MXPA98000715A

MXPA98000715A - Endovascular forced extensions, and yaparato method for your colocac

Info

Publication number: MXPA98000715A
Application number: MXPA/A/1998/000715A
Authority: MX
Inventors: Borghi Enzo; Rickards Anthony
Original assignee: Bard Galway Limited; Borghi Enzo; Rickards Anthony
Priority date: 1996-05-31
Filing date: 1998-01-26
Publication date: 1998-04-01

Abstract

A bifurcated endovascular extension is formed of a pair of individual tubular component extensions that can be placed independently in sequence in the branched region of a body vessel to form the bifurcated extension, in situ. The first component extension placed includes a side opening and can be positioned to extend both proximally and distally of the bifurcated joint or junction with the side opening facing the entrance to the branch vessel. The first component extension then expands into the vessel. The second component extension can then be advanced through the first component extension, through the lateral opening and into the branching vessel where it can expand. The portions of the first and second component extensions surrounding the joint region of the vessel are constructed to provide improved lateral support for the vessel walls of the junction joint region. A supply probe is provided and includes a guide wire duct adapted to facilitate the entry of a guide wire into the branch vessel while the first component extension is deployed in the other vessel conduit.

Description

"ENDOVASCULAR EXTENSIONS FORCED, AND METHOD AND APPARATUS FOR PLACEMENT" TECHNICAL FIELD The present invention relates to implantable bifurcated endovascular prostheses in a passageway of a human or animal body and to the relative method and apparatus for its placement, prostheses which are commonly referred to as "extensions".

BACKGROUND OF THE INVENTION A number of medical procedures involve or may be supplemented with the placement of an endoluminal prosthesis, which is commonly referred to as an extension that can be implanted in a conduit such as a blood vessel or other natural access route of a patient's body. These extensions typically define a generally tubular configuration, and are expandable from a relatively small diameter (low profile) to an enlarged diameter. While it is in its low profile configuration, the extension is advanced endoluminally, by means of a delivery device through the body conduit to the site where the extension will be placed. The extension can then expand to a larger diameter, in which it can firmly attach the inner wall of the body passageway. The delivery device is then removed, leaving the extension implanted in place. In this way, the extension can serve to keep open a blood vessel or other natural conduit, the functioning of which deteriorates as a result of a pathological or traumatic event. Among medical procedures where extensions have had increased use is in relation to percutaneous transluminal angioplasty (PTA) and particularly percutaneous transluminal coronary angioplasty (PTCA). PTA and PTCA involve the insertion and manipulation of a dilatation probe through the patient's arteries to place the dilatation balloon of the probe into a clogged portion (stenosis) of a blood vessel. The balloon then expands in a forced manner within 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 in a significant number of cases, the dilated site is again obstructed. By placing an extension within the blood vessel at the treated site, the tendency of these restenosis can be reduced. Stenoses can often develop in the branching region of a patient's blood vessel. The treatment of a stenosis in the branched region can present numerous additional difficulties in the design of devices for dilation of stenoses in the branched region. A number of extensions have been proposed and developed in the art, including single extensions defining a single luminal access path, as well as bifurcated extensions defining a branched access path and intended to be placed in a branch region of a vessel blood The development of the bifurcated extensions in comparison with the individual extensions presents numerous difficulties due to the ramified arrangement and the difficulty to supply and place a bifurcated extension in the branched region of a blood vessel. In a provision disclosed in International Application Number PCT / IB96 / 00569, filed on June 7, 1996 called "Bifurcated Endovascular Stent", a bifurcated extension of two initially independent component extensions is formed. In the preferred embodiment, each component extension is formed of wire and has an elongated spine and a plurality of modules that generally define the tube connected to the spine, in a formation placed in longitudinally sequence. Each component extension defines a generally tubular configuration, the modules in the two component extensions are placed to allow them to be combined, in situ, to form a bifurcated configuration. Each component extension can be considered as having a close set of modules and a distant set of modules. The modules in the next set of a component extension are placed longitudinally to allow them to interact with one set of the complementary module at the proximal end of the other component extension. The device is placed in the bifurcation of the vessel by first inserting one of the component extensions to place its proximal module set in the common blood vessel and its distant module set in one of the branches of the blood vessel. The first placed component extension is provided with a lateral opening between its ends and positioned so that the lateral opening is placed in the joint or union of the blood vessels to provide access to the branch vessel. The modules in the first component extension are then expanded to ensure the first component extension in their site. The second component extension is then advanced towards and through the first component extension and transversely through the lateral opening of the first extension to project the module set distant from the second component extension towards the second branch of the blood vessel. With the second component extension positioned in this manner, and with its next module set aligned to fit in a complementary manner with the next module set of the first component extension, the second component extension can be expanded into place. The present invention is directed to an improved method and apparatus for placing the component extensions in a bifurcated configuration in a branched vessel. A further object of the invention is to provide improvements in the construction of the extension whereby the extension can provide essentially continuous support for the vessel, including the region of the vessel junction.

EXHIBITION OF THE INVENTION In one aspect of the invention, a supply probe is provided to supply and position the first component extension so that the lateral opening between the proximal and distant module sets is placed in the joint or union of the common and branching blood vessels. with the lateral opening being exposed to the entrance to the branching vessel. The delivery probe includes an arrow with an extension expansion means such as a balloon at its distal end. The first component extension is mountable, in a low profile in the expansion medium. The delivery probe also includes an elongated tubular guide wire duct extending along and parallel to the arrow of the probe, the distal end of the guide wire duct terminating at approximately the middle portion of and remaining outside the duct. balloon. When the first component extension is mounted on the supply probe, it is placed around the balloon and with the distal region of the guide wire duct being placed in register with the lateral opening of the first component extension. With the first component extension mounted on the balloon, the probe can navigate through the patient's vasculature to place the extension at the bifurcation of the vessel with its next set of modules placed in the common blood vessel and the distant module set placed in the one of the branches beyond the union. The probe is manipulated to a position such as with the use of a conventional guidewire so that the side opening is in register with the conduit of the other branch vessel. When placed in this manner, a second guide wire is advanced through the guide wire duct and exits towards the branch vessel through a guide wire hole at the distal end of the guide wire duct. The expansion medium is then operated to expand the first component extension in firm engagement with the blood vessel. The expansion medium can then be deactivated and the delivery probe can be removed from the patient while keeping the second guide wire in place in the branch vessel. The second component extension mounted on the balloon delivery device can then be mounted on a delivery device that can be advanced along the second guide wire to guide the delivery device (e.g., a balloon probe) to the first component extension and laterally through the lateral opening of the first component extension and into the branching blood vessel. The second component extension is placed so that its next module set is aligned in complementary configuration with the extension of the module next to the first component extension. The second component extension can then be expanded to couple its module set next to that of the first component extension and deploy the distant module set in the branch vessel. The first and second component extensions positioned in this manner cooperate to define a bifurcated extension structure to support the branched blood vessels. In another aspect of the invention, modules of one or both of the component extensions that are placed immediately at the junction of the blood vessel are formed to provide lateral support for the junction region of the blood vessels. Among the objects of the invention is to provide a bifurcated endovascular extension that can be easily placed. Another object of the invention is to provide a bifurcated extension 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 extension formed of the component extensions that can be constructed in situ in the branched region of a patient's vasculature. A further object of the invention is to provide an endovascular extension that is formed of two generally tubular members., at least one of which has a side opening between its ends to allow part of the other extension to be partially passed through the first extension and transversely out of the side opening. Another object of the invention is to provide a bifurcated extension that can be tailored with respect to the vascular anatomy of the patient, where the device can be implanted. A further object of the invention is to provide a bifurcated vascular extension that has good radiographic characteristics to facilitate its placement and subsequent visualization of extension. A further object of the invention is to provide a supply probe adapted to facilitate the placement of a first component extension extending towards a branch vessel and a guide wire extending towards the other branch vessel and along which a second component extension can be directed towards the other branching vessel. Another object of the invention is to provide complementary component extensions which when placed in the blood vessel provide a support of considerable extension in the region of the junction of the branched blood vessels as well as in the branches themselves.

DESCRIPTION OF THE DRAWINGS The aforementioned 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 the far end of a supply probe for placing the first component extension in one of the branch vessels and a guide wire in another branch vessel; Figure 2 is a fragmentary illustration of a portion of a component extension illustrating a pair of adjacent modules connected with a spine; Figure 3 is an amplified illustration of the circle placed region of Figure 6 showing the junction region of the branched blood vessels and the manner in which the component extensions cooperate in that junction; Figures 4a-4g illustrate, in longitudinal section, the successive steps by which the first and second component extensions can be positioned to form the bifurcated extension; Figure 5 is an illustration in longitudinal section of a branched blood vessel in which the first component extension has been placed; Figure 6 is an illustration similar to Figure 5 where the second component has been placed; and Figure 7 is a diagrammatic illustration of another expansion means of another extension using electric power to cause expansion of the extension; Figure 8 is a side view of a first component extension in another embodiment of the invention; Figure 9 is a side view of a second component extension adapted for complementary association with the component extension of Figure 8; Figure 10 is a side view of the first and second component extensions of Figures 8 and 9, assembled to form a bifurcated extension in a vessel of the bifurcated body; Figure 11 is an illustration of another embodiment of a component extension with modules developed in a horizontal plane to better illustrate an arrangement for defining a lateral opening in the component extension; Figure 12 illustrates a bifurcated endovascular extension formed and in place within a bifurcated blood vessel and incorporating the construction of Figure 11; Figure 13 illustrates the additional details of a module in the extension shown in Figure 12; and Figure 14 illustrates a pair of modules of the arrangement as shown in Figure 12.

DESCRIPTION OF THE ILLUSTRATIVE MODALITIES Figures 2 and 5 illustrate the type of modular endoprosthesis 1 (extension) that can be used to practice the invention. The endoprosthesis can be considered to define a tubular arrangement 10 similar to a cage formed of wire-like components and having a central longitudinal axis 2. The extension 1 is constructed of a plurality of individual modules 7 connected to one another along a spine which can be considered as including a longitudinal support wire 6 and the connectors 9. The modules 7 are expandable from a low profile configuration contracted (Figure 4a) in order to facilitate the placement of the extension in the body conduit, up to an amplified diameter as suggested in Figure 4b, wherein the modules can be placed in firm engagement with the inner surface of the walls 11 of the duct 3 of the body, in order to keep the body's duct open to facilitate blood flow. In the preferred embodiment, the modules are non-elastically expandable. The generally tubular radially expandable modules 7 are mounted and aligned in a longitudinally sequential formation on the support wire 6 by a connector 9, associated with each of the modules 7. The modules, when mounted on the support wire 6 , can be considered as defining a virtual peripheral surface 12 which, in cross section is in the form of a curve or loop 8 closed virtual around the longitudinal axis 2. Each module 7 is formed of a wire 13 shaped and configured to allow radial expansion of the cylindrical peripheral surface 12. The module can be formed by first forming the wire 13 in a flat serpentine configuration and then wrapping the serpentine wire in its bonded configuration. The terminal ends of the serpentine wire are free. The free ends of the wire 13 can be fixed to each other and the support wire 6 by the connector 9. The serpentine arrangement of each of the modules can be considered as including a series of elongated segments 14 alternated with and connected by folds that can be bend (v.gr., circular) or may comprise shorter connective segments 15 connected to the elongate segments 14 at the cusps 17. The connecting folds between the longitudinal segments 14 may lie lengthwise and define a site of the closed loop 8. Preferably the wire 13 is formed so that the folds arrangement will be circumferentially spaced evenly around the virtual closed loop 8 to provide the modules 7 with uniform resistance in directions transverse to the support wire 6. When the modules are in their low profile, the configuration not expanded, the folds 15, 17 defining the connection between the adjacent longitudinal segments are such that the elongated segments 14 will be essentially parallel to each other, defining an angle of about zero degrees. The angle will increase when the module is expanded. The configuration of the connecting folds, including the cusps 17 can be varied to vary the angle or to vary their number circumferentially around the closed loop 8 to vary the characteristics of the modules 7, including varying their resistance to compressive radial loads in such a way that the endoprosthesis can also be tailored and made to conform ideally to the duct 3 of the specific body where it will be implanted. By way of illustrative example only, an extension may be provided to include the modules 7 formed of the wire having a diameter of approximately 0.15 millimeter with the elongated segments 14 (not including the connecting folds between the adjacent segments 14) of a length of approximately 1.8. millimeters When the conjunctive folds between the adjacent elongated segments 14 are uniformly curved they can have a radius of about 0.15 millimeter before expansion. An extension having the aforementioned dimensions can be expected to be expandable to diameters of between about 2.5 to about 4.0 millimeters without excessive expansion, and that this extension exhibits considerable resistance to radial crush that is well above the maximum radial compression loads and it can be expected to impose on the extension by contraction of an artery having a luminal diameter of about 2.5 to about 4.0 millimeters. In the preferred embodiment, the connectors 8 can be constructed to be mounted on the longitudinal support wire 6 by crimping them into the wire 6. The connector 9 can preferably comprise a small tube or ring defining an internal space sufficient to receive and enclose the free ends of the wire 13 while also allowing the firm connection of the ring with the longitudinal support wire 6. The ring collector 9, the free ends of the wire and the support wire 6 can be firmly connected by means of a permanent deformation, for example, by flanging or they can be fixed to each other by spot welding. When assembled using laser spot welding, it is preferred that the free ends of the wire 13 of the module 7 are first welded to the ring 9 and the ring then welded to the support wire 6. In some cases it may be desirable to modify the extension so that one or more of the modules, but not the end modules can be securely fixed on the support wire but instead, they are allowed to have some freedom of sliding movement along the support wire. This may allow a final adjustment to the position of the module after the device is placed in the patient's blood vessel in case it is desired. The ring 9 can be in the form of a relatively short segment and a tube that receives the support wire 6a and the free ends of the module 7. The inner surface of the ring 9 can be contoured to closely match with the contour defined by the support wire 6 and the free ends of the wire 13 passing through the connectors 9. The aforementioned construction allows an extension to be assembled especially to conform accurately to the specific anatomy of the patient where the extension will be placed. The modules can be placed as desired along the support wire 6 and can be secured in that configuration. The support wire 6 can be selected to provide the desired degree of longitudinal flexibility and can be fabricated from wire that is extremely flexible to facilitate placement of the device in the relatively inaccessible body conduit. With the construction above, wherein the extension has an independent support wire 6, the degree of stiffness or flexibility of the support wire can be selected independently of the wire from which the tubular modules 7 are formed. The support wire 6 can be highly flexible to allow extension to be carried through sinuous narrow vessels, such as the coronary arteries. It should be understood that while the presently preferred embodiment of the invention incorporates a metal support wire 6 (e.g., stainless steel) the modular construction of the invention allows the ication of an extension where the wire Support can be formed of non-metallic materials, such as polymeric materials, for example, nylon or a biologically absorbable material. Other kinds of mechanically and biologically appropriate materials can be select from including materials from among those that are biologically absorbable in the tissue of the vessel wall through the course of time. With a bio-absorbable support wire 6, it must be selected to maintain its desirable mechanical characteristics for a sufficient period of time to allow the modules 7 to be firmly embedded in the vessel wall. The extension modules can be formed from a shape memory material such as a nickel-titanium alloy (nitinol) whereby the expansion of the module can be effected by a resistance heating element 105 (Figure 7). In this way, the modular construction of the invention provides a considerably increased scale of materials and properties for the individual components, each selected to provide optimum results. The components of the extension can be coated with a protective material such as carbon or with anticoagulant materials such as heparin. These variations in the materials allow to balance the mechanical strength and the elastic limit of the tubular structure in order to allow the extension to be adapted to the specific needs of an individual patient. The connection rings 9, especially when assembled around two end segments 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 manufactured. In this way the region of the spine that includes the connecting rings 9 will have a considerably greater radiopacity than that presented by the wire 13 of the associated module. The considerably increased radiopacity of the connected region considerably improves the radiographic control of the stent 1 during implantation. It also allows the prosthesis to be observed radiographically for a later period without requiring the use of ultrasound procedures. The configuration of the extension allows the tubular frame 10 to be constructed to have a high mechanical strength while allowing the expansion of the device between a low profile configuration and maximum expansion wherein the wire 13 of the modules 7 will become essentially transparent to the X-rays at radiation levels that are typically used in these procedures.

Figures 5 and 6 illustrate the placement of spacers 50 between the pairs of successive rings 9 before the rings are secured in the support wire 6. The spacers are preferably cylindrical in shape and have a central hole through which they can slide in a manner similar to beads towards and along the longitudinal wire 6. When a series of connectors 9 and spacers 50 have been placed in the support wire 6, each successive pair of connectors 8 or sephers 50 can encompass each other. The length of the spacer (s) may be predetermined to allow precise control through the spacing between two successive modules as well as to reduce the risk of the support wire 6 being twisted or otherwise damaged. In most cases, the separation of the adjacent modules will desirably be done in such a way that they can be placed in close proximity (e.g., with their cusps 15 adjacent to each other) to provide considerable continuous support to the wall 11 of the vessel when the extension has been placed on the patient. In addition, the use of spacers 50 allows an extension to be assembled with only the two end connectors 9 anchored securely to the support wire 6. In this embodiment, the intermediate components (connectors 9 and spacers 50) will be retained in position in the support wire and will not separate. Either all or only the end connectors 9 are secured in the longitudinal support wire, the intermediate separators need not be directly secured to the wire 6., but instead can be held in place by and between its adjacent connectors. By way of a dimensional example, the cylindrical spacers 50 that can be used with the device having the dimensions described above can be approximately 1.10 millimeters in length, 0.30 millimeters in external diameter and having a wall thickness of approximately 0.075 millimeters. The spacers 50, being circular in cross section, can be positioned to be essentially flush or level 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 9 and portions of the wire extending through the rings, the arrangement defines a spine having an essentially continuous elongated mass having a considerably greater radiopacity than that of the wires 13 of the serpentine. All components of the device must be formed of materials that are compatible with each other and that do not form microcells that could lead to electrochemical corrosion of any part of the device after it has been implanted in the blood vessel. The longitudinal support wire 6, the wire 13 and the connector 9 should preferably have the same chemical composition or chemical compositions that are biologically compatible with one another. Exemplary materials that are preferred for making the stent include those from the group of annealed stainless steels, titanium alloys, gold-nickel alloys, nickel-chromium alloys and titanium-chromium alloys. The support wire 6 and the modules 7 can be treated and formed to vary the mechanical and functional characteristics independently of one another to obtain a desired configuration adapted to treat the anatomy of a specific patient. For example, the wire 13 from which the module is formed can be subjected to an annealing heat treatment to control the malleability of the wire. Figures 5 and 6 illustrate the manner in which a bifurcated extension can be placed in the branched blood vessels. In this modality, the bifurcated extension is formed of two individual component extensions (that is, not bifurcated) 1P (Figure 5) and ÍS (Figure 6). The first component extension 1P can be constructed in the manner described above to include an elongated spine in which the plurality of radially expandable modules 7 are fixed. Modules 7 of extension 1P can be considered as standing in games, including, a first game lPa (next) which may be the near end of the extension 1P and a second game lPb (distant) at the other end.

The modules 7 in the first set lPa are separated along the spine, at predetermined intervals. As described in detail below, the distance L between the adjacent modules 7 in the first set IPa must be sufficient to allow the modules 7 of another extension to be adjusted between the modules 7 in the first set lPa. In the preferred embodiment, the predetermined distance is not less than the length LM of a module 7 measured along a direction parallel to the spine. The modules 7 in the second set lPb can be placed in close longitudinal proximity to each other or other spacing which may be appropriate for the specific branch of the vasculature where it will be placed. The first component extension 1P is also constructed to have a space lPc defining a lateral opening SF between the first and second sets lPa, lPb of the module 7. The lateral opening SF allows a second component extension in a low profile configuration to be made pass through the first component extension (after the expansion of the first component extension) and protrude transversely out of the space lPc. By placing the lateral opening SF at the junction of the branched blood vessels, a second component extension can be advanced towards the branching artery 3c. In a preferred embodiment, the length of the lateral opening SF may be approximately that of the diameter 3S of the cross section of the branching passage 3c. The modules 7 in the first set can also be interconnected by a second longitudinal spine wire 6P as well as the modules in the second set lPd of the first set 1P component. When two spine wires are used, the continuity of the second spine wire 6P (placed further upwards as seen in Figure 5) is interrupted through the length of the side opening SF between the sets of modulus lPa and lPb. The second preferred component extension is provided only with a 6S single longitudinal spine wire. The extension can be constructed in situ in the patient by first placing and expanding the first component extension 1P with the lateral opening SF coinciding with one of the branches 3c of the body canal and then inserting the second component extension ÍS through the first extension 1P component and transversely through the lateral opening SF towards the other branch duct 3c. The proximal ends of the component extensions are preferably configured to cooperate with one another to define a single common tube. The first extension 1P may be delivered to and placed in the artery by a delivery device that will be described below having an expansion member that may include a balloon 104. The extension is mounted on the balloon 104 in a low profile. The construction of the first component extension 1P includes the spine arrangement which can be considered as being defined by the longitudinal support wire 6 and the connectors 9. The spacers 50 can also be provided between the pairs of adjacent connectors 9. The pattern of connectors 9 or connectors 9 and spacers 50 can be configured to allow distinct radiographic display of the space lPc in the intermediate portion of the extension to facilitate locating that portion at the desired site in the vascular branched region. It will be noted that in the illustrative embodiment, the region of the lateral opening SF in the first component extension 1P is capable of being radiographically distinguished from the other portions of the extension. In the illustrative mode that is achieved by omitting the separators or other components radiographically observable along that portion of the spine that extends between the groups lPa, lPb of near and distant module. Therefore the spine, in the lPc region, is defined only by the support wire 6 having considerably less mass than the other portions of the spine so that that region can be distinguished radiographically.

The second component extension IS may be similar in construction to the first component extension 1P, including a first set ISa of module 7 longitudinally separated to interengage with the spaces between the modules in the first set lPa of the first component extension, and a second set of lCb modules that can be placed in close proximity to each other. The first and second sets of module ISa, ISb can be separated by an ISc space of a length approaching the diameter of the cross section 3s of the branching passage 3c. The second component extension can be positioned as will be described below, by means of a balloon supply probe after at least the first set of modules lPa has expanded in secure engagement with the inner surface of the blood vessel 3. The second component extension IS is placed longitudinally within the vasculature so that the modules 7 of the next set ISa of the second component extension are aligned longitudinally with the spaces between the modules 7 in the first set lPa of the first component extension 1P. The relative positioning between the sets of modules can be facilitated by radiopaque portions of the spine, particularly the region of the connectors 9 and, if employed, the spacers 50. With the modules of the first set lPa, ISa being aligned, the modules 7 in the second game can expand. The structure of the resulting bifurcated extension can be configured to define an essentially continuous proximal extension portion within the blood vessel. Similarly, the second sets lPb, ISb of the module 7 expand in firm engagement with the portions of the branches of the blood vessel where they are placed. In order to improve the support for the wall 11 of the vessel at the junction of the branches 3, 3c of the blood vessel, either one or both of the component extensions 1P, IS can be provided with specially constructed module 7 which, when placed, they will surround the lateral SF opening. In these modified modules 7, the longitudinal portions 14, 14 'defining the virtual peripheral surface 12 can be formed to have different lengths so that they can extend towards and provide greater support in the region of the junction, particularly laterally of the region defined in FIG. side opening SF. In this way, the modules 7 in the region of the vessel junction can be considered as defining a virtual cylindrical surface that includes a portion of tongue 108 that projects longitudinally from the virtual cylindrical surface to thereby provide additional support for the wall of the vessel. the union, but without obstructing the lateral opening SF. Alternatively, a virtual cylinder defined by this module can be considered as defining a virtual surface that is oblique to the axis 2 longitudinal and is defined by the cusps 15 of the module set. Therefore, the end modules of each of the sets of modules lPa, lPb in the first component extension 1P can be positioned so that their cusps 15 are in close proximity to one another. If desired, the tabs of module 7 can be interspersed and alternate with each other, as suggested in the Figure 3 in 108a. In this way, the wall 11 of the affected vessels will be able to hold up better with little or no interruption in continuity along the length of the passage. Similarly, improved support can be provided in the region of the junction associated with the branching passage 3c by providing a tab 108 'in the module 7 of the second component extension IS placed at the junction of the branching passage 3c. The balance between the mechanical strength of the extension 1 and its ability to yield elastically can be further optimized by modulating the module 7 with the tongue 108 or 108 'of a wire 13 having a diameter different from that of the wire used for the others modules or alternatively, subjecting the modules to appropriate thermal treatment before assembling in the extension.

Figure 1 illustrates a delivery probe particularly adapted to supply and position the first component extension of the bifurcated extension in accordance with the invention. It should be understood that even when the probe 100 is illustrated as including an expansion means in the form of an inflatable balloon 104, other expansion means may be employed, for example, only an electric resistance heater 105 (Figure 7). The supply probe 100 may have a coaxial arrow including an internal tube 101 positioned within an external tube 110. The inner tube 101 extends through the balloon to a terminal portion 100o and opens at its distal end. The ends 104e of the balloon are secured at the distal end of the inner and outer tubes 101, 110, as is conventional in coaxial balloon probes. The annular space defined between the inner tube 101 and the outer tube 110 defines a first conduit through which the balloon can be inflated and deflated. The conduit (defined as a second) through the inner tube 101, receives a guide wire Gl to facilitate navigation of the probe 100. The delivery probe also includes a conduit 102 of elongate tubular guide wire extending along of the arrow of the probe and has a distal portion 102d terminating before the distal portion lOld of the inner tube 101. The distal end of duct 102 of the guidewire is formed to include an outlet orifice 102e oriented to allow a second guidewire G2 to protrude laterally away from the probe 100. the expansion medium, e.g., the balloon 104 , is mounted on the probe so that the hole 102e of the guide wire at the distal portion 102d of the guide wire duct 102 remains exposed. When the extension is loaded into the probe, the balloon is bent, for example, by two folds 106 modeled to surround the duct 102 of the guidewire. Alternatively, the guide wire conduit 102 should be directed through the inflation of the first conduit 110 and exit marginally before the point where the balloon is secured as required in outline in Figure 1. As will be described below in greater detail , when the device is placed in the patient, a second guidewire G2 can be advanced through the duct 102 of the guidewire and project laterally through the guidewire hole 102e and advanced towards the branch passage 3c. It will be appreciated that when the extension fits into the balloon, the distal section 102d of the duct 102 of the guidewire will be retained between the extension and the balloon. The guide wire hole 102e is positioned relative to the extension so that it coincides with the lateral opening SF of the first component extension. When the expansion means includes an electric resistance heater 105, the preparation of the probe 100 may comprise the step of placing the heater 105 between the first and second tubes 101, 102 (Figure 7). Extension 1 can be adjusted at the remote end of the probe by a loading device such as that described in International Application Number PCT / IB96 / 00918, filed on September 13, 1996, entitled "Device and Method for Mounting an Endovascular Stent Onto to Balloon Catheter "to which reference is made. The placement and creation of the bifurcated extension, in situ, is illustrated in the sequential drawings of Figures 4a-4g. Typically, before the component extensions 1P, IS are placed in the blood vessel, an angioplasty procedure is carried out in the blood vessels 3, 3c. The supply probe will first be placed with the first guidewire Gl extending through the inner tube 101 of the arrow of the probe. The first component extension 1P is then fitted on the probe 100 around the expansion means 104, 105, with the hole 102e of the duct guide wire 102 of the guide wire coinciding with the side opening SF. The probe 100 is then inserted into the patient's blood vessel and passed, together with and with the help of the guidewire Gl to place the assembly with the hole 102e of the guidewire placed at the junction of the branches of the blood vessel and oriented towards the branching passage 3c (Figure 4a). The second guide wire G2 is then inserted into the guide wire duct 102 advancing the guide wire G2 so that the tip comes out from the hole 102e of the guide wire. The guide wire G2 is then advanced to the branching passage 3c (Figure 4a). The expansion means 104, 105 is then operated to expand the first component extension 1P and stabilize its position in the blood vessel 3 (Figure 4C). The probe 100 and the guide wire Gl can then be removed from the blood vessel 3 while maintaining the second guide wire G2 in its position within the branching passage 3c (Figure 4c). The second component extension 1S is then adjusted in the same or in another probe in a low profile. That probe is then advanced along the second guide wire G2 until the second component extension IS and particularly the second set ISb of module 7 are placed in the branching passage 3c (Figure 4d). The expansion means 104, 105 is then operated to expand and stabilize the second component extension ΔS within the branch passage 3c, and the main passage 3c (Figure 4e). The second probe is then deflated and removed (Figure 4f). The second guide wire G2 is also removed (Figure 4g). It should be appreciated that because of the realistic facility by which the spine connection elements 9 can be monitored fluoroscopically, the first and second component extensions can be aligned and oriented relative to one another in the blood vessels. The use of a double spine for the first extension 1P components improves this capacity. A single spine is preferred for the second component extension IS. The single spine radiopacity allows the physician to place the second component extension IS to interpose the modules 7 of the first sets lPa and ISa with the single longitudinal wire 6 of the second component extension is rotated 90 ° relative to the two spines of the first component extension, all parts of the prosthetic structure being easily identifiable (see Figures 4d-4g). Figures 8 to 10 illustrate a variation of the invention. Figures 8 to 10 incorporate reference numbers in a pattern similar to that of the embodiment illustrated in Figures 5 and 6 but with the addition of "200" to the reference number. Therefore, as shown in Figures 8 to 10, the features of the invention and its reference numbers are the following: space (between two modules) 200sv extension 201 first extension component 201P next module suit of the first component extension 201Pa set of distant modules of the first component extension 201Pb space (between the next and distant module sets) 201Pc second component extension 201S next module set of the second component extension 201Sa set of distant modules of the second component component 201Sb space (between the proximal and distant module sets) 201Sc longitudinal axis 202 common conduit 203 branch vessel 203c section of branching branch 203s spine wire 206 module 207 virtual loop 208 tubular arrangement similar to a cage 210 vessel wall 211 virtual cylindrical surface 212 wire 213 longitudinal segment module 214 cusp 215 an The connector 219 The aforementioned components function essentially in the same manner as those described above in relation to the embodiments illustrated in Figures 5 and 6. In the variation illustrated in Figures 8 to 10, however, the set 201 of neighboring modules of the second component extension 201S includes only one module 207 that is adapted to be placed within the individual companion space 200sv in the next module set 20lPa of the first component extension 201P. In this modality, the space L of 200sv corresponds at least to the width LM of a module 207. The next set 201Sa of a single module is connected to the set 201Sb of distant modules by a relatively long spine wire 206. It should be noted that although the second component extension is shown in Figure 9 as being folded in the configuration it will adopt when two component extensions are assembled (Figure 10), the second component extension will be essentially straight when inserted into the first placed component extension. previously 201P. Figures 11 to 14 illustrate further modifications to the extensions described above, wherein the component extensions are constructed to still further improve the support they provide for the blood vessel in the junction region of vessels 203, 203c. For that end, the modules 207 placed immediately adjacent to the side opening 300 (referred to as SF in Figures 5 and 6) are assembled from two serpentine wires, one of which (207 ') has a greater amplitude than the other (207"), that is, one of the serpentine wires has longitudinal portions 214 shorter than the other. The arrangement is evident from Figure 11 which illustrates the first component extension with its modules shown as scattered and remaining in a flat plane. The serpentine wires defining the modules at each end of the side opening 300 (SF) are constructed of two wires having longitudinal portions 214 that are of different lengths and define a different inclination such as at 301 'and 301". The wire defining the side opening 300 (SF) is formed of serpentine wires of shorter length inclined more closely. When the first component extension (Figure 11) is in its generally cylindrical configuration similar to a cage, the two modules that are immediately adjacent to the lateral opening SF can be considered as each being formed of two portions, each portion defining a virtual arched element. 207 ', 207' '. The arcuate wire elements 207 ', 207"can be connected to each other by the connectors 219a. In addition, a spine 206a of short longitudinal connector wire is preferably connected to the ring connectors 219a. The arrangement of the spine wire 206, the short connector wire 206a and the segments 207"cooperate to define a cage-like structure having a high degree of local strength, particularly in the region of the side opening 300 (SF) which will define the entrance to the branch of the vessel 203c where the device is implanted. In addition, the arrangement of four rings 219, 219a fluoroscopically visible connectors placed in a rectangular array around the opening 300 (SF) provides a means by which the position and orientation of the lateral opening can be verified fluoroscopically. As shown in Figure 12, the second component extension 201S includes a module in close proximity to the junction of the common and branch vessels where the longitudinal portions 214p of the wire 13 extend to define a tongue-like configuration as shown in FIG. described above in relation to the embodiments of Figures 3, 5 and 6. This module associated with the second component extension can be formed entirely of a single wire, instead of forming the same of two serpentine wires that have 214 longitudinal segments of different lengths. It should be understood that the foregoing description of the invention is intended only to be illustrative thereof and that other embodiments, modifications and equivalents will be apparent to those skilled in the art without departing from its principles.

Claims

CLAIMS:

1. A method for forming a bifurcated extension with a body conduit having a common portion of two branches communicating with the common portion comprising: providing a first tubular component extension open at each end, having a lateral opening between its ends, and which is radially expandable from a low profile to an expanded configuration; providing a probe having an expandable member at its radial end and a guide wire duct having a guide wire hole positioned between the ends of the expansion member to allow the distal end of a guide wire to extend outwardly of the guide wire hole; mounting the first component extension on the expandable member with the side opening coinciding with the hole of the guide wire; advancing the probe assembly and the first component extension to the junction region of the common portion and branches of the body conduit, and with the transverse opening facing the entrance of one of the branches, a proximal portion of the The component extension is placed within the common portion of the body passageway, and the distal portion of the first component extension is placed in one of the branches of the body passageway; operating the expandable member to expand the first component extension within the body conduit in engagement with the body conduit surface; advancing a guide wire through the guide wire duct, the guide wire hole and the other branch of the body duct; while the guide wire is held in position in the other branch of the body passage, removing the patient's probe; advancing a second component extension towards the body conduit, guiding the second component extension by means of the guide wire to place at least a portion distant from the second component extension through the lateral opening of the first component extension and in the other branch of the body canal; and expanding the second component extension in engagement with the wall of the body passageway.

2. The method according to claim 1, wherein the expandable member comprises a balloon, the method further comprising folding a portion of the balloon around the distal portion of the guide wire before mounting the first component extension in the balloon. , the bend of the balloon being in such a way as to keep the orifice of the guidewire exposed.

3. A method according to claim 2, wherein the step of bending the balloon comprises making at least one on each side of the guide wire duct.

A method according to claim 1, wherein the expandable means comprises an electric resistance heater and wherein the step of adjusting the extension to the probe comprises placing the heater between an arrow of the probe and the wire duct of the probe. guide.

A method according to claim 1, wherein the probe includes an arrow that includes a conduit of the open guidewire at the distal tip of the arrow and wherein the step of advancing the probe assembly and the The first extension of the component comprises preliminarily extending the guidewire from the distal end of the probe and having the guide wire manipulated to provide a path for advancing and guiding the probe to the intended location of the extension placement.

6. A method for attaching a component extension of a bifurcated extension assembly comprising: mounting the component extension in a delivery device having an expandable member at its distal end, the component extension having a lateral opening between its ends; interposing a duct of the guide wire having an outlet hole of the guide wire between the expandable member of the supply device and the extension, with the duct of the guide wire having an outlet hole of the guide wire coinciding with the lateral opening of the component extension; advancing the assembled component supply and extension device to the junction region of the common portion and branches of the body conduit with the lateral opening and the exit port of the guide wire facing the entrance of one of the branches .

7. A component extension adapted to be positioned in a bifurcated region of a body conduit comprising: a member defining an elongated tube having a proximal section, a distal section and a lateral opening defined between the proximal and distal sections; the proximal and distal sections have adjacent portions that are laterally linked to the side opening, the adjacent portions extend toward and remain in close proximity to one another whereby the side portions can provide essentially continuous support of the conduit wall.

The component extension according to claim 7 further comprising: each of the proximal and distant sections includes at least one radially expandable module, the lateral opening being defined between the internal module of each of the next and distant sections , at least one of the internal modules has portions of different axial dimensions.

9. A component extension according to claim 8, further comprising: the modules are formed of wire placed in a serpentine pattern that includes longitudinal wire portions connected in series one to the other, at least some of the longitudinal portions in at least one of the internal modules being longer than the other longitudinal portions of that internal module.

A component extension according to claim 9, wherein the longitudinal portions of the internal module that are laterally positioned of the lateral opening are longer than the other longitudinal portions of that internal module.

11. A bifurcated extension formed of two component extensions, each of which includes a plurality of modules placed in a sequence to define a generally tubular configuration; a pair of modules placed in sequence that are placed to define a lateral opening between them; the second component extension extends through a portion of the first component extension and projects laterally through the lateral opening; the pair of modules in the first component extension having lateral portions laterally positioned in the lateral opening extending towards and in proximity to each other.

A bifurcated extension according to claim 11 further comprising: each of the modules of each component extension that is placed immediately adjacent to the branch junction of the two component extensions have projections extending axially toward the region of the joint or union.

A bifurcated extension according to claim 11 wherein the modules are formed of wire placed in a serpentine pattern to include longitudinal wire portions connected in series one to the other by means of cusps, the longitudinal wire portions of the modules being Place them so that their cusps are placed in close proximity to one another.

A bifurcated extension according to claim 13 wherein some of the cusps of a module overlap and extend beyond at least one cusp of the other of the modules.

15. A component extension according to claim 9, wherein the longitudinal wire portions are connected to each other at the cusps and where the cusps of the modules are placed in close proximity to one another.

16. A component extension according to claim 9, further comprising the longitudinal wire portions that connect one to the other at the cusps and wherein at least one of the cusps of one of the modules overlaps and extends further. beyond at least one of the cusps of the other of the modules.

17. A probe for supplying a component extension of a bifurcated extension wherein the component extension includes a lateral opening comprising: an elongate flexible arrow; an expandable member mounted on the distal end of the arrow around which the extension of the component can be mounted in a low profile configuration; an elongated guide wire duct extending longitudinally of the arrow, the guidewire duct has a distally exposed outer end of the expandable member and defines an outlet orifice of the guidewire at a site positioned longitudinally between the ends of the expandable member, the guidewire outlet orifice is configured to allow that a guide wire emerges from the guide wire duct in a direction extending at an angle with respect to the axis of the probe.

18. A supply probe according to claim 17, wherein the arrow of the probe is coaxial and includes an inner tube and an outer tube.

A supply probe according to claim 17, wherein the extension is adapted to expand during the application of heat and wherein the expandable element comprises a means carried by the probe to apply heat to the component extension.

20. A supply probe according to claim 17 wherein the expandable member comprises a balloon.

21. A supply probe according to claim 17, further comprising, in combination, a component extension mounted on the expandable member in low profile, the component extension has a side opening that is positioned to match the wire exit orifice. of guide wire duct guide.

22. A component extension of a bifurcated extension comprising: a plurality of loop-like modules connected in sequence with and along a spine to define a generally tubular configuration; at least two of the modules are formed of wire placed in a serpentine pattern to include longitudinal sections connected to each of the other cusps; a pair of modules placed in sequence defining a lateral opening; at least one of the modules in the pair has longitudinal portions of different lengths.

23. A component extension according to claim 22 wherein the module has a pair of serpentine wires, one of which has sections longer than those of the other section, the smaller serpentine wire is connected to one end of the module. Larger serpentine wire.

24. A component extension according to claim 23 wherein the smallest of the serpentine wires defines the axial ends of the lateral opening.

25. A component extension according to claim 23, wherein the larger serpentine wire defines portions of the component extension that is laterally positioned from the lateral opening.

26. A component extension according to claim 24 further comprising: each end of each of the small serpentine wires is connected to the spine, the other end of each of the small serpentine wires being connected to one end of the Larger serpentine wire.

27. A component extension according to claim 26, wherein the small serpentine wire is connected to the spine in a connector having a radiographic mass considerably larger than that of the wire.

28. A component extension according to claim 27, wherein the small serpentine wire is connected to the large serpentine wire in a connector having a radiographic mass considerably greater than the wires.

29. A component extension according to claim 28, wherein the connectors connecting the small serpentine wire on the spine of the large serpentine wire define a generally rectangular pattern defining the corners of the lateral opening.

30. A component extension according to claim 29 further comprising: a longitudinally extending, short connector wire connected to the joint and joint of the large and small serpentine wires.

31. A component extension according to claim 23, wherein the inclination of the small serpentine wire is smaller than the inclination of the large serpentine wire.