TIPS Stent Graft and Kit Comprising TIPS Stent Graft

Abstract

The invention relates to a TIPS stent graft, comprising: a hollow stent graft body, the stent body having a lumen extending between a first longitudinal end and a second longitudinal end to let fluid pass through the stent graft body from the first longitudinal end to the second longitudinal end, the lumen comprising at least two sublumens which are separated from one another, each of the sublumens extending from the first longitudinal end to the second longitudinal end, each of the sublumens being capable of being blocked so as to reduce blood flow through the TIPS stent graft.

Claims

1. A kit of parts, comprising: a Transjugular Intrahepatic Portosystemic Shunt (TIPS) stent graft comprising: a hollow stent graft body, the stent graft body having a lumen extending between a first longitudinal end and a second longitudinal end to let fluid pass through the stent graft body from the first longitudinal end to the second longitudinal end, the lumen comprising at least two sublumens which are separated from one another, each of the sublumens extending from the first longitudinal end to the second longitudinal end, each of the sublumens being capable of being blocked so as to reduce blood flow through the TIPS stent graft; and an occlusion device separate from the TIPS stent graft, the occlusion device being arranged to, when deployed, significantly reduce or block blood flow through one of the sublumens to allow for restricting blood flow in the TIPS stent graft post-placement.

2. The kit of parts according to claim 1, the TIPS stent graft comprising 3 or 4 sublumens.

3. The kit of parts according to claim 1, the stent graft comprising at least 6, preferably at least 8, more preferably at least 10 sublumens.

4. The kit of parts according to claim 1, the stent graft being a self-expanding stent graft.

5. The kit of parts according to claim 1, wherein at least one of the sublumens is formed of a tube which is adhered to an inner surface of the stent body.

6. The kit of parts according to claim 5, wherein the tube comprises a band extending diametrically through the interior of the tube.

7. The kit of parts according to claim 1, wherein at least one of the sublumens is formed by a sheet extending from one circumferential position of the stent graft body to another circumferential position of the stent graft body.

8. The kit of parts according to claim 1, the cross-sectional area of at least one, preferably all of the sublumens being essentially constant along the length of the respective sublumen(s).

9. The kit of parts according to claim 1, further comprising a balloon catheter arranged for expanding the sublumens to thus adjust the cross-sectional diameter of the hollow stent graft body which is available for blood flow.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows a TIPS stent graft according to a first embodiment of the invention.

[0022] FIG. 2 shows a TIPS stent graft according to the second embodiment of the invention.

[0023] FIGS. 3a) and b) show TIPS stent grafts according to the third and fourth embodiments of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1a)-c) show a TIPS stent graft 10 according to the first embodiment. A TIPS stent graft 10 comprises a stent graft body 12 having an essentially tubular shape. By means of a membrane 17, the inner lumen 14 of the stent graft 10 is separated into first and second sublumens 16, 18. As can be seen from the schematic diagrams, second sublumen 18 has a somewhat smaller cross-sectional diameter and cross-sectional area then first sublumen 16.

[0025] Whilst the drawing in FIG. 1a) shows the TIPS stent graft when not in use with all of the sublumens 16, 18 open, FIG. 1b) shows the TIPS stent graft when the second sublumen 18 is occluded by means of an occlusion device 36. Such an occlusion device can, for example, be in the shape of one or more occlusion spirals. Since blood flow is impeded through the second sublumen 18, the effective cross-sectional area of the TIPS stent graft 10 for blood flow is reduced. As pointed out previously, this can be used for treating hepatic encephalopathy.

[0026] FIG. 1c) shows yet another use condition of the TIPS stent graft 10 according to the first embodiment. Again, an occlusion device 36 is provided inside the second sublumen 18. However, so as to increase the cross-sectional area of the second sublumen 18, a balloon expandable stent 40 is provided which can be inflated and deflated by means of a catheter (not shown). By means of the balloon expandable stent 40, the cross-sectional area of the second sublumen 18 can be increased to thereby effectively decrease the cross-sectional area of the first sublumen 16 further. This can be used to adjust the cross-sectional area available for blood flow of the TIPS stent graft.

[0027] FIG. 2 shows a TIPS stent graft according to the second embodiment of the present invention. It shows a cross-sectional view of such a stent graft, where the cross-section has been taken in a plane perpendicular to the longitudinal axis of the stent graft.

[0028] As can be seen, the stent graft body 12 comprises a first sublumen 16 and a second sublumen 18. The stent graft body 12 itself comprises a stent 30 which is covered by an inner ePTFE layer 34 and an outer ePTFE layer 32. Adhered to an inside of the inner ePTFE layer 34 is a tube 15 which serves as the second sublumen 18. Provided on an inside of the tube 15 is a band 26 so as to keep it open. The band 26 is arranged so as to extend between points which are not identical with the point at which the tube 15 is adhered to the inner ePTFE layer 34.

[0029] The tube 15 inside the stent craft 12 could be incorporated on the inner surface of the inner ePTFE layer 34 of the stent graft 12 during the covering process of the stent 30 as follows: a tube 15 made of FEP or PTFE is placed inside the inner layer 34 of the covering and over a mandrel during a sintering process of the covering. In order to keep the extra lumen open, a silver band 26 is provided inside the sublumen 18 defined by the tube 15. Then an inner ePTFE layer 34, the stent 30 and the outer ePTFE layer 32 are placed over the mandrel and are then pressed with a PTFE tape material.

[0030] Using such an embodiment, during the loading process of the stent graft inside a deployment sheet, the inner catheter of the deployment sheath can be placed inside the sublumen 18 and a loading process can be performed. This has the advantage that a potential guidewire will be inside the sublumen 18 after stent graft deployment. A second guidewire can be placed inside the stent graft 12 in order to balloon the stent to its diameter. After the second balloon has been advanced over the guidewire that is already placed inside the lumen either to just balloon it to open up the lumen or to place the balloon expandable stent.

[0031] FIGS. 3a) and 3b) show the third and the fourth embodiment of the TIPS stent graft according to the present invention.

[0032] Turning to FIG. 3a) first, a third embodiment of the TIPS stent graft is shown in a cross-section perpendicular to the longitudinal axis of the TIPS stent graft. An inner lumen 14 of the stent graft 12 is separated by means of membrane 17 into first, second, and third sublumens 16, 18, 20. Also indicated are bare stent components 24 which are provided at one longitudinal end of the TIPS stent graft 12 and which will, when implanted, flare out to keep the TIPS stent graft 12 in place.

[0033] FIG. 3b) shows a TIPS stent graft according to the fourth embodiment. Again, by means of two membranes 17, a lumen of the TIPS stent graft body 12 has been separated into the first, second, third, and fourth sublumens 16, 18, 20, and 22. Again, bare parts 24 of the stent used for the TIPS stent graft are provided at one end of the stent graft.

[0034] In both FIGS. 3a) and 3b), the first to third or first to fourth sublumens 16 to 20 and 16 to 22 can be occluded by means of adequate occlusion devices so as to reduce the effective diameter available for blood to flow through the TIPS stent graft.