) the flow into the conduit that is feeding the diseased target tissue, or both.

[213] Directing the flow of oxygenated blood into the perfusion conduit vessel can cause the pressure in the arterialized veins (e.g., veins of the foot) to become hypertensive, forming pre-capillary arterial venous (AV) connections. These pre-capillary AV connections are a low resistance circuit between the arterial and venous system in the target treatment location (e.g., the foot), allowing blood from collateral arteries to flow into adjacent veins, or vice versa. The presence of these arterial venous connections can be detected by transformation of the venous flow in the associated veins from a spontaneous and phasic waveform to a waveform (e.g., an arterial waveform) as determined via a flow measurement (e.g., a doppler ultrasound measurement). The presence of an arterialized waveform with Class I vPAT in the associated veins (e.g., foot veins) surrounding the diseased target tissue is an indication that there is sufficient pre-capillary flow to heal the wound (e.g., and the channel may no longer be needed). Typically, it takes between 1 and 3 months for the pre-capillary connections to form, so the vPAT can be monitored in the veins surrounding the diseased target tissue on a regular basis (every 2 weeks to 1 month), such as to verify the vPAT is decreasing over time, or has reached Class I. If vPAT is not decreasing between timepoints or has not achieved Class I vPAT, a flow modification procedure can be performed to increase the flow through the source vessel and into the perfusion conduit vessel. In some embodiments, if Class I vPAT is present, a flow modification procedure is not performed.

[214] In some embodiments, a flow modification procedure, as described herein (e.g., performed using embolization device 500, valve treatment device 600, flow reducing device 700, vessel treatment device 800, channel modifier 950, vessel dilator 960, and/or other system 10 device), is performed if vPAT is above 180ms, such as to ensure proper wound healing. For example, a diseased artery (e.g., a heavily diseased or occluded artery) to provide blood to the channel can be treated (e.g., using vessel treatment device 800). For example, a guidewire 420 can be advanced in the diseased artery and its lumen restored (e.g., flow therethrough increased), and that artery can be used as a source vessel of the present inventive concepts. Alternatively, an artery in fluid communication with a source vessel can be similarly treated (e.g., to increase flow through the source vessel).

[215] In some embodiments, channel creation device 100 and/or other components of system 10 are configured to create a channel with a flow rate of at least lOOml/min, 125ml/min, 150ml/min, 175ml/min, and/or 200ml/min (e.g., create a channel to have and/or modify a channel to have a flow rate of at least lOOml/min, 125ml/min, 150ml/min, 175ml/min, and/or 200ml/min). In some embodiments, a channel is created to have and/or modified to have a flow rate of no more than 250ml/min. In some embodiments, a channel is created to have and/or modified to have a flow rate configured to cause minimal or no swelling nor edema. In some embodiments, a channel is created to have a flow rate configured to preserve patency and/or provide for wound healing, and then modified (e.g., dilated to increase the flow to an increased level). In some embodiments, a flow modification procedure (e.g., a channel flow modification procedure or other flow modification procedure that increases flow) is performed if the flow rate through the channel is below a threshold (e.g., below lOOml/min, 125ml/min, 150ml/min, 175ml/min, and/or 200ml/min) and/or if the flow rate through the perfusion vessel is below a threshold. In some embodiments, the flow rate through the channel created by system 10 is selected based on the anatomical location of the channel. In some embodiments, system 10 is configured to create a channel with a flow rate of no more than lOOOml/min, 1250ml/min, 1500ml/min, 1750ml/min, and/or 2000ml/min. In some embodiments, a flow modification procedure (e.g., a channel flow modification procedure or other flow modification procedure that decreases flow) is performed if the flow rate through the channel is above a threshold (e.g., above lOOOml/min, 1250ml/min, 1500ml/min, 1750ml/min, and/or 2000ml/min).

[216] In some embodiments, system 10 is configured to create a channel without blocking flow in the source vessel distal to the channel (e.g., without blocking or otherwise adversely affecting arterial flow).

[217] In some embodiments, system 10 is configured to create a channel that avoids a significant reduction in arterial flow that was present before the creation of the channel. System 10 can be configured to create a channel while avoiding significant reduction in antegrade flow in the source vessel distal to the channel. System 10 can be configured to create a channel that avoids significant reduction in flow in one or more arteries that are proximate the channel, such as to avoid significant flow reduction in the peroneal artery and/or collaterals of the peroneal artery. System 10 can be configured to avoid blocking or otherwise significantly reducing arterial flow, to avoid steal of arterial flow, or both.

[218] In some embodiments, system 10 is configured to treat the source vessel at an anatomical location proximal to the channel, such as a treatment performed using vessel treatment device 800. The treating of the source vessel with device 800 can be performed prior to the creation of the channel. The treating of the source vessel can comprise a treatment with a vessel treatment device comprising: an angioplasty catheter; an angioplasty catheter including a drug-coated balloon; a stent and/or stent delivery catheter; a stent with a drug-coated balloon delivery catheter; an intravascular lithotripsy device; an atherectomy device; a scoring device (e.g., a valve or other tissue scoring device) and combinations of these. The creation of the channel (e.g., via channel creation device 100) increases the flow of blood through the source vessel, which can improve long-term patency of the source vessel.

[219] In some embodiments, system 10 can be configured to perform a venous treatment procedure that is configured to improve venous retrograde flow and/or increase the pressure in the perfusion vessel (e.g., an increase in pressure that causes and/or improves venous retrograde flow). The venous treatment procedure can comprise a procedure that treats one or more venous valves, such as by using valve treatment device 600. Device 600 can be used to disrupt one or more venous valves, such as to disrupt the leaflet of each valve and/or the annulus of each valve. Device 600 can be configured to remove at least a portion of each of the one or more venous valves. In some embodiments, a venous treatment procedure performed by system 10 can be performed via the channel creation device 100 (e.g., device 100 comprises device 600). The venous treatment procedure can include application of Joule heating, heat energy, cryogenic energy, and/or other thermal energy (e g., via EDE 160 of device 100 and/or an energy delivery element of device 600). The venous treatment procedure can include providing retrograde catheter access with fluid distention of a vein; puncturing of a leaflet of a venous valve; and advancing of a balloon or other vessel dilator to tear the venous valve. The venous treatment procedure can comprise placing a stent at a location of a venous valve, such as when valve treatment device 600 and/or flow reducing device 700 comprises a stent and a stent delivery catheter. Device 600 and/or 700 can comprise a device similar to the Phillips Tack Stent device. Device 600 can be configured to score a venous valve prior to placing a stent, such as when the scoring is performed on the annulus of the venous valve. The venous treatment procedure can be performed using a device 600 comprising a valvulotome. The venous treatment procedure can be performed under image guidance provided by imaging device 50. The image guidance can comprise fluoroscopic and/or ultrasound image guidance provided by device 50. The image guidance can comprise performing intermittent venograms to position the device 600 (e.g., a valvulotome) and/or device 700. In some embodiments, device 600 comprises one or more of a sharp cutting element (e.g., a compressed sharp element configured to cut or otherwise delivery mechanical energy), a hole punch, a spiralized ribbon cutter, and/or a thermal energy delivery device used to treat the vein (e.g., treat one or more valves of a segment of vein). Device 600 can comprise a thermal energy delivery device comprising one or more plates and/or wires configured to deliver thermal energy. Device 600 can comprise a cutting balloon and/or a cutting sheath configured to treat a vein (e.g., treat one or more valves of a segment of vein). The venous treatment procedure can comprise a first treatment in which a valve annulus is treated and a second procedure in which one or more valve leaflets are treated. The venous treatment procedure can comprise a procedure that reduces venous shunting, such as using flow reducing device 700. For example, device 700 can comprise components (e.g., flow reducer 710) configured to at least partially occlude a vein segment, such as to prevent shunting of arterial blood to the heart and/or to prevent competing flow of blood through bridging and/or collateral veins. The vein can be at least partially occluded at a location within 5cm, 4cm, 3cm, 2.5cm, and/or 1cm of the location of the channel. System 10, using imaging device 50, can be configured to create one or more images used to locate one or more collateral venous branches, and the location of the at least partial occlusion of the vein performed by device 700 can be selected based on the location of the collateral venous branches. The at least partial occlusion of the vein can be performed using device 700 to increase flow of oxygenated blood to a target location, such as the foot of the patient. The venous treatment procedure performed using device 700 can comprise at least partially occluding a venous side-branch, such as a venous side-branch of the perfusion vessel. The venous treatment procedure can be performed at least one day after the creation of the channel. The venous shunting can be reduced via a device 700 that implants a flow reducer 710 of device 700 comprising: a coil; adhesive; a gel; a vascular plug; and/or an end-covered stent. The venous shunting can be reduced via closing of a vein segment via a device 700 that applies suture, clips, and/or heat. The venous shunting can be reduced by placing a device 700 that implants a covered stent in a vein (e.g., a device 700 comprising a covered stent and an associated delivery device), such as when the covered stent is implanted to cover the ostium of a venous side-branch. System 10 can be configured to perform a venous treatment procedure comprising imaging one or more veins with imaging device 50, and based on the imaging determine the size and/or implant locations of one or more occlusion devices (e.g., occlusion element 510 to be implanted by embolization device 500) to be implanted in the one or more veins. Embolization device 500 can be used to implant one or more occlusion elements 510, such as to prevent flow of blood back to the heart and/or to modify or prevent competing flow of blood through bridging and/or collateral veins.

[220] In some embodiments, system 10 is configured to perform a flow modification procedure configured to increase and/or decrease flow through the channel (a “channel modification procedure” herein). The channel flow modification procedure can comprise dilating the channel (e.g., to increase flow through the channel), such as a dilation performed using channel creation device 100 (e.g., when device 100 comprises a balloon and/or other expandable component) and/or using channel modifier 950. The channel flow modification procedure can comprise dilating a segment of the source vessel at a location proximate the channel. The channel flow modification procedure can comprise dilating a segment of the perfusion vessel at a location in or otherwise proximate the channel. The channel flow modification procedure can comprise at least partially occluding the source vessel at a location distal to the channel. The channel flow modification procedure can be performed at least one day after the creation of the channel. The channel flow modification procedure can be performed if flow through the channel falls below a threshold, such as when a channel flow assessment procedure is performed (e.g., using flow sensing device 920) to measure the flow through the channel.

[221] In some embodiments, system 10 is configured to perform a channel modification procedure comprising placing a scaffold or other implant in the channel, implant 951, such as a stent and/or other scaffolding element (“stent” herein) using channel modifier 950, such as to increase or decrease flow through the channel and/or to prevent undesired shunting of flow of blood that passes through the channel. For example, implant 951 can comprise: a stent; a stent with a covering (e.g., a covering configured to at least reduce undesired venous shunting); a stent with a porous covering; a drug-coated stent; suture; a clip; and/or adhesive.

[222] In some embodiments, system 10 includes an agent 60 comprising one or more pharmaceutical drugs, such as when system 10 and/or a clinician of the patient is configured to administer drug therapy to the patient.

[223] In some embodiments, system 10, using channel creation device 100, is configured to create a second channel between a first blood vessel and a second blood vessel. The second channel can be created using the same device 100 used to create the first channel, and/or using a second device 100 (e.g., a similar or dissimilar second device 100 as compared to the first device 100). The second channel can be created to increase venous retroperfusion. Alternatively, or additionally, the second channel can be created to divert blood flow back into the source vessel at a location distal to a fully occluded or at least partially occluded segment of the source vessel. The second channel can be created by introducing channel creation device 100 from the source vessel to a second vein, such as when the second vein does not comprise the perfusion vessel. The second channel can be created by introducing channel creation device 100 from the perfusion vessel to a second vein.

[224] In some embodiments, vessel dilator 960 is configured to perform a non-invasive blood vessel dilation procedure, as described herein. The non-invasive blood dilation procedure can be performed prior to the providing of vascular access and/or prior to the creation of the channe. Dilator 960 can comprise a nitroglycerin gel that is applied to the patient (e.g., a limb of the patient). Dilator 960 can further comprise a wrap that is applied about the limb of the patient receiving the gel. Dilator 960 can comprise: an intravascular vasodilator; a tourniquet; a manual compression device; a nerve block, such as a femoral or popliteal nerve block; and combinations of these. A non-invasive blood vessel dilation procedure performed using dilator 960 can be performed when a leg of the patient is positioned such that the calf of the leg is unsupported, such as to prevent compression of the venous anatomy of the calf.

[225] In some embodiments, system 10 is configured to perform a non-invasive venous outflow limiting procedure. For example, vessel dilator 960 can comprise a constricting device (e.g., a tourniquet or pressure cuff) that non-invasively limits venous outflow when applied. Dilator 960 can comprise a constricting device that is configured to apply a varied constriction, such as a varied constriction that is applied in a closed-loop arrangement.

[226] In some embodiments, system 10 is configured to perform a flow measuring and/or assessing procedure, such as using flow sensing device 920. Device 920 can be configured to provide an estimation of flow through a created channel, such as by subtracting an estimation of blood flow in the source vessel prior to channel creation from an estimation of blood flow in the source vessel distal to the channel after channel creation. Device 920 can be configured to: measure flow through the channel; measure flow through a vein segment carrying retrograde flow; or both. System 10 can be configured to perform a channel flow modification procedure (e.g., using device 100, channel modifier 950, and/or other system 10 component as described herein), if the measured flow is below a threshold (e.g., a flow modification that increases channel flow), or if it is above a threshold (e.g., a flow modification procedure that decreases channel flow). System 10 can be configured to modify flow through a vein, for example a “venous segment flow modification procedure” can be performed if a measured flow exceeds a threshold, and/or if a measured resistive index exceeds a threshold (e.g., to determine if there is high resistance impeding the flow of oxygenated blood to target tissue). The flow modifying can comprise performing a procedure selected from the group consisting of: angioplasty; stenting; valvuloplasty; embolization; and combinations of one or more of these The flow measuring and/or assessing procedure performed using system 10 can comprise performing real-time flow measurements using a flow sensing device 920 comprising ultrasound and/or other flow measurement devices and, based on the flow measurement and/or assessment, modifying (e.g., modifying the flow within) at least one of: the source vessel; the channel; and/or the perfusion vessel. The measuring of resistive index (e.g., as performed using flow sensing device 920) can comprise one, two, or more resistive index measurements that can be performed at various anatomical locations. One or more measurements can be performed above the channel in the source vessel or a vessel in fluid communication with the source vessel (e.g., a popliteal vessel), where a resistive index above a threshold (e.g., a threshold of 0.6 or 0.8) can indicate the channel and/or source vessel has a flow limiting occlusion and should be treated. Resistive index measured in the perfusion vessel (e.g., at the level of the ankle) that is above a threshold (e.g., a threshold of 0.5, 0.7 or 0.8) can indicate that there is resistance distal to that location, and that one or more vessels associated with the resistance should be treated. [227] In some embodiments, system 10 is configured to perform a second clinical procedure (e.g., in addition to a channel creation procedure performed prior to, or after the second clinical procedure). The second clinical procedure can comprise treating the source vessel at an anatomical location upstream of a previously created channel, such as using vessel treatment device 800 or other component of system 10. The second clinical procedure can be performed prior to the creating of the channel. The second clinical procedure can be performed at least one day prior to the creating of the channel. The second clinical procedure can comprise treating at least one lesion of the patient (e.g., using a vessel treatment device 800 comprising an angiography catheter and/or stent delivery device). The second clinical procedure can comprise: percutaneous transluminal angioplasty (PTA); implantation of a stent; and/or atherectomy of a source vessel, a perfusion vessel, or both. The second clinical procedure can comprise causing an artery to achieve a diameter of at least 3mm at a location proximate to (e g., proximal and proximate to) the channel. The second clinical procedure can comprise creation of a second channel between two blood vessels of the patient. The second channel can be created at least eight hours after the creation of the first channel. The second clinical procedure can comprise an amputation procedure (e.g., when the creation of the channel provides improved healing), such as an amputation procedure performed at least 1 week, 3 weeks, and/or 5 weeks after the creation of the channel . In some embodiments, the amputation procedure is performed after the confirmation of: granulation tissue forming proximate tissue surrounding a wound (e.g., a wound comprising an ulcer); and/or arterialized flow in veins surrounding a wound (e.g., a wound comprising an ulcer).

[228] In some embodiments, system 10 is configured to perform a “reversing procedure” in which flow through the channel is stopped (e.g., via the implantation of an embolization device, covered stent, and/or other flow-blocking component in the channel and/or a flow conduit in fluid communication with the channel, as described herein).

[229] In some embodiments, system 10 is configured to create a channel between a source vessel and a perfusion vessel to achieve one, two, or more efficacy endpoints that are present in the patient at least one week and/or at least 1 month after the creation of the channel. System 10 can be configured to create a channel between a source vessel and a perfusion vessel to achieve one, two, or more efficacy endpoints selected from the group consisting of: reversal of flow within a native vein; flow of oxygenated blood in one or more veins below the level of the ankle and into the foot; retrograde flow rate in a vein above a threshold; flow of oxygenated blood to a diseased area of the foot and/or diseased area of other target tissue; antegrade flow of oxygenated blood beyond the channel in a native vessel; redder and/or warmer foot tissue and/or other target tissue at one week or one month after creation of the channel; wound healing such as wound healing comprising at least 25% of skin growth; transmetatarsal amputation (TMA), other mid foot amputation, and/or other tissue amputation that is free of vascular complications and/or achieves accelerated healing; and combinations of these.

[230] In some embodiments, system 10 is configured to determine one, two, or more system 10 procedural parameters (e.g., automatically determine one, two, or more procedural parameters and/or provide information used by an operator to determine a procedural parameter). The one or more procedural parameters (“procedural parameter” or “procedural parameters” herein) can be determined by algorithm 85 described herein, which can comprise an Al algorithm.

Algorithm 85 can be configured to analyze data collected by one or more sensors or other devices of system 10. Algorithm 85 can be configured to analyze data selected from the group consisting of: images of the patient’s anatomy; vessel diameter data; lesion data; blood flow data; diagnostic data; and combinations thereof. The procedural parameter determined can comprise one or more proposed channel locations. The one or more proposed channel locations can be determined by algorithm 85 based on one, two, three, or more parameters selected from the group consisting of: diameter of one or more vessels at anatomical locations proximate the proposed channel location; distance of the proposed channel location to a bifurcation; location of a calcified segment of a blood vessel; tortuosity of one or more vessels at anatomical locations proximate the proposed channel location; proximity of one or more side-branches to the proposed channel location; proximity of the source and perfusion vessels to each other at the proposed channel location; desired flow rate through the channel; location and/or quantity of collateral arterial vessels proximate the proposed channel location; location and/or quantity of collateral venous vessels proximate the proposed channel location; location of a previous surgery or intervention; and combinations thereof. The procedural parameter determined by algorithm 85 can comprise a channel flow parameter and/or a channel geometry parameter (e.g., a channel size parameter), and/or any blood flow-related parameter (e.g., a resistive index parameter as described herein). The procedural parameter determined by algorithm 85 can comprise the addition of a channel modification procedure and/or other flow modification procedure to be performed (e.g., to modify the flow of blood in the source vessel, channel, and/or perfusion vessel). The procedural parameter determined by algorithm 85 can comprise one or more proposed anatomical locations for an embolization to be performed, and/or one or more parameters of the component used for achieving the embolization. The proposed anatomical locations can be chosen to optimize flow of oxygenated blood to the pedal loop of the foot. The procedural parameter determined by algorithm 85 can comprise a valve treatment procedure to be performed (e.g., where algorithm 85 identifies one or more valves to be treated) .

[231] System 10 can be configured to create a channel between a first artery and a first vein, to increase venous pressure (e.g., increase the pressure in the first vein and/or in veins in fluid communication with the first vein). The creation of the channel can result in: the primary vein loop and small tributary veins surrounding the wound having a distinct systolic and diastolic velocity waveform with a venous pedal acceleration time (vPAT) that is less than 180ms. Venous pressure can be increased to cause one or more venous valves to become incompetent, and/or to cause small tributary veins to become enlarged, such as to allow retrograde flow of arterial blood (i.e., oxygenated blood) to the associated capillary bed via these now arterialized small tributary veins. In some embodiments, system 10 is configured to create a channel between a source vessel comprising an artery, and a perfusion vessel comprising a vein, such that a primary vein loop (e.g., the lateral plantar vein) provides oxygenated blood to target tissue via retrograde flow. In these embodiments, oxygenated blood can continue to be delivered to the target tissue even after the primary vein loop (e.g., the lateral plantar vein) becomes occluded (e.g., due to arterialization of smaller veins that has occurred, such as an arterialization that occurs over at least 2 weeks, such as up to 2 months). In some embodiments, a vessel treatment procedure can be performed (e.g., via vessel treatment device 800) to a source vessel, perfusion vessel, and/or other vessel, after a primary vein loop (e.g., the lateral plantar vein) has fully or at least partially occluded, such as to improve flow through the small veins that have been arterialized, such as to improve therapeutic outcomes (e.g., maximize retrograde flow in the veins to improve healing).

[232] Referring now to Figs. 3A-C, a perspective and two side sectional views of a valve treatment device are illustrated, consistent with the present inventive concepts. Valve treatment device 600 of Figs. 3A-C can be of similar construction and arrangement to the similar components described in reference to Fig. 1 and otherwise herein. Valve treatment device 600 can comprise an expandable assembly, cage 610 shown. Cage 610 can comprise two, three, four, or more flexible struts and/or other flexible elements, such as the three struts 611 shown. Cage 610 can be positioned on the distal portion (e.g., the distal end) of an elongate shaft, shaft 601. In some embodiments, the proximal ends of struts 611 are fixedly attached to the distal end of shaft 601, such that cage 610 extends from the distal end of shaft 601, as shown. Alternatively, at least a portion of shaft 601 can extend through cage 610, for example the distal ends of struts 611 can be fixedly attached to the distal end of shaft 601, and the proximal ends of struts 611 can be attached to shaft 601 proximal to the distal end (e.g., such that cage 610 extends radially about the distal portion of shaft 601). In some embodiments, shaft 601 comprises two or more shafts, such as two or more shafts (e.g., concentric shafts or parallel shafts) configured to translate relative to each other, such as to control (e.g., manually and/or automatically control) the expansion and/or contraction of cage 610. For example, the distal ends of struts 611 can be fixedly attached to the distal end of a first, inner shaft, and the proximal ends of struts 611 can be fixedly attached to the distal end of a second, outer shaft, such that the relative position of the inner shaft and the outer shaft (e.g., the relative axial position of the shafts) can be adjusted by the operator to control the radial expansion and/or radial contraction of cage 610. Alternatively, as shown, valve treatment device 600 can include cage 610 positioned on the distal end of shaft 601, and can include a second shaft, sheath 602, comprising one or more lumens, lumen 6021 shown, that slidingly receives shaft 601 and cage 610. Cage 610 can be resiliently biased in an expanded geometry, such that when cage 610 is advanced from lumen 6021 (e g., when shaft 601 is advanced relative to sheath 602, and/or when sheath 602 is retracted relative to shaft 601), cage 610 transitions from a compact geometry to the expanded geometry shown. Cage 610 can be collapsed (e.g., transition from the expanded geometry to the collapsed geometry) when cage 610 is retracted into lumen 6021 (e.g., captured within lumen 6021 when shaft 601 is retracted relative to sheath 602, and/or when sheath 602 is advanced relative to shaft 601). In some embodiments, the distal end of cage 610 is “free-floating”, and does not attached to a shaft.

[233] In some embodiments, shaft 601 includes one or more lumens, such as lumen 6011 shown. Lumen 6011 can comprise a guidewire lumen, such as a lumen configured to slidingly receive a guidewire, for example, guidewire 420 not shown but described in reference to Fig. 1 and otherwise herein. In some embodiments, the guidewire lumen comprises a split lumen and/or an otherwise non-contiguous lumen, such as to allow the distal end of the expandable cage to translate relative to the at least one shaft as the diameter of the expandable cage changes. For example, lumen 6011 can comprise a proximal portion that terminates proximal to cage 610 that allows the distal end of cage 610 to freely change lengths as it expands and contracts. Lumen 6011 can further comprise a separate distal portion that is configured to guide the guidewire into the proximal portion of lumen 6011 when cage 610 transitions into its collapsed state. The proximal and distal portions of lumen 6011 can result in increased flexibility of cage 610. Cage 610 can include distal structure, hub 618 shown. The distal portions of struts 611 can be fixedly attached to each other (e.g., such that the distal portions of struts 611 form hub 618), and/or the distal portions of struts 611 can be fixedly attached to hub 618, such as when hub 618 comprises a section of a rod or tube that the distal portions of struts 611 are fixedly attached to. Hub 618 can comprise one or more passageways extending longitudinally therethrough, such as lumen 6181 shown. Lumen 6181 can comprise a guidewire lumen such as a lumen configured to slidingly receive guidewire 420, as described herein. In some embodiments, shaft 601 (including lumen 6011) extends through cage 610 to hub 618 (as described hereabove), such that guidewire 420 can be slidingly positioned through cage 610 within lumen 6011. Alternatively, guidewire 420 can be slidingly positioned through lumen 6011 as shown, exiting the distal end of lumen 6011, extending (e.g., extending unsupported) through the center of cage 610, and through lumen 6181 (as shown dashed in Fig. 3B). Valve treatment device 600 can be positioned in a blood vessel “over the guidewire”, such as by inserting guidewire 420 from the proximal end of valve treatment device 600 (e.g., such that guidewire 420 exits lumen 6011, extends through cage 610, and continues through the length of lumen 6181). Alternatively, guidewire 420 can be inserted from the distal end of valve treatment device 600, such as when guidewire 420 has been inserted into a blood vessel of a patient with its distal portion positioned proximate and/or distal to a treatment site (e.g., a venous valve location), and its proximal end inserted through lumen 6181, through cage 610, and into lumen 6011 (e.g., such that cage 610 can be advanced over the guidewire to the treatment site). In some embodiments, valve treatment device 600 can be positioned over guidewire 420 while cage 610 is in a compact geometry, for example, when cage 610 is positioned within sheath 602. As shown in Fig. 3B, the proximal and/or distal opening of lumens 6011 and/or 6181 can be tapered outward (e.g., flared outward), such as to allow for easier insertion of guidewire 420 into the respective lumens. [234] In some embodiments, cage 610 does not comprise a central shaft, as shown and described hereabove, and can comprise a greater axial flexibility than a similar cage that does comprise a central shaft, such as to allow cage 610 to be more easily and safely positioned into tortuous anatomy. For example, cage 610 shown can comprise a minimum bend radius of 5mm. The expanded configuration of cage 610 can be between 4mm and 10mm (e.g., cage 610 comprises an expanded diameter of at least 4mm, and/or no more than 10mm). The bend radius of cage 610 can be set such that the radial wall of cage 610 is of sufficient strength (e.g., sufficient radial strength) to overcome any spasm or narrowing in the vessel within which it is inserted. The closer the bend radius is to the expanded wall, the more radial force will be applied to vasculature (e.g., to the valve to be treated). The strut 611 can be configured to allow flexibility by adding a “z” or “s” shape into the strut, allowing the strut length to change along the lumen axis, thereby improving the flexibility without impacting the radial force. In some embodiments, the z-shaped or s-shaped geometry is configured to allow a venous valve leaflet to collapse to a smaller diameter than the diameter of the radially expandable assembly such that the one or more cutting elements are prevented from cutting the wall of the vein in which the venous valve leaflet is located. The flexibility of the strut 611 can be optimized to allow tracking of the expanded cage 610 to track from the posterior tibial vein into the lateral plantar vein and/or from the plantar veins through the perforator veins into the dorsal veins. Cage 610 can comprise a material selected from the group consisting of a shape memory material, such as a nickel-titanium alloy; stainless steel; cobalt chromium; and combinations of these.

[235] In some embodiments, cage 610 comprises an expanded geometry with a diameter of at least 2mm, such as at least 3mm, or at least 4mm. The expanded geometry of cage 610 can comprise a maximum diameter of no more than 10mm, such as no more than 9mm, or no more than 8mm. Cage 610 can be manufactured from a single tube, such as a nickel titanium tube, that is cut (e.g., laser cut) to form struts 611. One or more struts 611 can each comprise one or more tissue cutting and/or other tissue manipulation element, cutters 612 as shown, such as when one cutter 612 is located on each strut 611. Cutters 612 can comprise a hook-like geometry, such as a proximal facing hook configured to capture and cut (e.g., remove) tissue (e.g., valve tissue) as cage 610 is retracted through a lumen, such as a vessel. For example, valve treatment device 600 can be inserted into a patient (e.g., over a guidewire that has been previously positioned in a vessel such as a vein or an artery) such that cage 610 is positioned distal to a portion of tissue (e.g., a venous valve) to be removed or otherwise modified by valve treatment device 600. Cage 610 can be expanded (e.g., by retracting sheath 602), and cage 610 can be subsequently retracted proximally (e.g., shaft 601 and sheath 602 can be retracted simultaneously) such that cutters 612 are translated past the tissue to be modified.

[236] As shown in Fig. 3C, each cutter 612 can include one or more cutting surfaces, blade 6121 shown, comprising a leading section (e.g., a proximal facing section as shown), tip 6122. Cutter 612 can include one or more recesses, opening 6123 shown. Tissue to be modified can be caused to enter opening 6123 such that blade 6121 cuts or otherwise modifies the tissue. In some embodiments, the tissue to be modified extends from the walls of the vessel within which cage 610 has been positioned, and as such, as cage 610 is retracted, the portions of struts 611 proximal and distal to opening 6123 hold the wall of the vessel from entering opening 6123, while structures to be modified “fall” into the opening 6123. In some embodiments, tip 6122 is offset inward toward opening 6123, as shown, such as to prevent and/or at least limit unintended tissue structures (e.g., the vessel wall and/or side-branch ostium) from being “caught” by tip 6122 of cutter 612 as cage 610 is retracted. In some embodiments, system 10 comprises a kit of two or more valve treatment devices 600, such as two or more valve treatment devices 600 comprising cages 610 of different diameters configured to treat vessels of different sizes. In some embodiments, the offset of tip 6122 can be different based on the size of the vessel (e.g., based on the size of the device). The offset of tip 6122 can be at least 0.005”. In some embodiments, the offset of tip 6122 is no more than 0.050”. In some embodiments, the depth DI of opening 6123 can be selected (e.g., in a manufacturing process, and/or selected by a clinician from a kit of valve treatment devices 600 comprising varying depths of opening 6123) to set the depth of cut to be made into tissue to be manipulated. For example, the deeper opening 6123 extends, the more tissue can be positioned within opening 6123 to be modified by blade 6121. The depth DI of opening 6123 can be at least 0.0150”. In some embodiments, the depth D I of opening 6123 is no more than 0.150”.

[237] In some embodiments, one or more of struts 611 comprise one or more cutters 612 facing distally (e.g., tip 6122 and opening 6123 are oriented distally) such that valve treatment device 600 can modify tissue while being advanced distally. In some embodiments, at least two cutters 612 of cage 610 are oriented proximally and distally (e.g., at least one cutter 612 facing proximally and at least one cutter 612 facing distally), such that tissue can be modified by moving cage 610 in either or both directions within the vessel (e.g., in an oscillating motion).

[238] In some embodiments, hub 618 comprises an atraumatic distal end that prevents and/or at least limits unintended trauma to the vessel as valve treatment device 600 (e.g., cage 610) is advanced (e.g., advanced over guidewire 420). In some embodiments, the distal ends of struts 611 are not connected (e.g., cage 610 does not include hub 618). The distal ends of struts 611 can comprise atraumatic ends.

[239] The above-described embodiments should be understood to serve only as illustrative examples; further embodiments are envisaged. Any feature described herein in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the inventive concepts, which is defined in the accompanying claims.

Claims

WHAT IS CLAIMED IS:

1. A method of treating a medical condition of a patient comprising: selecting a patient for treatment; performing an identification procedure comprising: identifying a source vessel; identifying a perfusion vessel; and identifying an anatomical location for a channel; providing vascular access comprising: providing venous access; and/or providing arterial access; and creating the channel between the source vessel and the perfusion vessel at the channel location, wherein blood flow through the channel delivers oxygenated blood to target tissue which treats the medical condition of the patient.

2. The method as claimed in at least one of the preceding claims, wherein the medical condition treated comprises ischemia.

3. The method according to claim 2 and/or any other claim herein, wherein the ischemia comprises critical limb ischemia.

4. The method according to claim 3 and/or any other claim herein, wherein the critical limb ischemia comprises ischemia of the foot.

5. The method as claimed in at least one of the preceding claims, wherein the medical condition comprises end-stage plantar disease.

6. The method as claimed in at least one of the preceding claims, wherein the patient selected for treatment exhibits a criteria selected from the group consisting of: source vessel diameter of at least 1.2mm, 1.5mm, 1.7mm and/or 2.0mm; perfusion vessel diameter of at least 1.2mm, 1.5mm, and/or 2.0mm; patient has Rutherford Category 5/6 Ischemia with ulceration; patient has Small arterial disease (SAD); patient has slow pedal acceleration time (PAT), such as slow PAT in the lateral plantar artery, dorsalis pedis artery, distal tibial artery, arcuate artery, and/or peroneal vessel artery, such as when the PAT has a value of at least 225ms; a resistive index that exceeds a threshold; and combinations thereof.

7. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if one or more pedal arteries are not patent and/or if one or more tibial arteries are not patent.

8. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if a previous arterial revascularization procedure has failed.

9. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if diffuse calcium is present in one or more pedal arteries.

10. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if the patient’s MAC score is 4 or 5.

11. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if the patient exhibits small artery disease (SAD).

12. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if the patient exhibits an ankle-brachial index (AB I) of no more than 0.39.

13. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if the patient exhibits an absolute ankle pressure of no more than 50mmHg.

14. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if the patient exhibits a peak pressure of no more than 30mmHg.

15. The method as claimed in at least one of the preceding claims, wherein the patient is selected for treatment if the patient exhibits a Rutherford Category of 5 or 6.

16. The method as claimed in at least one of the preceding claims, wherein the patient is excluded from treatment if the ratio of the diameter of the source vessel at the channel location to the diameter of the perfusion vessel at the channel location is below a threshold.

17. The method according to claim 16 and/or any other claim herein, wherein the threshold comprises a ratio of 3: 1, 2.5: 1, and/or 2:1.

18. The method as claimed in at least one of the preceding claims, wherein the patient is excluded from treatment if the patient has a source vessel with a stenosis above a threshold.

19. The method according to claim 18 and/or any other claim herein, wherein the threshold comprises a stenosis percentage of 20%, 30%, and/or 40%.

20. The method as claimed in at least one of the preceding claims, wherein the patient is excluded from treatment if the patient has a quantity of digit wounds above a threshold.

21. The method according to claim 20 and/or any other claim herein, wherein the threshold is 2 digit wounds or 3 digit wounds.

22. The method as claimed in at least one of the preceding claims, further comprising amputating one or more digits of the patient, wherein the creation of the channel is configured to promote healing of the amputation site.

23. The method according to claim 22 and/or any other claim herein, wherein the amputating of the one or more digits is performed at least 1 week, 3 weeks, and/or 5 weeks after the creation of the channel.

24. The method according to claim 23 and/or any other claim herein, wherein the amputating of the one or more digits is performed at least 5 weeks after the creation of the channel.

25. The method as claimed in at least one of the preceding claims, wherein the patient is excluded from treatment if the patient has a wound surface area above a threshold in the area to be treated.

26. The method according to claim 25 and/or any other claim herein, wherein the patient is excluded from treatment if the patient has digit wounds that prevent healing or prevent successful amputation of tissue after creation of the channel.

27. The method according to claim 25 and/or any other claim herein, wherein the patient is excluded from treatment if the patient has digit wounds covering more than 50% of a digit of the patient.

28. The method according to claim 25 and/or any other claim herein, wherein the patient is excluded from treatment if the patient has a wound that covers or penetrates more than 50% of a metatarsal length.

29. The method as claimed in at least one of the preceding claims, further comprising performing an imaging procedure of a portion of the patient’s anatomy to gather information related to inclusion or exclusion of the patient for treatment.

30. The method according to claim 29 and/or any other claim herein, wherein the imaging procedure comprises a procedure selected from the group consisting of contrast-based imaging such as angiography and/or CT angiography; ultrasound; magnetic resonance angiography or venography; and combinations thereof.

31. The method according to claim 29 and/or any other claim herein, wherein the imaging procedure comprises obtaining retrograde access of a lateral plantar vein, median marginal vein and/or other veins of the foot, and then performing an angiogram to map the venous anatomy of the foot.

32. The method according to claim 31 and/or any other claim herein, further comprising dilating one or more blood vessels prior to performing the angiogram.

33. The method according to claim 32 and/or any other claim herein, wherein the dilating comprises a procedure selected from the group consisting of: warming of a leg, foot, or other tissue such as via a warming blanket; application of nitroglycerin gel; applying a tourniquet on the venous outflow; systemically inject nitro infused saline, such as via an IV line; and combinations thereof.

34. The method according to claim 29 and/or any other claim herein, wherein the patient is excluded from treatment if a communicating vein in a diseased area to be treated is not present.

35. The method according to claim 29 and/or any other claim herein, wherein the imaging procedure determines the diameter of one or more blood vessels of the patient, and wherein the patient is excluded from treatment if at least one of the determined diameters is not above a threshold.

36. The method according to claim 35 and/or any other claim herein, wherein the patient is excluded from treatment if the diameter of a source vessel or perfusion vessel at the channel location is not above a threshold.

37. The method according to claim 36 and/or any other claim herein, wherein the patient is excluded from treatment if the patient has a source vessel with a diameter at the channel location that is not above a threshold.

38. The method according to claim 37 and/or any other claim herein, wherein the threshold comprises a diameter of at least 2.0mm, 2.5mm, and/or 3.0mm.

39. The method according to claim 35 and/or any other claim herein, wherein the patient is excluded from treatment if the diameter of a downstream vein that receives blood via the channel is not above a threshold.

40. The method according to claim 39 and/or any other claim herein, wherein the downstream vein comprises the lateral plantar vein, and wherein the threshold comprises a diameter of at least 1.0mm, 1.2mm, and/or 1.5 mm.

41. The method according to claim 35 and/or any other claim herein, wherein the patient is excluded from treatment if the patient’s anatomy is missing the pedal loop and/or missing one or more segments of the pedal loop.

42. The method as claimed in at least one of the preceding claims, further comprising performing a treatment procedure on the source vessel and/or a vessel in fluid communication with the source vessel.

43. The method according to claim 42 and/or any other claim herein, wherein the treatment procedure comprises a treatment procedure selected from the group consisting of: a vessel dilation procedure; an atherectomy procedure; a stenting procedure; intravascular lithrotripsy (IVL) procedure; and combinations thereof.

44. The method as claimed in at least one of the preceding claims, wherein the source vessel comprises an artery selected from the group consisting of: femoral artery; popliteal artery; tibial artery; anterior tibial artery; posterior tibial artery; tibioperoneal (TP) trunk artery; peroneal artery; brachial artery; radial artery; ulnar artery; a cardiac artery; and combinations thereof.

45. The method as claimed in at least one of the preceding claims, wherein the perfusion vessel comprises a vein selected from the group consisting of: femoral vein; popliteal vein; tibial vein; anterior tibial vein; posterior tibial vein; tibioperoneal (TP) trunk vein; brachial vein; radial vein; ulnar vein; a cardiac vein; and combinations thereof.

46. The method as claimed in at least one of the preceding claims, wherein the source vessel comprises a popliteal artery, tibial artery and/or peroneal artery.

47. The method according to claim 46 and/or any other claim herein, wherein the tibial artery comprises a posterior tibial artery and/or anterior tibial artery.

48. The method as claimed in at least one of the preceding claims, wherein the perfusion vessel comprises a native in-situ vein.

49. The method according to claim 48 and/or any other claim herein, wherein the in-situ vein is comprised of a tibial vein and/or peroneal vein.

50. The method according to claim 48 and/or any other claim herein, wherein the tibial vein comprises a posterior tibial vein and/or anterior tibial vein.

51. The method as claimed in at least one of the preceding claims, wherein the identification procedure comprises performing an identification using x-ray imaging such as fluoroscopy or computed tomography (CT) scan.

52. The method as claimed in at least one of the preceding claims, wherein the identification procedure comprises performing an identification using ultrasound imaging.

53. The method according to claim 52 and/or any other claim herein, wherein the ultrasound imaging comprises intravascular ultrasound.

54. The method as claimed in at least one of the preceding claims, wherein the identification procedure comprises performing an identification using x-ray imaging and ultrasound imaging.

55. The method as claimed in at least one of the preceding claims, wherein the identification procedure comprises performing an identification using an endovascular non-radiating imaging device.

56. The method as claimed in at least one of the preceding claims, wherein the channel location is at least 5mm, 10mm, and/or 15mm proximal to a calcified and/or partially occluded portion of the source vessel.

57. The method as claimed in at least one of the preceding claims, wherein the identification procedure identifies a location for the channel at an anatomical location in which the source vessel and the perfusion vessel are separated by no more than a maximum threshold distance.

58. The method according to claim 57 and/or any other claim herein, wherein the maximum threshold distance comprises a distance of no more than 1.5mm.

59. The method as claimed in at least one of the preceding claims, wherein the identification procedure identifies a location for the channel at an anatomical location in which the source vessel has a diameter of at least 2.0mm.

60. The method as claimed in at least one of the preceding claims, wherein the identification procedure identifies a location for the channel at an anatomical location in which the source vessel has a diameter of less than 2.0mm, and wherein the source vessel is dilated to achieve a diameter of at least 2.0mm at the channel location.

61. The method according to claim 60 and/or any other claim herein, wherein the source vessel is dilated at least 25%, no more than 50%, or both.

62. The method as claimed in at least one of the preceding claims, wherein the identification procedure identifies a location for the channel at an anatomical location in which the perfusion vessel has a diameter of at least 2.0mm.

63. The method as claimed in at least one of the preceding claims, wherein venous access is provided into a vein selected from the group consisting of lateral plantar

- 1 - vein; posterior tibial vein; anterior tibial vein; peroneal vein; medial marginal vein; a perforator vein; arcuate vein; and combinations thereof.

64. The method as claimed in at least one of the preceding claims, wherein the providing venous access comprises providing pedal access.

65. The method according to claim 64 and/or any other claim herein, wherein the providing pedal access comprises providing access to the lateral plantar vein and/or the arcuate vein.

66. The method as claimed in at least one of the preceding claims, wherein venous access is provided using image guidance, image assistance, or both.

67. The method according to claim 66 and/or any other claim herein, wherein the image guidance and/or image assistance is performed using ultrasound, a venogram, and/or a vein finder.

68. The method as claimed in at least one of the preceding claims, wherein providing venous access comprises using a vein finder to access a superficial vein; performing a venography via the superficial vein to find a deep vein; and accessing the deep vein using fluoroscopy and/or ultrasound imaging.

69. The method as claimed in at least one of the preceding claims, wherein providing venous access comprises finding a vein with image assistance and performing a surgical cutdown.

70. The method as claimed in at least one of the preceding claims, wherein the providing venous access comprises placing a guidewire into one or more veins under image guidance.

71. The method according to claim 70 and/or any other claim herein, wherein the image guidance comprises ultrasound image guidance, x-ray image guidance, or both.

72. The method according to claim 70 and/or any other claim herein, wherein the placing a guidewire comprises advancing the guidewire to a perforating vein.

73. The method according to claim 70 and/or any other claim herein, wherein the guidewire is placed directly into a perforating vein, such as a perforating vein that connects the dorsal and plantar veins.

-n-

74. The method according to claim70 and/or any other claim herein, wherein the guidewire is advanced through the lateral plantar vein into the posterior tibial vein.

75. The method according to claim 74 and/or any other claim herein, wherein the guidewire is advanced into the tibioperoneal trunk.

76. The method according to claim 70 and/or any other claim herein, wherein the providing venous access comprises placing a guide catheter with a diameter less than or equal to a threshold diameter.

77. The method according to claim 76 and/or any other claim herein, wherein the threshold diameter equals 6Fr.

78. The method according to claim 76 and/or any other claim herein, wherein the guide catheter is configured to allow injection of visualizable material when a guidewire is positioned within the guide catheter.

79. The method according to claim 78 and/or any other claim herein, wherein the guide catheter comprises a tapered lumen and a distal portion including fluid delivery ports for delivery of the visualizable material.

80. The method according to claim 70 and/or any other claim herein, wherein the guidewire comprises a lumen through which visualizable material can be delivered.

81. The method according to claim 80 and/or any other claim herein, wherein the guidewire comprises a proximal end with a rotating connector and an atraumatic distal portion including fluid delivery ports.

82. The method according to claim 80 and/or any other claim herein, wherein the guidewire comprises a hypotube with a laser cut pattern.

83. The method as claimed in at least one of the preceding claims, wherein arterial access is provided into an artery selected from the group consisting of: femoral artery; common femoral artery; superficial femoral artery; popliteal artery; and combinations thereof.

84. The method as claimed in at least one of the preceding claims, wherein providing arterial access comprises placement of a sheath in a femoral artery, such as a sheath with a diameter of at least 4Fr and/or no more than lOFr, such as an 8cm or 10cm sheath.

85. The method as claimed in at least one of the preceding claims, wherein the providing arterial access comprises placing a guidewire into one or more arteries under image guidance.

86. The method according to claim 85 and/or any other claim herein, wherein the guidewire comprises a lumen through which visualizable material can be delivered.

87. The method according to claim 85 and/or any other claim herein, wherein the guidewire comprises a proximal end with a rotating connector and an atraumatic distal portion including fluid delivery ports.

88. The method as claimed in at least one of the preceding claims, wherein the channel is void of an implanted device.

89. The method as claimed in at least one of the preceding claims, wherein a stent, a covered stent, and/or another scaffolding device is implanted within or at least proximate the channel, wherein the scaffolding device remains in place for a limited time period, such as a time period of no more than 1 week, 1 month, and/or 3 months.

90. The method according to claim 89, wherein the scaffolding device is configured to be removed and/or bioabsorbed within the limited time period.

91. The method as claimed in at least one of the preceding claims, wherein creating the channel comprises placing a guidewire between the source vessel and the perfusion vessel.

92. The method according to claim 91 and/or any other claim herein, wherein the guidewire is placed with a device similar to an Outback Elite re-entry catheter.

93. The method according to claim 91 and/or any other claim herein, wherein the guidewire is placed from artery to vein.

94. The method according to claim 91 and/or any other claim herein, wherein the guidewire is placed from vein to artery.

95. The method according to claim 91 and/or any other claim herein, wherein the guidewire is placed by advancing the needle from a starting vessel to a target vessel, and then advancing the guidewire through a hole created by the needle.

96. The method according to claim 95 and/or any other claim herein, wherein the guidewire is advanced through the hole via a lumen of the needle.

97. The method according to claim 95 and/or any other claim herein, further comprising performing an ultrasound imaging procedure to determine the angle of the source vessel and the perfusion vessel relative to each other, and setting a fluoroscopy angle such that the source vessel and the perfusion vessel overlap and/or are side-by-side in the fluoroscopy image.

98. The method according to claim 95 and/or any other claim herein, further comprising performing simultaneous contrast injections and/or roadmap contrast injections to align and/or target the source vessel and the perfusion vessel.

99. The method according to claim 95 and/or any other claim herein, wherein a target is placed in the target vessel.

100. The method according to claim 99 and/or any other claim herein, wherein the target comprises an expandable funnel that slidingly receives the guidewire.

101. The method according to claim 95 and/or any other claim herein, further comprising positioning a vascular occlusion element in the perfusion vessel proximate to a proposed channel location and prior to releasing the vascular occlusion element performing a venogram to confirm proper positioning of the vascular occlusion element.

102. The method according to claim 101 and/or any other claim herein, further comprising repositioning the vascular occlusion elements to occlude one or more side-branches and/or adjusting the channel location, such as a repositioning and/or an adjustment performed based on the venogram.

103. The method according to claim 101 and/or any other claim herein, wherein the guidewire is placed from the source vessel to the perfusion vessel after the performance of the venogram.

104. The method according to claim 95 and/or any other claim herein, further comprising rotating an imaging device to provide an image in which the source vessel and perfusion vessel are shown on top of each other.

105. The method according to claim 95 and/or any other claim herein, further comprising deploying one or more stabilizing elements to assist in advancing the needle.

106. The method according to claim 105 and/or any other claim herein, wherein a first stabilizing element is positioned in the starting vessel.

107. The method according to claim 105 and/or any other claim herein, wherein a first stabilizing element is positioned in the target vessel.

108. The method according to claim 95 and/or any other claim herein, further comprising positioning a target in the target vessel.

109. The method according to claim 91 and/or any other claim herein, further comprising snaring the guidewire using a snare device.

110. The method according to claim 109 and/or any other claim herein, wherein the snare device comprises a device similar to the EN Snare 6- 10mm device.

111. The method according to claim 109 and/or any other claim herein, wherein the snare device is configured to provide a target during the placement of the guidewire into the target vessel.

112. The method according to claim 91 and/or any other claim herein, wherein the channel creation procedure includes performing the VAST technique.

113. The method according to claim 91 and/or any other claim herein, further comprising: deploying a first device comprising a basket device or snare device in the source vessel; deploying a second device comprising a basket device or a snare device in the perfusion vessel; advancing a needle through both the first device and the second device; advancing the guidewire through the needle and retracting the needle; capturing a distal portion of the guidewire with the second device and bringing a distal end of the guidewire outside of the patient via retraction of the second device; and capturing a proximal portion of the guidewire with the first device and bringing a proximal end of the guidewire outside of the patient via retraction of the first device.

114. The method according to claim 113 and/or any other claim herein, wherein the guidewire comprises a double floppy wire.

115. The method according to claim 113 and/or any other claim herein, further comprising dilating the source vessel with the first device; dilating the perfusion vessel with the second device, or both.

116. The method according to claim 91 and/or any other claim herein, wherein once the guidewire is placed between the source vessel and the perfusion vessel, an elongate tube is advanced over the wire such that it is positioned in each vessel.

117. The method according to claim 116 and/or any other claim herein, wherein a distal venous sheath is advanced.

118. The method according to claim 116 and/or any other claim herein, wherein the elongate tube provides a conduit to the source vessel.

119. The method as claimed in at least one of the preceding claims, wherein the creating a channel is performed using a catheter that applies energy to create a fused anastomosis.

120. The method according to claim 119 and/or any other claim herein, wherein the catheter further applies pressure to create the fused anastomosis.

121. The method according to claim 119 and/or any other claim herein, wherein the energy comprises energy in a form selected from the group consisting of electromagnetic energy such as radiofrequency energy; sound energy such as ultrasound energy; light energy such as laser light energy; mechanical energy; thermal energy such as Joule heating and/or other heat energy and/or cryogenic energy; chemical energy; and combinations thereof.

122. The method according to claim 119 and/or any other claim herein, wherein the energy delivery comprises closed loop energy delivery.

123. The method according to claim 119 and/or any other claim herein, wherein the energy is delivered between distal and proximal heating elements, and wherein the energy is focused on vessel walls captured between the distal and proximal heating elements.

124. The method according to claim 119 and/or any other claim herein, wherein the energy is delivered via an energy delivery element with low thermal mass, and/or wherein the energy is delivered at a minimum of 500°F/s , a maximum of 700°F/s, or both, such as to ablate the tissue captured between the heating elements and minimize undesired heating of non-target tissue outside the heating elements.

125. The method according to claim 124, wherein the ablation of the tissue results in a channel with a non-circular cross section.

126. The method according to claim 125 and/or any other claim herein, wherein the non-circular cross section has an aspect ratio of at least 2: 1.

127. The method according to claim 119 and/or any other claim herein, wherein the energy is delivered in durations of no more than 1 second, such as to minimize undesired heating of non-target tissue.

128. The method according to claim 119 and/or any other claim herein, further comprising dilating the channel location prior to the application of the energy.

129. The method according to claim 119 and/or any other claim herein, wherein the channel is created using a Boomerang catheter and/or a catheter similar to the Boomerang catheter.

130. The method according to claim 129 and/or any other claim herein, wherein the catheter includes a pair of markers that are parallel with an angled surface of a heating element of the catheter.

131. The method according to claim 130 and/or any other claim herein, wherein an imaging device is oriented such that the imaged vessels are shown in a parallel arrangement and the catheter is oriented such that the pair of markers overlap in the image of the parallel vessels.

132. The method as claimed in at least one of the preceding claims, wherein the creation of the channel comprises: inserting a channel creation device from a first vessel into a second vessel such that one or more markers of the channel creation device are positioned in the second vessel; and applying tension to the channel creation device to cause a hook or other engagement mechanism of the channel creation device to engage a wall of the second vessel.

133. The method as claimed in at least one of the preceding claims, further comprising modifying the created channel.

134. The method according to claim 133 and/or any other claim herein, wherein the channel modification is performed based on a change in flow rate of the source vessel.

135. The method according to claim 133 and/or any other claim herein, wherein the channel modification is performed if the flow rate through the channel is below a threshold.

136. The method according to claim 135, wherein the threshold comprises a flow rate of at least 150ml/min, 175ml/min, and/or 200ml/min.

137. The method according to claim 133, wherein the channel modification is performed if the flow rate through the channel is above a threshold, and wherein the threshold comprises a flow rate of no more than 175ml/min, 200ml/min, and/or 250ml/min.

138. The method according to claim 133 and/or any other claim herein, wherein the channel modification is performed via a device placed over the same guidewire that is used to create the channel.

139. The method according to claim 133, wherein the channel modification causes an increase in flow through the channel.

140. The method according to claim 139 and/or any other claim herein, wherein the channel modification comprises a dilation of the channel.

141. The method according to claim 140 and/or any other claim herein, wherein the dilation is performed via expansion of a balloon and/or other expandable component within the channel.

142. The method according to claim 140 and/or any other claim herein, wherein the channel is dilated to a diameter of at least 2mm and/or no more than 4mm.

143. The method according to claim 133 and/or any other claim herein, wherein the modification causes a reduction of flow through the channel.

144. The method according to claim 143 and/or any other claim herein, wherein the flow reduction is performed to prevent or at least reduce cardiac complications and/or to prevent or at least reduce steal of arterial blood flow.

145. The method according to claim 143 and/or any other claim herein, wherein the flow reduction is performed if the flow through the channel is above a threshold.

146. The method according to claim 145 and/or any other claim herein, wherein the threshold comprises a flow rate of at least lOOOml/min; 1250ml/min; 1500ml/min; 1750ml/min; and/or 2000ml/min.

147. The method according to claim 143 and/or any other claim herein, wherein the flow reduction is achieved via banding of the channel and/or banding of the source vessel.

148. The method according to claim 143 and/or any other claim herein, wherein the channel modification procedure comprises a procedure selected from the group consisting of implanting a stent; implanting a stent graft; implanting of a closure device; implanting of an occlusion device; and combinations thereof.

149. The method according to claim 133 and/or any other claim herein, wherein the modification is performed via a device that is introduced from a first artery, into the channel, and into a first vein.

150. The method according to claim 133 and/or any other claim herein, wherein the modification is performed via a device that is introduced from a first vein, into the channel, and into a first artery.

151. The method as claimed in at least one of the preceding claims, further comprising determining whether a flow modification procedure should be performed.

152. The method according to claim 151 and/or any other claim herein, further comprising measuring at least one resistive index in one or more blood vessels, wherein the determining of whether a flow modification procedure should be performed is based on one or more of the at least one resistive index measurements.

153. The method according to claim 152 and/or any other claim herein, wherein the resistive index comprises the following calculation: (PSV - EDV) / PSV; where the PSV is the peak systolic velocity, and the EDV is the end diastolic velocity, in a blood vessel to be measured.

154. The method according to claim 152 and/or any other claim herein, wherein the resistive index is measured in a source vessel, and wherein a flow modification procedure is performed if the measured resistive index is above a threshold.

155. The method according to claim 154 and/or any other claim herein, wherein the threshold comprises a value of at least 0.6, a value of no more than 0.85, or both.

156. The method according to claim 152 and/or any other claim herein, wherein the resistive index is measured in a location in a proximal perfusion conduit, such as a location in the mid-calf region, and wherein a flow modification procedure is performed if the measured resistive index is above a threshold.

157. The method according to claim 156 and/or any other claim herein, wherein the threshold comprises a value of at least 0.5, a value of no more than 0.8 or both.

158. The method according to claim 152 and/or any other claim herein, wherein the resistive index is measured in location in a distal perfusion conduit, such as a location proximate the ankle, and wherein a flow modification procedure is performed if the measured resistive index is above a threshold.

159. The method according to claim 158 and/or any other claim herein, wherein the threshold comprises a value of at least 0.5, a value of no more than 0.7 or both.

160. The method according to claim 151 and/or any other claim herein, further comprising assessing perfusion of the target tissue, wherein the determining of whether a flow modification procedure should be performed is based on the perfusion assessment.

161. The method according to claim 160 and/or any other claim herein, wherein the perfusion assessment comprises a measurement of vPAT in a vein providing oxygenated blood to the target tissue, and wherein a flow modification procedure is performed if the measured vPAT is above 180.

162. The method according to claim 161 and/or any other claim herein, wherein vPAT is measured in the plantar vein.

163. The method according to claim 161 and/or any other claim herein, wherein vPAT is measured in a vein distal to the plantar vein.

164. The method as claimed in at least one of the preceding claims, wherein the flow rate through the channel comprises a flow rate of at least lOOml/min, 125ml/min, 150ml/min, 175ml/min, and/or 200ml/min.

165. The method as claimed in at least one of the preceding claims, wherein the flow rate through the channel comprises a flow rate of no more than 250ml/min.

166. The method as claimed in at least one of the preceding claims, wherein the flow rate through the channel comprises a flow rate configured to cause minimal and/or no swelling and/or to cause minimal and/or no edema.

167. The method as claimed in at least one of the preceding claims, wherein the channel is created to have a flow rate configured to preserve patency and/or provide for wound healing, and then modified such as to increase the flow to an increased level.

168. The method as claimed in at least one of the preceding claims, wherein if the flow rate through the channel is below a threshold and/or the flow rate through the perfusion vessel is below a threshold, then an additional procedure is performed to increase the flow rate through the channel and/or the perfusion vessel.

169. The method as claimed in at least one of the preceding claims, wherein the flow rate through the channel is selected based on the anatomical location of the channel.

170. The method as claimed in at least one of the preceding claims, wherein the flow rate through the channel comprises a flow rate of no more than lOOOml/min, 1250ml/min, 1500ml/min, 1750ml/min, and/or 2000ml/min.

171. The method as claimed in at least one of the preceding claims, wherein if the flow rate through the channel is above a threshold and/or the flow rate through the perfusion vessel is above a threshold, then an additional procedure is performed to decrease the flow rate through the channel and/or the perfusion vessel.

172. The method as claimed in at least one of the preceding claims, wherein the channel is created without blocking flow in the source vessel distal to the channel.

173. The method as claimed in at least one of the preceding claims, wherein the method avoids a significant reduction in arterial flow that was present before the creation of the channel.

174. The method according to claim 173 and/or any other claim herein, wherein the method avoids significant reduction in antegrade flow in the source vessel distal to the channel.

175. The method according to claim 174 and/or any other claim herein, wherein the method avoids significant reduction in flow in one or more arteries that are proximate the channel.

176. The method according to claim 175 and/or any other claim herein, wherein the one or more arteries comprise the peroneal artery and/or collaterals of the peroneal artery.

177. The method according to claim 174 and/or any other claim herein, wherein the method avoids significantly reducing arterial flow distal to the channel and avoids steal of arterial flow.

178. The method as claimed in at least one of the preceding claims, further comprising treating the source vessel at an anatomical location proximal to the channel.

179. The method according to claim 178 and/or any other claim herein, wherein the treating of the source vessel is performed prior to the creation of the channel.

180. The method according to claim 178 and/or any other claim herein, wherein the treating of the source vessel comprises a treatment selected from the group consisting of: angioplasty; angioplasty with a drug-coated balloon; stenting; stenting with a drug-coated balloon; intravascular lithotripsy; valve or other tissue scoring; and combinations thereof.

181. The method as claimed in at least one of the preceding claims, further comprising performing a venous treatment procedure that is configured to improve venous retrograde flow.

182. The method according to claim 181 and/or any other claim herein, wherein the venous treatment procedure comprises a procedure that treats one or more venous valves.

183. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure disrupts each of the one or more venous valves, such as to disrupt the leaflet of the valve and/or the annulus of the valve.

184. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure removes at least a portion of each of the one or more venous valves.

185. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure is performed with the same device that creates the channel.

186. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure includes application of Joule heating, heat energy, cryogenic energy, and/or other thermal energy.

187. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure includes providing retrograde catheter access with fluid distention of a vein; puncturing of a leaflet of a venous valve; and advancing of a balloon or other vessel dilator to tear the venous valve.

188. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure comprises placing a stent at a location of a first venous valve.

189. The method according to claim 188 and/or any other claim herein, wherein the stent is placed using a device similar to the Phillips Tack Stent device.

190. The method according to claim 188 and/or any other claim herein, wherein the venous treatment procedure comprises scoring the first venous valve prior to placing the stent, such as when the annulus of the first venous valve is scored.

191. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure is performed using a valvulotome.

192. The method according to claim 191 and/or any other claim herein, wherein the venous treatment procedure is performed under image guidance.

193. The method according to claim 192 and/or any other claim herein, wherein the image guidance comprises fluoroscopic and/or ultrasound image guidance.

194. The method according to claim 192 and/or any other claim herein, wherein the image guidance comprises performing intermittent venograms to position the valvulotome.

195. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure is performed using one or more of a sharp cutting element; a hole punch; a spiralized ribbon cutter; and/or a thermal energy delivery device, such as a device comprising plates and/or wires configured to deliver thermal energy.

196. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure is performed using a cutting balloon and/or a cutting sheath.

197. The method according to claim 182 and/or any other claim herein, wherein the venous treatment procedure comprises a first treatment in which a valve annulus is treated and a second procedure in which one or more valve leaflets are treated.

198. The method according to claim 181 and/or any other claim herein, wherein the venous treatment procedure comprises a procedure that reduces venous shunting.

199. The method according to claim 198 and/or any other claim herein, wherein the venous treatment procedure comprises at least partially occluding a vein segment to prevent shunting of arterial blood to the heart and/or to prevent competing flow through bridging and/or collateral veins.

200. The method according to claim 199 and/or any other claim herein, wherein the vein is at least partially occluded at a location within 5cm, 4cm, 3cm, 2.5cm, and/or 1cm of the location of the channel.

201. The method according to claim 199 and/or any other claim herein, further comprising performing an imaging procedure to locate one or more collateral venous branches, wherein the location of the at least partial occlusion of the vein is selected based on the location of the collateral venous branches.

202. The method according to claim 199 and/or any other claim herein, wherein the at least partial occlusion of the vein is performed to increase flow of oxygenated blood to the foot of the patient.

203. The method according to claim 198 and/or any other claim herein, wherein the venous treatment procedure comprises at least partially occluding a venous side-branch, such as a venous side-branch of the perfusion vessel.

204. The method according to claim 198 and/or any other claim herein, wherein the venous treatment procedure is performed at least one day after the creation of the channel.

205. The method according to claim 198 and/or any other claim herein, wherein the venous shunting is reduced via implantation of: a coil; adhesive; a gel; a vascular plug; and/or an end-covered stent.

206. The method according to claim 198 and/or any other claim herein, wherein the venous shunting is reduced via closing of a vein segment via application of suture, clips, and/or heat.

207. The method according to claim 198 and/or any other claim herein, wherein the venous shunting is reduced by placing a covered stent in a vein, wherein the covered stent covers the ostium of a venous side-branch.

208. The method according to claim 181 and/or any other claim herein, wherein the venous treatment procedure comprises imaging one or more veins and based on the imaging determining the size and/or implant locations of one or more occlusion devices to be implanted in the one or more veins.

209. The method according to claim 208 and/or any other claim herein, wherein the implanting of the one or more occlusion device prevents flow of blood back to the heart and/or modifies or prevents competing flow of blood through bridging and/or collateral veins.

210. The method as claimed in at least one of the preceding claims, further comprising performing a flow modification procedure configured to modify flow through the source vessel, the channel, and/or the perfusion vessel.

211. The method according to claim 210 and/or any other claim herein, wherein the flow modification procedure comprises dilating the channel.

212. The method according to claim 210 and/or any other claim herein, wherein the flow modification procedure comprises dilating a segment of the source vessel at a location proximate the channel.

213. The method according to claim 210 and/or any other claim herein, wherein the flow modification procedure comprises dilating a segment of the perfusion vessel at a location in or otherwise proximate the channel.

214. The method according to claim 210 and/or any other claim herein, wherein the flow modification procedure comprises at least partially occluding the source vessel at a location distal to the channel.

215. The method according to claim 210 and/or any other claim herein, wherein the flow modification procedure is performed at least one day after the creation of the channel.

216. The method as claimed in at least one of the preceding claims, further comprising placing a scaffold in the channel.

217. The method according to claim 216 and/or any other claim herein, wherein the scaffold comprises a covering configured to at least reduce undesired venous shunting.

218. The method according to claim 216 and/or any other claim herein, wherein the scaffold includes a porous covering.

219. The method according to claim 216 and/or any other claim herein, wherein the scaffold comprises a drug-coated scaffold.

220. The method as claimed in at least one of the preceding claims, further comprising administering drug therapy to the patient.

221. The method as claimed in at least one of the preceding claims, further comprising creating a second channel between a first blood vessel and a second blood vessel.

222. The method according to claim 221 and/or any other claim herein, wherein the second channel is configured to increase venous retroperfusion.

223. The method according to claim 221 and/or any other claim herein, wherein the second channel is configured to divert blood flow back into the source vessel at a location distal to a fully occluded or at least partially occluded segment of the source vessel.

224. The method according to claim 221 and/or any other claim herein, wherein the second channel is created by introducing a channel creation device from the source vessel to a second vein, wherein the second vein does not comprise the perfusion vessel.

225. The method according to claim 221 and/or any other claim herein, wherein the second channel is created by introducing a channel creation device from the perfusion vessel to a second vein.

226. The method as claimed in at least one of the preceding claims, further comprising performing a non-invasive blood vessel dilation procedure.

227. The method according to claim 226 and/or any other claim herein, wherein the non-invasive blood dilation procedure is performed prior to the providing vascular access and/or prior to the channel creation.

228. The method according to claim 226 and/or any other claim herein, wherein the non-invasive blood dilation procedure comprises applying nitroglycerin gel and a wrapping to a limb of the patient.

229. The method according to claim 226 and/or any other claim herein, wherein the non-invasive blood vessel dilation procedure includes a procedure selected from the group consisting of: delivery of an intravascular vasodilator; application of a tourniquet; application of manual compression; application of a nerve block; application of a femoral or popliteal nerve block; and combinations thereof.

230. The method as claimed in at least one of the preceding claims, further comprising performing a non-invasive venous outflow limiting procedure.

231. The method according to claim 230 and/or any other claim herein, wherein the non-invasive venous outflow limiting procedure comprises applying a constricting device to a limb of the patient.

232. The method according to claim 231 and/or any other claim herein, wherein the constricting device comprises a tourniquet or pressure cuff.

233. The method according to claim 231 and/or any other claim herein, wherein the constricting device is configured to apply a varied constriction in a closed-loop arrangement.

234. The method as claimed in at least one of the preceding claims, further comprising performing a flow measuring and/or assessing procedure.

235. The method according to claim 234 and/or any other claim herein, wherein the flow measuring and/or assessing procedure comprises providing an estimation of flow through the channel by subtracting an estimation of blood flow in the source vessel prior to channel creation from an estimation of blood flow in the source vessel distal to the channel after channel creation.

236. The method according to claim 234 and/or any other claim herein, wherein the flow measuring and/or assessing procedure is configured to measure flow through the channel.

237. The method according to claim 234 and/or any other claim herein, wherein the flow measuring and/or assessing procedure is configured to measure flow through a vein segment carrying retrograde flow.

238. The method according to claim 234 and/or any other claim herein, further comprising performing a channel flow modification procedure and/or other flow modification procedure if the measured flow is below a threshold.

239. The method according to claim 238 and/or any other claim herein, wherein the flow modification procedure performed comprises a venous segment flow modification procedure if the measured flow is below a threshold.

240. The method according to claim 234 and/or any other claim herein, where the flow measuring and/or assessing procedure comprises performing real-time flow measurements using ultrasound or other flow measurement devices and, based on the flow measurement and/or assessment, modifying at least one of: the source vessel; the channel; and/or the perfusion vessel.

241. The method according to claim 240 and/or any other claim herein, wherein the modifying comprises performing a procedure selected from the group consisting of: angioplasty; stenting; and/or embolization.

242. The method as claimed in at least one of the preceding claims, further comprising performing a second clinical procedure.

243. The method according to claim 242 and/or any other claim herein, wherein the second clinical procedure comprises treating the source vessel at an anatomical location upstream of the channel.

244. The method according to claim 243 and/or any other claim herein, wherein the second clinical procedure is performed prior to the creation of the channel.

245. The method according to claim 244 and/or any other claim herein, wherein the second clinical procedure is performed at least one day prior to the creation of the channel.

246. The method according to claim 243 and/or any other claim herein, wherein the second clinical procedure comprises treating at least one lesion of the patient.

247. The method according to claim 246 and/or any other claim herein, wherein the second clinical procedure comprises percutaneous transluminal angioplasty (PTA); implantation of a stent; and/or atherectomy.

248. The method according to claim 243 and/or any other claim herein, wherein the second clinical procedure comprises causing the artery to achieve a diameter of at least 3mm proximal the channel.

249. The method according to claim 243 and/or any other claim herein, wherein the second clinical procedure comprises creation of a second channel between two blood vessels of the patient.

250. The method according to claim 249 and/or any other claim herein, wherein the second channel is created at least eight hours after the creation of the first channel.

251. The method as claimed in at least one of the preceding claims, further comprising performing a reversing procedure in which flow through the channel is stopped.

252. The method as claimed in at least one of the preceding claims, wherein the method achieves one, two, or more efficacy endpoints selected from the group consisting of: reversal of flow within a native vein; flow of oxygenated blood in one or more veins below the level of the ankle and into the foot; retrograde flow rate in a vein above a threshold; flow of oxygenated blood to a diseased area of the foot and/or diseased area of other tissue; antegrade flow of oxygenated blood beyond the channel in a native vessel; redder and/or warmer foot tissue and/or other tissue at one week or one month after creation of the channel; wound healing such as wound healing comprising at least 25% of skin growth; transmetatarsal amputation, other mid foot amputation, and/or other tissue amputation that is free of vascular complications and/or achieves accelerated healing; and combinations of these.

253. The method as claimed in at least one of the preceding claims, wherein the creation of the channel results in: an increase in venous pressure; and/or the primary vein loop and small tributary veins surrounding the wound having a distinct systolic and diastolic velocity waveform with a venous pedal acceleration time (vPAT) that is less than 180ms.

254. The method according to claim 253 and/or any other claim herein, wherein the increase in venous pressure causes one or more venous valves to become incompetent.

255. The method according to claim 253 and/or any other claim herein, wherein the increase in venous pressure can cause arterialization of both a primary vein loop and of one or more small tributary veins.

256. The method according to claim 255 and/or any other claim herein, wherein the method is configured such that the small tributary veins provide oxygenated blood to tissue after the primary vein loop becomes at least partially occluded.

257. The method as claimed in at least one of the preceding claims, wherein the method comprises determining a procedural parameter.

258. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter is determined by an algorithm.

259. The method according to claim 258 and/or any other claim herein, wherein the algorithm comprises an artificial intelligence algorithm.

260. The method according to claim 258 and/or any other claim herein, wherein the algorithm analyzes data selected from the group consisting of: images of the patient’s anatomy; vessel diameter data; lesion data; blood flow data; diagnostic data; and combinations thereof.

261. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter determined comprises one or more proposed channel locations.

262. The method according to claim 261 and/or any other claim herein, wherein the one or more proposed channel locations are determined based on one, two, three, or more parameters selected from the group consisting of: diameter of one or more vessels at anatomical locations proximate the proposed channel location; distance of the proposed channel location to a bifurcation; location of a calcified segment of a blood vessel; tortuosity of one or more vessels at anatomical locations proximate the proposed channel location; proximity of one or more side-branches to the proposed channel location; proximity of the source and perfusion vessels to each other at the proposed channel location; desired flow rate through the channel; location and/or quantity of collateral arterial vessels proximate the proposed channel location; location and/or quantity of collateral venous vessels proximate the proposed channel location; location of a previous surgery or intervention; and combinations thereof.

263. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter determined comprises a channel flow parameter.

264. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter determined comprises a channel size parameter.

265. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter determined comprises a channel modification procedure to be performed.

266. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter determined comprises one or more proposed anatomical locations for embolization to be performed.

267. The method according to claim 266 and/or any other claim herein, wherein the proposed anatomical locations are chosen to optimize flow of oxygenated blood to the pedal loop of the foot.

268. The method according to claim 257 and/or any other claim herein, wherein the procedural parameter determined comprises a valve treatment procedure to be performed.

269. A system for treating a patient as described in reference to any one or more method claims herein, the system comprising: a channel creation device configured to create a channel between a source vessel and a perfusion vessel, wherein the system is configured to treat a medical condition of the patient.

270. The system as claimed in at least one of the preceding claims, further comprising a venous access device through which the channel creation device is inserted, wherein the channel creation device comprises a shaft that is at least 2cm, 4cm, and/or 5cm longer than the shaft of the venous access device.

271. The system as claimed in at least one of the preceding claims, wherein the channel creation device comprises a shaft that comprises a length of at least 47cm, 49cm, and/or 50cm.

272. The system as claimed in at least one of the preceding claims, wherein the channel creation device is configured to deliver energy to tissue during the creation of the channel.

273. The system according to claim 272 and/or any other claim herein, wherein the channel creation device is configured to apply a heat gradient in which a center portion of the channel is heated to a higher temperature than one or more edge portions of the channel.

274. The system according to claim 273 and/or any other claim herein, wherein the channel creation device is configured to ablate tissue of the center portion and to denature and/or fuse tissue of the one or more edge portions.

275. The system as claimed in at least one of the preceding claims, further comprising a console that operably attaches to the channel creation device.

276. The system as claimed in at least one of the preceding claims, further comprising a guidewire that is delivered across the channel location, wherein the channel creation device is introduced over the guidewire.

277. The system according to claim 276 and/or any other claim herein, wherein the guidewire comprises a 0.014” guidewire.

278. The system according to claim 276 and/or any other claim herein, wherein the guidewire comprises a proximal end portion, a mid portion, and a distal end portion, and wherein the proximal end portion is more flexible than the mid portion, and wherein the distal end portion is more flexible than the mid portion.

279. The system as claimed in at least one of the preceding claims, further comprising a guidewire placement device.

280. The system according to claim 279 and/or any other claim herein, wherein the guidewire placement device comprises a curved needle.

281. The system according to claim 279 and/or any other claim herein, wherein the guidewire placement device comprises a side-access needle.

282. The system according to claim 279 and/or any other claim herein, wherein the guidewire placement device comprises one or more stabilization elements.

283. The system as claimed in at least one of the preceding claims, further comprising a venous access device.

284. The system as claimed in at least one of the preceding claims, further comprising an arterial access device.

285. The system as claimed in at least one of the preceding claims, further comprising an embolization device.

286. The system according to claim 285 and/or any other claim herein, wherein the embolization device is configured to prevent or at least limit flow in a blood vessel by delivery of one or more of a coil; glue; a gel; a vascular plug; and/or an end-covered stent.

287. The system as claimed in at least one of the preceding claims, further comprising a valve treatment device that is configured to improve continuous flow through a vein at a location proximate a valve.

288. The system according to claim 287 and/or any other claim herein, wherein the valve treatment device is configured to apply heat to at least a portion of a valve, cut a portion of a valve, and/or score a portion of a valve.

289. The system according to claim 287 and/or any other claim herein, wherein the valve treatment device comprises a first valve treatment device, wherein the system comprises a second valve treatment device that is configured to improve continuous flow through a vein at a location proximate a valve, and wherein the second valve treatment device is of different construction and arrangement as compared to the first valve treatment device.

290. The system according to claim 289 and/or any other claim herein, wherein the first valve treatment device comprises a first radially expandable assembly with a first expanded diameter, and wherein the second valve treatment device comprises a second expandable assembly with a second expanded diameter that is different than the first expanded diameter.

291. The system according to claim 289 and/or any other claim herein, wherein the first valve treatment device comprises a first offset tip, wherein the second valve treatment device comprises a second offset tip, and wherein the first offset tip and the second offset tip comprise different amounts of offset.

292. The system according to claim 289 and/or any other claim herein, wherein the first valve treatment device comprises a first recess, wherein the second valve treatment device comprises a second recess, and wherein the first recess and the second recess comprise different depths.

293. The system according to claim 287 and/or any other claim herein, wherein the valve treatment device comprises a radially expandable assembly comprising one or more cutting elements that are configured to treat the valve.

294. The system according to claim 293 and/or any other claim herein, wherein the radially expandable assembly comprises a cage that is resiliently biased in a radially expanded geometry.

295. The system according to claim 294 and/or any other claim herein, wherein the valve treatment device further comprises a sheath that is configured to capture and radially compress the cage.

296. The system according to claim 294 and/or any other claim herein, wherein the valve treatment device comprises a first shaft and a second shaft, wherein the first shaft is configured to translate relative to the second shaft, and wherein the translation causes the expandable assembly to radially expand and/or radially contract.

297. The system according to claim 296 and/or any other claim herein, wherein the expandable assembly comprises a distal end that is free- floating and does not attach to the first shaft.

298. The system according to claim 293 and/or any other claim herein, wherein the radially expandable assembly comprises a cage with an expanded diameter of at least 2mm, 3mm, or 4mm, and/or an expanded diameter of no more than 8mm, 9mm, or 10mm.

299. The system according to claim 293 and/or any other claim herein, wherein the radially expandable assembly comprises a cage including at least three flexible struts, and wherein the at least three flexible struts each include a cutting element of the one or more cutting elements.

300. The system according to claim 293 and/or any other claim herein, wherein the radially expandable assembly comprises a cage with at least one strut, wherein the at least one strut comprises at least one cutting element of the one or more cutting elements, and wherein the at least one strut is configured in a z-shaped or an s-shaped geometry.

301. The system according to claim 300 and/or any other claim herein, wherein the z-shaped or s-shaped geometry is configured to allow a venous valve leaflet to collapse to a smaller diameter than the diameter of the radially expandable assembly such that the one or more cutting elements are prevented from cutting the wall of the vein in which the venous valve leaflet is located.

302. The system according to claim 293 and/or any other claim herein, wherein the radially expandable assembly comprises a cage including at least one strut, and/ wherein the at least one strut comprises a cutting element.

303. The system according to claim 302 and/or any other claim herein, wherein the cutting element comprises a hook-like geometry.

304. The system according to claim 302 and/or any other claim herein, wherein the cutting element comprises a cutting surface.

305. The system according to claim 302 and/or any other claim herein, wherein the cutting element comprises a recess configured to capture tissue of the valve to be treated.

306. The system according to claim 305 and/or any other claim herein, wherein the recess comprises a depth of at least 0.0150”, of no more than 0.150”, or both.

307. The system according to claim 305 and/or any other claim herein, wherein the valve treatment device comprises an offset tip.

308. The system according to claim 307 and/or any other claim herein, wherein the offset tip comprises an offset of at least 0.006”, at most 0.060”, or both.

309. The system according to claim 305 and/or any other claim herein, wherein the cutting element comprises a distal-facing cutting element.

310. The system according to claim 305 and/or any other claim herein, wherein the cutting element comprises a proximal -facing cutting element.

311. The system according to claim 305 and/or any other claim herein, wherein the cage comprises a minimum bend radius of 5mm.

312. The system according to claim 287 and/or any other claim herein, wherein the valve treatment device comprises a guidewire lumen.

313. The system according to claim 312 and/or any other claim herein, wherein the valve treatment device further comprises an expandable cage and at least one shaft, and wherein the guidewire lumen comprises a split lumen and/or an otherwise non-contiguous lumen that allows the distal end of the expandable cage to translate relative to the at least one shaft as the diameter of the expandable cage changes.

314. The system as claimed in at least one of the preceding claims, further comprising a flow reducing device configured to reduce flow through a blood vessel and/or the channel created by the channel creation device.

315. The system according to claim 314 and/or any other claim herein, wherein the flow reducing device is configured to reduce flow in a blood vessel and/or the channel by delivering: a coil; glue; a gel; and/or an end-covered stent.

316. The system as claimed in at least one of the preceding claims, further comprising at least one imaging device.

317. The system according to claim 316 and/or any other claim herein, wherein the at least one imaging device comprises: an x-ray device such as a fluoroscope or CT scanner; an ultrasound imaging device; and/or an MRI.

318. The system as claimed in at least one of the preceding claims, further comprising a flow sensing device.

319. The system according to claim 318 and/or any other claim herein, wherein the flow sensing device comprises a device selected from the group consisting of: a flow wire; a doppler ultrasound device; and combinations thereof.

320. The system as claimed in at least one of the preceding claims, further comprising at least one sensor configured to produce a signal.

321. The system according to claim 320 and/or any other claim herein, wherein the system is configured to perform closed loop energy delivery during channel creation, wherein the energy is delivered based on the signal produced by the at least one sensor.

322. The system according to claim 320 and/or any other claim herein, wherein the at least one sensor comprises a flow sensor.

323. The system as claimed in at least one of the preceding claims, further comprising a processor and a memory module that stores instructions, wherein the system is configured to perform one or more algorithms based on the instructions.