Device for treating an obstructive lesion at an anatomical bifurcation
The treatment system for obstructive lesions at anatomical bifurcations uses a monobloc body with an expansible radial mesh to adapt to the anatomical morphology of the bifurcation, effectively stabilizing the stent and reducing the risk of thrombotic or embolic events.
Patent Information
- Application Number
- FR2021007755
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-07-19
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2041-07-19
AI Technical Summary
Existing treatments for obstructive lesions at anatomical bifurcations, such as those in the vascular system, often result in stents that do not adequately adapt to the main vessel wall, leading to risks of thrombosis or embolism.
A treatment system featuring a monobloc body with an expansible radial mesh, designed to extend in length within both the main channel and a secondary branch, with distinct terminal and intermediate parts that adapt to the anatomical morphology of the bifurcation.
The system effectively stabilizes the stent within the bifurcation, preventing extrinsic compression and ensuring reliable communication between the main channel and secondary branches, thereby reducing the risk of thrombotic or embolic events.
Smart Images
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Abstract
Description
Title of the invention: Device for treating an obstructive lesion for an anatomical bifurcation
[0001] The present invention relates to a device for treating an obstructive lesion for an anatomical bifurcation connecting a main canal and two secondary branches.
[0002] The human body comprises 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 blood circulates, thus comprises various bifurcations connecting a main vessel and two secondary branches. Thus, the venous system comprises, for example, a bifurcation, called the venous iliac bifurcation, connecting the inferior vena cava and the two common iliac veins. Similarly, the arterial system comprises, for example, a bifurcation, called the aortoiliac 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 passage section for the blood.These obstructive lesions result in particular from stenoses, occlusions and / or thromboses in the regions of the main vessel and secondary branches, which are located in the immediate vicinity of the confluence of the secondary branches.
[0003] 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 expandable radially to its longitudinal direction, so as to make the stent pass between an unexpanded state and an expanded state.The first of the two stents is, in the unexpanded state, introduced into one of the two secondary branches of the bifurcation, then moved to the bifurcation where the first stent is passed into the expanded state, while, at the same time, the second stent is, in the unexpanded state, introduced into the other secondary branch, then moved to the bifurcation where it is passed into the expanded state: the two stents in the expanded state are found extended on either side of the junction of the secondary branches, each having a first long part. tudinal that extends into one or other of the secondary branches, while respective second longitudinal parts of the two stents emerge into the main vessel from the junction of the two secondary branches, these two second parts pressing transversely against each other. These techniques result in several disadvantages. Indeed, in the main vessel, the stent(s) 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 subsequent techniques are also used in the coronary system.
[0004] The aim 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.
[0005] To this end, the invention relates to a device for treating an obstructive lesion for an anatomical bifurcation connecting a main canal and first and second secondary branches.The device comprises a single-piece body which (i) is hollow, (ii) has an elongated shape in a longitudinal direction, (iii) is made of a mesh which is expandable radially to said longitudinal direction so as to make the single-piece body pass between non-expanded and expanded states, and (iv) comprises three successive parts in said longitudinal direction, namely respectively main and secondary end parts, which are opposite to each other in said longitudinal direction and which are intended to be implanted respectively in the main channel and in the first secondary branch, and an intermediate part, 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 the expanded state of the one-piece body, the main terminal portion has a tubular shape, which extends in length along said longitudinal direction, and includes ends opposite each other along said longitudinal direction, namely a first end, which is turned away from the intermediate portion, and a second end, the first end being centered on a first axis, which extends along said longitudinal direction, and having a substantially circular cross-section. In addition, this main terminal portion has a cross-section which, in orthogonal projection onto a geometric plane containing the cross-section of the first end of the terminal portion, remains inscribed in the cross-section of this first end when the main terminal portion is traversed from its first to its second end along the longitudinal direction.In the expanded state of the one-piece body, the secondary end portion has a cylindrical shape centered on a second axis that is parallel and offset from the first axis and includes ends opposite each other along the second axis, namely a first end, which is rotated. opposite the intermediate portion, and a second end. In addition, this secondary end portion has a cross-section, which is substantially circular and which, in orthogonal projection on said geometric plane, is inscribed in the cross-section of the first end of the main end portion. In the expanded state of the single-piece body, the intermediate portion has a radial stiffness, which is greater than that of the main end portion and that of the secondary end portion.In addition, this intermediate part delimits (i) on its side which, in said longitudinal direction, is turned towards the main terminal part, a main opening which is fitted to the second end of the main terminal part, and (ii) on its side which, in said longitudinal direction, is turned towards the secondary terminal part, a first secondary opening, which is fitted to the second end of the secondary terminal part, and a second secondary opening, which interrupts the mesh of the single-piece body so as to put the interior of the intermediate part in free communication directly with the exterior of the single-piece body, this second secondary opening being intended to open into the second secondary branch.
[0006] One of the ideas underlying the invention is to use a single-piece body with a radially expandable mesh, which, once implanted, extends lengthwise both in the main channel and in a first of the two secondary branches, and in which three successive parts are differentiated, along its longitudinal direction, which have their own shape and stiffness characteristics.A first of these three parts is a main end part of the monobloc body, which is to be implanted in the main channel and which, in the expanded state of the monobloc body, is adapted to the morphology of the main channel, having a tubular shape which, at its apex, that is to say opposite the rest of the monobloc body, has a circular cross-section, centered on a first axis extending in the longitudinal direction of the monobloc body, and which, as one moves away from this apex, remains within 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 along the longitudinal direction of the monobloc body, is a secondary end part of the monobloc body, which is to be implanted in the first secondary branch and which, in the expanded state of the monobloc body, 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 from the first axis, and which extends inside the aforementioned envelope. The third part is an intermediate part of the monobloc 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, at . the expanded state of the monobloc body, the lumen of the main end part has, on the one hand, the lumen of the secondary end part and, on the other hand, a through opening, which interrupts the mesh of the monobloc body and which is intended 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 monobloc body in this intermediate part, to have, in the expanded state of the monobloc body, a radial stiffness which is greater than each of the respective radial stiffnesses of the main and secondary end parts: in this way, the monobloc body in the expanded state generates, at its intermediate part, a greater radial force than in the rest of the monobloc body,which counteracts the strong extrinsic compression applied by the bifurcation at the junction between its secondary branches and which thus guarantees effective and reliable communication between, on the one hand, the main canal and the first branch of the bifurcation, thanks to the connection between the respective lumens of the main and secondary terminal parts via the interior of the intermediate part, and, on the other hand, the main canal and the second branch of the bifurcation, thanks to the connection between the lumen of the main terminal part and the lumen of the second branch via the aforementioned through opening of the intermediate part. The single-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 monobloc structure of the body of the device according to the invention facilitates the implantation of this device: the positioning of the monobloc body can in particular be carried out by endovascular introduction of the monobloc body in the non-expanded state, then its movement to the bifurcation where it is passed to the expanded state. An ad hoc implantation ancillary makes it possible to control the orientation of the monobloc body around its longitudinal direction inside the patient's canals, then to deploy it at the desired level of the patient's bifurcation.
[0007] According to additional advantageous characteristics of the device according to the invention, taken in isolation or in all technically possible combinations:
[0008] - in the expanded state of the one-piece body, the cross-section of the end part main part gradually decreases as one travels along the main terminal part from its first to its second end in the longitudinal direction.
[0009] - in the expanded state of the one-piece body, the second end of the terminal part main has a cross-section which is substantially elliptical and whose major axis extends perpendicular to the first axis and the second axis.
[0010] - in the expanded state of the single-piece body, the main end part has a cylindrical shape, which is centered on the first axis and whose cross-section is unchanged when traversing the main terminal part from its first to its second end along the longitudinal direction.
[0011] - the mesh of the single-piece body presents, in all or part of the inter part medial, strands which are sized to exert a greater radial force than that exerted by strands of the mesh in the main and secondary end parts.
[0012] - in the expanded state of the single-piece body, the secondary end part is deformable relative to the intermediate part so as to be able to incline the second end relative to the first end of the secondary terminal part:
[0013] - of at least 70° in a first plane, which contains the first and second axes, and
[0014] - of at least 90° in a second plane, which contains the second axis and which is perpendicular dicular to the foreground.
[0015] - the mesh of the monobloc body includes, at least in the terminal part condary, several cylindrical rings which, in the expanded state of the monobloc body, are:
[0016] - centered on the second axis, following one another along this second axis,
[0017] - each designed to exert a radial expansion force, and
[0018] - connected two by two in a flexible manner by flexible bridges of the mesh.
[0019] - the rings are each made up of strands which form, along the periphery of the ring, a succession of Vs having respective points, which are directed along said longitudinal direction and whose orientation alternates along the periphery of the ring, and in which the flexible bridges are each folded accordion-style along said longitudinal direction and each connect two of the points of the Vs to each other.
[0020] - the single-piece body is provided with:
[0021] - radiopaque markers which are located at the first end of the main terminal part,
[0022] - radiopaque markers which are located at the first end of the secondary terminal part, and
[0023] - radiopaque markers which are located in the intermediate part.
[0024] - the device further comprises a stent, which is separate from the single-piece body and which is intended to, while the single-piece body is already implanted in the bifurcation, be implanted in the second branch, the stent being adapted to extend in length from the outside of the single-piece body in the expanded state, to the inside of the main terminal part, passing through the second secondary opening.
[0025] The invention will be better understood on reading the following description, given solely by way of example and with reference to the drawings in which:
[0026] - [Fig.l] [Fig.l] is a diagram of a part of the human body, illustrating elements of the latter's cardiovascular system;
[0027] - [Fig.2] [Fig.2] is an elevational view of a first embodiment of a device according to the invention;
[0028] - [Fig.3] [Fig.3] is an elevation view along arrow III of [Fig.2];
[0029] - [Fig.4] [Fig.4] is a section along line IV-IV of [Fig.2];
[0030] - [Fig.5] [Fig.5] is a section along line VV of [Fig.4];
[0031] - [Fig.6] [Fig.6] is a detailed view of zone VI of [Fig.2];
[0032] - [Fig.7] [Fig.7] is a detailed view of zone VII of [Fig.2];
[0033] - [Fig.8] [Fig.8] is a diagram illustrating the installation of the device of figures 2 to 7 in a bifurcation of the cardiovascular system of [Fig.l]; and
[0034] - [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.
[0035] [Fig.l] schematically shows part of the cardiovascular system of a human patient. This cardiovascular system thus comprises a venous iliac bifurcation, which connects the inferior vena cava 2 and the two common iliac veins 3 and 4, as well as an aortic iliac bifurcation, which connects the abdominal aorta 5 and the two common iliac arteries 6 and 7.
[0036] Figures 2 to 8 show a device 1 for treating a vascular obstructive lesion for the iliac venous bifurcation. The nature and 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 regard.
[0037] The device 1 comprises a single-piece body 10. In Figures 2 to 7, the single-piece body 10 is shown alone and not yet implanted, while, in [Fig.8], the single-piece body 10 is shown in the iliac venous bifurcation.
[0038] As clearly visible in Figures 2 to 4, the single-piece body 10 has an elongated shape which extends in length in a longitudinal direction which is noted D in the figures.
[0039] As more specifically visible in Figures 4 and 5, the single-piece body 10 is hollow, and this over its entire extent along the direction D. The single-piece body 10 thus internally delimits a lumen, that is to say a free space, separated from the exterior of the single-piece body 10 by the wall of the latter. As specified below, the single-piece body 10 is open along the direction D at each of its two opposite ends along the direction D. The lumen of the single-piece body 10 thus communicates with the exterior of the single-piece body via each of its two ends.
[0040] The single-piece body 10 is made 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 single-piece body 10 will not be described here further. Moreover, the The structure of the mesh of the monobloc body 10, which is made up of strands, typically metallic, secured to each other in a flexible manner either by interlacing or by continuity of material, is not detailed in Figures 2 to 5 for visibility purposes. In practice, the mesh of the monobloc body 10 may 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 provided that this mesh has a capacity for radial expansion in the direction D so as to make the monobloc body 10 pass between a non-expanded state and an expanded state. In Figures 2 to 7, the monobloc body 10 is shown in the expanded state.
[0041] Depending on the structure of the mesh of the single-piece body 10, various techniques for manufacturing this mesh are possible, such as braiding one or more wires or shaping by removing material from a tubular part. These various manufacturing techniques are well known in the field of endovascular stents.
[0042] Whatever the specificities of the mesh of the single-piece body 10, the latter is divided into three distinct parts which follow one another in the direction D. These three parts of the single-piece body 10 include two end parts which are opposite one another in the direction D, namely a main end part 20 and a secondary end part 30. The third part of the single-piece body 10 is an intermediate part 40 which connects the main 20 and secondary 30 end parts to one another. These parts 20, 30 and 40 will now be successively detailed.
[0043] The main terminal portion 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.
[0044] For this purpose, the main end portion 20 has, in the expanded state of the single-piece body 10, a tubular shape which extends in length in the direction D. The main end portion 20 includes two ends opposite each other in the direction D, namely one end 21, which is turned away from the intermediate portion 40, and one end 22, which is turned towards the intermediate portion 40.
[0045] The main end portion 20 internally delimits a lumen 23 which extends over the entire dimension of the main end portion 20 in the direction D. The lumen 23 is separated from the exterior of the main end portion 20 by the tubular wall of this main end portion, this tubular wall extending continuously over the entire periphery of the main end portion 20. The lumen 23 opens to the exterior of the main end portion 20 via the end 21 which is open in the direction D, the lumen 23 thus opening to the exterior of the single-piece body 10. The lumen 23 also opens to the exterior of the main end portion 20 via the end 22 which is open in the direction D, the lumen 23 de- thus closing inside the intermediate part 40.
[0046] 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 ir perpendicular to the axis X21, is circular, as clearly visible in [Fig.5] on which the cross-section of the end 21 is represented in dotted lines, in orthogonal projection in the plane of [Fig.5].
[0047] When the main terminal part 20 is traversed from its end 21 to its end 22 in the direction D, the cross-section of the main terminal part 20 gradually decreases, while remaining inscribed, in orthogonal projection on the geometric plane ji, in the cross-section of the end 21. In other words, at any given point of the extent of the main terminal part 20 in the direction D, this main terminal part has a cross-section, that is to say a section in a plane perpendicular to the direction D and containing the aforementioned 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 in the direction D, located between the end 21 and the aforementioned given point.This amounts to saying that the tubular shape of the main terminal part 20 is progressively constricted from the end 21 to the end 22.
[0048] This constricted tubular shape of the main terminal part 20 is well adapted to the anatomy of the inferior vena cava 2, corresponding to the morphology of this inferior vena cava 2 in the region of the iliac venous bifurcation, as illustrated by [Fig.8].
[0049] 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 single-piece body 10, a cylindrical shape, centered on the axis X21. By occupying a longitudinal extent of the main terminal part 20, which is limited and which is located opposite the rest of the single-piece body 10, the cylindrical shape of the end 21 promotes the centering and retention of the main terminal part 20 in the inferior vena cava 2 during implantation of the single-piece body 10.
[0050] 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 single-piece body 10, a cross-section which is elliptical, as clearly visible in [Fig. 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 common iliac veins 3 and 4.
[0051] According to yet another advantageous arrangement, which is implemented here and of which the interest will appear a little further on, the main terminal 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],
[0052] In all cases, the mesh of the single-piece body 10 is, in the main end portion 20, shaped according to the constricted tubular shape which was described above. As a non-limiting example, [Fig. 6] details an embodiment of the mesh of the single-piece body 10 in the main end portion 20. In this embodiment, the strands of the mesh, which are secured to each other in the formation of diamonds, are shaped, during the manufacture of the single-piece body 10, to respect the desired constricted tubular shape, for example by being plastically deformed by a shaping die.
[0053] The secondary terminal portion 30 is designed to, when the device 1 is implanted in the iliac venous bifurcation, be implanted in the common iliac vein 3, as illustrated in [Fig.8].
[0054] For this purpose, the secondary terminal part 30 has, in the expanded state of the single-piece body 10, a cylindrical shape, centered on an axis X30 which is parallel and offset relative to the axis X21, as clearly visible in FIGS. 3 to 5. The secondary terminal part 30 includes ends opposite 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.
[0055] The secondary end portion 30 internally delimits a lumen 33 which extends over the entire dimension of the secondary end portion 30 in the direction D. The lumen 33 is separated from the exterior of the secondary end portion 30 by the cylindrical wall of the secondary end portion 30, which extends continuously over the entire periphery of this secondary end portion 30. The lumen 33 opens outside the secondary end portion 30 via the end 31 which is open in the direction D, the lumen 33 thus opening outside the single-piece body 10. The lumen 33 also opens outside the secondary end portion 30 via the end 32 which is open in the direction D, the lumen 33 thus opening inside the intermediate portion 40.
[0056] The secondary terminal part 30 of cylindrical shape has a cross-section which is circular, as shown in dotted lines in [Fig. 5] on which the cross-section of the secondary terminal part 30 is projected onto the plane of this [Fig. 5] along the axis X30. This circular cross-section is, in orthogonal projection onto the geometric plane ji, 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 less than that of the cross-section of the end 21.
[0057] The cylindrical shape of the secondary terminal part 30 is well adapted to the anatomy of the common iliac vein 3, respecting the generally cylindrical morphology with a circular base of this common iliac vein, as illustrated schematically in [Fig.8].
[0058] In particular to promote adaptation to the anatomy of the iliac venous bifurcation, the offset of the axis X30 relative to the axis X21 is advantageously provided so that the major axis of the elliptical cross-section of the end 22 of the main terminal part 20 extends perpendicular to the axes X21 and X30, as clearly visible in [Fig.5].
[0059] According to an advantageous arrangement, which is implemented in the embodiment considered in the figures and the interest of which will appear later, the secondary terminal part 30 includes a lateral portion 34, which connects the ends 31 and 32 to each other and which is aligned with the lateral portion 24 along a straight line parallel to the axes X21 and X30, as clearly visible in [Fig.4].
[0060] According to yet another advantageous arrangement, the secondary terminal part 30 has, in the expanded state of the single-piece body 10, a high capacity for deformation relative to the intermediate part 40. The adaptation of the secondary terminal part 30 to the morphology of the iliac venous bifurcation is thus reinforced, by allowing the secondary terminal part 30 to adapt to the anatomical curvature, sometimes significant, of the common iliac vein 3, as illustrated schematically in [Fig. 8]. In particular, the secondary terminal part 30 is, in the expanded state of the single-piece body 10, deformable relative to the intermediate part 40 so as to be able to incline its second end 32 relative to its first end 31:
[0061] - with an angulation a, of at least 70°, in the section plane of [Fig.4], that is, in a plane containing the axes X21 and X30, as indicated in dotted lines in [Fig.3], and
[0062] - with an angulation [3, of at least 90°, in a plane which contains the X30 axis and which is perpendicular to the aforementioned plane containing the axes X21 and X30, as indicated in dotted lines in [Fig.2].
[0063] In all cases, the mesh of the single-piece body 10 in the secondary end portion 30 gives this secondary end portion its cylindrical shape with circular section, as well as, where appropriate, its capacity for deformation. Multiple embodiments are possible for this mesh. The mesh of the single-piece body 10 in the secondary end portion 30 can thus be different from the mesh of the single-piece body in the main end portion 20. In the preferred but non-limiting embodiment illustrated in [Fig. 7], the mesh of the single-piece body 10 in the secondary end portion 30 includes several cylindrical rings 35 which, the expanded state of the monobloc body 10, are centered on and follow one another along the axis X30. The rings 35 are connected two by two 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 monobloc body, while being adjustable in position relative to each other by means of the flexible deformation of the bridges 36, which ensures great flexibility to the secondary end part 30. To this end, according to a 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 along the direction D and whose orientation alternates along the periphery of the ring 35.The bridges 36 are each folded accordion-style along the direction D and each connect two of the points of the Vs formed by the strands of the rings 35 to each other. This embodiment of [Fig.7] gives the cylindrical shape with circular section of the secondary terminal part 30 a high degree of deformability transversely to the direction D, in particular along the angles a and [3, by means of the flexible deformation of one or more of the bridges 36 between the two rings 35 which each of these bridges 36 connects.
[0064] The intermediate portion 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 common iliac veins 3 and 4.
[0065] For this purpose, the intermediate part 40 comprises a peripheral wall 41 which, in the direction D, connects to each other the tubular wall of the main terminal part 20 and the cylindrical wall of the secondary terminal part 30. The intermediate part 40 delimits an internal volume 42 which is separated from the exterior of the intermediate part 40 by the peripheral wall 4L
[0066] On its side which, in the direction D, is turned towards the main terminal part 20, the intermediate part 40 delimits a main opening 43 through which the internal volume 42 communicates freely with the light 23 of the main terminal part 20. As clearly visible in [Fig. 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 end 22 of the latter.
[0067] On its side which, in direction D, is turned towards the secondary terminal part 30, the intermediate part 40 delimits a secondary opening 44 through which the internal volume 42 communicates freely with the light 33 of the secondary terminal 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 end 32 of the latter.
[0068] Also on its side which is turned towards the secondary terminal part 30, the intermediate part 40 delimits, in addition to the secondary opening 44, a secondary opening 45, which is distinct from the secondary opening 44 and by which the internal volume 42 is put in free communication directly with the exterior of the monobloc body 10. As clearly visible in Figures 2 and 4, the secondary opening 45 passes through the peripheral wall 41 from one side to the other transversely to the direction D, interrupting the mesh of the monobloc body 10 in the intermediate part 40. The profile of the secondary opening 45, which is shown diagrammatically in the shape of a trapezium in [Fig. 2], is not limiting and may be more or less rounded.
[0069] Furthermore, the intermediate portion 40 has, in the expanded state of the single-piece body 10, a radial stiffness which is greater than the radial stiffness of the main end portion 20 and the radial stiffness of the secondary end portion 30. In other words, in the expanded state of the single-piece body 10, the intermediate portion 40 is more rigid, in a direction radial to the direction D, than the main 20 and secondary 30 end portions. This implies that, when the single-piece body 10 is implanted, the intermediate portion 40 exerts a greater radial force on the vascular wall of the iliac venous bifurcation than the rest of the single-piece body 10. In other words, when the single-piece body 10 is traversed in the expanded state between its two opposite ends in the direction D, the radial force produced on the vascular wall by the single-piece body 10 is not constant, but varies by being maximum at the level of the intermediate part 40.
[0070] The shape and stiffness characteristics specific to the intermediate portion 40 allow the latter to be well adapted to the morphological constraints of the junction zone between the inferior vena cava 2 and the common iliac veins 3 and 4. Indeed, when the monobloc body 10 is implanted, as illustrated in [Fig. 8], the intermediate portion 40 occupies this junction zone, extending on either side of the confluence of the two common iliac veins 3 and 4. The substantial radial stiffness of the intermediate portion 40 allows it to resist the extrinsic compression, otherwise called "anatomical clamp", that this junction zone exerts on the monobloc body 10 and, thereby, to prevent the main 43 and secondary 44 and 45 openings from being substantially closed by radial crushing under the effect of this extrinsic compression.By thus maintaining substantially open the main opening 43 and the secondary opening 44, the blood flow between the common iliac vein 3 and the inferior vena cava 2 circulates via, jointly, the lumens 23 and 33 and the internal volume 42, entering them through the end 31 of the secondary terminal part 30 and leaving them through the end 21 of the main terminal part 20. Likewise, by maintaining substantially open the opening . main 43 and the secondary opening 45, the blood flow between the common iliac vein 4 and the inferior vena cava 2 circulates via, jointly, 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.
[0071] These shape and stiffness characteristics of the intermediate part 40 are given by the mesh of the single-piece body 10 in this intermediate part 40. In practice, numerous embodiments of this mesh are conceivable, which are based on structural differences between the respective meshes of the intermediate part 40 and of the main 20 and secondary 30 end parts.
[0072] According to a preferred embodiment, which is efficient and easy to manufacture, the mesh of the single-piece body 10 has, in all or part of the intermediate part 40, strands sized to exert a greater radial force than that exerted by strands of the mesh in the main 20 and secondary 30 end parts. For this purpose, according to a structural possibility, the strands of the mesh in all or part of the intermediate part 40 have a larger section than that of the strands of the mesh in the main 20 and secondary 30 end parts. To do this, it is possible to vary the width of the strands, i.e. their orthoradial dimension to the direction D, and / or the depth of the strands, i.e. their radial dimension to the direction D.Thus, by way of non-limiting example, the mesh of the region of the intermediate portion 40, located in the immediate vicinity of the secondary terminal portion 30, includes one or more rings, which are individually similar to the rings 35 of the mesh of the secondary terminal portion 30, described above, but whose strands are wider and / or deeper than the strands of the rings 35.
[0073] According to an advantageous embodiment, the intermediate part 40 includes a lateral portion 46 connecting to each other the lateral portion 24 of the main terminal part 20 and the lateral portion 34 of the secondary terminal part 30. In the expanded state of the single-piece body 10, the lateral 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 lateral portion 46 is located opposite the secondary opening 45 along the periphery of the peripheral wall 41, which promotes the adaptation of the intermediate part 40 to the anatomy of the junction zone between the inferior vena cava 2 and the common iliac veins 3 and 4, while contributing to the structural rigidity of this intermediate part 40.
[0074] In order to place the monobloc body 10 in the iliac venous bifurcation, the monobloc body 10 is made available in a placement ancillary, inside which the monobloc body 10 is retained in the unexpanded state and the orientation of this monobloc body 10 around the direction D is predetermined. This placement ancillary is then introduced into the patient's body, for example by puncture of the femoral vein, and brings the one-piece body 10 to the iliac venous bifurcation. Before being passed 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 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 placement ancillary relative to the patient's body.In practice, this positional adjustment is for example enabled by orientation markers of the one-piece body 10 relative to the insertion ancillary and / or radiopaque markers 50 with which the one-piece body 10 is provided. These radiopaque 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 radiopaque markers 53 which are located in the intermediate part 40. The radiopaque markers 53 are advantageously arranged on one side and / or the other side, in the direction D, of the secondary opening 45, as shown schematically in [Fig. 2].Once the monobloc body 10 is satisfactorily positioned in the iliac venous bifurcation, the insertion ancillary is controlled to release the monobloc body 10, by moving the latter into its expanded state. The monobloc body 10 is then 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.
[0075] According to an option of the device 1, which is only illustrated in [Fig. 8] and in dotted lines, the device 1 comprises, in addition to the monobloc body 10, a stent 60. This stent 60, which is distinct from the monobloc body 10, is intended to be implanted in the common iliac vein 4 while the monobloc body 10 is already implanted in the iliac venous bifurcation. The stent 60 is thus able to treat an obstructive lesion of the common iliac vein 4, located outside the field of action of the monobloc body 10. The stent 60 is similar to a conventional endovascular stent and is made up 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 end portion 20, passing through the secondary opening 45.While the monobloc body 10 is already implanted in the iliac venous bifurcation, as described above, and therefore while the monobloc body 10 is in the expanded state, the . stent 60 is, in the unexpanded state, introduced into the secondary opening 45, until a desired position is reached in the iliac venous bifurcation, then the stent 60 is passed to the expanded state, finding itself implanted as illustrated in [Fig.8].
[0076] Figures 9 and 10 show an alternative embodiment of the device 1, referenced 1', having the same purpose as the device 1. The device 1' comprises a body 10' which is distinguished from the body 10 of the device 1 only by the geometric shape of its main terminal part, referenced 20', so that the rest of the body 10' will not be described further and will be designated with the same numerical references as those used for the body 10.
[0077] Like the main end portion 20 of the body 10, the main end portion 20' is, in the expanded state of the body 10', tubular along the direction D and has ends 21' and 22' opposite each other along the direction D, the end 21' being turned away from the intermediate part 40 of the device 1'. In addition, like the end 21, the end 21' is centered on an axis X21' extending along the direction D and has a circular cross-section. Unlike the main end portion 20, the main end portion 20' does not narrow when traversed from its end 21' to its end 22', but has a cross-section which is unchanged and which therefore remains circular, centered on the axis X21'. In other words, in the expanded state of the body 10', the main terminal part 20' has, from its end 21' to its end 22', a cylindrical shape of circular cross-section, centered on the axis X21'.
[0078] Due to its cylindrical shape over its entire extent along the direction D, the main terminal part 20' can be simpler to manufacture than the main terminal 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 of the stiffness of the body 10' along the direction D, as explained in detail previously for the body 10 of the device 1. In the implanted state in the iliac venous bifurcation, the body 10' thus has substantially the same configuration as that illustrated in [Fig.8] for the body 10.
[0079] 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 single-piece body 10 consists of:
[0080] - in the expanded state of the single-piece body 10 or 10', the main terminal part 20 or 20' has a dimension, along 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 terminal part 30 has a dimension, along direction D, of between 50 and 150 mm, preferably between 80 and 120 mm, the cross-section of the cylindrical wall of the terminal part is secondary part 30 has a diameter of between 10 and 16 mm, and the intermediate part 40 has a dimension, along the direction D, of between 1 and 20 mm, preferably between 2 and 8 mm; and
[0081] - in the unexpanded state of the single-piece body 10 or 10', the installation ancillary which retains this the latter has a diameter between 5 and 20 French, preferably 9 and 12 French.
[0082] This being the case, as variants, the device 1 or 1' may be envisaged for treating an obstructive lesion of other vascular bifurcations, i.e. 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. As a non-limiting example of such variants, the device 1 or 1' may thus be adapted, in particular by a dimensioning different from the preferred dimensioning given above, to treat an obstructive lesion of the aortoiliac bifurcation, the femoral bifurcation, the carotid bifurcation or the coronary bifurcation.
[0083] Similarly, and more generally, the device 1 or 1' can be adapted, particularly in terms of size, to treat an obstructive lesion of other anatomical bifurcations, connecting a main channel and two secondary branches. For example, we can cite the biliary bifurcation of the common bile duct, or the bifurcations of the airways, such as the bifurcation of the tracheal carina.
Claims
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 single-piece body (10; 10') which: - is hollow, - has an elongated shape in a longitudinal direction (D), - is made of a mesh which is expandable radially to said longitudinal direction so as to make the single-piece body pass between non-expanded and expanded states, and - comprises three successive parts in said longitudinal direction (D), namely respectively main end parts (20;20') and secondary (30), which are opposite each other in said longitudinal direction and which are intended 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, wherein, in the expanded state of the single-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 each other along said longitudinal direction, namely a first end (21; 21'), which is turned 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 in said longitudinal direction, and having a substantially circular cross-section, and - has a cross-section which, in orthogonal projection on a geometric plane (jt) containing the cross-section of the first end of the main terminal part, remains inscribed in the cross-section of this first end when the main terminal part is traversed from its first to its second end in the longitudinal direction, in which, in the expanded state of the single-piece body (10), the secondary terminal part (30): - has a cylindrical shape centered on a second axis (X30) which is parallel and offset from the first axis (X21; X21'), - includes ends opposite each other along the second axis, namely a first end (31), which is turned 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 (jt), 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 end part (30), and delimits: - on its side which, in said longitudinal direction (D), is turned towards the main terminal part (20;20'), a main opening (43) which is fitted to the second end (22; 22') of the main terminal part, and - on its side which, in said longitudinal direction, is turned towards the secondary terminal part (30), a first secondary opening (44), which is fitted to the second end (32) of the secondary terminal part, and a second secondary opening (45), which interrupts the meshing of the single-piece body (10; 10') so as to put the interior of the intermediate part in free communication directly with the exterior of the single-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 portion (20) progressively decreases when traversing the main end portion from its first (21) to its second end (22) in the longitudinal direction (D).
3. A device according to claim 2, wherein, in the expanded state of the one-piece body (10), the second end (22) of the main terminal portion (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, in which, 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 the cross-section is unchanged when traversing the main terminal part from its first (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 single-piece body (10; 10') has, in all or part of the intermediate part (40), strands which are sized to exert a radial force greater than that exerted by strands of the mesh in the main (20; 20') and secondary (30) end parts.
6. Device according to any one of the preceding claims, wherein, in the expanded state of the one-piece body (10; 10'), the secondary end portion (30) is deformable relative to the intermediate portion (40) so as to be able to incline the second end (32) relative to the first end (31) of the secondary end portion: - by at least 70° in a first plane, which contains the first and second axes (X21, X21', X30), and - by 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 single-piece body (10; 10') includes, at least in the secondary end part (30), several cylindrical rings (35) which, in the expanded state of the single-piece body, are: - centered on the second axis (X30), succeeding one another 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) are each made up of strands which form, along the periphery of the ring, a succession of Vs having respective points, which are directed along said longitudinal direction (D) and whose orientation alternates along the periphery of the ring, and in which the flexible bridges (36) are each folded accordion-style 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 with: - radiopaque markers (51) which are located at the first end (21) of the main terminal 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. A device according to any preceding claim, wherein the device (1; 1') further comprises a stent (60), which is separate from the one-piece body (10; 10') and which is intended to, while the one-piece body is already implanted in the bifurcation, be implanted in the second branch (4), the stent (60) being adapted to extend in length from the outside of the one-piece body (10; 10') in the expanded state, to the inside of the main terminal part (20; 20'), passing through the second secondary opening (45).