Abstract
The invention relates to an endoprosthesis (1), in particular a vascular stent or a heart stent, comprising at least one body (3) part. At least one area (5,6) of an outer surface, preferably the whole outer surface, of the at least one body part (3) is provided with thrombogenic fibers (2). The invention further relates to methods of manufacturing endoprostheses (1).
Claims
1.-37. (canceled)
38. An endoprosthesis, comprising at least one body part, wherein at least one area of an outer surface of the at least one body part is provided with thrombogenic fibers.
39. The endoprosthesis according to claim 38, wherein the thrombogenic fibers are one of biodegradable and adapted to elute a drug.
40. The endoprosthesis according to claim 38, wherein at least one of the thrombogenic fibers comprises a biomarker or a biosensor.
41. The endoprosthesis according to claim 38, wherein the thrombogenic fibers are made of an elastic material and are adapted to expand upon deployment of the endoprosthesis.
42. The endoprosthesis according to claim 38, wherein at least one of the length, diameter, and density of the thrombogenic fibers is adapted to minimize or prevent endoleaks.
43. The endoprosthesis according to claim 38, wherein at least one of the length, diameter, and density of the thrombogenic fibers is optimized based on the characteristics of the aneurism to be treated.
44. The endoprosthesis according to claim 38, wherein the thrombogenic fibers comprise an active agent.
45. The endoprosthesis according to claim 44, wherein the active agent inhibits at least one of plasmin and metallo protease.
46. The endoprosthesis according to claim 38, wherein the thrombogenic fibers comprise a pharmaceutical substance that promotes and/or increases coagulation.
47. The endoprosthesis according to claim 38, wherein the thrombogenic fibers comprise two ends, both of which are attached or attachable to the endoprosthesis by way of two separate anchor points.
48. The endoprosthesis according to claim 47, wherein the shortest distance between the anchor points along the surface of the endoprosthesis in its deployed form is shorter than the length of the fiber that is connected to the two anchor points.
49. The endoprosthesis according to claim 38, wherein at least one of the thrombogenic fiber extends around the longitudinal axis of the endoprosthesis at least once.
50. The endoprosthesis according to claim 49, comprising a strip or suture extending substantially along the longitudinal axis, wherein said strip or suture is attached or attachable to the at least one thrombogenic fiber at least one attachment point.
51. The endoprosthesis according to claim 50, wherein the at least one thrombogenic fiber that is oriented along a circumference is cuttable or cut at at least one cutting point so that cut ends of the fibers extend away from the attachment point of said strip or suture.
52. The endoprosthesis according to claim 38, wherein the thrombogenic fibers are attached to the endoprosthesis along their length by means of an adhesive composition and wherein the adhesive composition is biodegradable so that release of the fiber from the surface of the endoprosthesis occurs only post-implantation due to degradation of the adhesive composition.
53. The endoprosthesis according to claim 38, wherein a diameter of at least one of the thrombogenic fibers, is varying from one end of the fiber towards another end of the fiber over at least a section of the fiber.
54. The endoprosthesis according to claim 38, comprising a fabric with directly integrated thrombogenic fibers.
55. The endoprosthesis according to claim 54, wherein the fabric is woven, braided, or knitted.
56. The endoprosthesis according to claim 38, wherein the thrombogenic fibers comprise a foot that promotes attachment into a endoprosthesis layer.
57. The endoprosthesis according claim 38, comprising at least two different types of thrombogenic fibers.
58. The endoprosthesis according to claim 53, wherein the at least two different types of thrombogenic fibers differ in at least one of length, diameter, or composition.
59. The endoprosthesis according to claim 38, comprising at least one nonthrombogenic fiber.
60. The endoprosthesis according claim 38, wherein at least a part of the endoprosthesis is manufactured by additive manufacturing.
61. The endoprosthesis according claim 53, wherein at least the fibers are manufactured by additive manufacturing.
62. The endoprosthesis according to claim 61, wherein the whole endoprosthesis is manufactured by additive manufacturing.
63. The endoprosthesis according to claim 38, wherein the thrombogenic fibers are provided with a connection interface for separately attaching the fibers to the endoprosthesis such as to allow subsequent fixation of the fibers to the endoprosthesis.
64. The endoprosthesis according to claim 63, wherein the connection interface is adapted to establish a connection based on magnetic forces.
65. The endoprosthesis according to claim 38, comprising an inner and an outer layer, wherein the thrombogenic fibers are attached or attachable to the outer layer, and the outer layer is attached or attachable to the inner layer.
66. The endoprosthesis according to claim 65, wherein the inner layer and the outer layer are attached or attachable by means of a glue and/or a suture.
67. A method of manufacturing an endoprosthesis, comprising the steps of: providing a base body of an endoprosthesis; attaching a fiber at a first anchor point; wrapping said fiber around the longitudinal axis of the endoprosthesis such that it extends at least around a full circumference of the endoprosthesis; attaching the fiber at a second anchor point; providing a fixing mechanism, and attaching it along the longitudinal axis of the endoprosthesis such that the fixing mechanism fixes the fiber to the endoprosthesis at at least one attachment point; and cutting the fiber at a cutting point, such that two ends of the fiber can extend away from the fixing mechanism.
Description
[0059] In the following, the invention is described in detail with reference to the following figures, showing:
[0060] FIG. 1a-1d: different embodiments of an endoprosthesis.
[0061] FIG. 2: a fiber comprising a biosensor.
[0062] FIG. 3a-3d: different types of fibers.
[0063] FIG. 4: a detailed depiction of fibers on a surface.
[0064] FIG. 5: a schematic depiction of an implanted endoprosthesis with two aneurysms.
[0065] FIG. 6: a schematic depiction of an implanted endoprosthesis with an aneurysm.
[0066] FIG. 7: an alternative embodiment of an endoprosthesis.
[0067] FIG. 8: another alternative embodiment of an endoprosthesis.
[0068] FIG. 9: another alternative embodiment of an endoprosthesis.
[0069] FIG. 10: a schematic depiction of a fabric with fibers.
[0070] FIG. 11: another alternative embodiment of an endoprosthesis.
[0071] FIG. 12a-12d: a schematic illustration of a method to manufacture an endoprosthesis
[0072] FIG. 13a-13b: a schematic illustration of an alternative method to manufacture an endoprosthesis.
[0073] FIG. 1 shows schematically a particularly preferred embodiment of an endoprosthesis 1. The outer surface of a body 3 of the endoprosthesis is entirely provided with thrombogenic fibers 2. Here the fibers are spread evenly over the entire surface. By contrast, FIGS. 1b-1d show different embodiments of an endoprosthesis 1 wherein only a part of the body 3 is provided with thrombogenic fibers 2. In FIG. 1b, only a distal part 5 of the body 3 of the endoprosthesis body 3 provided with fibers 2. Of course, it would also be possible to only provide the endoprosthesis body 3 with fibers on a proximal end instead, or on both ends. FIG. 1c shows an embodiment wherein only a middle part 6 of the endoprosthesis body 3 is provided with fibers 2. Finally, FIG. 1d shows an embodiment of the endoprosthesis 1 where only a part, for example half of the circumference 7, is provided with fibers 2. However, there is no gradient in the density of fibers along the longitudinal axis. On the part of the circumference 7 that is provided with fibers 2, the fibers are spread evenly from the distal to the proximal end of the endoprosthesis. On the other part of the circumference 7, there are no fibers at all. It shall be understood any of the embodiments described in FIGS. 1a-1d can be combined with any of the features or embodiments described below.
[0074] FIG. 2 shows a fiber 2 that is provided with a biomarker 4. The biomarker comprises molecules than can attach to other molecule that can indicate an inflammation. When attached to such molecules, the biomarker 4 changes its optical properties such that an inflammation can be detected easily.
[0075] FIG. 3a-3d show, by way of example, different types of surface textures of thrombogenic fibers. FIG. 3a shows an embodiment wherein micro-hooks 8 are spread over the surface of the fiber 2. The micro-hooks 8 consist, in this example, of metallic anchor-shaped and pointed pieces that can mechanically engage in different types of tissue. Micro-hooks are thus particularly advantageous in applications where the fibers need attach to different types of surfaces simultaneously, or if the exact nature of the surface is not known before the treatment. For example, the metallic micro-hooks 8 shown here may help attach the fibers to a blood clot in an aneurysm, while other micro-hooks may provide attachment to a vessel wall. Of course, it would also be possible to use micro-hooks of other biocompatible materials such as polymers.
[0076] FIG. 3b shows a fiber 2 comprising a knot 9. Such a knot 9 provides better retention from a coagulum that forms around the fiber and is particularly easy and cheap to manufacture because no additional material is needed. Instead, the knot can be formed from the fiber itself.
[0077] FIG. 3c shows an embodiment of a fiber 2 wherein secondary fibers 10 extend from the fiber 2. The mechanism of increased retention at a blood coagulum is the same as for a fiber containing a knot 9 as shown in FIG. 3b. However, secondary fibers as shown here provide the additional advantage that different lengths or types of secondary fibers 10 can be used along the length of the fiber 2. Thus, the attachment strength as well as the thrombogenicity can be tuned with more versatility.
[0078] FIG. 3d show an embodiment of a fiber 2 comprising loops 11. It will be understood by a person skilled in the art the textures shown here are mere examples.
[0079] FIG. 4 shows a close-up schematic view of the surface of an endoprosthesis body 3. Several fibers 2 are arranged on the surface. The fibers 2 are individually adapted in the diameter 13 and length 12 to the patient that is treated in this situation. It is well visible that here, the fibers have a varying diameter 13 along their length. The variation is random and the increased surface-to-volume ratio further promotes blood coagulation. It would of course be possible to adapt the fibers 2 to have any diameter profile. For example, the fibers could also become thicker toward their free end, or thinner, or have an hour-glass shape. Here, the fibers are made of biodegradable polylactic acid are adapted such that they degrade in the human body within eight months.
[0080] FIG. 5 shows an example of a treatment with an endoprosthesis 1 according to the invention. In this illustration, the endoprosthesis 1 is in its deployed state in a human vessel V. The vessel V has two aneurysms A1, A2 of different sizes. The embodiment of the endoprosthesis 1 shown here is particularly adapted to the treatment situation and the patient. The fibers 2 are arranged on the surface of the endoprosthesis body 3 at the location of the aneurysms A1, A2. At the location of the larger aneurysm A2, the fibers 2a are longer to fill substantially the entire volume of the aneurysm. At the location of the smaller aneurysm A1, the fibers 2b are shorter but achieve the same effect because of the smaller aneurysm size. In addition, short fibers 2c are arranged around the entire circumference of the endoprosthesis 2 at the proximal and the distal end in order to prevent endoleaks.
[0081] FIG. 6 shows another example of a treatment of an aneurysm A1 with an endoprosthesis 1 according to the invention. The vessel V in this example has only one aneurysm A1. The embodiment shown here is only provided with fibers 2 at the location of the aneurysm A1, while the rest of the surface of the endoprosthesis body 3 is free of fibers. The fibers 2 here are adapted in their length to fill the entire volume of the aneurysm A1 and additionally are provided with an active agent that additionally promotes blood coagulation. Thus, the formation of a blood clot C is relatively rapid. In addition, the fibers are provided with micro-hooks (not shown) on their free ends that significantly increase the retention of the fibers in the blood clot C.
[0082] FIG. 7 shows another embodiment of an endoprosthesis 1. The surface of the endoprosthesis body 3 is provided with several anchor points 14 to which fibers 2 are attachable. One fiber 2a is attached to two anchor points in such a way as to form a loop. This is achieved by employing a fiber that has a length which is longer that the shortest distance 15 between the two anchor points to which is attached. Thus, the fiber 2a extends from the surface of the endoprosthesis body 3 and promotes blood coagulation and retention of the endoprosthesis 1. Another fiber 2b is arranged around the circumference 7 of the endoprosthesis body 3. Here, it extends exactly once around the longitudinal axis L of the endoprosthesis. Thus, the ends of the fiber 2a and the anchor points 14 to which they are attached are at the same angular position relative to the longitudinal axis L of the endoprosthesis. The anchor points shown here consist of loops. The ends of the fibers 2 have foots, here in the form of mechanical retainers, that can engage the loops and thus attach the fiber to the anchor points 14 and the endoprosthesis body 3. It shall be understood that the both arrangement of fibers depicted in FIG. 7, either as a partial loop extending away from the endoprosthesis 2a or as a loop 2b around the longitudinal axis L of the endoprosthesis, can be used individually or in combination.
[0083] FIG. 8 shows a more schematic illustration of an embodiment of an endoprosthesis 1. Here, the fibers are attached to the endoprosthesis body 3 the same way as the fiber 2b in FIG. 7. Briefly, the fibers 2 are primarily attached to an anchor point (not shown) and wrapped around the circumference 7 of the endoprosthesis body 3 before attaching to a second anchor point. Here, the anchor points are aligned along the longitudinal axis L of the endoprosthesis 1. For permanent attachment to the endoprosthesis, a fabric strip 16 made of Dacron is glued along the longitudinal axis L such that it covers the anchor point and thereby attaches the fibers 2a, 2b, 2c to the endoprosthesis body 3 at an attachment point 25. It will of course be understood by the person skilled in the art the strip 16 could be made of any other biocompatible material as well. In addition, while gluing of the strip is a preferred method of attaching the strip, other methods such as sewing, stitching, or stapling are also possible. The fiber 2c forms a loop around the longitudinal axis of the endoprosthesis and thus promotes blood coagulation all around the circumference. This is particularly advantageous to prevent endoleaks. The other two fibers 2a, 2b shown here initially consisted of only one fiber that was arranged in the same way as the fiber 2c. However, the fiber was cut at a cutting point (not shown) on the opposite side of the endoprosthesis body 3 such that two fibers 2a, 2b formed whose ends are free and extend away from the endoprosthesis. For example, this be done at the location of an aneurysm. It shall be understood that the both arrangement of fibers depicted in FIG. 7, either cut fibers 2a, 2b extending away from the endoprosthesis or formed as a loop 2c around the longitudinal axis L of the endoprosthesis, can be used individually or in combination.
[0084] FIG. 9 shows an embodiment of an endoprosthesis before deployment. Here, the fibers 2 are attached to the endoprosthesis body 3 along their length by means of a biodegradable glue 17, here a polylactide. Thus, all the fibers are contiguous with the surface of the endoprosthesis body 3 before deployment. Here, they are oriented along the circumference 7 of the endoprosthesis body 3. Because the glue 17 used here is biodegradable, the fibers will be released upon implantation and eventually extend away from the endoprosthesis body 3. Here, the glue is adapted to degrade in the human body within five months. However, the degradation rate can be tuned to any appropriate depending on the patient and the application.
[0085] FIG. 10 shows schematically a fabric 18 that can be used to manufacture an endoprosthesis according to the invention. The fabric 18 is woven and has fibers 2 that are directly integrated into the fabric 18, here by weaving fibers during manufacturing of the fabric 18.
[0086] FIG. 11 shows schematically an attachment of fibers via a connection interface 20. The endoprosthesis body 3 comprises a magnetic connection interface. The fiber 2 has a foot which is a magnetic as well. Thus, the fiber is automatically attracted to the connection interface 20 on the endoprosthesis body 3 and attaches there. This method is particularly advantageous because the fibers 2 are automatically pulled to the desired location by magnetic forces. Thus, it provides for a simple mechanism to accurately distribute the fibers 2 on the endoprosthesis body 3.
[0087] FIGS. 12a-12d show schematically a method of manufacturing an endoprosthesis. A base body 21 of an endoprosthesis is provided as shown in FIG. 12a. It has a longitudinal axis L and a circumference 7. Two anchor points 14a, 14b are provided on the surface of the base body 21. Here, the anchor points are not at the same angular position relative to the longitudinal axis L, meaning that a hypothetical straight line connecting them is not parallel to the longitudinal axis L. As shown in FIG. 12b, a fiber 2 is attached to one of the anchor points 14a. The fiber 2 is subsequently wrapped around the base body 21 and its longitudinal axis L and attached to the anchor point 14b. Because the two anchor points 14a, 14b are not at the same angular position, the fiber 2 extends over more than one circumference in this example. Here, this is particularly advantageous because it allows for an arrangement of a suture 22 as in between the anchor points 14a, 14b. The suture 22 is provided on the surface of the base body 21 and arranged along the longitudinal axis L. It is placed such that is fixes the fiber 2 in between the two anchor points 14a, 14b. Finally, the fiber 2 is cut on a side opposite of the suture 22, leading to the endoprosthesis shown in FIG. 12d. The cut had divided the fiber into two segments 2a, 2b, each extending away from the endoprosthesis base body 21.
[0088] FIGS. 13a-13b show an alternative method to manufacture an endoprosthesis. An endoprosthesis base body 21 is provided and the location of anchor points is determined based on a planned treatment. Here, the predetermined geometry consists of a band 23 around the circumference of the base body 21. This is particularly advantageous to prevent endoleaks because the formation of blood coagula around the circumference of the endoprosthesis can seal the vessel. In addition, here, a safety distance 24 is kept from the end of the endoprosthesis to further prevent the formation of blood clots that could be rinsed off into the blood stream. In a next step, illustrated in FIG. 13b, fibers 2 are attached to the anchor points 14, thus forming an area on the endoprosthesis surface provided with fibers according to a predetermined geometry.
