Abstract
The invention relates to an endoprosthesis (60), in particular a vascular stent or a heart stent, comprising a graft (2) with a graft surface (3). The endoprosthesis (60) further comprises at least one fiber (1) which is arranged on the graft surface (3). The graft surface is adapted to directly attach the fiber (1).
Claims
1-16. (canceled)
17. An endoprosthesis comprising a graft with a graft surface, further comprising at least one fiber arranged on the graft surface, wherein the graft surface is adapted to attach the fiber.
18. The endoprosthesis according to claim 17, wherein at least one of the graft or fiber has a surface that is adapted such that the fiber is retained by friction on at least one of the graft surface and a graft material.
19. The endoprosthesis according to claim 17, wherein the graft surface is at least partially coated with an adhesive material that is adapted to provide adhesion to the surface of the fiber.
20. The endoprosthesis according to claim 19, wherein the adhesive material is bioactive or comprises a bioactive material.
21. The endoprosthesis according to claim 19, wherein the adhesive material is adapted such that it is activatable by at least one of heat, pressure, and radiation.
22. The endoprosthesis according to claim 19, wherein the adhesive material is coated on discrete positions of the graft surface.
23. The endoprosthesis according to claim 17, wherein the fiber comprises a material which is, in a molten or partially molten state, at least partially miscible with a material that at least one of the graft and the graft surface comprise.
24. The endoprosthesis according to claim 17, wherein the graft comprises a mechanical structure that is adapted to be attached to a fiber.
25. The endoprosthesis according to claim 24, wherein the graft comprises a mechanical structure selected from the group consisting of a hole, a loop, and a rivet.
26. The endoprosthesis according claim 17, wherein the fiber is a thrombogenic fiber having a free portion configured to extend at least partly away from the surface of the graft.
27. The endoprosthesis according to claim 17, further comprising a stent on which the graft is carried.
28. The endoprosthesis according to claim 27, wherein the graft is attached to the stent by one or more attachment sutures, and wherein the fiber is distinct from the one or more attachment sutures.
29. The endoprosthesis according to claim 27, wherein the graft surface is configured to keep the fiber attached to the graft after implantation.
30. A method of attaching a fiber to a surface, wherein a graft comprising a graft surface is provided, and a fiber is attached to the surface, wherein the attachment of the fiber is performed by at least one from the group consisting of welding, gluing, heating by exposure to ultra-sound waves, heating by exposure to electromagnetic radiation, and mechanical attachment.
31. The method according to claim 30, where the surface is a surface of a graft for an endoprosthesis.
32. The method according to claim 30, wherein the fiber is attached to the surface in a separate step after manufacturing the endoprosthesis.
33. The method of claim 30, wherein the fiber is a thrombogenic fiber.
34. A catheter including an endoprosthesis according to claim 17, wherein the endoprosthesis is detachably mounted to a holder of the catheter.
Description
[0026] FIG. 1: a first embodiment of a graft surface with an attached fiber.
[0027] FIG. 2: a second embodiment of a graft surface with an attached fiber.
[0028] FIG. 3: a third embodiment of a graft surface with an attached fiber.
[0029] FIG. 4: a fourth embodiment of a graft surface with an attached fiber.
[0030] FIG. 5: a fifth embodiment of a graft surface with an attacked fiber.
[0031] FIG. 6: a sixth embodiment of a graft surface with an attached fiber.
[0032] FIG. 7: a seventh embodiment of a graft surface with an attached fiber.
[0033] FIG. 8: an eighth embodiment of a graft surface with an attached fiber.
[0034] FIG. 9: an endoprosthesis with attached fibers on a graft surface.
[0035] FIG. 1 shows a first embodiment of a graft 2 with a graft surface 3 adapted to attach a fiber 1, optionally a thrombogenic fiber. In the shown embodiment, the graft 2 consists of a biocompatible Dacron fabric with a thickness of 0.1 mm. Alternatively, the graft may have any thickness in the range of 0.05 to 0.2 mm. The fiber 1 consists of the same material and has a total length of 2 mm. Alternatively, the fiber may up to 50 mm in length. The fiber 1 was stitched through the graft 2. The surface 4 of the fiber 1 is thus arranged in a channel 9 within the graft 2. The channel 9 has an inner surface that is not specifically treated and therefore is substantially identical to the graft surface 3. The graft surface 3 within the channel 9 or on the side opposite the fiber 1 provides sufficient friction with the surface 4 of the fiber 1 such that the fiber 1 cannot be longitudinally displaced within the channel 9. Thus, the fiber 1 is attached to the graft 2 without the need for any additional mechanisms such as gluing, melting, or welding. It would, however, be possible to use such an additional mechanism for increased attachment. Additionally or alternatively, the fiber 1 and/or the graft surface 3, in particular within the channel 9, could be additionally modified and provided with a surface structure to enhance friction.
[0036] FIG. 2 shows an alternative embodiment wherein the graft 2 has been provided with an adhesive material 5 on the graft surface. The adhesive material 5 is a hot melt glue based on polyethylene terephthalate and is applied on the graft surface 3 with a thickness of 40 μm. The fiber 1, which in the shown embodiment consists of polyethylene terephthalate with a higher molecular mass than the hot melt, was arranged on the adhesive layer 5. Heating temporarily liquified the hot melt adhesive material 5 and allowed the fiber 1 to be incorporated in the adhesive material 5. Because the fiber 1 has a higher molecular mass than the adhesive material 5, the temperature for heating can be selected such the adhesive material 5 melts, but not the fiber 1. However, because both consist of the same polymer, the wetting between the two surfaces 3, 4 is sufficient for the fiber 1 to be incorporated in the adhesive material 5. Upon cooling, the fiber 1 is fixedly attached in the adhesive material.
[0037] FIG. 3 shows an embodiment where an adhesive material 5 is only placed on the graft surface 3 at a discrete location. As such, the attachment of the fiber 1 is similar to the embodiment of FIG. 2. However, the fiber 1 can only be attached at the position where the adhesive material 5 is located. In the shown embodiment, the adhesive material 5 is based on an avidin protein. The fiber 1 is functionalized with a biotin protein. By pressing the fiber 1 on the adhesive material 5, the fiber 1 is strongly attached to the adhesive material 5 by forming an avidin-biotin complex. The adhesive-material further comprises a bioactive substance, in this case an enzyme. Alternatively, the bioactive substance may also be a protein, DNA, RNA, antibodies or antigens.
[0038] FIG. 4 shows an alternative embodiment. The fiber 1 consists of isotactic polypropylene. The graft 2 is made of a material that is miscible with isotactic polypropylene. Thus, the fiber 1 placed on the graft surface 3 will form an integral connection with the graft if both are partially melted. Thus, the fiber 1 is connected to the graft 2 by heating up to approximately 200° C.
[0039] FIG. 5 shows an alternative embodiment wherein the graft 2 is provided with a hole 6. The fiber 1 further comprises a retention ball 11 arranged at a free end. The fiber 1 is arranged within the hole 6. The retention ball 11 has a larger diameter than the hole 6 and thus provides a form-fit connection and prevents the fiber 1 from being removed from the hole 6. Additionally or alternatively, it would also be possibly to arrange an element with a different shape, such as a disk, a cross, an eggshape, or any other shape that provides retention in the hole 6.
[0040] FIG. 6 shows an embodiment of a fiber 1 that is attached to the graft surface 3 by exposure to radiation 12. Here, the graft 2 has a functionalized graft surface 3 that allows for chemical cross-linking. The fiber 1 is made of a cross-linkable polymer. Thus, the fiber 1 can be placed on the graft surface 3 and irradiated with electromagnetic radiation 12, for example UV light. As a consequence of the exposure to radiation, the fiber 1 is chemically cross-linked with the graft surface 3 and permanently attached thereto, corresponding to an activatable adhesive that is adapted to be activated by exposure to radiation.
[0041] FIG. 7 shows an alternative embodiment of a fiber 1 being attached to a graft 2 by means of a mechanical attachment. The graft surface 3 comprises a loop 7. The loop 7 is made by a separate thread sewn into the graft 2. The fiber 1 is arranged within the loop 7 and held within the loop 7 by friction. It would also be conceivable to further attach the fiber 1 by means of an adhesive, or to provide fiber 1 with a knot.
[0042] FIG. 8 shows a further alternative embodiment of a fiber 1 being attached to a graft 2 by a mechanical attachment. Here, a rivet 8 is arranged through the graft 2 and fixes the fiber 1 on the graft surface 3.
[0043] FIG. 9 shows an exemplary endoprosthesis 60 according to the invention. The endoprosthesis comprises a scaffold formed by a stent known to the skilled person and carrying the graft material. The graft may optionally be sutured to the stent. At least one, and preferably several, fibers 1 are arranged on the graft surface 3 of the graft 2. The fibers 1 can be thrombogenic fibers for promoting thrombosis around or adjacent the endoprosthesis 60. The fibers 1 may have a portion (e.g. at least one end and/or or at least one intermediate portion) that is free to extend away from the graft surface 3, for example, by at least a certain distance. The fibers 1 may be distinct from attachment sutures, if used, that attach the graft 2 to the stent.
[0044] Any of the above-mentioned attachment mechanisms is suitable to attach the fibers 1 to the graft surface 3. The fibers 1 may remain attached to the graft 2 after implantation using these attachment mechanisms. In the present embodiment, all the fibers are attached by the same mechanism. However, it would also be conceivable to attach different fibers 1 with different mechanisms and thus include several of the above-described mechanisms in one endoprosthesis. In particular, fibers with varying lengths between 2 and 50 mm may be attached to the graft surface by the above-described mechanisms. Additionally or alternatively, fibers 1 may be attached to the graft surface by the above-described mechanisms such that a free portion of the fiber may have a length of, and/or be able to extend away from the graft surface 3 by a distance of, between 2 and 50 mm. Similarly, the present embodiment shows a plurality of fibers 1 attached on the graft surface 2 with a substantially uniform distribution. The person skilled in the art will understand that this is merely an exemplary embodiment and that any number of fibers 1 could be attached to the graft surface 3, or with any distribution desired for a particular application. The endoprosthesis may be self-expandable and/or balloon expandable. It can be deployed by means of a catheter in a minimally invasive manner and can be fixed to the catheter.
