MULTIPLE STENT WITH MEMBRANE

Abstract

The invention relates to a multiple stent comprising at least two coaxially arranged stents (1, 3) and at least one membrane (2, 4), wherein a first stent (1) being arranged on the inside and a second stent (3) being arranged on the outside, wherein a first membrane (2) is arranged on the inside of the first stent (1) and/or a second membrane is arranged on the outside of the second stent (3), wherein the respective membrane ends (2A, 2B; 4A, 4B) are folded around the respective ends of the stent (1, 3) on which they are arranged, in such a way that the membrane ends (2A, 2B; 4A, 4B) are clamped in place between two stents (1, 3).

Claims

1. Multiple stent comprising at least two coaxially arranged stents (1, 3) and at least one membrane (2, 4), wherein a first stent (1) being arranged on the inside and a second stent (3) being arranged on the outside, characterized in that a first membrane (2) is arranged on the inside of the first stent (1) and/or a second membrane (4) is arranged on the outside of the second stent (3), wherein the respective membrane ends (2A, 2B; 4A, 4B) are folded around the respective ends (1A, 1B; 3A, 3B) of the stent (1, 3) on which they are arranged, in such a way that the membrane ends (2A, 2B; 4A, 4B) are guided between the first and the second stent (1, 3).

2. Multiple stent according to claim 1, characterized in that the more inwardly arranged stents (1) have a nominal diameter of at least the same size as the more outwardly arranged stents (3), wherein the more inwardly arranged stents (1) preferably have a larger nominal diameter than the more outwardly arranged stents (3).

3. Multiple stent according to claim 1, characterized in that the at least one membrane (2, 4) is provided in tubular form.

4. Multiple stent according to claim 1, characterized in that the at least one membrane (2, 4) is 5 to 25% longer, preferably 25 to 50% longer, further preferably 50 to 75% and in particular 75% to 100% longer than the stent (1, 3) on which it is arranged.

5. Multiple stent according to any one of the preceding claims claim 1, characterized in that the at least one membrane (2, 4) is more than twice as long as the stent (1, 3) on which it is arranged, so that the folded-over membrane ends (2A, 2B; 4A, 4B) overlap between the stents (1, 3), respectively.

6. Multiple stent according to claim 1, wherein the membranes (2, 4) may be made of a film or provided knitted, woven or sewn from a thread.

7. Multiple stent according to claim 1, comprising two coaxially arranged stents (1, 3) and two membranes (2, 4), with the first stent (1) being provided on the inside and the second stent (3) being provided on the outside, characterized in that the first membrane (2) is arranged on the inside of the first stent (1) and the membrane ends (2A, 2B) of the first membrane (2) are folded over to the outside of the first stent (1) and the second membrane (4) is arranged on the outside of the second stent (3) and the membrane ends (4A, 4B) of the second membrane (4) are folded over to the inside of the second stent (3) so that the membrane ends (2A, 2B; 4A, 4B) are clamped in place between the stents (1, 3).

8. Multiple stent according to claim 1, comprising two coaxially arranged stents (1, 3) and one membrane (2), wherein the first stent (1) is provided on the inside and the second stent (3) is provided on the outside, characterized in that the membrane (2) is arranged on the inside of the first stent (1) and the membrane ends (2A, 2B) are folded over onto the outside of the first stent (1) so that the membrane ends (2A, 2B) are clamped in place between the stents (1, 3).

9. Multiple stent according to claim 1 with two coaxially arranged stents (1, 3) and one membrane (4), wherein the first stent (1) is provided on the inside and the second stent (3) is provided on the outside, characterized in that the membrane (4) is arranged on the outside of the second stent (3) and the membrane ends (4A, 4B) are folded over onto the inside of the second stent (3) so that the membrane ends (4A, 4B) are clamped in place between the stents (1, 3).

10. Multiple stent according to claim 1, comprising three coaxially arranged stents and two membranes, wherein the first stent being arranged on the inside, the second stent being provided on the outside, and the third stent being provided between the first stent and the second stent, characterized in that the first membrane is arranged on the inside of the first stent and the membrane ends of the first membrane are folded over to the outside of the first stent and are clamped in place between the first and the third stent and the second membrane is arranged on the outside of the second stent and the membrane ends of the second membrane are folded over to the inside of the second stent and are clamped in place between the second and the third stent.

11. Multiple stent according to claim 1, wherein retaining elements (5) are provided at least at one end of a stent of the multiple stent (M).

12. Multiple stent according to claim 1, wherein the retaining elements (5) are provided as an extension of at least one end portion of at least one stent of the multiple stent (M).

13. Multiple stent according to claim 1, wherein the retaining elements (5) are provided to be of hook-shaped configuration and directed radially outward.

14. Multiple stent according to claim 1, characterized in that at least one stent of the multiple stent (M) comprises a plurality of individual stent elements.

Description

[0054] Further elucidation of the invention is provided through the enclosed figures showing preferred embodiments of the invention. It goes without saying that the characteristics shown in the figures shall in each case be regarded individually as being part of the invention and should not be understood exclusively in the context of the other characteristics illustrated in the figures, where

[0055] FIG. 1 shows the schematic structure of a first embodiment of the multiple stent according to the invention;

[0056] FIG. 2 shows detail B of FIG. 1 illustrating the arrangement of the stents and membranes according to the first embodiment of the inventive multiple stent;

[0057] FIG. 3 shows the schematic structure of a second embodiment of the multiple stent according to the invention;

[0058] FIG. 4 shows detail B of FIG. 3 illustrating the arrangement of the stents and the membrane according to the second embodiment of the inventive multiple stent;

[0059] FIG. 5 shows the schematic structure of a third embodiment of the multiple stent according to the invention;

[0060] FIG. 6 shows detail B of FIG. 5 illustrating the arrangement of the stents and the membrane according to the third embodiment of the inventive multiple stent;

[0061] FIG. 7 illustrates the application of the multiple stent according to the invention in a multilumen implant;

[0062] FIG. 8 is a detailed view of a further development of the inventive multiple stent provided with retaining elements for use in a multilumen implant;

[0063] FIG. 1 shows a first embodiment of the multiple stent M according to the invention with an inner stent 1 having a first end 1A and a second end 1B and an outer stent 3 having a first end 3A and a second end 3B, wherein the stents 1, 3 are arranged coaxially to each other. The multiple stent M is shown in the non-expanded state. An is inner membrane 2 is arranged on the inside of the inner stent 1 and an outer membrane 4 is arranged on the outside of the outer stent 3.

[0064] Membranes 2, 4 are folded around the ends 1A, 1B, 3A, 3B of the stents 1, 3 causing them to be clamped with their ends between the stents 1, 3, respectively.

[0065] The stents 1, 3 may be provided so as to be balloon-expandable or self-expandable, with all known materials being suitable for use. The stents 1, 3 can be fabricated from different materials. The nominal diameter of the inner stent 1 is at least as large as that of the outer stent 3; preferably, the nominal diameter of the inner stent 1 should even be chosen to be slightly larger than that of the outer stent 3 to bring about a higher clamping effect.

[0066] The membranes 2, 4 can be made of the widest variety of known materials, but with tubular membranes made of ePTFE being preferred. The membranes 2, 4 can also be provided from different materials.

[0067] FIG. 2 shows a detailed view B of FIG. 1 as a closer view of the arrangement of the stents 1, 3 and the membranes 2, 4 relative to each other. The inner membrane 2 and the outer membrane 4 are folded over with their two ends 2A, 2B, 4A, 4B respectively around the end 1A, 1B, 3A, 3B of the stent 1, 3 on which they rest inside and outside, respectively, in the area between the stents 1, 3. The ends 2A, 2B, 4A, 4B or more precisely the end regions of the membranes 2, 4 are thus clamped in place between the two stents 1, 3. As shown in the figure, the membranes 2, 4 can be of different lengths, but they can also be provided with the same length. The length of the membranes 2, 4 may be selected, as illustrated, such that the respective ends 2A, 2B or 4A, 4B between the stents 1, 3 do not touch or overlap, however the length of the membranes 2, 4 may also be selected such that the respective ends 2A, 2B or 4A, 4B between the stents 1, 3 touch or overlap.

[0068] FIG. 3 shows a second embodiment of the multiple stent M according to the invention with a first inner stent 1 having a first end 1A and a second end 1B and a second outer stent 3 having a first end 3A and a second end 3B, wherein the stents 1, 3 are arranged coaxially to each other. The multiple stent M is shown in the non-expanded state. In this embodiment, only one membrane 2 is arranged on the inside of the inner stent 1.

[0069] The membrane 2 is folded around the ends 1A, 1B, of the inner stent 1 causing the membrane to be clamped with their ends between the two stents 1, 3.

[0070] The stents 1, 3 may be provided so as to be balloon-expandable or self-expandable, with all known materials being suitable for use. The stents 1, 3 can be fabricated from different materials. The nominal diameter of the inner stent 1 is at least as large as that of the outer stent 3; preferably, the nominal diameter of the inner stent 1 should even be chosen to be slightly larger than that of the outer stent 3 to bring about a higher clamping effect.

[0071] The membrane 2 can be made of the widest variety of known materials, but with tubular membranes made of ePTFE being preferred.

[0072] FIG. 4 shows a detailed view B of FIG. 3 as a closer view of the arrangement of the stents 1, 3 and the membrane 2 relative to each other. The inner membrane 2 is folded over with its two ends 2A, 2B respectively around the end 1A, 1B of the inner stent 1 into the area between the stents 1, 3. The ends 2A, 2B of the membrane 2 are thus clamped in place between the two stents 1, 3. The length of the membrane 2 may be selected, as shown, such that its ends 2A, 2B between the stents 1, 3 do not touch or overlap; however, the length of the membrane 2 may also be selected such that its ends 2A, 2B between the stents 1, 3 touch or overlap.

[0073] FIG. 5 shows a third embodiment of the multiple stent M according to the invention with a first inner stent 1 having a first end 1A and a second end 1B and a second outer stent 3 having a first end 3A and a second end 3B. The stents 1, 3 are arranged coaxially to each other. The multiple stent M is shown in the non-expanded state. In this embodiment, only one membrane 4 is arranged on the outside of the outer stent 3.

[0074] The membrane 4 is folded around ends 3A, 3B, of the outer stent 3 causing the membrane to be clamped with their ends between the two stents 1, 3.

[0075] The stents 1, 3 may be provided so as to be balloon-expandable or self-expandable, with all known materials being suitable for use. The stents 1, 3 can be fabricated from different materials.

[0076] The nominal diameter of the inner stent 1 is at least as large as that of the outer stent 3; preferably, the nominal diameter of the inner stent 1 should even be chosen to be slightly larger than that of the outer stent 3 to bring about a higher clamping effect.

[0077] The membrane 4 can be made of the widest variety of known materials, but with tubular membranes made of ePTFE being preferred.

[0078] FIG. 6 shows a detailed view B of FIG. 5 as a closer view of the arrangement of the stents 1, 3 and the membrane 4 relative to each other. The outer membrane 4 is folded over with its two ends 4A, 4B respectively around the end 3A, 3B of the outer stent 3 into the area between the stents 1, 3. The ends 4A, 4B of the membrane 4 are thus clamped in place between the two stents 1, 3.

[0079] The length of the membrane 4 may be selected, as shown, such that its ends 4A, 4B between the stents 1, 3 do not touch or overlap; however, the length of the membrane 4 may also be selected such that its ends 4A, 4B between the stents 1, 3 touch or overlap.

[0080] FIG. 7 shows the application of a further development of multiple stent M proposed by the invention for use in a multilumen implant ML, i.e. in a branched stent graft.

[0081] FIG. 8 shows in detail the end region of a further development of the multiple stent M according to the invention for use in a multilumen implant ML as illustrated in FIG. 7. Said further development provides for the retaining elements 5 to be arranged at least at one end of the multiple stent M; by means of said elements multiple stent M can be secured in a multilumen implant ML. Multilumen implants ML are often offered in the form of kits, with the individual branches of the multilumen implant ML being selected to match the respective diameters of the vessels to be treated. Critical in this context is the connection of the individual components. With this in mind, the further development preferably provides for the retaining elements 5 to be composed of hook-shaped and radially outwardly directed elements 5. Preferably, these can be part of the uncovered stent, because the ends of the covered stent are covered by the folded-over membrane. A piercing of the membrane by the retaining elements would result in unnecessary material damage. It is also conceivable that the retaining elements 5 are provided so as to perform a dual function in that they are provided on the covered stent and, aside from their retaining function in the multilumen implant ML, enable the membrane to be additionally secured at the folding-over point. In any case, the retaining elements 5 must be arranged such that they protrude sufficiently far from the multiple stent to allow adequate anchorage in a multilumen implant.

LIST OF REFERENCE NUMERALS

[0082] 1 inner (first) stent (1A, 1B: ends of the inner stent) [0083] 2 inner (first) membrane (2A, 2B: ends of the inner membrane) [0084] 3 outer (second) stent (3A, 3B: ends of the outer stent) [0085] 4 outer (second) membrane (4A, 4B: ends of the outer membrane) retaining elements [0086] M multiple stent [0087] ML multilumen implant