WO2023001775A1

WO2023001775A1 - Device for treating an obstructve lesion for an anatomical bifurcation

Info

Publication number: WO2023001775A1
Application number: PCT/EP2022/070092
Authority: WO
Inventors: Marco MIDULLA; Christophe Moureaux; Sébastien DAVID
Original assignee: Cisteo Medical
Priority date: 2021-07-19
Filing date: 2022-07-18
Publication date: 2023-01-26
Also published as: FR3125217B1; FR3125217A1

Abstract

This device has a hollow, elongate one-piece body (10) formed of a radially expansible mesh and comprising a main end part (20), a secondary end part (30) and an intermediate part (40). The main end part has a tubular shape, includes a first end (21), centred on a first axis (X21) and having a circular cross section, and has a cross section which, in orthogonal projection on a geometric plane containing the cross section of the first end, remains inscribed within the latter when going from its first end to its second end (22). The secondary end part (30) has a cylindrical shape centred on a second axis (X30), parallel and offset with respect to the first axis, and has a cross section which is circular and which, in orthogonal projection on the geometric plane, is inscribed within the cross section of the first end. The intermediate part (40) has a radial stiffness greater than those of the main end part and secondary end part and delimits a main opening (43) adapted to the second end, a first secondary opening (44) adapted to a second end (32) of the secondary end part, and a second secondary opening (45) which interrupts the mesh of the body.

Description

Device for treating an obstructive lesion for an anatomical bifurcation

The present invention relates to a device for treating an obstructive lesion for an anatomical bifurcation connecting a main canal and two secondary branches.

The human body includes various anatomical bifurcations connecting a main channel, in which a fluid or air circulates, and two secondary branches. The vascular system of the human body, in particular the cardiovascular system in which the blood circulates, thus comprises various bifurcations connecting a main vessel and two secondary branches. Thus, the venous system includes, for example, a bifurcation, called the iliac venous bifurcation, connecting the inferior vena cava and the two primitive iliac veins. Similarly, the arterial system includes, for example, a bifurcation, called aorto-iliac bifurcation, connecting the abdominal aorta and the two common iliac arteries. Just like the rest of the vascular system, these bifurcations can suffer from obstructive lesions which tend to strangle the section of passage for the blood. These obstructive lesions result in particular from stenoses, occlusions and/or thrombosis in the regions of the main vessel and the secondary branches, which are located in the immediate vicinity of the confluence of the secondary branches.

To treat such obstructive lesions, multiple techniques are known, using one or more stents depending on the vascular territory concerned. For the treatment of lesions of the venous bifurcation between the inferior vena cava and the iliac veins, the placement of a single cylindrical stent in one of the two iliac veins towards the inferior vena cava, floating in the lumen of the latter, is the reference solution. For lesions of the aorto-iliac arterial bifurcation, on the other hand, the so-called “kissing” technique consists of simultaneously implanting two identical cylindrical stents in the bifurcation. Each stent consists of a mesh which is radially expandable in its longitudinal direction, so as to cause the stent to pass between an unexpanded state and an expanded state. The first of the two stents is, in the non-expanded state, introduced into one of the two secondary branches of the bifurcation, then moved to the bifurcation where the first stent is passed in the expanded state, while, at the same time, the second stent is, in the non-expanded state, introduced into the other secondary branch, then moved to the bifurcation where it has passed into the expanded state: the two stents in the state expanded are extended on either side of the junction of the secondary branches, each having a first longitudinal portion which extends into one or the other of the secondary branches, while respective second longitudinal portions of the two stents emerge in the main vessel from the junction of the two secondary branches, these two second parts resting

SUBSTITUTE SHEET (RULE 26) transversely against each other. These techniques lead to several drawbacks. Indeed, in the main vessel, the stent or stents tend to “float”, without adapting to the wall of the main vessel, which induces a risk of thrombotic effect or embolism or even restenosis. Many later techniques are also used in the coronary system.

FR 2995206 discloses a vascular treatment kit, comprising a first tubular implant, a second tubular implant, and a ring which retains the second implant attached transversely to the first implant in a window of this first implant. The first implant is described as formed of a framework defining a mesh, a priori isotropic over the entire longitudinal extent of the first implant. In the embodiment of Figures 13 and 14 of FR 2995206, the corresponding treatment kit makes it possible to treat an anatomical bifurcation which typically has a Y shape. The first implant is described as having its tubular shape which is centered on a single axis and as comprising a main trunk and a first leg, which is coaxial with the main trunk and which has the same diameter as the main trunk. The main trunk can be implanted in a main channel of the anatomical bifurcation and the first leg can be implanted in one of the two secondary branches of the anatomical bifurcation. The second implant forms a second leg which is implantable in the second secondary branch of the anatomical bifurcation.

For its part, WO 2019/213215 discloses a steering device for interventional procedures. The device comprises an expandable structure, which is made up of expandable strands and which, once released from a sheath, expands inside a vessel or a stent to apply a circumferential force thereto and thus anchor fixedly relative to the vessel or stent. In Figures 19A and 20 of WO 2019/213215, the expandable structure is used with a shaped stent which is a priori non-flexible, without the body of this stent being detailed.

The object of the present invention is to propose a new treatment device which, while being easy to implant, is better adapted to the anatomy of anatomical bifurcations and thus particularly effective.

To this end, the subject of the invention is a device for treating an obstructive lesion for an anatomical bifurcation connecting a main channel and first and second secondary branches, as defined in claim 1.

One of the ideas underlying the invention is to use a one-piece body with a radially expandable mesh, which, once implanted, extends in length both in the main channel and in a first of the two secondary branches, and in which one differentiates, according to its longitudinal direction, three successive parts which present proper shape and stiffness characteristics. A first of these three parts is a main end part of the one-piece body, which is to be implanted in the main channel and which, in the expanded state of the one-piece body, is adapted to the morphology of the main channel, having a tubular shape which , at its top, that is to say opposite the rest of the one-piece body, has a circular cross section, centered on a first axis extending in the longitudinal direction of the one-piece body, and which, as as one moves away from this vertex, remains in the cylindrical envelope defined by the projection of the aforementioned circular cross-section along the first axis, either by gradually narrowing, or by remaining unchanged. A second of the three parts, which is opposite the main end part in the longitudinal direction of the one-piece body, is a secondary end part of the one-piece body, which is to be implanted in the first secondary branch and which, in the expanded state of the body monobloc, is adapted to the morphology of this first branch, by having a cylindrical shape with a circular section, which is centered on a second axis, both parallel and offset with respect to the first axis, and which extends inside of the aforementioned envelope. The third part is an intermediate part of the one-piece body, which is to be implanted at the confluence of the two secondary branches and which connects the main and secondary end parts to each other, by connecting, in the expanded state of the one-piece body , the light of the main end part to, on the one hand, the light of the secondary end part and, on the other hand, a through opening, which interrupts the mesh of the one-piece body and which is provided to open into the second of the two secondary branches of the bifurcation. In addition, the intermediate part is designed, in particular by the mesh of the one-piece body in this intermediate part, to have, in the expanded state of the one-piece body, a radial stiffness which is greater than each of the respective radial stiffnesses of the main end parts and secondary: in this way, the one-piece body in the expanded state generates, at its intermediate part, a greater radial force than in the rest of the one-piece body, which counteracts the strong extrinsic compression applied by the bifurcation to the level of the junction between its secondary branches and which thus guarantees effective and reliable communication between, on the one hand, the main channel and the first branch of the bifurcation, thanks to the connection between the respective openings of the main terminal parts and secondary via the interior of the intermediate part, and, on the other hand, the main channel and the second branch of the bifurcation, thanks to the connection nt between the light of the main terminal part and the light of the second branch via the aforementioned through opening of the intermediate part. The one-piece body of the device according to the invention thus has a shape and a structural rigidity which are dedicated to the anatomy of the bifurcation presenting the lesion to be treated. In addition, the one-piece structure of the body of the device according to the invention facilitates the implantation of this device: the positioning of the one-piece body can in particular be carried out by endovascular introduction of the one-piece body in the non-expanded state, then its displacement to the bifurcation where it passed to the expanded state. An ad hoc positioning ancillary makes it possible to control the orientation of the one-piece body around its longitudinal direction inside the patient's channels, then to deploy it at the desired level of the patient's bifurcation.

Additional advantageous characteristics of the device according to the invention are specified in the other claims.

The invention will be better understood on reading the following description, given solely by way of example and made with reference to the drawings in which:

- [Fig. 1] Figure 1 is a diagram of a part of the human body, illustrating elements of the cardiovascular system of the latter;

- [Fig. 2] Figure 2 is an elevational view of a first embodiment of a device according to the invention;

- [Fig. 3] Figure 3 is an elevational view along the arrow III of Figure 2;

- [Fig. 4] Figure 4 is a section along the line IV-IV of Figure 2;

- [Fig. 5] Figure 5 is a section along the line V-V of Figure 4;

- [Fig. 6] Figure 6 is a detailed view of area VI of Figure 2;

- [Fig. 7] Figure 7 is a detailed view of area VII of Figure 2;

- [Fig. 8] Figure 8 is a diagram illustrating the implantation of the device of Figures 2 to 7 in a bifurcation of the cardiovascular system of Figure 1; and

- [Fig. 9] [Fig. 10] Figures 9 and 10 are views respectively similar to Figures 2 and 3, illustrating a second embodiment of the device according to the invention.

Figure 1 schematically shows part of the cardiovascular system of a human patient. This cardiovascular system thus comprises an iliac venous bifurcation, which connects the inferior vena cava 2 and the two primitive iliac veins 3 and 4, as well as an aortic iliac bifurcation, which connects the abdominal aorta 5 and the two primitive iliac arteries 6 and 7.

In Figures 2 to 8 is shown a device 1 for treating a vascular obstructive lesion for the iliac venous bifurcation. The nature and the cause of the obstructive connection to be treated by the device 1 are not limiting of the invention and reference is made to the introductory part of this document in this respect.

The device 1 comprises a one-piece body 10. In FIGS. 2 to 7, the one-piece body 10 is shown alone and not yet implanted, while, in FIG. 8, the one-piece body 10 is shown in the iliac venous bifurcation. As clearly visible in Figures 2 to 4, the one-piece body 10 has an elongated shape which extends in length in a longitudinal direction which is denoted D in the figures.

As more specifically visible in Figures 4 and 5, the one-piece body 10 is hollow, and this over its entire extent in the direction D. The one-piece body 10 thus internally delimits a slot, that is to say a free space, separated from the outside of the one-piece body 10 by the wall of the latter. As specified below, the one-piece body 10 is open in the direction D at each of its two opposite ends in the direction D. The lumen of the one-piece body 10 thus communicates with the outside of the one-piece body via each of its two ends.

The one-piece body 10 consists of a mesh, typically metallic, which is radially expandable in the direction D. This type of mesh is well known in the field of endovascular stents, so that the general characteristics of the mesh of the one-piece body 10 do not will not be further described here. Moreover, the structure of the mesh of the one-piece body 10, which consists of strands, typically metallic, secured to each other in a flexible manner either by interlacing or by continuity of material, is not detailed in FIGS. 5 for visibility purposes. In practice, the mesh of the one-piece body 10 can have various embodiments, some of which will be discussed in more detail later in connection with Figures 6 and 7, but which, more generally, are not limiting of the invention as long as this mesh has a capacity for radial expansion in the direction D so as to cause the one-piece body 10 to pass between an unexpanded state and an expanded state. In Figures 2 to 7, the one-piece body 10 is shown in the expanded state.

Depending on the structure of the mesh of the one-piece body 10, various techniques for manufacturing this mesh can be envisaged, such as the braiding of one or more threads or else the shaping by removal of material from a tubular part. These various manufacturing techniques are well known in the field of endovascular stents.

Whatever the specificities of the mesh of the one-piece body 10, the latter is divided into three distinct parts which follow one another in the direction D. These three parts of the one-piece body 10 include two end parts which are opposite one another along the direction D, namely a main end part 20 and a secondary end part 30. The third part of the one-piece body 10 is an intermediate part 40 which connects the main end parts 20 and secondary end parts 30 to each other. 20, 30 and 40 will now be successively detailed. The main terminal part 20 is designed to, when the device 1 is implanted in the iliac venous bifurcation as in FIG. 8, be implanted in the inferior vena cava.

To this end, the main end part 20 has, in the expanded state of the one-piece body 10, a tubular shape which extends in length along the direction D. The main end part 20 includes two ends opposite one to the other. another in direction D, namely one end 21, which faces away from intermediate part 40, and one end 22, which faces towards intermediate part 40.

The main terminal part 20 internally delimits a slot 23 which extends over the entire dimension of the main terminal part 20 in the direction D. The slot 23 is separated from the outside of the main terminal part 20 by the tubular wall of this main end part, this tubular wall extending continuously over the entire periphery of the main end part 20. The slot 23 opens outside the main end part 20 via the end 21 which is open in the direction D , the slot 23 thus opening outside the one-piece body 10. The slot 23 also opens outside the main end part 20 via the end 22 which is open in the direction D, the slot 23 thus opening outside the inside the intermediate part 40.

As clearly visible in Figures 2 to 4, the end 21 is centered on an axis X21 extending in the direction D. The cross section of the end 21, that is to say the section of the latter in a geometric plane p perpendicular to the axis X21, is circular, as clearly visible in figure 5 on which the cross section of the end 21 is shown in dotted lines, in orthogonal projection in the plane of figure 5.

When the main end part 20 is traversed from its end 21 to its end 22 in the direction D, the cross section of the main end part 20 gradually decreases, while remaining inscribed, in orthogonal projection on the geometric plane TT, in the cross section of the end 21. In other words, at any given point of the extent of the main end part 20 along the direction D, this main end part has a cross section, that is to say a section in a plane perpendicular to the direction D and containing the aforesaid given point, which is inscribed in the cross section of the end 21 and which is also inscribed in the cross section of any point of the extent of the main terminal part following the direction D, located between the end 21 and the aforementioned given point. This means that the tubular shape of the main end part 20 is gradually narrowed from the end 21 to the end 22. This constricted tubular shape of the main terminal part 20 is well suited to the anatomy of the inferior vena cava 2, by corresponding to the morphology of this inferior vena cava 2 in the region of the iliac venous bifurcation, as illustrated by FIG. .

According to an advantageous arrangement, which is implemented in the embodiment considered in the figures, the end 21 has, in the expanded state of the one-piece body 10, a cylindrical shape, centered on the axis X21. By occupying a longitudinal extent of the main end part 20, which is limited and which is located opposite the rest of the one-piece body 10, the cylindrical shape of the end 21 favors the centering and the retention of the main end part 20 in the inferior vena cava 2 during implantation of the one-piece body 10.

Also according to an advantageous arrangement, which is implemented in the example considered here, the end 22 of the main terminal part 20 has, in the expanded state of the one-piece body 10, a cross section which is elliptical, as clearly visible in Figure 5. This elliptical section favors the adaptation of the main terminal part 20 to the junction zone between the inferior vena cava 2 and the primitive iliac veins 3 and 4.

According to yet another advantageous arrangement, which is implemented here and the interest of which will appear a little further on, the main end part 20 includes a lateral portion 24, which connects the ends 21 and 22 to each other and which extends parallel to the axis X21, this lateral portion 24 being cut longitudinally in the plane of FIG. 4.

In all cases, the mesh of the one-piece body 10 is, in the main end part 20, shaped according to the constricted tubular shape which has been described above. By way of non-limiting example, FIG. 6 details an embodiment of the mesh of the one-piece body 10 in the main end part 20. In this embodiment, the strands of the mesh, which are secured to each other by forming diamonds, are shaped, during the manufacture of the one-piece body 10, to respect the desired constricted tubular shape, by being for example plastically deformed by a shaping die.

The secondary terminal part 30 is designed to, when the device 1 is implanted in the iliac venous bifurcation, be implanted in the primitive iliac vein 3, as illustrated in figure 8.

To this end, the secondary end part 30 has, in the expanded state of the one-piece body 10, a cylindrical shape, centered on an axis X30 which is parallel and offset with respect to the axis X21, as clearly visible in FIGS. to 5. The final part secondary 30 includes ends opposite to each other along the axis X30, namely an end 31, which is turned away from the intermediate part 40, and an end 32, which is turned towards the intermediate part 40.

The secondary terminal part 30 internally delimits a slot 33 which extends over the entire dimension of the secondary terminal part 30 in the direction D. The slot 33 is separated from the outside of the secondary terminal part 30 by the cylindrical wall of the secondary end part 30, which extends continuously over the entire periphery of this secondary end part 30. The opening 33 opens outside the secondary end part 30 via the end 31 which is open in the direction D, the slot 33 thus opening outside the one-piece body 10. The slot 33 also opens outside the secondary end part 30 via the end 32 which is open in the direction D, the slot 33 thus opening outside the interior of the intermediate part 40.

The secondary end part 30 of cylindrical shape has a cross section which is circular, as shown in dotted lines in FIG. 5 in which the cross section of the secondary end part 30 is projected onto the plane of this figure 5 along the axis X30. This circular cross-section is, in orthogonal projection on the geometric plane TT, inscribed in the cross-section of the end 21 of the main terminal part 20, as clearly visible in FIG. 5. Thus, the diameter of the circular cross-section of the terminal part 30 is lower than that of the cross section of the end 21.

The cylindrical shape of the secondary terminal part 30 is well suited to the anatomy of the primitive iliac vein 3, respecting the overall cylindrical morphology with a circular base of this primitive iliac vein, as illustrated schematically in FIG. 8.

In particular to promote adaptation to the anatomy of the iliac venous bifurcation, the offset of the axis X30 with respect to the axis X21 is advantageously provided so that the major axis of the elliptical cross section of the end 22 of the main end part 20 extends perpendicular to the axes X21 and X30, as clearly visible in Figure 5.

According to an advantageous arrangement, which is implemented in the embodiment considered in the figures and whose interest will appear later, the secondary end part 30 includes a lateral portion 34, which connects the ends 31 and 32 and which is aligned with the side portion 24 along a straight line parallel to the axes X21 and X30, as clearly visible in Figure 4. According to yet another advantageous arrangement, the secondary end part 30 has, in the expanded state of the one-piece body 10, a great capacity for deformation with respect to the intermediate part 40. The adaptation of the secondary end part 30 to the morphology of the iliac venous bifurcation is thus reinforced, allowing the secondary terminal part 30 to adapt to the sometimes significant anatomical curvature of the primitive iliac vein 3, as illustrated schematically in FIG. 8. In particular, the secondary terminal part 30 is, in the expanded state of the one-piece body 10, deformable with respect to the intermediate part 40 so as to be able to tilt its second end 32 with respect to its first end 31:

- with an angulation a, of at least 70°, in the cutting plane of figure 4, that is to say in a plane containing the axes X21 and X30, as indicated in dotted lines in figure 3, and

- with an angulation b, of at least 90°, in a plane which contains the X30 axis and which is perpendicular to the aforementioned plane containing the X21 and X30 axes, as shown in dotted lines in figure 2.

In all cases, the meshing of the one-piece body 10 in the secondary end part 30 gives this secondary end part its cylindrical shape with a circular section, as well as, where appropriate, its capacity for deformation. Multiple embodiments are possible for this mesh. The mesh of the one-piece body 10 in the secondary end part 30 can thus be different from the mesh of the one-piece body in the main end part 20. In the preferred but non-limiting embodiment illustrated in FIG. 10 in the secondary end portion 30 includes several cylindrical rings 35 which, in the expanded state of the one-piece body 10, are centered on and follow one another along the axis X30. The rings 35 are connected in pairs in a flexible manner by flexible bridges 36 of the mesh. The rings 35 are provided to each exert a radial expansion force, thus participating in the stiffness of the corresponding part of the mesh of the one-piece body, while being adjustable in position relative to each other by means of the flexible deformation of the bridges 36, which provides great flexibility to the secondary end part 30. To this end, according to one possible embodiment which is illustrated in FIG. 7, each of the rings 35 is made up of strands which form, along the periphery of the ring 35, a succession of Vs having respective points, which are directed in the direction D and whose orientation alternates along the periphery of the ring 35. The bridges 36 are each folded like an accordion in the direction D and each connect one to the other two of the tips of the Vs formed by the strands of the rings 35. This embodiment of FIG. 7 gives the cylindrical shape with a circular section of the secondary end part 30 a great deformability transversely to the direction D, in particular along the angulations a and b, by means of the flexible deformation of one or more of the bridges 36 between the two rings 35 that each of these bridges 36 connects.

The intermediate part 40 is designed to, when the device 1 is implanted in the iliac venous bifurcation, be implanted at the junction between the inferior vena cava 2 and the primitive iliac veins 3 and 4.

To this end, the intermediate part 40 comprises a peripheral wall 41 which, in the direction D, connects the tubular wall of the main end part 20 and the cylindrical wall of the secondary end part 30 to one another. intermediate 40 delimits an internal volume 42 which is separated from the outside of the intermediate part 40 by the peripheral wall 41.

On its side which, in the direction D, is turned towards the main end part 20, the intermediate part 40 delimits a main opening 43 through which the internal volume 42 communicates freely with the opening 23 of the main end part 20. As clearly visible in figure 4, the main opening 43 is fitted to the end 22 of the main terminal part 20, by means of the continuous connection of the peripheral wall 41 with the tubular wall of the main terminal part 20 at the level of the end 22 of the latter.

On its side which, in the direction D, is turned towards the secondary end part 30, the intermediate part 40 delimits a secondary opening 44 through which the internal volume 42 communicates freely with the opening 33 of the secondary end part 30. As clearly visible in FIG. 4, the secondary opening 44 is fitted to the end 32 of the secondary terminal part, by means of the continuous connection of the peripheral wall 41 with the cylindrical wall of the secondary terminal part 30 at the level of the end 32 of the the latter.

Also on its side which faces the secondary end part 30, the intermediate part 40 delimits, in addition to the secondary opening 44, a secondary opening 45, which is separate from the secondary opening 44 and through which the internal volume 42 is placed in free communication directly with the exterior of the one-piece body 10. As clearly visible in FIGS. 2 and 4, the secondary opening 45 crosses the peripheral wall 41 right through transversely to the direction D, interrupting the mesh of the one-piece body 10 in the intermediate part 40. The profile of the secondary opening 45, which is shown schematically in the shape of a trapezium in FIG. 2, is not limiting and can be more or less rounded.

In addition, the intermediate part 40 has, in the expanded state of the one-piece body 10, a radial stiffness which is greater than the radial stiffness of the end part main 20 and to the radial stiffness of the secondary end part 30. In other words, in the expanded state of the one-piece body 10, the intermediate part 40 is more rigid, in a direction radial to the direction D, than the main end parts 20 and secondary 30. This implies that, when the one-piece body 10 is implanted, the intermediate part 40 exerts on the vascular wall of the iliac venous bifurcation a greater radial force than the rest of the one-piece body 10. In other words, when traversing the one-piece body 10 in the expanded state between its two opposite ends in the direction D, the radial force produced on the vascular wall by the one-piece body 10 is not constant, but varies being maximum at the level of the intermediate part 40 .

The shape and stiffness characteristics, specific to the intermediate part 40, allow the latter to be well adapted to the morphological constraints of the junction zone between the inferior vena cava 2 and the primitive iliac veins 3 and 4. Indeed, when the one-piece body 10 is implanted, as illustrated in FIG. 8, the intermediate part 40 occupies this junction zone, extending on either side of the confluence of the two primitive iliac veins 3 and 4. The radial stiffness of the intermediate part 40 enables it to resist the extrinsic compression, otherwise called "anatomical gripper", exerted by this junction zone on the one-piece body 10 and, thereby, to prevent the main 43 and secondary openings 44 and 45 are substantially closed by radial crushing under the effect of this extrinsic compression. By thus keeping the main opening 43 and the secondary opening 44 substantially open, the blood flow between the primitive iliac vein 3 and the inferior vena cava 2 circulates via, jointly, the lumens 23 and 33 and the internal volume 42, therein entering through end 31 of secondary terminal portion 30 and exiting through end 21 of primary terminal portion 20. Similarly, by keeping primary opening 43 and secondary opening 45 substantially open, blood flow between the primitive iliac vein 4 and the inferior vena cava 2 circulate jointly via the lumen 23 and the internal volume 42, leaving it through the end 21 of the main terminal part 20 and entering it through the secondary opening 45 which opens into the common iliac vein 4.

These characteristics of shape and stiffness of the intermediate part 40 are given by the mesh of the one-piece body 10 in this intermediate part 40. In practice, many embodiments of this mesh are possible, which are based on structural differences between the meshes respective of the intermediate part 40 and the main 20 and secondary 30 end parts.

According to a preferred embodiment, which is efficient and easy to manufacture, the mesh of the one-piece body 10 has, in all or part of the part intermediate 40, strands sized to exert a greater radial force than that exerted by the strands of the mesh in the main 20 and secondary 30 end portions. To this end, according to a structural possibility, the strands of the mesh in all or part of the intermediate part 40 have a section greater than that of the strands of the mesh in the main 20 and secondary 30 end parts. D, and/or on the depth of the strands, that is to say their radial dimension in the direction D. Thus, by way of nonlimiting example, the mesh of the region of the intermediate part 40, located near immediate of the secondary end portion 30, includes one or more rings, which are individually similar to the rings 35 of the mesh of the secondary end portion 30, described above, but whose strands are wider and/or deeper s than the strands of the rings 35.

According to an advantageous embodiment, the intermediate part 40 includes a side portion 46 connecting to each other the side portion 24 of the main end part 20 and the side portion 34 of the secondary end part 30. In the state expanded from the one-piece body 10, the side portions 24, 34 and 46 are aligned along a straight line which is parallel to the axes X21 and X30, as clearly visible in FIG. 4. In this way, the side portion 46 is located opposite of the secondary opening 45 following the periphery of the peripheral wall 41, which favors the adaptation of the intermediate part 40 to the anatomy of the junction zone between the inferior vena cava 2 and the primitive iliac veins 3 and 4, while contributing to the structural rigidity of this intermediate part 40.

With a view to positioning the one-piece body 10 in the iliac venous bifurcation, the one-piece body 10 is made available in a placement ancillary, inside which the one-piece body 10 is retained in the non-expanded state and the orientation of this one-piece body 10 around the direction D is predetermined. This fitting ancillary is then introduced into the patient's body, for example by puncturing the femoral vein, and brings the one-piece body 10 to the iliac venous bifurcation. Before passing into the expanded state, the one-piece body 10 is precisely positioned in the iliac venous bifurcation, so that the main terminal part 20 is located in the inferior vena cava 2, the secondary terminal part 30 is located in the common iliac vein 3, and that the secondary opening 45 of the intermediate part 40 is located opposite the outlet of the common iliac vein 4. The position of the one-piece body 10 is thus adjusted both along the blood vessels, and angularly in these blood vessels, by correspondingly adjusting the positioning ancillary in relation to the patient's body. In practice, this positional adjustment is for example permitted by orientation marks of the one-piece body 10 relative to the installation ancillary and/or radio-opaque markers 50 with which the one-piece body 10 is provided. These radio-opaque markers 50 include in particular radiopaque markers 51 which are located at the end 21 of the terminal part 20, as illustrated in FIGS. 2 and 6, radiopaque markers 52 which are located at the end 31 of the secondary terminal part 30, as illustrated in FIGS. 2 and 7, and radio-opaque markers 53 which are located in the intermediate part 40. The radio-opaque markers 53 are advantageously arranged on one side and/or on the other side, in the direction D , of the secondary opening 45, as shown diagrammatically in FIG. 2. Once the one-piece body 10 is positioned satisfactorily in the iliac venous bifurcation, the fitting ancillary is controlled to release the one-piece body 10, by making not ss the latter in its expanded state. The one-piece body 10 is then found implanted in the iliac venous bifurcation, as illustrated in FIG. 8. The device 1 thus makes it possible to treat the obstructive lesion presented by the iliac venous bifurcation.

According to an option of device 1, which is only illustrated in FIG. 8 and in dotted lines, device 1 comprises, in addition to one-piece body 10, a stent 60. This stent 60, which is distinct from one-piece body 10, is provided for, while the one-piece body 10 is already implanted in the iliac venous bifurcation, to be implanted in the primitive iliac vein 4. The stent 60 is thus able to treat an obstructive lesion of the primitive iliac vein 4, located outside the field of action of the one-piece body 10. The stent 60 is similar to a usual endovascular stent and consists of a radially expandable mesh which, in the expanded state, has a cylindrical shape, as illustrated schematically in FIG. 8. The stent 60 is adapted to extend in length from the exterior of the one-piece body 10 in the expanded state, to the interior of the main terminal part 20, passing through the secondary opening 45. Whereas the one-piece body 10 is already implanted in the bifu iliac venous cation, as described above, and therefore while the one-piece body 10 is in the expanded state, the stent 60 is, in the non-expanded state, introduced into the secondary opening 45, until reaching a desired position in the iliac venous bifurcation, then the stent 60 is moved to the expanded state, finding itself implanted as illustrated in Figure 8.

In FIGS. 9 and 10 is shown an alternative embodiment of device 1, referenced 1′, having the same purpose as device 1. Device 1′ comprises a body 10′ which is distinguished from body 10 of device 1 only by the geometric shape of its main end part, referenced 20', so that the rest of the body 10' will not be described further and will be designated with the same reference numerals as those used for the body 10.

Like the main end part 20 of the body 10, the main end part 20' is, in the expanded state of the body 10', tubular in the direction D and has ends 21' and 22' opposite one another. in the direction D, the end 21' being turned away from the intermediate part 40 of the device 1'. Moreover, like end 21, end 21' is centered on an axis X21' extending in direction D and has a circular cross section. Unlike the main end part 20, the main end part 20' does not narrow when it is traversed from its end 21' to its end 22', but has a cross section which is unchanged and which therefore remains circular, centered on axis X21'. In other words, in the expanded state of the body 10', the main end part 20' has, from its end 21' to its end 22', a cylindrical shape of circular cross-section, centered on the axis X21'.

Due to its cylindrical shape over its entire extent in the direction D, the main end part 20′ can be simpler to manufacture than the main end part 20 of constricted tubular shape. The adaptation of the main terminal part 20' to the anatomy of the inferior vena cava 2 remains satisfactory thanks to the variation in the stiffness of the body 10' in the direction D, as explained in detail previously for the body 10 of the device 1 In the state implanted in the iliac venous bifurcation, the body 10′ thus has substantially the same configuration as that illustrated in FIG. 8 for the body 10.

As indicated above, the devices 1 and 1' described so far are specifically dedicated to the treatment of obstructive lesions of the iliac venous bifurcation. To this end, a preferential dimensioning of the one-piece body 10 consists in:

- in the expanded state of the one-piece body 10 or 10', the main end part 20 or 20' has a dimension, in the direction D, of between 20 and 50 mm, preferably 30 and 40 mm, the cross section of the 'end 21 or 21' has a diameter of between 22 and 26 mm, the secondary end part 30 has a dimension, in direction D, of between 50 and 150 mm, preferably between 80 and 120 mm, the cross section of the cylindrical wall of the secondary end part 30 has a diameter of between 10 and 16 mm, and the intermediate part 40 has a dimension, in the direction D, of between 1 and 20 mm, preferably between 2 and 8 mm; and - In the non-expanded state of the one-piece body 10 or 10', the fitting ancillary which retains the latter has a diameter of between 5 and 20 French, preferably 9 and 12 French.

This being so, by way of variants, the device 1 or 1′ can be envisaged for treating an obstructive lesion of other vascular bifurcations, that is to say bifurcations connecting a main vessel, such as the inferior vena cava 2 in the case of the iliac venous bifurcation, and two secondary branches, such as the common iliac veins 3 and 4 in the case of the iliac venous bifurcation. By way of non-limiting example of such variants, the device 1 or 1' can thus be adapted, in particular by a dimensioning different from the preferential dimensioning given above, to treat an obstructive lesion of the aorto-iliac bifurcation, of the bifurcation femoral, carotid bifurcation or coronary bifurcation.

Similarly, and more generally, the device 1 or 1′ can be declined, in particular in dimensioning, to treat an obstructive lesion of other anatomical bifurcations, connecting a main channel and two secondary branches. Mention may be made, for example, of the biliary bifurcation of the bile duct, or else the bifurcations of the airways, such as the bifurcation of the tracheal carina.

Claims

1. Device (1; 1') for treating an obstructive lesion for an anatomical bifurcation connecting a main channel (2) and first and second secondary branches (3, 4), the device comprising a one-piece body (10; 10 ') who :

- is hollow,

- has an elongated shape in a longitudinal direction (D),

- consists of a mesh which is expandable radially to said longitudinal direction so as to cause the one-piece body to pass between unexpanded and expanded states, and

- comprises three successive parts in said longitudinal direction (D), namely respectively main (20; 20') and secondary (30) end parts, which are opposite one another in said longitudinal direction and which are provided to be implanted respectively in the main channel (2) and in the first secondary branch (3), and an intermediate part (40), which connects the main and secondary end parts to each other and which is intended to be implanted at the junction between the main channel and the first and second secondary branches, in which, in the expanded state of the one-piece body (10; 10'), the main end part (20; 20'):

- has a tubular shape which extends in length along said longitudinal direction (D),

- includes ends opposite to each other along said longitudinal direction, namely a first end (21; 21'), which faces away from the intermediate part (40), and a second end (22 22'), the first end being centered on a first axis (X21; X21'), which extends along said longitudinal direction, and having a substantially circular cross-section, and

- has a cross section which, in orthogonal projection on a geometric plane (TT) containing the cross section of the first end of the main terminal part, remains inscribed in the cross section of this first end when traversing the main terminal part of its first to its second end in the longitudinal direction, in which, in the expanded state of the one-piece body (10), the secondary end part (30):

- has a cylindrical shape centered on a second axis (X30) which is parallel and offset with respect to the first axis (X21; X21'),

- includes ends opposite each other along the second axis, namely a first end (31), which faces away from the intermediate part (40), and a second end (32), and - has a cross section which is substantially circular and which, in orthogonal projection on said geometric plane (TT), is inscribed in the cross section of the first end (21; 21') of the main end part (20; 20' ), and in which, in the expanded state of the one-piece body (10; 10'), the intermediate part (40) has a radial stiffness which is greater than that of the main end part (20; 20') and that of the secondary terminal part (30), and delimits:

- on its side which, in said longitudinal direction (D), faces the main end part (20; 20'), a main opening (43) which is fitted to the second end (22; 22') of the part main terminal, and

- on its side which, in said longitudinal direction, faces the secondary end part (30), a first secondary opening (44), which is fitted to the second end (32) of the secondary end part, and a second opening secondary (45), which interrupts the mesh of the one-piece body (10; 10') so as to place the interior of the intermediate part in free communication directly with the exterior of the one-piece body, this second secondary opening being provided to open into the second secondary branch (4).

2. Device according to claim 1, wherein, in the expanded state of the one-piece body (10), the cross-section of the main end part (20) gradually decreases when traversing the main end part of its first (21) at its second end (22) in the longitudinal direction (D).

3. Device according to Claim 2, in which, in the expanded state of the one-piece body (10), the second end (22) of the main terminal part (20) has a cross section which is substantially elliptical and whose major axis extends perpendicular to the first axis (X21) and to the second axis (X30).

4. Device according to claim 1, wherein, in the expanded state of the one-piece body (10'), the main end part (20') has a cylindrical shape, which is centered on the first axis (X21') and of which the cross section is unchanged when the main end part is traversed from its first end (21') to its second end (22') in the longitudinal direction (D).

5. Device according to any one of the preceding claims, in which the mesh of the one-piece body (10; 10′) has, in all or part of the intermediate part (40), strands which are dimensioned to exert a greater radial force. greater than that exerted by the strands of the mesh in the main (20; 20') and secondary (30) end portions.

6. Device according to any one of the preceding claims, in which, in the expanded state of the one-piece body (10; 10'), the secondary end part (30) is deformable with respect to the intermediate part (40) so as to be able to tilt the second end (32) with respect to the first end (31) of the secondary end part:

- at least 70° in a first plane, which contains the first and second axes (X21, X21\ X30), and

- of at least 90° in a second plane, which contains the second axis (X30) and which is perpendicular to said first plane.

7. Device according to any one of the preceding claims, in which the mesh of the one-piece body (10; 10') includes, at least in the secondary end part (30), several cylindrical rings (35) which, in the state expanded from the one-piece body, are:

- centered on the second axis (X30), in succession along this second axis,

- designed to each exert a radial expansion force, and

- Connected two by two in a flexible manner by flexible bridges (36) of the mesh.

8. Device according to claim 7, in which the rings (35) each consist of strands which form, along the periphery of the ring, a succession of Vs having respective points, which are directed in said longitudinal direction (D) and whose orientation alternates along the periphery of the ring, and wherein the flexible bridges (36) are each accordion-folded along said longitudinal direction and each connect two of the points of the Vs to each other.

9. Device according to any one of the preceding claims, in which the one-piece body (10; 10') is provided:

- radiopaque markers (51) which are located at the first end (21) of the main end part (20),

- radiopaque markers (52) which are located at the first end (31) of the secondary terminal part (30), and

- radiopaque markers (53) which are located in the intermediate part (40).

10. Device according to any one of the preceding claims, in which the device (1; 1') further comprises a stent (60), which is separate from the one-piece body (10; 10') and which is provided for, then the one-piece body is already implanted in the bifurcation, to be implanted in the second branch (4), the stent (60) being adapted to extend in length from the exterior of the one-piece body (10; 10') to the expanded state, to the inside of the main end part (20; 20'), passing through the second secondary opening (45).