WO2010028039A2

WO2010028039A2 - Device and method for positioning a guidewire around the myocardium

Info

Publication number: WO2010028039A2
Application number: PCT/US2009/055726
Authority: WO
Inventors: Jean Paul Rasschaert
Original assignee: Epitek, Inc.
Priority date: 2008-09-02
Filing date: 2009-09-02
Publication date: 2010-03-11
Also published as: WO2010028039A3

Abstract

A medical device is disclosed for performing procedures on anatomical structures, including various tissue, body lumen and/or cavity inside a body of a patient. In one particular application, the medical device can be used through minimally invasive access to position a guidewire around the myocardium of the heart, so that other devices, instruments, and/or tools can be introduced over the guidewire. The medical device generally includes first and second positioning assemblies, where the first positioning assembly is introduced to a target area inside the body of a patient and used to surround an anatomical structure, and the second positioning assembly is used to engage a guidewire of the first positioning assembly through a retriever member. The retriever member is used to pull one end of the guidewire of the first positioning assembly around the target tissue and out of the target area.

Description

DEVICE AND METHOD FOR POSITIONING A GUlDEWIRE AROUND THE

This application claims the benefit of U.S. Provisional Application Serial No. 60/- 093,527, filed on September 2, 2008, and titled "DEVICE AND METHOD FOR POSITIONING A GUlDEWIRE AROUND THE MYOCARDIUM"', the entirety of which is incorporated herewith by reference.

This disclosure relates to methods and devices useful for performing a variety of medical procedures on tissue, body lumen and/or cavity, for example minimally invasive access and positioning of a guidewire around the myocardium for medical procedures.

Medical devices for performing medical procedures on tissue, body lumen and/or cavity structures within a patient's body are known and widely used. Various medical devices employ different tools to access an anatomical area where tissue, lumen and/or cavity reside and to treat such areas inside the body of a patient, particularly cardiac tissues and structures of the heart.

For example, during procedures within the pericardial space, various devices including access instruments, catheters, and guidewires have been known to be inserted into the pericardial space to gain access to the surface of the myocardium, so that other instruments and tools can be used on the target area. Typically, different imaging and guidance equipment also are employed to help navigate such devices to target epicardial locations, including the surface of the myocardium. Implementations of such imaging equipment have included known techniques such as fluoroscopy, video-endoscopes, and echography.

Problems remain, however, in navigating such devices to effectively gain intimate contact with desired target areas and surfaces within a subject's body. For example, fat tissues, uneven surfaces, and generally difficult to reach areas remain problematic using existing designs. Particularly, such problems have remained in the access and treatment of epicardial surfaces, for example the myocardium. Despite existing devices and imaging technologies, improvements can be made in the navigation of such devices to target areas within the body of a patient to better increase contact with such target areas and surfaces, Particularly, improvements can be made to better navigate and contact/position devices used for cardiac ablation of surfaces on the myocardium.

An improved medical device is described that can be used in medical procedures on anatomical structures, such as tissue, body lumen and/or cavity inside the body of a patient, In one specific application described herein, the medical device can be used for minimally invasive access and positioning of a guidewire around the myocardium. However, the medical device and its components can be used for positioning a guidewire around other tissue, body lumen and/or cavity for use in other medical procedures.

When used for minimally invasive access, the medical device generally includes first and second positioning assemblies. The first positioning assembly is introduced to a target area inside the body of a patient and used to surround an anatomical structure, and the second positioning assembly includes a retriever member that is used to engage a guidewire of the first positioning assembly, The retriever member is used to pull one end of the guidewire of the first positioning assembly around the target tissue and out of the target area.

In one embodiment, a device for positioning a guidewire around the myocardium includes a first positioning assembly having a guidewire, a connector portion disposed proximate one end of the guidewire, and a tube having a lumen. The guidewire and connector portion are insertable through the lumen, where the connector portion is positionable into a retracted state within the tube and an exposed state outside the tube. A second positioning assembly includes a retriever member attached proximate one end of a line of material and a tube having a lumen. The line of material and the retriever are insertable through the lumen, where the retriever member is positionable into a retracted state within the tube and an exposed state outside the tube, The guidewire includes an adjustable free end and is configured to surround the myocardium. The connector portion and the retriever member are engageable with each other where, through engagement with connector portion, the retriever member is configured to pull the adjustable free end of the guidewire of the first positioning assembly around the myocardium. In one embodiment, a method for positioning a guidewire around the myocardium includes introducing a first positioning assembly to the myocardium and within the pericardial sac, The first positioning assembly includes a connector portion connected proximate an adjustable free end of a guidewire. The first positioning assembly is extended around the myocardium. The connector portion is then exposed from a protective tube of the first positioning assembly. A second positioning assembly is introduced to the myocardium and within the pericardia! sac. The second positioning assembly includes a retriever member. The retriever member is exposed from a protective tube of the second positioning assembly. The retriever member is then engaged with the connector portion. The adjustable free end is pulled through the engagement of the retriever member and connector portion. Pulling the adjustable free end includes pulling the guidewire around the myocardium and out of the pericardial sac.

An improved guidewire technique is described herein that can allow for firm and solid intimate contact within target areas and around anatomical structures inside the body of a patient, such as the myocardium. Such contact can allow other devices introduced over a guidewire to be maneuvered and navigated from both sides of the guidewire. For example, devices moved over the guidewire can be pushed and pulled from both sides of the guidewire. The devices and method described herein generally can allow for improved contact and navigation of devices to certain target areas.

Fig. 1 shows one embodiment of a device for positioning a guidewire having a first and second positioning assembly.

Fig. 2 shows entry into the pericardial space using the first positioning assembly of the device of Fig. 1.

Fig. 3 shows positioning of the first positioning assembly of Fig. 1 around the myocardium.

Fig. 4 shows a connector portion and guidewire of the first positioning assembly of Fig. 1 being deployed out of a tube. Fig. 5 shows a retriever member being deployed from a tube of the second positioning assembly of Fig. 1 and engaging the connector portion of the first positioning assembly.

Fig. 6 shows the guidewire of the first positioning assembly of Fig, 1 surrounding the myocardium. Fig. 7 shows a position of the heart in an associated chest cavity and illustrates a percutaneous access site for performing sub-xiphoid access methods.

Fig. 8 shows one embodiment of a subassembiy for sub-xiphoid introduction of various individual tools, including for introduction of the device for positioning a guidewire as in Fig. 1.

Fig. 9 is a side view in partial section of the tip of the device of Fig, 8 with individual tools retracted within a lumen tube.

Fig, 30 is a side view in partial section of the tip of the device of Fig. 8 with some of the individual tools extended from the tip. Fig. 1 1 is a perspective view of one embodiment of a multi-lumen tube of the device of Fig. 8.

Fig. 12 is an embodiment of an endoscope extending through the multi-lumen tube of Fig. 1 1.

Fig. 13 shows one embodiment of an access sheath together with one embodiment of an expander sub-assembly.

Fig. 14 shows the tip of the expander sub-assembly with one embodiment of an expander tool covered by a loading sheath.

Figs. 15A-C are cross-sectional views of the expander sub-assembly of Fig. 14 in operation. Fig. 16 is one embodiment of a medical device for sub-xiphoid introduction of various individual tools including use for introduction of the device for positioning a guidewire as in Fig. 1.

Generally, an improved medical device is described that can be used in medical procedures on anatomical structures, such as tissue, body lumen and/or cavity inside the body of a patient. In one specific application described herein, the medical device can be used for minimally invasive access and positioning of a guidewire around the myocardium. However, the medical device and its components can be used for positioning a guidewire around other tissue, body lumen and/or cavity for use in other medical procedures.

The medical device and its operation generally include first and second positioning assemblies. The first positioning assembly is introduced to a target area inside the body of a patient and includes a guidewire that is used to surround an anatomical structure, and the second positioning assembly includes a retriever member that is used to engage the guidewirε of the first positioning assembly. The retriever member is used to pull one end of the guidewire of the first positioning assembly around the target tissue and out of the target area.

Among other benefits, the improved guidewire device and technique described herein can allow for firm and solid intimate contact within target areas and around anatomical structures inside the body of a patient, for example the myocardium, so that other devices introduced over a guidewire can be maneuvered and navigated from both sides of the guidewire. For example, devices moved over the guidewire can be pushed and pulled from both sides of the guidewire. The devices and method described herein can allow for improved contact and navigation of devices to certain target areas.

Figs. 1 -6 illustrate a medical device for positioning a guidewire around an anatomical structure inside the body of a patient. In one particular application discussed herein, the device is described in the context of positioning a guidewire around the myocardium M of the heart and within the pericardial space PS. The device generally includes a first positioning assembly 10 and a second positioning assembly 12. The assemblies 10, 12 are configured to be used together during a procedure for positioning a guidewire. The device can be used for minimally invasive access and is particularly configured for use in non-traumatic sub-xiphoid procedures (further described below), but could be used in other types of access procedures as well. As shown in Fig. 1 , the first positioning assembly 10 includes a guidewire 22 having a connector portion 14 disposed proximate an adjustable free end. The guidewire 22 is housed inside a tube 18, where the guidewire 22 and connector portion 14 can be extended into and out of an opening at the end of the tube 18 (see double sided arrows). The guidewire 22 can be any guidewire known in the art, and in some embodiments is made of a metal material such as stainless steel, which is biologically compatible for use in the body of a patient. In one preferred embodiment, the tube 18 is a flexible material having a lumen extending from end to end so that the guidewire 22 can extend within the lumen. The flexibility of the tube 18 can allow for softer and non-traumatic navigation and positioning inside the body. The guidewire 22 can be put into exposed and retracted positions relative to the tube 18. It will be appreciated that the guidewire 22 or the tube 18 can be moved relative to the other, so that the guidewire 22 can be put into the exposed and retracted positions.

Further in Fig. 1 , the second positioning assembly 12 includes a retriever member 16 housed inside a tube 20. As shown, the retriever member 16 is connected to a line 24, Both the retriever member 36 and the line 24 are housed inside the tube 20, where the line 24 and retriever member 16 can be extended into and out of an opening at the end of the tube 20 (see double sided arrows). As with the guidewire 22, the line 24 may also be a guidewire as known in the art. It will be appreciated, however, that the line /wire 24 is not required to be a guidewire and may be any suitable line of materia! that is biologically compatible and suitable for use in the body of a patient and which has sufficient strength to pull the guidewire 22 when the retriever member 16 engages the connector portion 14. In some examples, line 24 can be made from either metal or plastic biocompatible materials. In other examples, the line 24 could be nitinol, stainless steel, or materials based from polyimide, polyethylene, or PEEK. As with tube 38, the tube 20 in one preferred embodiment is a flexible material having a lumen extending from end to end so that the line 24 can extend within the lumen. The line 24 can be put into exposed and retracted positions relative to the tube 20. It will be appreciated that the line 24 or the tube 20 can be moved relative to the other, so that the guidewire 22 can be put into the exposed and retracted positions.

As shown, each positioning assembly has its own tube. It further will be appreciated that the same or a single tube may be employed at different times to expose and retract both the connector portion 14 and retriever member 16.

With further reference to the connector portion 14 and the retriever member 16, the connector portion 14 and the retriever member 16 generally are sub-tools of the device that can engage one another. Both the connector portion 14 and retriever member 16 are connected at an end or proximate an end of their respective guidewire 22 and line 24. The line 24 in one preferred embodiment is a pull leg that can be pulled from the end opposite where the retriever member 16 is connected. Likewise, the guidewire 22 can be a pull leg that can be pulled from the end opposite of where the connector portion 14 is connected (further described below and shown in Fig. 6). It will be appreciated that the guidewire 22 and line 24 can be pulled manually and/or through various mechanical actuators that one of skill in the art can design.

As discussed, the connector portion 14 and the retriever member 16 are sub-tools that can engage each other. In Fig. 1 , the connector portion 14 and retriever member 16 are shown as hook-like structures. In one preferred embodiment, the connector portion 14 and the retriever member 16 have engagement structures that can be released from engagement with each when desired. For example, the hook-like structures shown in Fig. 1 can be unhooked for disengagement such as after a procedure has been performed. It will be appreciated that the specific structure shown for either the connector portion 14 or the retriever member 16 is not meant to be limiting and that generally the connector portion 14 and retriever member 16 can be constructed of any tools that can suitably connect, mate, link, attach with each other to provide a suitable engagement relationship during operation. It also will be appreciated that the connector portion 14 and the retriever member 16 are not required to be the same structure (e.g. two hook-like structures).

As other non-limiting examples, the connector portion 14 and the retriever member 16 may be a clip, grasper, jaws, loops or other suitable mechanical structure or fastener such as a screw, bolt, or rivet that can suitably mate and engage with each other. In other examples, either or both of the connector portion 14 and retriever member 16 may include one or more magnets and/or magnetically attracting elements that can attract and engage the magnet(s).

Generally in operation, the retriever member 16 can engage and hold the connector portion 14 and the adjustable free end of the guidewire 22, so that the retriever member 16 can pull the guidewire 22 around a target anatomical structure (see e.g. myocardium in Figs. 5 and 6).

With further reference to the operation of the device, Figs. 2-6 show a procedure of positioning a guidewire around the myocardium of the heart. The devices and methods described herein can be particularly useful in navigating other instruments and tools into the pericardial space and around the myocardium while providing sufficient contact with the myocardium. For example, such devices and methods can help facilitate cardiac ablation procedures in treating heart disease and various heart conditions as arrhythmia, where sufficient contact of ablation tools with target heart surfaces is desired. Fig, 2 shows that the pericardium or pericardial sac P is punctured at an access point

A to gain access to the pericardial space PS and myocardium M. For example, a needle is introduced by itself or through a catheter or suitable lumen tube to puncture the pericardial sac, and then dilators can subsequently be introduced to achieve a desired size opening for introduction of the positioning assemblies described herein. It will be appreciated that a variety of instruments or tools may be employed to access the target area so that the positioning assemblies can be introduced.

For example, such suitable instruments and tools can be found in U.S. Patent 6,488,689 and U.S. Patent Application Publication 2007/0027456, as well as in the Left Atrial Appendage devices described in copending US Application Nos. 12/1 19008 (filed on May 12, 2008) and 12/183345 (filed on July 31 , 2008), respectively published as US 2008/0312664 and US 2008/0294175, all of which are herewith incorporated by reference in their entirety, Other approaches for entering the pericardia! sac can include such introducer sheath and access device principles, such as described in copending US Applications titled "Methods and Apparatus for Pericardial Access" (filed on May 12, 2008) having US Application No. 12/1 18915 and published as US 2008/0294174, and titled "Introducer Sheath" (filed on May 12, 2008) having US Application No. 12/1 39026 and published as US 2008/0306442, both of which also are incorporated by reference in their entirety, These references are merely illustrative of the various tools that may be employed for introducing the positioning assemblies to a desired target area.

With further reference to Fig. 2, the first positioning assembly 10 is introduced into the pericardial space PS through the access point A. During insertion and introduction, the guidewire 22 of the first positioning assembly 10 is covered by the tube 18 so that it is protected and so that bodily tissues are not damaged. In Fig. 3, the first positioning assembly 10 is pushed around the myocardium M or other target anatomical structure. For example, the first positioning assembly 10 is pushed around the myocardium M and back toward the puncture or access point A.

In Fig. 4, the connector portion 14 of the guidewire 22 is deployed, for example by pushing the guidewire so that the connector portion 14 is pushed out of the tube 18 from the retracted or protected position to the exposed position. The connector portion 14 can also be exposed by pulling the tube 18 back to expose or uncover the connector portion 14.

In Fig. 5, the second positioning assembly 12 is then inserted and introduced into the target area, the pericardial space PS. In one preferred embodiment, the second positioning assembly 12 is inserted into the pericardial space PS through the same access point A that the first positioning assembly 10 was inserted,

With further reference to Fig, 5, the retriever member 16 of the second positioning assembly 12 is deployed, As with the connector portion 14, the retriever member 16 can be exposed either by being pushed out of the tube 20 or by pulling the tube 20 to uncover the retriever member 16. Once exposed, the retriever member 16 can be moved to find and engage the connector portion 14 of the first positioning assembly 10,

In Fig. 6, after the retriever member 16 engages the connector portion 14, the adjustable end of the guidewire 22 can be pulled out of the pericardial space PS and out of the subject, The tubes 18, 20 can be removed, and a resulting two line guidewire is left around and in contact with the target area (e.g. the myocardium). Additional instruments or tools can then be delivered over the guidewire 22 from both ends or lines, and can be pushed and/or pulled from both ends or lines to further position such instalments or tools on the myocardium. As shown, the two line feed can allow for a firm hold on the myocardium so that good contact can be made with instruments, tools, or other devices that may be introduced over the guidewire 22, and so that good navigation and positioning can be obtained. The guidewire 22 and line can be pulled manually and/or through various mechanical actuators that one of skill in the art can design. Such an actuator can be, for example, as shown and described for a left atrial appendage closure device which is referenced below. As described, one preferred implementation of the devices and methods described herein is through a sub-xiphoid access procedure. Referring to FlG. 7, access through the sub-xiphoid is illustrated. The heart is located within the pericardial space PS located beneath a patient's rib cage RC. The sternum S is located in the center of the rib cage RC and terminates at its lower end in the xiphoid X, On either side of the xiphoid are the costal cartilage CC, and potential percutaneous access points for performing a sub-xiphoid procedure are shown located beneath the rib cage RC, and for example between the xiphoid X and an adjacent costal cartilage CC at access location AL (shown by a broken line). Recently, sub-xiphoid approaches, for example to access and close a left atrial appendage have been proposed, See, for example, U.S. Patent 6,488,689 and U.S. Patent Application Publication 2007/0027456 and copending US Application Nos. 12/1 19008, filed on May 12, 2008 and 12/183345, filed on July 31. 2008, respectively published as US 2008/0312664 and US 2008/0294175, all of which are herewith incorporated by reference in their entirety. Similar to Fig. 7, in these approaches a percutaneous penetration is first made beneath the rib cage, preferably between the xiphoid and adjacent costal cartilage, and an atrial appendage closure tool is advanced through the penetration, over the epicardial surface (in the pericardial space) to reach a location adjacent to the exterior of the left atrial appendage. The appendage is then closed using a suitable closure mechanism, for example a closure loop.

It will be appreciated that various access devices, such as the lumen tube and actuator structures and principles described in the above US patent documents, can be employed to achieve such delivery of the guidewire as described herein and through the sub-xiphoid to achieve a minimally invasive result,

Ii also will be appreciated devices and methods described herein can be used in conjunction with suitable visualization components as may be known and accomplished by one of skill in the art, for example by using fluoroscopy, ECHO, and/or endoscope(s) to assist in, navigation, placement, and operation,

With further reference to tools used to introduce the device for positioning a guidewire as in Fig. 1 , various devices may be employed as described above. Figs. 8-16 show one example of such a device that may employ its lumen structure for introduction of the device for positioning a guidewire in Fig. 1. Figs. 8-16 show tools for sub-xiphoid closure of the left atrial appendage, which are disclosed in US Application Nos. 12/1 19008, filed on May 12, 2008 and 12/183345, filed on July 31 , 2008, and respectively published as US 2008/0312664 and US 2008/0294175. That is, the device 100 shown in Figs. 8-16 can also be used to first introduce a guidewire before performing any additional procedures. It will be appreciated that the tools for the device of Fig. 1 may be inserted through any one of the lumens in the lumen structure of device 100 (see below) to introduce a guidewire as described in Figs. 2-6.

Referring to Figs. 8-12 and 36 (in operation), device 100 can be manufactured and used for minimally invasive access and closure of a left atrial appendage LAA of a human heart (see LAA 2 and human heart 4 in Fig. 16). The device 100 is configured for use in a sub-xiphoid procedure for left atrial appendage closure, but could be used in other procedures as well. That is, it is to be understood that the device 300 and individual components of the device 100 discussed below are not necessarily limited to left atrial appendage closure applications. The medical device 100 can be used in a number of differing medical applications and clinical procedures, including where one or more of nontraumatic grasping, manipulation, closure, and inspection of anatomical tissue is required.

For example, the device 100 can be leveraged for use in the pericardial space to first introduce the device for positioning a guidewire as in Fig. 1 , so that another procedure may be performed (e.g. LAA closure). That is, the device 100 can be adapted for suitably introducing the device for positioning a guidewire as in Fig. 1 , before performing a procedure within the pericardial space.

With some specific reference to Figs. 8-12, the medical device 100 generally includes a sub-assembly 5 of various tools and an implementation of delivering the tools, Figs. 13-15C generally show an expander sub-assembly 6, and an introducer sheath 7. In one embodiment, the sub-assemblies 5, 6 and the sheath 7 together form the medical device, and are configured to be used together during a procedure as needed (e.g. LAA closure) and can be used to first introduce the device for positioning a guidewire as in Fig. 1. With reference to Fig. 8, the sub-assembly 5 is illustrated. The sub-assembly 5 includes a tube 3 1 composed of a multi-lumen tube 12a having a proximal end 14a, and a lumen tube 13, which may be a single or multi-lumen tube as further described below, that is connected to an end of the multi-lumen tube 12a, with the lumen tube 13 having a distal end 36a. A number of tools, the purpose, construction and function of which are described below, extend through the multi-lumen tube 12a and the lumen tube 13. At the proximal end 14a. a number of actuators 18a are provided that are connected to the tools for manipulating the tools. The actuators 18a can include, for example, an actuator 20a for actuating a grasping tool, and an actuator 22a for actuating a closure member, A viewing scope (shown in Fig. 52 for example) connected to a camera can also be disposed at the proximal end 34a, In addition, a free end 28 of a pull suture 30 can extend from the proximal end 34a and can act as an actuator for contracting a closure member, if a procedure calls for closure or further manipulation of a certain structure.

As will be described below, many of the tools of the sub-assembly 5 are mounted within the tubes 52a, 33 to permit independent operation, including axial movement relative to the tubes 52a, 53, actuated by the respective actuators. Furthermore, one or more of the tools of the sub-assembly are intended to be exchangeable with other tools. For example, the device 500 can be used to introduce other tools such as the device for positioning a guidewire as in Fig, 1. Fig, 8 illustrates the distal end 16a of the tube 13 with the tools fully retracted, or in a stowed position, within the end of the tube ] 3, Figs. 9 and 10 illustrate a grasping tool 32 and a constricting tool 34 advanced axially by the respective actuators 20a and 22a relative to the tube 33 so that they extend beyond the distal end 16a (i.e. a deployed position).

A ring 36 is connected near the end 16a of the tube 13, as shown in Fig. 8 The ring 36 is used for visualization, for example using fluoroscopy, of the end 16a of the tube 53 during a procedure to be able to determine the location of the end 36a in the pericardial

With reference now to Figs. 1 3 and 52, details of the multi-lumen tube 12a will now be discussed. The multi-lumen tube 52a includes the proximal end 54a and a second end 40 to which will be connected an end 42 of the tube 13, The tube 52a can have a diameter suitable for its intended purpose. For procedures to be performed on the heart, for example, the tubes 12a can have a maximum diameter of about 5.9-8.6 mm or 38-26 Fr. The tube 52a comprises a polymer extrusion, for example Pebax^®, urethane, nylon, polyethylene, or polypropylene, defining a plurality of separate and distinct lumens. In the illustrated embodiment, the tube 12a has for example 5 lumens. A larger or smaller number of lumens can be used depending upon the number of tools to be used in the device 100. In the illustrated embodiment, the tube 12a includes for example a guidewire lumen 48, a suction lumen 50, an endoscope lumen 52, a grasper lumen 54, and a closure deploying lumen 56. The lumens 48-56 extend from the end 14a to the end 40.

The tube 13 is also a polymer extrusion, for example Pebax^®, urethane, nylon, polyethylene, or polypropylene, defining less lumens than the multi-lumen tube, preferably having one or two lumens. The tube 13 can be a clear or transparent material, and can be employed to create a field of view for a visualization or scoping device, The tube 13 is joined to the end 40 of the tube 12a at juncture 44 (Fig. 8) in a suitable manner, for example using a thermal bond or an adhesive bond. In some embodiments, the tube 13 has a single lumen 66 that extends from the end 42 to the end 16a. The space defined by the lumen 66 is large enough to receive portions of the grasping tool 32, the constricting tool 34, and other tools used during the procedure when they are retracted or stowed, as shown in Fig. 9. In embodiments where a guidewire is used, the tube 13 also includes a guidewire lumen that extends from the end 42 to the end 16a and which is aligned with the guidewire lumen 48 of the tube 12a when the tubes 12a, 13 are connected, The guidewire lumen 48 may be employed for introduction of the device for positioning a guidewire as in Fig, 1 , however, it will be appreciated that any of the lumens may also be used when appropriate. With respect to the entire tube 1 1, it will be appreciated that both the multi-lumen tube 12a and the lumen tube 13 may be formed of a single lumen, where various instruments and treatment materials are not compartmentalized into separate and distinct lumens or channels.

When a guidewire is used, the guidewire lumen 48 of the tube 12a and the guidewire lumen in the tube 13 allow the sub-assembly 5 to be inserted over a guidewire, and through an access or introducer sheath when employed (see e.g. Figs. 13-15C below), to where the end of the guidewire has previously been positioned at a desired location of the heart. This facilitates positioning of the end 16a of the tube 13 adjacent the desired location of the heart, and helps ensure that the proper position of the sub-assembly 5 is maintained. A guidewire also can help maintain and/or regain access to the heart if the device 100 or another instrument is needed to be withdrawn and/or re-introduced. It will be appreciated that guidewires are well known and are commercially available.

The suction lumen 50 allows removal of blood and other fluids and tissue from the pericardial space to improve visibility during the procedure, and can help clear an area for performing the guidewire positioning procedure and any subsequent operating procedure. For example, removal of bleeding caused by any of the tools of the device 100 may be desired, as well as removal of bleeding caused by other tools that may be used with the device 100 (e.g. the device for positioning a guidewire as in Fig, 1 ). Suction can be applied through the lumen 50, or via a suction device that can be introduced through the lumen 50,

In some embodiments an endoscope lumen 52 can be used to introduce an endoscope through the sub-assembly 5 to allow further visualization of the pericardial space and desired heart structure during treatment. The endoscope that is used can be a single use, disposable endoscope that is devoid of steering, and can include a lens, vision and light fibers, each of which are conventional in construction. In this embodiment, the endoscope would be discarded after use along with the remainder of the closure sub-assembly 5. The disposable endoscope can be built into the closure sub-assembly 5 so that it is in the optimal position to provide the required direct vision of the desired heart structure. However, the operator will have the ability to unlock the endoscope and reposition it if the procedure requires.

Alternatively, the endoscope can be a commercially available reusable endoscope currently used in the medical field. However, many commercial endoscopes are too large for the direct vision requirements of the device 100 and its tools, because they contain features, for example steering, excessive light and vision fibers, and working channels, which are unnecessary for the device 100 disclosed herein. Further, the field of view and the working distance of the lens of many commercially available endoscopes may be wrong for use in the pericardial sac and through the sub-xiphoid approach. Further, reusable endoscopes are often damaged either in use or during reprocessing so that they are not available for use when needed. Fig. 12 shows a schematic illustration of an endoscope 52a extending through the endoscope lumen 52 of multi-lumen tube 12a. Like reference numbers as in Fig, 33 are not further described. It will be appreciated that the endoscope 52a is structured and functions as described above so as to be suitable for use with the device.

The grasper lumen 54 and the closure deploying lumen 56 of the tube 12a open into the lumen 66 (Fig. 9) that is formed in the tube 33. The grasping tool 32 extends through the grasper lumen 54 and into the lumen 66, and the constricting tool 34 extends through the closure deployment lumen 56 and into the lumen 66.

With reference to Figures 8-10, the grasping tool 32 comprises a clamp device 170 formed by two jaw members 572a, 172b that are pivotally connected to each other at pivot 174. A flexible support 176 is connected to the clamp device 170 and extends through the tubes 12a, 13 to the actuator 20a, The support 176 is used to axially advance the clamp device 170 past the end 16a of the tube 13 from the stowed position shown in Fig. 9 to the extended position shown in Figs. 8 and 10. The flexible support 176 can bend during use. Actuating wires 178 extend through the support 176 and are connected at one end of the jaw members 172a, 172b and at their opposite ends to the actuator 20a. The actuating wires 178 are used to open and close the jaw members 172a, 172b for clamping and releasing various heart tissue(s), by pivoting the jaw members 172a. 172b relative to each other.

The jaw members 172a, 172b each include front teeth and a rear portion 180 formed without teeth to provide an open space between the jaw members. This improves clamping by the jaw members, by allowing desired tissue, such as the left atrial appendage, to be disposed in the space between the jaw members at the rear, while the front teeth of the jaw members clamp directly onto the desired tissue.

The constricting tool 34 can take on a number of configurations. Generally, the tool 34 includes a closure member that is designed to constrict around certain tissue such as the left atrial appendage and to close such tissue if it is desired. The constricting tool 34 includes at least one tool to deploy, control, and position the closure member.

The tool 34 is visible in Fig. 8-10. The tool 34 includes a support encased in a polymer sleeve. In addition, the sleeve substantially encapsulates the closure member, which may be a snare 76. A slit or thin film can formed in the sleeve through which the snare 76 can be pulled out of the sleeve when the snare 76 is constricted.

The support, which is connected to the actuator 22a, for instance through mechanism 82, is used to axially advance and retract the constricting too! between the positions shown in Figs. 9 and 10, The snare support is formed from a suitable shape memory material, for example nitinol or other metal or polymer material which can provide a suitable level of elastic deformation. The snare support expands to generally the shape shown in Figs. 8 and 10 when extended from the tube 13 in order to expand the snare 76 and maintain the profile of the snare loop. The snare support should expand sufficiently to open the snare 76 sufficiently to ensure a large enough loop so that the snare can fit around the desired tissue (e.g. the left atrial appendage). The polymer sleeve prevents the snare support from damaging tissue of the patient during use. The sleeve need only encase those portions of the snare support that in use will project past the end 16a of the tube 13.

The snare 76 can be made of any material suitable for encircling and constricting anatomical tissue, and that is biologically compatible with the tissue. For example, the snare 76 can be made of polyester or polypropylene. The snare material can have a diameter of, for example, 0,5 Fr,

The snare 76 includes a pre-tied knot 78, and the mechanism 82 is provided for engaging the knot 78 during tightening or constricting of the snare 76 and cutting the snare 76. The knot 78 can be any suitable knot that allows tightening of the snare 76 by pulling on the suture pull wire 30 that is connected to the snare 76. For example, a knot 78 commonly used in endoscopic surgery, for example a locking slip knot called a Meltzer's knot, can be employed.

The construction of the tool 34 provides a number of advantages. For example, the loop formed by the snare support permits approach of tissue from different angles, with the loop and the snare 76 being maintained in their fully expanded condition at all angles of approach, In addition, when the snare 76 is constricted and pulls out of the sleeve, no other material or portion of the snare holding structure gets pinned between tissue and the snare 76 when the snare is constricted. In such a configuration, loosening of the constricted snare does not occur, for instance, when the snare holding structure is retracted.

Entering the pericardial sac via the sub-xiphoid can include various other sub- assemblies and introducer sheath/access device principles. Such exemplary implementations of pericardial access devices which may be used are described in US Patent No. 6,423,051 (issued on July 23, 2002) and in copending US Application No. 12/1 18915 (filed on May 12, 2008) and published as US 2008/0294174, both of which are titled "Methods and Apparatus for Pericardial Access" and both of which are herewith incorporated by reference in their entirety. An example of expander subassemblies and introducer sheaths are described in US Application No, 12/1 19026 and titled "Introducer Sheath" (filed on May 12, 2008), published as US 2008/0306442, which also is incorporated by reference in its entirety.

These references also are illustrative of the various other devices and tools that may be employed for accessing the pericardial space PS and for introduction of the device for positioning a guidewire as in Fig, 1 , so that subsequent procedures may be performed.

Referring to Figs. 13-15C, the expander sub-assembly 6 and the introducer sheath 7 are shown. The introducer sheath 7 is used to create a working channel in a sub-xiphoid procedure for introducing the expander sub-assembly 6 and the sub-assembly 5 of various tools into the patient. Further details on the introducer sheath 7 can be found in U.S. Patent Application No. 12/1 19026 incorporated by reference above. The expander sub-assembly 6 is designed to be introduced through the sheath 7 and into the pericardial space for expanding the pericardial space during a procedure (e.g. LAA closure) after it has been located. Once in position, the expander sub-assembly 6 and the introducer sheath 7 can be locked relative to one another using a locking mechanism 200, the details and operation of which are described in U.S. Patent Application No. 12/1 19026 incorporated by reference above.

The expander sub-assembly 6 is illustrated in Figs, 13-15C. The expander sub- assembly 6 includes an expanding structure 902 that is a collapsible tool that is self- expanding, collapsible, and constructed of a material utilizing an elastic property, The expander sub-assembly 6 provides key functions in that the expanding structure 902 is retractable and is self-expanding once it is released. In one example, the expanding structure 902 can be configured as a self-expanding shape memory material, which can also be temporarily collapsed when confined. In one embodiment, the expanding structure 902 is a cylindrically hollow part when in an expanded configuration. In this configuration, the expanding structure 902 can allow the constricting tool 34 and the grasping tool 32 to be passed into and through the hollow part of the expanding structure 902, such as when it is expanded,

The material of the expanding structure 902 allows it to be collapsed on itself, when it is not deployed. When the expanding structure 902 is not to be deployed, it can be collapsed into a smaller dimension or diameter by being retracted within the elongated body of the introducer sheath 7 (i.e. the shaft structure of the sheath). In operation, the expander sub-assembly 6 can be delivered to a target site of the heart, such as by extending the expanding structure 902 from the distal end of the elongated body of the introducer sheath, or by retracting the sheath 7 to expose the expanding structure 902. As one example, the expanding structure 902 can be delivered by using a shaft portion 904 that is connected to the end of the expanding structure. The shaft portion 904 is hollow and has an outer diameter that is slightly smaller than the inner diameter of the introducer sheath 7. In this configuration, the shaft portion 904 can be inserted into the sheath and be longitudinally moved within the sheath. As the shaft portion 904 is hollow, the tools and lumens of the sub-assembly 5 can be passed therethrough.

As shown in Figs. 13 and 14, the expanding structure 902 is initially held in its collapsed configuration via a loading sheath 910, This permits the expander sub-assembly 6 to be inserted into the introducer sheath 7 as shown in Fig. 13. Once in the sheath 7, the loading sheath 910 is removed or pulled back to free the expanding structure 902. Since the sub-assembly is in the introducer sheath 7, the introducer sheath 7 will hold the expanding structure 902 in its collapsed configuration until the expanding structure 902 is advanced beyond the end of the sheath 7.

The shaft portion 904 can be moved relative to the introducer sheath 7 to extend and retract the expanding structure 902. In the expanded configuration, the expanding structure 902 would be extended past the end of the sheath 7 by pushing it forward relative to the introducer sheath 7, or by pulling the introducer sheath back relative to the expanding structure 902. That is, the introducer sheath can act to cover and uncover the expanding structure 902 based on relative movement of the introducer sheath and expanding structure. In either configuration, the expanding structure 902 can extend from the distal end of the elongated body of the introducer sheath 7. In the non-expanded configuration, the expanding structure 902 could be collapsed by pulling the expanding structure back inside the introducer sheath 7 through the distal end of the elongated body, or could be collapsed by pushing the introducer sheath over the expanding structure 902 to cover it. When the expanding structure 902 is extended from the sheath, the material of the expanding structure 902 is such that it self-expands to create a working space. That is, due to the expanding structure's propensity to expand when the expanding structure 902 is not contained/retracted inside the access sheath, a space inside a patient can be expanded by the expanding structure. The expanding structure 902 may be a flexible material with an elastic-like quality, and that includes a self-expanding force that can sufficiently open a working space in the body of a patient. As one example, the expanding structure 902 may be a nitinol cage-like structure. It will be appreciated that the expanding structure 902 may be made of materials other than nitinol, for example elastic resins or plastics. It further will be appreciated that the expanding structure 902 may be constructed as a combination of materials, rather than as one material. Likewise, the shaft portion 904 may be sufficiently flexible or have varied flexibility, as necessary or desired, and so as to be suitable for use with the introducer sheath.

Figures 15A-C illustrate side views of the expander sub-assembly 6 in operation with the introducer sheath 7. Figure 15A shows the sub-assembly 6 in a non-expanded configuration inside the introducer sheath 7. Figure 15B shows the sub-assembly being advanced axially in the direction of the arrow, with the expanding structure 902 in a partially expanded configuration and partially extended from the sheath 7. Figure 15C

37 shows the sub-assembly 6 advanced further axially, with the expanding structure 902 in a fully expanded configuration,

In operation for example, when using the device 100 for left atrial appendage closure, the device 100 can be introduced using a sub-xiphoid approach similar to that described in US Patent 6,488,689. In use, once the sheath 7 is in place in the patient, the expander sub-assembly 6 is introduced into the sheath 7. The loading sheath 910 is then removed or pulled back to free the expanding device 902, and the sub-assembly 6 is advanced further axialSy toward the end of the introducer sheath 7 and the pericardial space. Once it is deteπnined that the end of the sheath 7 is positioned properly, the expander sub- assembly 6 is advanced further until the expanding structure 902 extends past the end of the sheath 7. The expanding structure 902 self-expands to increase the working space. The sub-assembly 5 is then introduced through the expander sub-assembly 6 and advanced toward the pericardial space. Once the closure sub-assembly 5 is fully inserted, a locking mechanism can be used to lock the sub-assemblies 5 and 6 together. The locking mechanism can be similar to the locking mechanism 200. The constricting tool 34 and the grasping tool 32 can then be actuated as discussed above to achieve manipulation and/or closure of a desired tissue (e.g. left atrial appendage). The procedure can be reversed to remove the device and other sub-assemblies from the patient.

Alternative embodiments are possible. It will be appreciated that the expander sub- assembly is not limited to the specific structure shown and described, and that other expander constructions and modifications may be employed that are equally or more suitable. For instance, other implementations may include inflatable expanders such as inflatable balloons, or general injection of air into the pericardial space (e.g. CO₂). The use of gas, for example, can allow for an expanded operating cavity. The introduction of gas can be performed using the sub-xiphoid approach and delivered through the medical device 100. By way of example, a syringe or fluid line or catheter as may be known in the art can be used to deliver the gas to the heart through the device 100. It will be appreciated that any gas(es) (e.g. CO₂) that are biologically suitable for use and performance of medical procedures within the body may be employed. It further will be appreciated that any expander structure as may be known in the art may be suitably adapted for performing procedures on the heart and via a sub-xiphoid, minimally invasive approach.

As described above, the medical device 100, including its sub-assemblies and introducer sheath, could be used in procedures other than left atrial appendage closure. That is, the device 100 and individual components of the device 100 are not necessarily limited to left atrial appendage closure applications, and can be used in a number of differing medical applications and clinical procedures, including where one or more of non-traumatic grasping, manipulation, closure, and inspection of anatomical tissue is required. In general, the device 100 can deliver various tools into the pericardial space through a single shaft, catheter-like structure, which allows an operator to pass various other tools (e.g. the device for positioning a guidewire as in Fig. 1) and other devices to a target site of the heart for treatment. For example, the device 100 can be used in the pericardial space to first introduce the device for positioning a guidewire as in Fig. 1. The lumen structure of the device 100 can be suitably adapted and configured for introducing the device for positioning a guidewire as in Fig, 1 using the sub-xiphoid approach.

As described, the device 100 includes a scope (e.g. endoscope 52a), suction or aspiration capability (e.g. suction lumen 50), a grasper (e.g. grasping tool 32), and a snare (e.g. snare 76). In one implementation of the device 100, the scope can provide visualization while performing a procedure at an area of the heart, and the suction capability can allow for aspirating fluid (e.g. blood) from the pericardial sac to further assist with visualization. Further, the grasper and snare structures can be used to manipulate and maneuver various cardiac tissue and structures, such as the right atrial appendage, left atrial appendage, myocardial tissue epicardial tissue, endocardial tissue, and pericardial sac tissue, as needed to obtain clearance to the area of the heart tissue to be located and targeted for a procedure,

In general, a device such as device 100 can be configured to allow various devices and tools to be passed through its lumen structure (e.g. multi-lumen), so as to offer an operator greater flexibility to perform a procedure using the subxiphoid approach. The device 100 is intended to be suitable for allowing adaptation and exchangeability of tools through the lumen structure of the device 100, so that the device for positioning a guidewire as in Fig. 1 can be introduced and so that a subsequent procedure can be easily and safely performed. For example, one or more of the tools discussed above for device 100 may be changed out so that the lumen structure can support introduction of other tools that may be first needed to locate and facilitate positioning at a targeted site. It also will be appreciated that the lumen structure can be adapted to have additional lumens and/or be sized to support all of the tools needed for positioning a guidewire (e.g. the device for positioning a guidewire as in Fig. L). It further will be appreciated, however, that the device 100 is meant to represent an example of such a device that introduces tools for procedures on certain anatomical structure or tissue through a single tube, catheter-like structure, It will be appreciated that various modifications and changes to the device 100 may be made as needed and/or desired. The invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. A method for positioning a guidewire around the myocardium comprising; introducing a first positioning assembly to the myocardium and within the pericardia] sac, the first positioning assembly having a connector portion connected proximate an adjustable free end of a guidewire; extending the first positioning assembly around the myocardium; exposing the connector portion from a protective tube of the first positioning assembly; introducing a second positioning assembly having a retriever member; exposing the retriever member from a protective tube of the second positioning assembly; engaging the retriever member with the connector portion; pulling the adjustable free end through the engagement of the retriever member and connector portion, so as to contact and surround a portion of the myocardium,

2. The method of claim 1 , further comprising pulling the adjustable free end of the guidewire of the first positioning member out of the pericardial sac to create a two line feed,

3, The method of claim 1 , further comprising introducing the first positioning assembly and introducing the second positioning assembly through a same access point,

4. The method of claim 1 , further comprising introducing the first positioning assembly and introducing the second positioning assembly through an access instrument via a sub- xiphoid approach.

5. The method of claim 1 , wherein the step of exposing the connector portion comprising one of pulling the protective tube relative to the connector portion and pushing the connector portion out of the protective tube,

6. The method of claim 1 , wherein the step of exposing the retriever member comprising one of pulling the protective tube relative to the retriever member and pushing the retriever member out of the protective tube.

7. The method of claim 1 , further comprising disengaging the retriever member from the connector portion when the gυidewire is positioned.

8. The method of claim 1 , further comprising introducing the first and second positioning assemblies with a same protective tube at different times,

9. A device for positioning a guidewire around the myocardium comprising: a first positioning assembly including a guidewire, a connector portion disposed proximate one end of the guidewire, and a tube having a lumen, the guidewire and connector portion are insertable through the lumen, where the connector portion is positionable into a retracted state within the tube and an exposed state outside the tube; a second positioning assembly including a line, a retriever member disposed proximate one end of the line, and a tube having a lumen, the line and the retriever are insertable through the lumen, where the retriever member is positionable into a retracted state within the tube and an exposed state outside the tube; the guidewire includes an adjustable free end that is configured to surround the myocardium, the connector portion and the retriever member are engageable with each other where, through engagement with connector portion, the retriever member is configured to pull the adjustable free end of the guidewire of the first positioning assembly around the myocardium,

10. The device of claim 9, wherein the guidewire of the first positioning assembly is adapted for a two-line feed configuration, where the adjustable free end of the guidewire is configured as one feed line and an opposite end of the guidewire of the first positioning assembly is configured as another feed line.

3 1. The device of claim 9, further comprising an access instrument having a lumen structure, the first and second positioning assemblies configured to be insertable through the lumen structure of the access instrument, the access instrument is adapted for a sub-xiphoid

12. The device of claim 9, wherein the respective tubes are of a flexible material.

13. The device of claim 9, wherein the tube of the first positioning assembly and the tube for the second positioning assembly are a same tube adapted for use at different times.

14. The device of claim 9, wherein the connector portion and the retriever member are hook-like structures that are engageable and disengageable,