MXPA97009208A - Endovascular bifurc presenter - Google Patents

Abstract

An andovascular bifurcated stentor which is formed by means of one for limbs defining a tube, one of the channels having open ends and having the lateral opening between its ends. The other tubular structure is adapted to advance at one end of the first tube and exit through the lateral opening. The members defining the tube are formed in a modular construction, each including an elongate spine and a plurality of modules that generally define a tube attached to the spine in a longitudinal sequence order. The modular construction facilitates a wide variety in the characteristics of the stentor, including the characteristics of longitudinal flexibility, radial expansion, among others.

Description

ENDOVASCULAR FORK BIFURCED Background of the Invention A large number of medical procedures involve the placement of an endo-endoscopic prosthesis or can be supplemented with it, which is commonly referred to as a stent that can be implanted in a lumen, such as a blood vessel and another natural path of the body. of a patient. These stents typically define a generally tubular configuration, and can extend from a relatively small diameter (low profile) to an elongated diameter. In this "low profile configuration of the stentor can move edoluminar through a device through the lumen of the body to a -site" where the stentor is going to be placed. Then, the stent may extend toward a larger diameter to firmly join the inner wall of the lumen of the body. The discharge device is then removed, leaving the implanted stent in place. In this way, the stent may serve to maintain an open blood vessel or other natural duct, whose operation was damaged as a result of a pathological or traumatic event.

Among the medical procedures in which stents have increased their use are those in connection with percutaneous transluminal angioplasty (PTA) and particularly with percutaneous transluminal coronary angioplasty (PTCA). ATP and PTCA involve the insertion and manipulation of the dilated catheter through the patient's arteries to place a balloon of expansion within the obstructed portion (stenosis) of a blood vessel. It then forcibly extends to the central balloon of the obstruction to dilate that portion of the blood vessel, thereby restoring blood flow through the blood vessel. Among the most significant complications that can result from this angioplasty, is that the dilated site becomes obstructed in a significant number of cases. By placing a stentor within the blood vessel at the treated site, the tendency for these restenosis can be reduced.

Stenosis often develops in the branched region of the patient's blood vessels. The treatment of an estensosi in a branched one can present many additional difficulties in the design of the devices to dilate the stenosis in the branched region. Techniques and devices that have been developed to affect a dilation in a branched region such as that of the "kissing balloon" technique are described in U.S. Patent 4,896,670. The need for an effective stentor that can be placed in a bifurcated region has been recognized, although it is believed that this effective device has not yet been developed.

A large number of stents have been proposed and developed in the art, including stents-simple ones that define a simple luminar path, as well as stents that define a branched path and that are intended to be placed in a branched region of a blood vessel. The development of the bifurcated stent, as compared to the simple stent, presents many difficulties, due to the ramified placement and the difficulty in the discharge and placement of a bifurcated stentor in the region of a blood vessel.

U.S. Patent 4,994,071 (MacGregor) discloses a design for a bifurcated stentor that is intended to be inserted into a bifurcated blood vessel. The stentor is constructed from two lengths of continuous wire, one of which is formed in a series of interconestate circuits to define a common tubular branch and one of the bifurcated branches. The other length of the wire is also formed in a series of similarly interconnected circuits to define the other branch of the bifurcation. The two sets of interconnected circuits are connected together to define a Y-shaped structure. The interconnection between the structure that defines the branched branches is the one that allows them to bend to conform the shape of the vessels in which the device intends to insert itself. . The circuits are formed so that they can expand from an initial diameter to facilitate insertion into the blood vessel toward an expanded, expanded diameter.

The MacGregor device presents a number of difficulties. The construction of its continuous wire does not allow it to easily specify the adaptation of the vascular anatomy of the pathological situation of the specific patient in which the stentor is going to be placed.- In a practical way, the construction is only adapted to be manufactured in configurations and standard lengths When a standard length of the stentor is not ideally suited to the patient's anatomy, "the physician sees the need to choose between the length and the configuration that is available in an effort to make a choice that can be considered compromising. . An additional difficulty with the device described in the MacGregor patent is that it is proposed to be placed in the patient while being kept in its preformed Y-shaped configuration.

Although the intention is that the device advances and is placed in the target site with its circumferential circuits in a radially contracted configuration (Low profile) One would expect that the advancement and insertion in that configuration would significantly complicate the procedure of the download and placement. The description of the device is that of being placed by means of the advance through a guide catheter, so that the circuits of the bifurcating stentor do not join the inner walls of the blood vessel. Therefore, the device may not be placed in a narrow blood vessel, such as a coronary artery, that is, too small to accommodate a guide catheter in addition to the other components of the device. Yet another difficulty that the device presents is that it can not be expected to present an image easily visualized under fluoroscopy or X-rays during the implementation, as well as at a later time. The stent that is formed from a pair of thin single wires may be difficult to visualize under fluoroscopy or X-rays, if not impossible.

Within the general objects of the invention is to provide an improved bifurcated endovascular stentor that overcomes the above disadvantages.

Compendium, of the Invention According to the invention, a stentor is constructed in modular form to include an elongate spine and a plurality of modules that generally define a tube, attached to the spine in a sequential order ** longitudinally. Each module, together with the spine, defines a closed structure as annular, with the modules aligned in an order to define a tubular structure as a box generally. Each of the modules is formed of wire and can be radially extended from a small diameter, low profile configuration to an extended diameter that can be attached to the inner luminal surface of the blood vessel or other lumen of the body. Each spine includes a longitudinal wire of the support to which the modules can be individually assembled in succession.

In one embodiment of the invention, the bifurcated stentor is formed from two initially independent single stenters, each defining a simple tubular configuration having its own order of modules connected to and spreading along a spine. The modules on the two stents are constructed to allow the two stents to be combined, in situ, to form the bifurcated configuration. Each simple stent can be considered to have a proximal group of modules and a distal group of modules. The modules in the proximal group of one of the single stent are spaced to allow them to inter-locate between the similarly spaced modules over the proximal end of the other single stent. The device is placed in the bifurcation by first inserting one of the simple stents to place its proximal group of modules in the common blood vessel and its distal group of modules in one of the branches of the blood vessel. The first placed stentor is provided with a lateral opening between its ends. The first single stent is positioned such that the lateral opening is placed in the branch region of the blood vessels to provide access to the branch vessel. The modules in the first stent of the place then expand to secure the first stentor in place. The second single stentor can be advanced on the first stentor and transversely through a lateral opening of the first stentor to project the distal group. of the modules on the second stentor that will advance in the second branch of the blood vessel. With the second stentor thus placed and with its proximal modules aligned with the spaces between the modules of the proximal group on the first stentor, the second stentor can be expanded in * its place.

In another embodiment of the invention, a longitudinal support wire of a simple modular stentor is connected in a junction, between its ends, to a longitudinal support wire. The radially expandable modules * "are connected to the main support wire, both proximally and distantly from the intersection and the support wire of the branch." The distal modules of the juncture of the support wires are spaced apart to alternate, so that the bifurcated stentor segments can be brought together along a common axis with each other and with the axis of the modules proximally to the juncture.The bifurcated device can thus be compacted in a simple tubular configuration With the bifurcated modules placed between each one in an alternating manner, in this configuration the device can be discharged with a discharge catheter that has a tubular lining at its distal end to contain the compacted device. deployment, the liner can be removed to leave the device in its place where it is Because it can expand to stabilize its position in the blood vessel.

Among the objectives of the invention is to provide a bifurcated endovascular stent with easy placement.

Another object of the invention is to provide a bifurcated stentor that can be placed in the coronary arteries, as well as in other branched vessels.

Another object of the invention is to provide a bifurcated stentor formed from simple stents, but which can be constructed in situ in the branched region of a vascularity of the patient.

Another object of the invention is to provide an endovascular stentor which is formed from two generally tubular members; at least one of which has a side opening between its ends to allow part of another stent to partially pass through the first stent and laterally out of the opening.

A further object of the invention is to provide a bifurated stent in which the bifurcated portions of the stentor can be brought together to be recharged along a common axis to facilitate the insertion of the bifurcated stentor into a vascular anatomy.

Another objective of the invention is to provide a bifurcated stentor that can be tailored according to the vascular anatomy of the patient to whom the device is to be implanted.

A further objective of the invention is to provide a bifurcated vascular stentor which has radiographic characteristics to facilitate its placement and the subsequent visualization of the stentor.

Another object of the invention is to provide a bifurcated stentor that is medullary.

Description of the Drawings The foregoing and other objects and advantages of the invention will be more fully appreciated from the following description thereof, with reference to the accompanying drawings, wherein: Figure 1 is an illustration of a type of a simple modular stentor that can be used in the invention, disposed within a portion of a blood vessel with the stentor in its low profile, unexpanded configuration; Figure 2 is somehow a schematic illustration of a stentor disposed on a balloon that has been inflated to expand the stentor to its largest diameter; Figure 3 is somehow a schematic illustration of a pair of adjacent modules of a stentor illustrating its connection to the support wire; Figure 4 is an illustration of a first single stent that forms a first component of a bifurcated stentor modality and placed in a branched arterial region; Figure 5 is an illustration similar to that of Figure 4, but with a second simple stentor which has been placed in cooperative relation to the first single stent to form the bifurcated stentor.

Figure 6 is somehow a schematic illustration of another embodiment of a bifurcated stentor in place within a bifurcated region of a blood vessel; Figure 7 is an illustration of a modified additional embodiment of a bifurcated stentor positioned within a bifurcated vessel, and; Figures 8 (A) - 8 (E) schematically illustrate the manner in which -the bifurcated stentorian modalities shown in Figures ß and 7 can be displayed.

Description of the Illustrative Modes Figure 1 illustrates the type of a stent 1 (stentor) that can be used in the practice of the invention. The endoprosthesis can be considered to define a tubular method as a box, formed of components such as wires and having a central longitudinal axis 2. The stent 1 is constructed from a plurality of individual modules 7 connected to one another along a spine which can be considered to include a longitudinal support wire 6 and the connectors 9. The modules 7 can be extended from a contracted configuration of low profile, to facilitate the placement of the stentor in the lumen of the body towards an elongated diameter as suggested in Figure 2, by which it can be brought in firm connection with the outer surface of the walls 11 of the lumen 3 of the body to keep open the lumen of the body and facilitate blood flow. In the preferred embodiment, the module can be inelasticly extended. The generally tubular modules 7 that can be radially extended, are assembled and aligned in a longitudinal sequence order on the support wire 6 by a connector 9 associated with each of the modules 7. The modules, when mounted on the wire of the support 6 can be considered to define a virtual peripheral surface 12 which in the cross-section are in the form of a virtual closed curve or track 8 around the longitudinal axis 2.

Each module 7 is formed of a wire 13 shaped and configured to facilitate radial extension of the cylindrical peripheral surface 12. The module can be first molded by forming the wire 13 in a flat wavy configuration and then wrapping the corrugated wire in its loop configuration. The terminal ends 16 of the corrugated wire are free. The free ends 16 of the wire 13 can be connected to each other and to the support wire 6 by the connector 9. The ordering of each of the modules can be considered to include a series of first elongated segments alternated and connected by curvatures which may be curved (for example, circular) or may include smaller connecting segments 15 connected to the elongated segments 14"at the cusps 17. The connecting curvatures between the longitudinal segments 14 may be" placed along and define a locus "of the closed path 8. Preferably, the wire 13 is formed so that the ordering of the curvatures will be uniformly spaced circumferentially around the closed virtual path 8 to provide the modules with a uniform force in the direction crosswise to the support wire 6.

As illustrated in Figure 8, when the modules are in their low profile, non-expanded configuration, the curvatures 15, 17 define the connection between the adjacent elongated segments, such that the elongated segments 14 are recharged. They will substantially parallel each other, defining an angle close to zero degrees. The angle will increase when the module expands. The configuration of the connecting curvatures, including the cusps 17 could be varied to vary the angle a or vary their number circumferentially around the closed curve 8 to vary the characteristics of the modules 7, including the variation of their resistance to the radial loads of compression, so that the endoprosthesis can also be adapted and processed to ideally form the lumen 3 of the specific body where it is to be implanted.

By way of illustrative example only, a stent may be provided to include the modules 7 formed from a wire having an approximate diameter of 0.15 millimeters with elongated segments 14 (not including the connection curvatures between the adjacent segments 14) of an approximate length of 1.8 millimeters. When the connecting curvatures between the adjacent elongated segments 14 curve smoothly, it may have a radius of about 1.5 millimeters before the extension. It can be expected that a stentor having the above dimensions can extend to diameters between about 2.5 to about 4.0 millimeters without an excessive extension, and that this "stentor shows a substantial resistance to radial collapse, which is far more than the maximum of radial compression loads of what can be expected to be imposed on the stentor, by contraction of an artery that Triene a luminal diameter of approximately 2..5 to approximately 4.0 millimeters.

In the preferred embodiment, the connectors 9 can be constructed to be mounted on the longitudinal support wire 6, as by screwing them onto the wire. The connector 9 preferably "must comprise a ring that defines the internal sufficient space to receive and circumscribe the free ends 16 of the wire 13, while also allowing the firm connection of the ring to the longitudinal support wire 6. , the free ends 16 of the wire and the support wire 6 can be firmly connected by means of a permanent deformation, such as corrugation, or they can be joined to each other by means of a spot welding When it is assembled using the laser welding by stitches, it is preferred that the terminal portions 16 of the modules 7 are first welded to the ring 9 and then the ring 9 is soldered to the support wire 6. In some instances, it may be desirable to modify the stentor, so that one or more modules (but the end modules) are not securely attached to the support wire 6, but instead allow some freedom of sliding movement along the support wire 6. This allows a final adjustment to the position of the module after the device has been placed in the patient's blood vessel, if desired.

The ring 19 may be in the form of a relatively small segment of a tube responsive to the support wire ßa and the free ends 16 of the module 7.

The above construction allows a stentor to be specially assembled to conform exactly to the specific anatomy of the patient to whom the stent is to be placed. The modules can be placed as desired, along the support wire 6 and can be secured in that configuration. The wire of the support 6 can be selected to provide the desired degree of longitudinal flexibility and can be made of a wire that is extremely flexible to facilitate the positioning of the wire. - device. in the lumen of the relatively inaccessible body. With the previous construction where the stentor "has an inductive support wire, the degree of flexibility or rigidity of the support wire can be selected independently of the wire with which the tubular modules are formed. be highly flexible to allow the stentor to travel through narrow, tortuous vessels, such as the coronary arteries.

It should be understood that although the current preferred embodiment of the invention incorporates a wire of the metal support 6 (e.g., stainless steel) the modular construction of the invention allows a fabrication of a stentor in which the support wire can be formed. From non-metallic materials, such as polymeric materials, for example, nylon, other kinds of materials can also be selected mechanically and biologically., including materials from among those that can be biologically absorbed over time within a tissue of the blood wall. With a wire of the bioabsorbent support 6, its desirable mechanical characteristics should be selected for a sufficient time to allow the modules 7 to be firmly embedded in the blood wall. Thus, the modular construction of the invention provides a substantially increased range of materials and properties for the individual components; Each one is selected in order to provide optimal results.

The connecting rings 9, especially when assembled around two end segments 16 of the modules 7 and the support wire 6, have a mass significantly greater than that of the wire 13 from which the modules are formed. In this way, the region of the spine that includes the connecting rings 9 will have a radiation opacity substantially greater than that of the wire 13 of the associated module. The opacity to the radiations of the connected region that was substantially increased totally allows the radiographic control of the stent 1 during implantation. It also facilitates the observation of the prosthesis graphically, without requiring the use of ultrasound procedures. The configuration of the stentor allows the tubular frame 10 to be constructed to have a high mechanical force while allowing the extension of the device between its low profile configuration and maximum expansion, in which the wire 13 of the modules 7 will be Substantially transparent to X-rays at same radiation levels that are typically used in this type of procedure.

Figures 4 and 5 illustrate a further feature of the invention, in which the spacers 50 placed between the pairs of the successive rings 9 can be provided, before the rings are secured to the support wire or. - The separators are preferably cylindrical in shape and have a central hole through which the spacers can slide, similarly to a globule, on and along the longitudinal wire 6. When a series of connectors 9 and spacers 50 have been placed on the support wire 6, each successive pair of connectors 9 or spacers 50 can be joined to one another. The length of the separators can be predetermined to allow precise control on the swath between the two successive modules, as well as to reduce the risk of the wire of the support 6 being twisted or damaged. An additional result that can be achieved using the spacers 50, is how easy it is to assemble a stentor using only the two most extreme connectors 9 securely gripped to the support wire 6. In this mode, the intermediate components (the connectors 9 and the spacers 50) will hold their same position on the support wire and will not separate. Whether all of the connectors 9 or only the end connectors are secured to the longitudinal support wire 6, the intermediate spacers 50 need not be secured directly to the wire 6, but instead, they can be held in place by means of the adjacent connectors 9 and between them. By way of a dimensional example, the cylindrical spacers 50 that can be used with a device having the dimensions described above should have a length of approximately 1.10 millimeters, 0.03 millimeters in the outer diameter and have a wall thickness of approximately 0.075 millimeters. .

The spacers 50 that are circular in cross-section can be placed to fully recharge fully with the rounded outer face of the adjacent connecting elements.

An additional advantage in the use of the spacers 50 is that together with the rings and the portions of the wire extending through the rings, the positioning defines a spine which has a substantially continuous elongated mass having an opacity to the radiation considerably greater than that of corrugation wires 13.

All components of the device should be formed of materials that are compatible with each other and thus will not form microcells that can lead to electrochemical corrosion of any part of the device after it has been implanted in the blood vessel. The wire of the longitudinal support 6, the wire 13 and the connectors 9 must have the same chemical composition. Preferred exemplary materials * in the manufacture of stents include those from the group of annealed stainless steels, titanium alloys, gold-nickel alloys, chromium-nickel alloys, and titanium-chromium alloys.

The wire of the support 6 and the modules 7 can be treated and formed to vary the mechanical and functional characteristics, independently of each one to obtain a desired configuration that is adapted to treat the anatomy of a specific patient. For example, the wire 13 from which the module is formed can be subjected to a heat recognition treatment to control the malleability of the wire.

Also, within the characteristics of the invention, is the way in which the tubular modules 7 protect the balloon from a balloon catheter 4 (Figure 1) that is used in the placement of the stent 1. When the device is mounted on the bent balloon of the catheter and is adapted in its low profile phase for delivery, the elongated segments 40 will be placed close to one another, substantially parallel and in close proximity circumferentially around the balloon. Additionally, the individual tubular modules can be placed in close longitudinal proximity, so that the balloon can be completely protected within the stent either longitudinally or circumferentially. After the device and the catheter have navigated to locate the deployment site, the expansion of the device causes the elongated segments 14 to unfold and expand circumferentially along the walls 11 toward the lumen of the body 3 to be rubbed against the walls 13 and soften the rough surfaces that may be present, including particularly the softening of hard or sharp regions that could damage the balloon and possibly cause a balloon puncture. As the segments 14 of the module rub against the walls 11 of the passage 3, they "" affect a significant cutting action. " Figures 4 and 5 illustrate the manner in which a bifurcated stentor can be placed in the branched blood vessels. In this modality the bifurcated stentor is formed from two simple 1P stentcres (ie, not bifurcated) (Figures.4 and 5) and 1S (Figure 5). This first single stent 1P can be constructed in the manner described above to include an elongate spine in which a plurality of radially expandable modules 7 are joined. The modules 7 of the 1P stentor can be considered within the groups, including a first group lPa which can be at the proximal end of the stent 1P and a second group lPb-at the other end. The modules 7 in the first group IPa should be sufficient to allow the modules 7 of another stentor to be fixed between the modules 7 in the first group lPa. In the preferred embodiment the predetermined distance is not less than the length of one of the modules 7 measured along a direction parallel to the spine. The modules 7 in the second group lPb can be placed in a longitudinal close proximity to each other and another module that could be appropriate for the particular branch of a vascularity in which it is to be placed. The first stent 1P is also constructed to define a space lPc between the first and second groups lPa, lPb of .module 7, enough to allow a second stentor, in a low profile configuration, to pass through the first stentor ( after the expansion of the first stentor) and stand out transversally out of space lPc. By placing the spaced lPc region at the juncture of the branched blood vessels, a second single stentor can be advanced into the branched 3C artery. In a preferred embodiment, the length of the transverse aperture lPc may be approximate to the diameter of the cross section 3S of the branch passage 3C.

The first stent 1P can be discharged into the artery and placed therein by means of a discharge device having an expansion member that can include a balloon 4. The stentor is mounted on the balloon 4 in a low profile.

The construction of the first stent 1P includes the order of the spine that can be considered to be defined by means of the longitudinal wire of the support 6 and the connectors 9. The spacers 50 are also provided between the adjacent pairs of the connectors-9. The pattern of the connectors 9 or connectors 9 and spacers 50 can be configured to allow distinct radiographic visualization of the IPc space in the intermediate portion of the stentor to facilitate location of that portion at the desired location in the branched vascular region.

It will be noted that in the illustrative embodiment, the region of the transverse opening in the first stent 1P can be distinguished radiographically from the other portions of the stentor. In the illustrative mode that is achieved by omitting the separators or other components that can be observed radiographically along the portion of the spine that extends between the groups of proximal and distal modules lPa, lPb. In this way the spine in the IPc region is defined solely by means of the support wire 6 which has a mass substantially smaller than that of the other portions of the spine (TRANSPOSE The stentor can be built in situ in the patient, first by placing and expanding the first tubular member with the lateral opening in register with one of the branches of the lumen of the body and then inserting the second tubular member through the first tubular member and laterally through the lateral opening in the other branch lumen. proximal ends of the tubular members are preferably configured to cooperate with each other to define a simple common tube) that the region that can be distinguished radiographically. The second stent 1S of the module 7 longitudinally spaced to interpose with the spaces between the modules in the first group lPa of the first stentor and a second stentor ISB which can be ordered in close proximity to each other. The first and second groups ISA, ISB can be separated by a 1SC space of a length approaching the diameter of the 3S cross section of the branching passage 3C. The second stentor is placed as by means of a balloon discharge catheter, in the same way as the first stent 1P, after at least the first group of the modules lPa has expanded in a secure connection with the inner surface of the vessel 3. The second stent is placed longitudinally within the vascularity, so that the modules 7 of the proximal group ISA of the second stentor are aligned longitudinally with the spaces between the modules 7 on the first group 1PA of the first stent 1P. The relative position between the groups of the modules can be facilitated by the radiation opacity portions of the spine, particularly the region of the connectors 9 and -of the separators 50 if they are used. With the modules of the first group lPa, ISa aligned, the modules 7 on the "second group can be expanded." The structure of the resulting bifurcated stentor can be configured to define a portion of the proximal stent that is substantially continuous within the blood vessel. , the second groups lPb, iSb of the module 7 expand at the firm junction with the portions of the branches of the blood vessels in which they are placed.

It will be noted that the stenters, both in the right and bifurcated configurations, can be constructed with multiple spines. Figure 4 illustrates a placement in which each of the segments IPa, lPb includes a second spine, spaced circumferentially around the virtual periphery 12 from the first spine. In this embodiment, each of the wires 13 of the modules 7 are formed to be circumscribed close to 180 ° of the circuit defined by the module, in such a way that they can cooperate to define the generally cylindrical configuration. In the bifurcated embodiment shown in Figures 4 and 5, it may be preferred to include the double configuration of the spine, only along each of the groups lPa, lPb, omitting the wire 6 of the second spine in the intermediate region IPc in -where the second stentor tries to emerge transversely from the first stentor. The inclusion of the multiple spines can facilitate the relative orientation of the first and second 1P, 1S stents when they are visualized radiographically.

Figure 6 shows another embodiment of a bifurcated stentor including a tubular frame, indicated generally at 10, constructed with two longitudinal wires 6 of the support; one of which is connected to an intermediate portion of the other by means of a connection such as that of the rings 9. The modules 7 are connected to their respective wire of the support 6 by means of the connectors 9. The modules on the bifurcated portions of the stentor are spaced apart from each other. along the wire of the support 6, so that they are arranged in alternating longitudinal positions to define sufficient space between a pair of adjacent modules on a branch to receive a module disposed on the other branch. By allowing the modules of the bifurcated branches to be interposed in this way the two branches can be brought together along an axis generally in common with the axes of the unbranched portion, thereby defining a simple cylindrical structure that it could be introduced into a branched region and advancing in this same branched region of the vascularity of the patient.

Figure 7 illustrates yet another embodiment of the invention, in which the tubular frame 10 comprises a longitudinal wire of the support 6, to which a group 90 of modules 7 is connected. A second wire of the branch bracket 13 is connected to the wire support 6 at one end 16A by means of a connector 9. A second group 91 of modules are joined to the support wire 13. A portion of the support wire 13 indicated in 7A is constructed to allow effective length of the wire 13 '. which is to be adjusted, towards or outside the joint 16A. To this end, the portion "7A" of the wire 13 can be formed in a heiix or other longitudinally adjustable pattern The modules 7 in the group 91 are joined to the support wire 13 spaced apart from the region 7A. of the modules 7 carried by means of the wire 6 includes the formation of sufficient gaps between the selected modules, in which the modules of group 91 are to be received, which allows the bifurcated device to be contained within a cladding tubular in order to deploy the device in the blood vessel.

Figures 8 (A) -8 (E) illustrate the sequence by which the bifurcated stent of Figures 6 and 7 can be inserted and deployed in the vascularity of the patient. Figure 8A illustrates a bifurcating stentor, as shown in Figures 6 or 7, loaded in a sleeve 80 at the distal end of the discharge catheter. Sleeve 80 has a distal open end. A driving rod 81 associated with the catheter can be attached to the proximal end of the stentor within the sleeve. The bifurcated portions of the stentor are brought together to a compact tubular configuration that has a common access to the remaining stentor and in that configuration is inserted into the sleeve. The catheter is then advanced and manipulated to locate the sleeve within a first branch 85 of the blood vessel of patient 3, in a position in which the direct section 83 of the stent is initially implanted. The sleeve 80 is then retracted from the first branch, while the driving rod 81 is controlled to effect a gradual ejection of the direct section 83 from the stent. The section 83 of the stent may then be stabilized * - within the stentor by expanding the modules on the direct section 83 as described above "(expansion means 4 or 5 are omitted in the Figure 8 for better clarity). -With direct section 83 of the Stentor firmly implanted in place in branch 85 of the blood vessel, sleeve 80 is then retracted to a location proximal to that of the junction of blood vessel 86. During further retraction, section 82 of the stent will be exposed. within the blood vessels and can be guided to the second branch 86 with the use of conventional guide elements "(not-shown) including a variety of catheters or guide wires. - With the secondary section 82 in place, the means 4 or 5 of the second expansion (not shown) function to secure and stabilize the section 82 in the branch vessel 86. Figure 8 (D) illustrates an optional step Subsequent in which the longitudinal dimension of the stent may be varied, particularly in space 89 between the secondary section 82 and the rear section 84. The longitudinally compact portion "A, 99 of the wire, allows the physician to adjust the relative longitudinal position of the direct section 83 with respect to the back section 84. The longitudinal dimension of the stentor can be reduced by advancing the sleeve 80 directly towards the direct section 84 previously positioned, whereby a portion 99 of the wire is longitudinally compacted. 6, 13. After the position has been adjusted as desired, the helical portion 99 can be expanded by the expansion means 4 or 5. After the The first and second members have been stabilized, the sleeve 80 is retracted from the third branch 87 of the passage to release the back section 84 of the stentor which can then be stabilized as described.

If desired, the wires wrapped in the stent may be covered with a protective material such as carbon or with an anticoagulant substance such as heparin.

In an alternative additional embodiment, the stent may be expandable by other means, for example, by forming the module 7 of a shape memory alloy such as nitinol. The stent may be provided with an electric resistance heater 5 to generate sufficient heat to thermally induce the controlled expansion of a shape memory alloy module.

It should be understood that the foregoing description of the invention is intended only to be illustrative thereof and that the other embodiments, modifications and equivalents thereof will be apparent to those skilled in the art without having to depart from its principles. -

Claims (40)

1. A method for forming a bifurcated stentor to place it in a lumen of the body having a common portion and two branches communicating with the common portion comprising: providing a first member defining an open tube at each end and having a transverse opening that is formed between its ends; the member defining the tube can be expanded radially from a low profile to an expanded configuration; providing a second member defining a tube having openings at least at its ends the second member defining a tube can be expanded from a low profile configuration to an expanded configuration; advancing the second tube in the first tube and through the transverse aperture, thereby defining a bifurcated configuration, and expanding the second tube from its low profile to an expanded configuration.

2. A method as defined in claim 1, wherein the first member defining the tube is initially in a low profile configuration and expands to its expanded configuration prior to insertion of the second member defining the tube.

3. A method as defined in claim 2, wherein the second member defining the tube is inserted in a low profile and then expanded to form the bifurcated configuration.

4. A method as defined in each of the preceding claims, wherein the members defining the tube expand inelastically.

5. A "method" as defined in claim 3, wherein each of the members defining the tube has a proximal portion and a distal portion, the proximal portions of the members defining the tube extending longitudinally to along a common portion of the stentor; the distal portions of the limbs defining the tube separate and adapt to extend independently into the branched portions of the blood vessel.

6. A method as defined in claim 5, wherein the proximal portion of the first and second limb defining the tube are constructed to complement one another and can be combined to cooperatively define a single tubular portion of the tube. bifurcated stentor.

7. A method as defined in claim 6, wherein each of the members defining the tube comprises an elongated spine that has a plurality of modules defining the tube connected thereto in a sequential order along the length of the tube. the length of the spine; the modules on the proximal portion of each of the members defining the tube are separated along their respective spines to allow their combination in a complementary manner.

8. A method as defined in claim 5, wherein the lateral opening between the proximal segments "and distal from the first tube comprises a space between the modules of the proximal and distal portions of the first member defining the tube.

9. A method as defined in claim 7, wherein the spines have a mass substantially greater than that of the modules to allow "radiographic" visibility.

10. "A method as defined in claim 1, wherein the bifurcated stentor assembly is performed in situ within the patient.

11. A method for placing a bifurcated stentor in a body lumen that has a common portion and two

"Branches communicating with the" common portion comprising: provide a first member defining an open tube at each end. and that it has a transversal opening formed between its ends; the member defining the tube can be expanded radially from a low profile to an expanded configuration; advancing the first member through the lumen of the body to a branched region with the transverse opening at the juncture and exposed at the juncture of the ramifications of the lumen of the body; expanding the first member defining the tube in a firm connection with the inner surface of the common portion and a branch of the lumen of the body; providing a second member defining the tube and having openings, at least at its ends; the second member defining the tube can be expanded from a low profile configuration to an expanded configuration; expanding the first member from its low profile diameter sufficiently to allow it to receive the second member, while the second member is in its low profile configuration; advancing the second member in the first member and through the lateral opening with a portion of the second member extending in the other branch; and a portion disposed within the common lumen portion of the body and the first limb defining the tube, and; -expand the second member that defines the tube from its per-fil -low_ to an expanded configuration and in a union with the lumen of the common portion and the -other branching. - - 12. A method as defined in claim 11, wherein the members defining the tube comprise: an elongated spine; a plurality of modules connected to the spine in sequential locations along the spine; each module defines a circuit or closed circumferential way; the modules are placed on the spine to define the tubular member; the modules are built to be able to expand from a low profile configuration to an expanded configuration.

13. A method as defined in claim 12, wherein each of the modules is formed from a corrugated wire having a plurality of elongated segments alternating with smaller connection curvatures; the modules can be expanded by a balloon placed inside the tubular member, so that when the balloon expands it causes the expansion of the modules; the elongated segments of the modules are separated and rubbed against the inner lumen surface of the lumen, thereby smoothing the surface of the lumen.

14. A method as defined in claim 12, wherein the spine defines a mass substantially greater than that of the modules, which is sufficient to present a radiographic visual image of the spine when the device is placed in the body, and; place the stentor inside the lumen of the body by reference to the radiographic image of the spine.

15. A stentor comprising: an elongated spine having proximal and distal ends; a plurality of modules defining the tube connected to the longitudinal sequence to the spine and along it; the modules are placed to define a proximal group and a distal group; the modules in the proximal group are spaced longitudinally along the spine. .

16. a bifurcated stentor comprising a first stent comprising an elongated spine having "distal" and proximal ends, and a plurality of modules, defining the tube, connected in a longitudinal sequence to the spine and along the spine, the modules are placed To define a proximal group and a distal group, the modules in the proximal group are separated longitudinally along the spine; the longitudinal and proximal groups of the modules defining the tube on the first stentor are separated from one another to define a lateral opening along the defined tube, and; a second stentor that has proximal and distal ends; the proximal end has a plurality of spaced modules inter-positioned with the modules spaced in the first group of the first stentor; the far end! of the second stent protrudes laterally through the opening.

17. A bifurcated stent as defined in claim 16, wherein each module is formed from a corrugated wire having a plurality of elongated segments alternating with the shorter connection bends.

18. A stent as defined in claim 17, wherein the corrugated wire has terminal free ends and is connected to the spine by means of a connector.

19. A bifurcated stentor as defined in claim 18, wherein the spine comprises a wire of the longitudinal support and the connectors.

20. A bifurcated stent as defined in claim 19, wherein at least one of the modules or the support wire has a different malleability from one another.

21. A stent as defined in claim 16, further comprising a second spine connected to at least some of the modules on at least one of the members and extending generally parallel to the first spine. - "

22. A stentor as defined in claim 19, wherein each of the modules, the support wire and the connectors are formed from a material sufficiently similar in composition as to inhibit the development of corrosion at their respective junctures.

23. A stenter as defined in claim 16, wherein the modules are formed from materials belonging to the group comprising annealed stainless steel, titanium alloys, nickel and gold alloys, chrome and nickel alloys and chromium alloys. and titanium.

24. A stentor as defined in claim 16, wherein the stentor is covered with a protective material.

25. A stent as defined in claim 16, wherein the protective material comprises carbon.

26. A stent as defined in claim 16, wherein the stent is covered with a medicament.

27. A stent as defined in claim 26, wherein the medicament comprises an anticoagulant.

28. A stentor as defined in claim 18, wherein the modules of the end of the stentor are joined to the support wire with the terminal free ends of one of the end modules facing the terminal free ends of the other end module.

29. a bifurcated stentor as defined in claim 6, wherein the modules can be deformed inelastically during expansion.

30. A bifurcated stentor as defined in claim 16, which is dimensioned to be able to be received in a human coronary artery, while it is in a low profile configuration and which can "expand within the artery at the junction with the walls of the coronary artery.

31. A bifurcated stentor as defined in claim 19, further comprising a spacer divided between the adjacent connectors; The separators are formed from the same "materials as the filters, the separators" and the connectors define in a substantial manner the continuous regions of high opacity to the radiations when they are visualized radiographically.

32. A bifurcated stentor comprising: an elongated support wire; a second support wire connected at one end "towards the first support wire" at a junction between the ends of the first support wire, thereby defining a proximal portion on one side of the joint and a pair of branched portions on the other side of the joint; a plurality of modules defining the tube, connected to the support wire proximally to the juncture and to each of the branched portions of the support wire. the modules defining the tube on the branched portions of the support wire that is placed at spaced intervals along the branched portions of the support wires to facilitate the modules on the branched wires to inter-position and recharge along a substantially common axis with the axis defined by means of modules on the proximal portion of the first support wire, whereby the bifurcated stentor can be compacted into a substantially simple tubular configuration which can be inserted into a coating of discharge.

33. A bifurcated stentor as defined in claim 32, further comprising: the portion of the second support wire extending between the joint and the modules on the second support wire that is formed to allow relative longitudinal movement between the modules on the second support wire and the joint.

34. A bifurcated stent as defined in claim 33, wherein the portion of the second wire of the support is formed in a helical configuration.

35. A method to place a bifurcated stentor in a bifurcated screed of a lumen of! body comprising: "- **" providing a constructed stent as defined in any of claims 33 or 34, wherein a group proximal to the first support wire is connected proximally to the junction; a distal group of modules connected to each of the branches of the branched support; The distal and intermodial groups of the modules are spaced apart on their respective support wires to allow the groups of the distal and intermediate modules to be brought together in alignment along a common axis with that of the proximal group of the modules. modules; compact the branched portions of the stentor to cause the stentor to assume a singularly tubular singular configuration: charging the compacted stent at the distal end of a coating of a discharge catheter; advancing the discharge catheter to the site where the stentor is to be implanted; placing the covering, so that the distal group of the modules on the second support wire is placed on a branch of the lumen of the body; the next proximal group of the modules is placed in the junction region of the branches of the body lumen and the most proximal group of the modules is placed in the common lumen portion of the body; removing the coating while maintaining the position of the stent enough to expose the distal group of the modules in one of the ramifications of the lumen of the body; expand the distal group of the modules in the firm union with the ramification of the lumen of the body; also remove the coating to expose the intermediate group of the modules; - direct the intermediate group of modules in another - branch of the body lumen; "expand the intermediate group of modules in the firm union with the other branch of the lumen of the body; then further removing the coating to expose the proximal group of the modules within the lumen portion of the proximal body of the branch, and; - - expand the proximal group of the modules at the firm junction with the proxmal portion of the body lumen.

36. A method - as defined in claim 35, further comprising: . before "expanding the proximal group of modules, adjust the longitudinal position of the proximal group of modules relative to the distal group of the modules by longitudinally adjusting the extension of the variable segments of the second support wire.

37. A bifurcated stent as defined in claim 19, wherein at least the wire of the elongate support is formed from a material that is not metallic.

38. A stent as defined in claim 37, wherein the non-metallic material comprises a polymeric material.

39. An endoprosthesis as defined in claim 38, wherein the material comprises nylon.

40. An endoprosthesis as defined in claim 38 wherein the material for the elongate wire of the support comprises a bioabsorbent material.