Vascular Prosthesis

Abstract

A vascular prosthesis (1) for connection to a natural cardiovascular system, includes a volume chamber (2), wherein the volume chamber (2) has, in a blood pressure range below a pressure threshold value D, a pressure-expansion behavior substantially corresponding to the pressure-expansion behavior of a natural blood vessel, while the volume of the volume chamber (2), depending on the pressure, increases by at least 10 cm.sup.3 in a blood pressure range above the pressure threshold value D. The vascular prosthesis (1) is configured as a textile tube, wherein the textile tube includes in the region of the volume chamber (2) an elastic yarn having a core made from silicone yarn around which a yarn made from polyethylene terephthalate (PET) is wrapped.

Claims

1. A vascular prosthesis for connection to a natural cardiovascular system, comprising a volume chamber, wherein the volume chamber has, in a blood pressure range below a pressure threshold value D, a pressure-expansion behavior substantially corresponding to the pressure-expansion behavior of a natural blood vessel, while the volume of the volume chamber, depending on the pressure, increases by at least 10 cm.sup.3 in a blood pressure range above the pressure threshold value D, the vascular prosthesis being configured as a textile tube, wherein the textile tube includes in the region of the volume chamber an elastic yarn having a core made from silicone yarn around which a yarn made from polyethylene terephthalate (PET) is wrapped.

2. The vascular prosthesis according to claim 1, wherein the core of the elastic yarn is a highly elastic silicone yarn.

3. The vascular prosthesis according to claim 1, wherein the silicone yarn is configured as a monofil made from silicone with a Shore hardness of 30 to 70.

4. The vascular prosthesis according to claim 1, characterized in that wherein the elastic yarn has a thread count of 100 to 3000 dtex.

5. The vascular prosthesis according to claim 1, wherein the vascular prosthesis is configured as a fabric tube comprised of warp threads and weft threads, wherein the weft threads in the region of the volume chamber are formed from the elastic yarn.

6. The vascular prosthesis according to claim 5, wherein the warp threads are formed from a PET yarn.

7. The vascular prosthesis according to claim 6, wherein the PET yarn forming the warp threads has a thread count of 50 to 300 dtex.

8. The vascular prosthesis according to claim 6, wherein the PET yarn forming the warp threads is configured as a multifilament yarn comprised of 20 to 300 filaments.

9. The vascular prosthesis according to claim 6, wherein the PET yarn forming the warp threads is configured as one of: a flat yarn or textured yarn.

10. The vascular prosthesis according to claim 5, wherein the fabric tube is woven in one of: a twill weave, a satin weave or a plain weave.

11. The vascular prosthesis according to claim 1, wherein the vascular prosthesis comprises connecting portions adjacent to the volume chamber, for connection to the natural cardiovascular system, wherein the connecting portions have a lower elasticity than the volume chamber.

12. The vascular prosthesis according to claim 11, wherein the connecting portions are configured as a woven fabric and include warp and weft threads comprised of PET configured as a multifilament yarn, and wherein the weft threads are configured as one of: a flat yarn or a high shrinkage yarn.

13. The vascular prosthesis according to claim 1, wherein end-side portions of the volume chamber function as connecting portions for connection to the natural cardiovascular system, wherein the vascular prosthesis has a uniform elasticity in the region of the volume chamber inclusive of the connecting portions.

14. The vascular prosthesis according to claim 11, wherein the vascular prosthesis has a double-layer configuration in the region of the connecting portions.

15. The vascular prosthesis according to claim 11, wherein the vascular prosthesis has a dumbbell-shaped configuration such that, in a non-pressurized state, it is conically expanded in the region of the connecting portions compared with a central region of the volume chamber.

16. A method for producing a vascular prosthesis according to claim 1, comprising the following steps: providing weft and warp threads, wherein the weft threads are formed from the elastic yarn at least in the region of the volume chamber, warping ground and pile warps, weaving the textile tube on a shuttle ribbon loom, thermosetting the woven textile tube, and washing the vascular prosthesis in order to remove finishing agents.

17. The vascular prosthesis according to claim 1, wherein the silicone yarn is configured as a monofil made from silicone with a Shore hardness of 40 to 60.

18. The vascular prosthesis according to claim 1, wherein the elastic yarn has a thread count of 200 to 2000 dtex.

Description

[0043] The invention will be explained in more detail below with reference to exemplary embodiments and to the attached schematic drawings. In the Figures:

[0044] FIG. 1: shows a first embodiment of the elastic vascular prosthesis in a schematic perspective view;

[0045] FIG. 2: shows a portion from an illustration of a second embodiment of the elastic vascular prosthesis;

[0046] FIG. 3: shows a portion from an illustration of a third embodiment of the elastic vascular prosthesis;

[0047] FIG. 4: shows a portion from an illustration of a fourth embodiment of the elastic vascular prosthesis;

[0048] FIG. 5: shows a portion from an illustration of a fifth embodiment of the elastic vascular prosthesis.

[0049] In a schematic perspective view, FIG. 1 shows a first embodiment of the elastic vascular prosthesis which, as a whole, is given the designation 1. The vascular prosthesis 1 comprises a volume chamber 2 and connecting portions 3 adjacent to the volume chamber 2, for connecting the vascular prosthesis 1 to a natural cardiovascular system not shown here. The vascular prosthesis 1 is configured as a seamless, textile fabric tube consisting of warp threads and weft threads, wherein the weft threads in the region of the volume chamber 2 are formed from a highly elastic yarn having a core of silicone yarn, around which a yarn of polyethylene terephthalate wrapping yarn is wrapped once. The elastic yarn is a yarn suitable for medical purposes. The warp threads in the region of the volume chamber 2 are formed from PET multifilament yarn suitable for medical purposes. The end-side connecting portions 3 of the vascular prosthesis 1 are configured as a non-elastic woven fabric, wherein both the warp threads and weft threads are formed from a PET multifilament yarn.

[0050] The vascular prosthesis 1 according to FIG. 1 has a dumbbell-shaped configuration, that is, in a non-pressurized state shown in FIG. 1, it is conically expanded in the region of the connecting portions 3 compared with the central region of the volume chamber 2. Here, the maximum diameter D1 in the region of the connecting portions 3 is larger by about one third than the diameter D2 in the region of the volume chamber 2, which is shown merely schematically, and not to scale, in FIG. 1.

[0051] FIG. 2 shows a second embodiment of a vascular prosthesis 1 according to the invention, wherein only one half of the symmetrically configured vascular prosthesis 1 is shown here and also in FIGS. 3 to 5. The exemplary embodiment of FIG. 2 differs from that in FIG. 1 only in that the conical expansion in the region of the connecting portions 3 is less pronounced. In the example shown here, the maximum diameter in the region of the connecting portions may be larger by maximally one fourth than the diameter in the region of the volume chamber in a non-pressurized state of the latter.

[0052] FIG. 3 shows an embodiment the vascular prosthesis 1 having a double-layer configuration in the region of the connecting portions 3. For this purpose, the connecting portion 3 of the vascular prostheses 1 according to FIG. 1 is folded back outwards in an end portion 4, with the outer layer being sewn in a manner not shown in detail to the inner layer for the purpose of fixing it. If such a vascular prosthesis 1 is sutured to a natural blood vessel in the region of the double-layered connecting portion, a tear-out of the suture can be counteracted by the double layers.

[0053] FIG. 4 shows an embodiment of the vascular prosthesis 1 in which the diameter in the region of the connecting portions 3 substantially corresponds to the diameter in the region of the volume chamber 2 in the non-pressurized state. At the same time, the vascular prosthesis 1, in the region of the connecting portions 3, has a pleated section 5 in the circumferential direction. The pleated section 5 may be configured in a helical shape or in the form of closed rings and provides the vascular prosthesis with a high level of flexibility in the region of the connecting portions 3. In particular, the vascular prosthesis 1 can thus be prevented from kinking in the region of the connection to a natural blood vessel.

[0054] FIG. 5 shows another embodiment of the vascular prosthesis 1 according to the invention, in which end-side portions of the volume chamber 2 themselves function as connecting portions 3. In this case, the vascular prosthesis 1 as a whole is woven from a uniform elastic material, wherein the elastic yarn of silicone yarn with PET wrapping yarn is used for the weft threads, and a PET multifilament yarn is used for the warp threads. In the non-pressurized state, the vascular prosthesis 1 has a substantially uniform diameter over its entire length. The volume chamber 2 is configured in a beveled manner in the region of the connecting portions 3. The angle of the bevel is about 45 in relation to the longitudinal axis L of the vascular prosthesis 1. Thus, such a vascular prosthesis 1 is particularly suitable for being implanted as a bypass. Such a vascular prosthesis 1 can be manufactured from a corresponding textile endless tube by simply cutting it to length and providing it with a bevel in the region of the cutting edges. Beveling may in this case be carried out by means of laser cutting, for example. Particularly smooth cutting edges that do not become frayed can be realized in this manner. A vascular prosthesis configured in such a manner has a particularly simple structure and is particularly uncomplicated to produce.