AU753166B2 - A prosthesis - Google Patents

Description

FIELD OF INVENTION This invention relates to a prosthesis which may be straight, tubular or bifurcated in form and intended for the endovascular repair of diseased or damaged vessels.

Throughout this specification the terms proximal and proximally are used for a position or direction towards the patient's heart and the terms distal and distally are used for a position or direction away the patient's heart.

It is the object of this invention to provide a new form of prosthesis or at least provide an alternative arrangement.

BRIEF DESCRIPTION OF THE INVENTION According to one aspect of the present invention there is provided an intraluminal prosthesis having a tubular graft and a plurality of self expanding stents along the length of the graft the prosthesis having a proximal end and a distal end, the prosthesis being characterised by the stents at the proximal end and at the distal end being inside the tubular graft and the remainder of the stents being on the outside of the graft.

There may be further included a self expanding stent mounted to the proximal end of 20 the graft and extending beyond the said proximal end.

The further stent may include attachment devices.

The attachment devices may comprise barbs extending towards the distal end of the prosthesis.

The prosthesis may be bifurcated at its distal end to provide a shorter prosthesis leg and a longer prosthesis leg.

The shorter leg may have a terminal stent on the outside of the prosthesis and the longer leg may have the internal distal stent.

There may be further included an extension prosthesis for insertion into the shorter prosthesis leg, the extension prosthesis comprising a tubular extension prosthesis and a plurality of self expanding stents, the extension prosthesis having a proximal end and a distal end, stents at the proximal and distal ends being inside the tubular extension prosthesis and the remaining stents being on the outside of the prosthesis.

Both the shorter leg and longer leg may have external terminal stents and extension prostheses for each leg, each extension prosthesis comprising a tubular extension prosthesis and a plurality of self expanding stents, the extension prosthesis having a proximal end and a distal end, stents at the proximal and distal ends being inside the tubular extension prosthesis and the remaining stents being on the outside of the prosthesis.

Each stent may be a zig-zag stent.

Generally it will be seen that by this invention there is provided a prosthesis which can be compressed into a thin insertion device and then the insertion device advanced through a vessel such as a femoral artery until the prosthesis is :i 20 substantially in the position required and then by careful positioning before release of the attachment means at a proximal end of the prosthesis and then repositioning if necessary before release of the distal end of the prosthesis, the prosthesis can be placed and released accurately.

25 DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION The construction of preferred embodiments of the prosthesis according to this invention will now be discussed with reference to the accompanying drawings.

In the drawings: FIG 1 shows an embodiment of a bifurcated prosthesis with an extension prosthesis according to this invention, FIG 2 shows an embodiment of a bifurcated prosthesis with two extension prostheses according to this invention, FIG 3 shows an embodiment of a prosthesis according to this invention intended for aortouni-iliac deployment, and FIG 4 shows a deployed prosthesis according to this invention within an aorta with an aneurism.

Now looking more closely at the drawings and particularly FIG 1 there will be seen an embodiment of a bifurcated prosthesis with an extension prosthesis according to this invention.

The bifurcated prosthesis 90 has a generally inverted Y- shaped configuration having a body portion 91, a shorter leg 92 and a longer leg 93. The body of the prosthesis is constructed from a tubular woven synthetic material such as dacron. At the proximal end 94 of the prosthesis 90 is a first zigzag stent 95 which extends beyond the end of the prosthesis and has distally extending barbs 96. The prosthesis has a number of zigzag stents mounted to it and extending along its length. The stent 97 nearest the proximal end 94 is inside the tubular material so that the outside presents :i 20 a smooth surface which in use engages against the inner wall of the vessel into which it is deployed to provide a barrier to the flow of blood. The stent 98 nearest the distal end 99 of the longer leg is also inside the tubular material so that the outside presents a smooth surface which in use engages against the inner wall of the vessel into which it is deployed to provide a barrier to the flow of blood. Between these internal stents the rest of the stents 100 are arranged on the outside of the tubular material so that they present minimal restriction to the flow of blood through the prosthesis and present minimal sites for the growth of thromboses within the prosthesis. Each stent S-is sewn to the tubular material as shown particularly at 101.

The longer leg 93 has one loop 43 of the terminal internal stent 98 extending beyond the end of the tubular material to act as the distal attachment means.

In use the prosthesis according to this embodiment of the invention is adapted for fitting into aorta such that the end 94 is just distal of the renal arteries and the first zigzag stent 95 extend up to or over the renal arteries. As it is constructed from thin wire it does not obstruct the renal arteries if it extends over them. The longer leg 93 extends down one of the iliac arteries and the shorter leg terminates in the aorta just short of the other iliac artery.

The terminal stent 102 nearest the distal end 92 of the shorter leg is outside the tubular material so that the inside presents a smooth surface which in use engages against the outside of one end of an extension prosthesis.

An extension prosthesis 104 is adapted for fitting into the shorter leg. The extension prosthesis 104 is constructed from a tubular synthetic material such as dacron and has terminal internal stents 105 and a plurality of external intermediate stents 106.

FIG 2 shows an embodiment of a bifurcated prosthesis with two extension prostheses :i 20 according to this invention.

The bifurcated prosthesis 110 has a generally inverted Y- shaped configuration having a body portion 111, a shorter leg 112 and a longer leg 113. The body of the prosthesis is constructed from a tubular woven synthetic material such as dacron. At the proximal end 114 of the prosthesis 110 is a first zigzag stent 115 which extends beyond the end of the prosthesis and has distally extending barbs 116. The prosthesis has a number of zigzag stents mounted to it and extending along its S•length. The stent 117 nearest the proximal end 114 is inside the tubular material so that the outside presents a smooth surface which in use engages against the inner wall of the vessel into which it is deployed to provide a barrier to the flow of blood.

The terminal stents 118 nearest the distal end 99 of the both the shorter and longer legs are outside the tubular material so that the inside presents a smooth surface which in use engages against the outside of one end of an extension prosthesis.

Between these terminal stents the rest of the stents 119 are arranged on the outside of the tubular material so that they present minimal restriction to the flow of blood through the prosthesis and present minimal sites for the growth of thromboses within the prosthesis.

The longer leg 113 has one loop 43 of the terminal external stent 118 extending beyond the end of the tubular material to act as the distal attachment means.

Extension prostheses 120 and 121 are adapted for fitting into both the shorter and longer leg. Each of the extension prostheses 120 and 121 are constructed from a tubular synthetic material such as dacron and have terminal internal stents 122 and a plurality of external intermediate stents 123.

••o•i In use the prosthesis according to this embodiment of the invention is adapted for 20 fitting into aorta such that the end 114 is just distal of the renal arteries and the first zigzag stent 115 extend up to or over the renal arteries. As it is constructed from thin wire it does not obstruct the renal arteries if it extends over them. The longer leg 113 extends down one of the iliac arteries and the shorter leg terminates in the aorta just short of the other iliac artery. The extension prostheses when deployed extend down each iliac artery.

FIG 3 shows an embodiment of a prosthesis according to this invention intended for aortouni-iliac deployment.

The prosthesis 130 has a generally tapering tubular configuration having a body portion 131 extending down to a single leg 132 of lesser diameter than the body portion. The body of the prosthesis is constructed from a tubular woven synthetic material such as dacron. At the proximal end 134 of the prosthesis 130 is a first zigzag stent 135 which extends beyond the end of the prosthesis and has distally extending barbs 136. The prosthesis has a number of zigzag stents mounted to it and extending along its length. The stent 137 nearest the proximal end 134 is inside the tubular material so that the outside presents a smooth surface which in use engages against the inner wall of the vessel into which it is deployed to provide a barrier to the flow of blood. The stent 138 nearest the distal end 132 of the leg is also inside the tubular material so that the outside presents a smooth surface which in use engages against the inner wall of the vessel into which it is deployed to provide a barrier to the flow of blood. Between these internal stents the rest of the stents 140 are arranged on the outside of the tubular material so that they present minimal restriction to the flow of blood through the prosthesis and present minimal sites for the growth of thromboses within the prosthesis.

ei The leg 132 has one loop 43 of the terminal external stent 138 extending beyond the 20 end of the tubular material to act as the distal attachment means.

In use the prosthesis according to this embodiment of the invention is adapted for fitting into aorta such that the end 134 is just distal of the renal arteries and the first zigzag stent 135 extends up to or over the renal arteries. As it is constructed from thin wire it does not obstruct the renal arteries if it extends over them. The leg 132 extends down one of the iliac arteries. The other iliac artery is intended to be closed of with a plug inserted via the femoral artery and a cross graft is surgically inserted between the iliac arteries to provide blood flow to both iliac arteries.

FIG 18 shows a deployed prosthesis according to the embodiment this invention within an aorta with an aneurism.

The aneurism 150 is a ballooning of the aorta 152 between the renal arteries 153 and the iliac arteries 154. The prosthesis as shown in FIG 15 is deployed into the aorta so that it spans the aneurism allows blood flow from the aorta to the two iliac arteries.

It will be noted that the proximal portion 94 of the prosthesis 90 which has the stent on the inside bears against the wall of the aorta 152 above the aneurism so that a good seal is obtained. The zigzag stent 95 which extends beyond the portion 94 extends over the entrances to the renal arteries but as the wire of the stent is fine occlusion does not occur. The distal end of the prosthesis 99 seals against the wall of one of the iliac arteries and the distal end 155 of the extension prosthesis 104 bears against the wall of the other iliac artery.

The join 156 between the prosthesis 90 and the extension prosthesis 104 seals because there is a smooth connection between the smooth inner surface on the shorter leg 112 and the smooth outer surface of the proximal end of the extension prosthesis 104.

S The size of the prostheses according to this invention may be selected so that there is in effect an interference fit in the sound parts of the vessels to give good sealing onto °i 20 the inner walls of the vessels. The prosthesis at its widest may range in diameter from 20 mm to 32 mm where it fits into the aorta and from 8 mm to 24 mm where it fits into the iliac arteries.

00 The embodiment shown in FIG 1 may have an overall length of from 120 mm to 180 25 mm not counting the length of the uncovered proximal stent and the extension prosthesis may have a length of from 35 mm to 125 mm and a diameter of from 8 mm °to 24 mm. The amount of overlap between the shorter leg of the prosthesis and the proximal end of the extension prosthesis is from 15 mm to 21 mm.

The embodiment shown in FIG 2 may have an overall length of from 100 mm to 130 mm not counting the length of the uncovered proximal stent. The difference in length between the shorter and longer legs of the bifurcated prosthesis may be mm. The shorter extension prosthesis may have a length of from 65 mm to 125 mm and a diameter of from 8 mm to 24 mm. The amount of overlap between the shorter leg of the prosthesis and the proximal end of the longer extension prosthesis is from nmm to 22 mm. The longer extension prosthesis may have a length of from 35 mm to 125 mm and a diameter of from 8 mm to 24 mm. The amount of overlap between the longer leg of the prosthesis and the proximal end of the shorter extension prosthesis is from 15 mm to 22 mm.

The embodiment shown in FIG 3 may have an overall length of from 90 mm to 180 mm not counting the length of the uncovered proximal stent. The prosthesis at its widest may range in diameter from 20 mm to 32 mm where it fits into the aorta and from 8 mm to 24 mm where it fits into one of the iliac arteries Throughout this specification unless the context requires otherwise, the words 'comprise' and 'include' and variations such as 'comprising' and 'including' will be :i •20 understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Throughout this specification various indications have been given as to the scope of this invention but the invention is not limited to any one of these but may reside in 25 two or more of these combined together. The examples are given for illustration only and not for limitation.

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Claims (9)

1. An intraluminal prosthesis having a tubular graft and a plurality of self expanding stents along the length of the graft the prosthesis having a proximal end and a distal end, the prosthesis being characterised by the stents at the proximal end and at the distal end being inside the tubular graft and the remainder of the stents being on the outside of the graft.

2. An intraluminal prosthesis as in claim 1 further including a further self expanding stent mounted to the proximal end of the graft and extending beyond the said proximal end.

3. An intraluminal prosthesis as in claim 2 when the further stent includes attachment devices.

4. An intraluminal prosthesis as in claim 3 wherein attachment devices comprise barbs extending towards the distal end of the prosthesis.

5. An intraluminal prosthesis as in claim 1 wherein the prosthesis is bifurcated 20 at its distal end to provide a shorter prosthesis leg and a longer prosthesis leg.

6. An intraluminal prosthesis as in claim 5 wherein the shorter leg has a terminal stent on the outside of the prosthesis and the longer leg has the internal distal stent.

7. An intraluminal prosthesis as in claim 5 or 6 further including an extension prosthesis for insertion into the shorter prosthesis leg, the extension prosthesis comprising a tubular extension prosthesis and a plurality of self expanding stents, the extension prosthesis having a proximal end and a distal end, stents at the proximal and distal ends being inside the tubular extension prosthesis and the remaining stents being on the outside of the prosthesis.

8. An intraluminal prosthesis as in claim 5 wherein both the shorter leg and longer leg have external terminal stents and extension prostheses for each leg, each extension prosthesis comprising a tubular extension prosthesis and a plurality of self expanding stents, the extension prosthesis having a proximal end and a distal end, stents at the proximal and distal ends being inside the tubular extension prosthesis and the remaining stents being on the outside of the prosthesis.

9. An intraluminal prosthesis as in any one of Claims 1 to 8 wherein each stent is a zig-zag stent. Dated this 25 th day of June 2001 WILLIAM A COOK AUSTRALIA PTY LTD By it Patent Attorneys MADDERNS a