STENT

Abstract

The invention relates to a stent for transluminal implantation into hollow organs, in particular into blood vessels, ureters, esophagi, the colon, the duodenum, the airways or the biliary tract, comprising an at least substantially tubular body that extends along a longitudinal direction and that can be converted from a compressed state having a first cross-sectional diameter into an expanded state having an enlarged second cross-sectional diameter. The stent in accordance with the invention is characterized in that the tubular body comprises an inner body and an outer body, with the outer body surrounding the inner body at least regionally, with the outer body completely running around at least one section of the inner body, and the outer body is formed from a bioresorbable material or comprises a bioresorbable material.

Claims

1. A stent for transluminal implantation into hollow organs, the stent comprising an at least substantially tubular body that extends along a longitudinal direction and that can be converted from a compressed state having a first cross-sectional diameter into an expanded state having an enlarged second cross-sectional diameter, wherein the tubular body comprises an inner body and an outer body, with the outer body surrounding the inner body at least regionally, with the outer body completely running around at least one section of the inner body, and the outer body being formed from a bioresorbable material or comprises a bioresorbable material.

2. The stent in accordance with claim 1, wherein the inner body comprises a plurality of annular sections.

3. The stent in accordance with claim 2, wherein the annular sections are held by the outer body.

4. The stent in accordance with claim 1, wherein at least one of the inner body and/or the outer body is an independent stent.

5. The stent in accordance with claim 1, wherein the inner body is self-expanding and/or the outer body is balloon-expandable.

6. The stent in accordance with claim 1, wherein the inner body comprises a plurality of cells that are defined by bordering elements formed by the inner body, and/or wherein the outer body comprises a plurality of cells that are defined by bordering elements formed by the outer body.

7. The stent in accordance with claim 6, wherein cells of the inner body and/or of the outer body form a convex polygon and in particular have a diamond shape.

8. The stent in accordance with claim 6, wherein cells of the inner body and of the outer body have the same shape or a similar shape, wherein the cells of the inner body and the outer body lie congruently on one another or are arranged offset from one another.

9. The stent in accordance with claim 1, wherein the outer body comprises rails that extend along the longitudinal direction.

10. The stent in accordance with claim 1, wherein the inner body presses against the outer body at least in the expanded state.

11. The stent in accordance with claim 1, wherein at least one of the inner body and the outer body has fastening means to fasten the respective other body.

12. The stent in accordance with claim 1, wherein one of the inner body and the outer body is surrounded by a stent graft.

13. The stent in accordance with claim 1, wherein the bioresorbable material comprises zinc, wherein the bioresorbable material includes 90.0 to 99.95 mass % zinc and 0.05 to 10.0 mass % silver.

14. A stent system comprising a for transluminal implantation into hollow organs, the stent comprising an at least substantially tubular body that extends along a longitudinal direction and that can be converted from a compressed state having a first cross-sectional diameter into an expanded state having an enlarged second cross-sectional diameter, wherein the tubular body comprises an inner body and an outer body, with the outer body surrounding the inner body at least regionally, with the outer body completely running around at least one section of the inner body, and the outer body being formed from a bioresorbable material or comprises a bioresorbable material and a balloon that is arranged within the inner body and that is configured to transfer the stent from the compressed state into the expanded state.

15. The stent in accordance with claim 1, wherein the hollow organs comprise one of blood vessels, ureters, esophagi, the colon, the duodenum, the airways and the biliary tract.

16. The stent in accordance with claim 2, wherein the plurality of annular sections are separate from one another.

17. The stent in accordance with claim 9, wherein the rails are arranged at an outer side of the outer body.

18. The stent in accordance with claim 11, wherein the fastening means comprise hooks, projections, recesses and/or bonding means or adhesive means.

19. The stent in accordance with claim 13, wherein the bioresorbable material consists of zinc and silver.

Description

[0052] The invention will be described purely by way of example with reference to the drawings in the following. There is shown:

[0053] FIG. 1 schematically, a stent with an inner body and an outer body in a perspective view;

[0054] FIG. 2 schematically, the stent of FIG. 1 in a view in the direction of the longitudinal direction;

[0055] FIG. 3 cells of the inner body and the outer body of a first embodiment;

[0056] FIG. 4 cells of the inner body and the outer body of a second embodiment;

[0057] FIG. 5 an outer body with additional rails in accordance with a third embodiment; and

[0058] FIG. 6 cells of the inner body and the outer body of a fourth embodiment.

[0059] FIG. 1 shows a stent 10 in the expanded state. The stent 10 has a tubular shape and extends along a longitudinal direction L. The stent comprises a tubular inner body 12 that is surrounded by a likewise tubular outer body 14.

[0060] The inner body 12 is formed from a material that is permanently durable in the human body, for example, nitinol. In contrast, the outer body 14 is formed from a bioresorbable material, for example, from a zinc alloy.

[0061] Inner and outer bodies 12, 14 at least substantially have the same length along the longitudinal direction L. The inner body 12 has a smaller cross-sectional diameter than the outer body 14. The inner body 12 presses against the outer body 14 from the inside and is fastened to the outer body 14 by a force fit in this manner. An—alternative or additional—form-fitting fastening is not shown in the Figures.

[0062] FIG. 2 shows the stent of FIG. 1 in a view in the direction of the longitudinal direction. It can be seen that the inner and outer bodies 12, 14 form concentric rings in cross-section, i.e. that the outer body 14 surrounds the inner body 12.

[0063] FIG. 3 now shows the design of the stent 10 in more detail. The inner body 12 is formed from (inner) cells 16. Accordingly, the outer body is formed from (outer) cells 18. The cells 16, 18 each have a diamond shape and are formed from strut-like bordering elements 20.

[0064] FIG. 3 shows a section of an unwinding of the stent 10 in this respect. This means that the stent 10 can comprise even more cells 16, 18 than shown in FIG. 3. The inner cells 16 are each coupled to two other inner cells 16 via two connection sections 22. The inner cells 16 thus form separate annular sections 24 that have an equal spacing from one another in the longitudinal direction L.

[0065] The outer cells 18, in contrast, are not divided into separate annular sections. The outer cells 18 are each connected to one another via three or four connection sections 22 to form a continuous composite over the total length of the outer body 14 in this manner. Viewed in the longitudinal direction, the outer cells 18 are longer than the inner cells 16 since no spacing is provided in the longitudinal direction L between the outer cells 18.

[0066] The cells 16, 18, each shown at the top in FIG. 3, are each connected to the cells shown at the bottom in FIG. 3 to create the tubular body.

[0067] In the first embodiment of FIG. 3, the inner cells 16 and the outer cells 18 are arranged offset from one another in the longitudinal direction. This means that the connection sections 22, which connect two outer cells 18 arranged next to one another in the longitudinal direction, lie approximately centrally (e.g. above the diagonal point of intersection) above the diamond-shaped inner cell 16.

[0068] The second embodiment of the stent 10 shown in FIG. 4 differs from the first embodiment of FIG. 3 in that the inner cells 16 and the outer cells 18 are almost congruently superimposed. A small offset between the cells 16, 18 is caused by the different lengths of the cells 16, 18. In all other respects, the explanations regarding the first embodiment apply.

[0069] FIG. 5 shows a third embodiment of the stent 10. The third embodiment differs from the first embodiment only in that the outer body 14 additionally has rails 26 extending in the longitudinal direction L. The rails 26 can facilitate an insertion of the stent 10 with an insertion set of instruments. In all other respects, the explanations regarding the first embodiment apply.

[0070] Finally, FIG. 6 shows a fourth embodiment of the stent 10. In the fourth embodiment, the outer body 14 comprises significantly more cells 18 than in the first embodiment. The outer cells 18 are also usually smaller than the inner cells 16. Accordingly, the outer body 14 comprises a dense mesh of outer cells 18. In all other respects, the explanations regarding the first embodiment apply.

[0071] In all the embodiments, the outer body 14 is decomposed or resorbed in the hollow organ after a certain period of time. After that, only the inner body 12 remains in the hollow organ. Due to the separate annular sections 24, the thus remaining part of the stent 10 has a high flexibility in the longitudinal direction L, but simultaneously also has a high radial supporting effect (i.e. a high force in directions perpendicular to the longitudinal direction L).

REFERENCE NUMERAL LIST

[0072] 10 stent [0073] 12 inner body [0074] 14 outer body [0075] 16 inner cells [0076] 18 outer cells [0077] 20 bordering element [0078] 22 connection section [0079] 24 annular section [0080] 26 rail [0081] L longitudinal direction