Implant For Treating Aneurysms

Abstract

An implant (6, 18) for influencing the flow of blood in the area of bifurcation aneurysms with the implant (6, 18) having a first (1, 14) and a second tubular braided section (2, 15) each having an opening (4, 5, 16, 17) in the wall, wherein the openings (4, 5, 16, 17) in the walls being produced in such a way that the wires (3) forming the braided sections (1, 2, 14, 15) are radially displaced at the positions of the openings (4, 5, 16, 17), and the first braided section (1, 14) is guided through the opening (5, 17) in the wall of the second braided section (2, 15) such that the opening (4, 16) in the wall of the first braided section (1, 14) points to the opening (5, 17) in the wall of the second braided section (2, 15).

Claims

1. An implant for influencing the flow of blood in the area of aneurysms which are localized at vessel branchings, with the implant (6, 18) being provided in an expanded state in which it is implanted in the blood vessel and in a contracted state in which it is movable through the blood vessel, with the implant (6, 18) having a first (1, 14) and a second braided section (2, 15) which are tubular in the expanded state and the walls of which are composed of individual wires (3) interwoven with one another, the first (1, 14) and second braided sections (2, 15) each having an opening (4, 5, 16, 17) in the wall, with at least the size of the opening (5, 17) in the second braided section (2, 15) being sufficient for the passage of the first braided section (1, 14) wherein the openings (4, 5, 16, 17) in the walls being produced in such a way that the wires (3) forming the braided sections (1, 2, 14, 15) are radially displaced at the positions of the openings (4, 5, 16, 17), and the first braided section (1, 14) is guided through the opening (5, 17) in the wall of the second braided section (2, 15) such that the opening (4, 16) in the wall of the first braided section (1, 14) points to the opening (5, 17) in the wall of the second braided section (2, 15).

2. An implant according to claim 1, wherein the number of wires (3) forming the respective braided sections (1, 2, 14, 15) is 24 to 96.

3. An implant according to claim 1, wherein in the expanded state, the first (1) and second braided sections (2) overlap in the segment (7) in which the two braided sections (1, 2) jointly extend, in such a way that the inner braided section (1) projects beyond the outer braided section (2).

4. An implant according to claim 1, wherein the first (14) and the second braided sections (15) are connected to each other at the outer end (20) of the segment (19) in the segment in which the two braided sections (14, 15) jointly extend.

5. An implant according to claim 1, wherein the first (1, 14) and second braided sections (2, 15) are attached to each other in the region of their openings (4, 5, 16, 17).

6. An implant according to claim 5, wherein the fixation in the area of the openings (4, 5, 16, 17) is performed by sewing and/or by loops guided around the wires (3).

7. An implant according to claim 1, wherein the openings (4, 5, 16, 17) in the walls of the first (1, 14) and/or second braided section (2, 15) are arranged approximately in the middle with respect to the longitudinal extension.

8. An implant according to claim 1, wherein the wires (3) are composed at least partially of a material having shape memory properties.

9. An implant according to claim 8, wherein the material having shape memory properties is a nickel-titanium alloy.

10. An implant according to claim 8, wherein the wires (3) comprise a core of a radiopaque material and a sheath of a material having shape memory properties.

11. An implant according to claim 1, wherein the implant (6, 18) is provided with radiopaque markers.

12. An implant according to claim 1, wherein the implant (6,18) is provided with one or several membranes at least partially covering the braided sections (1, 2, 14, 15).

13. An implant according to claim 12, wherein the membrane has an antithrombogenic effect or an effect that promotes endothelial formation.

14. An implant according to claim 1, wherein the number of wires (3) forming the respective braided sections (1, 2, 14, 15) is 36 to 64.

Description

[0086] Clarification of the invention is provided by the following figures where

[0087] FIG. 1 shows a first braided section according to the first embodiment;

[0088] FIG. 2 shows a second braided section according to the first embodiment;

[0089] FIG. 3 illustrates the implant assembled from first and second braided sections according to the first embodiment;

[0090] FIG. 4 is a plan view of a braided structure according to the second embodiment;

[0091] FIG. 5 is a side view of a braided structure according to the second embodiment; and

[0092] FIG. 6 shows the implant formed from the braided structure according to the second embodiment.

[0093] FIGS. 1 to 3 show the first embodiment of the invention. In FIG. 1 the first braided section 1 is shown according to the first embodiment of the invention. This section is made up of a plurality of wires 3 which are interwoven with each other. Wires 3 in the foreground are shown with a solid line, wires 3 in the background with a dashed line. Braided section 1, when expanded, forms a substantially tubular structure having an opening 4 in the wall, said opening being suitably sized so as to allow the other braided section 2 to be passed through the opening.

[0094] FIG. 2 corresponds to FIG. 1, but shows second braided section 2, which is of essentially identical configuration, i.e. also made of interwoven wires 3. This braided section 2 also has an opening of a size that enables the other braided section 1 to be passed through.

[0095] FIG. 3 is an illustration of the implant 6 assembled from the first and second braided sections 1, 2. Implant 6 has a Y-shape, with the two openings 4, 5 in the braided sections 1, 2 facing each other so that the flow of blood between arms 7, 8, 9 is not impeded. One of the arms 7 is of double-layered configuration, because the two braided sections 1, 2 are superimposed in this area. The other two arms 8, 9 are each single-layered because merely the first and second braided sections 1, 2 are located here. Accordingly, the surface coverage is greater in the double-layer arm 7 than in the two single-layer arms 8, 9.

[0096] The standard placement procedure of the implant 6 is such that area 10 comes to be located in front of the aneurysm, respectively in the aneurysm neck. This arrangement results in the double-layered arm 7 to be anchored in the parent blood vessel, while the two single-layered arms 8, 9 extend into the branching blood vessels. Blood is thus allowed to flow unimpeded from the parent blood vessel into the two branching blood vessels via openings 5, 6 facing each other in the braided sections 1, 2. Furthermore, the aneurysm is largely isolated from flow of blood because the braid density at position 10 is sufficiently high.

[0097] Optionally, the implant 6 may be placed so that either area 11 or area 12 comes to be located in front of the aneurysm. In this case, the double-layered arm 7 is positioned in one of the branching blood vessels, while one of the two single-layered arms 8, 9 being placed in the parent blood vessel. This can be advantageous in that the braid density in areas 11 and 12 is usually even higher than in area 10.

[0098] FIGS. 4 to 6 are illustrations of the second embodiment of the invention. In FIG. 4 the braided structure 13 is depicted, which comprises first and second braided sections 14, 15. However, unlike in the first embodiment, both braided sections 14, 15 form part of a single braided structure 13 and are arranged one after the other in the longitudinal direction. An opening 16, 17 can be seen in each of the two braided sections 14, 15, with, in the representation chosen here, opening 17 pointing upward and opening 16 pointing downward as shown. Accordingly, the openings 16, 17 are thus located on opposite sides. The braided structure 13 is as well composed of interwoven wires 3, wherein wires 3 located in the foreground are again shown with a solid line, and wires 3 located in the background are shown with a dashed line.

[0099] FIG. 5 is identical to the illustration in FIG. 4, but shown in a side view, with the opposite arrangement of the openings 16, 17 being clearly visible.

[0100] In FIG. 6, the implant 18 according to the second embodiment is shown in its entirety after it has been formed into the appropriate shape. To achieve this, the first braided section 14 was turned to the inside and passed through the braided structure 13 such that it was allowed to exit at the opening 17 in the second braided section 15. In this way, a Y-shaped implant 18 is again obtained overall with three arms 19, 21, 22, of which one arm 19 is double-layered, while the other two arms 21, 22 are single-layered. Unlike the first embodiment, however, the outer end 20 of the double-layered arm 19 does not exhibit free wire ends since the outer layer is connected to the inner layer due to the manufacturing method described. The absence of free wire ends is advantageous in that it makes the implant 18 less traumatic at this point so that the risk of injury to the vessel wall is reduced.

[0101] Also in the second embodiment, the two openings 16, 17 face each other so that blood flow through the parent blood vessel and the two branching blood vessels is unobstructed. On the other hand, however, the aneurysm in front of which implant 18 is positioned is effectively separated from the blood stream because implant 18 has a sufficiently high surface density at the position where it is located in front of the aneurysm neck. Following the standard positioning procedure, this is area 23, but also in this embodiment it is alternatively possible to place areas 24 or 25 in front of the aneurysm to achieve an even higher braid density immediately in front of the aneurysm neck. Whereas the standard positioning procedure calls for placing the double-layered arm 19 in the parent blood vessel, the two alternative methods of positioning require the double-layered arm 19 to be placed in one of the branching vessels. Accordingly, one of the two single-layer arms 21, 22 must then be placed in the parent blood vessel.