GB2363989A

GB2363989A - Aneurysm repair device

Info

Publication number: GB2363989A
Application number: GB0015546A
Authority: GB
Inventors: Michael Charles Ormiston
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-27
Filing date: 2000-06-27
Publication date: 2002-01-16
Also published as: GB0015546D0

Abstract

The device comprises a first canalisation balloon (8) adapted to be deflatably inflatable both to block blood flow along the artery and provide a form for a required profile for a lumen of the artery, and a second cast balloon (9) surrounding the canalisation balloon (8). The cast balloon (9) is capable of being expanded independently of the canalisation balloon (8) by injection of a settable medium to fill such voids as are present between the canalisation balloon (8) and a wall of the aneurysm (3). The canalisation (8) and cast (9) balloons, in deflated form, are introducable to the aneurysm along the lumen of an artery. The cast balloon (9) filled with a solid settable medium such as silicone remains in place after deflation and removal of the canalisation balloon (8) to define an arterial lumen which is isolated from the weakened wall of the aneurysm by the solid mass of the set medium.

Description

2363989 ANEURYSM REPAIR DEVICE The present invention relates to a device

for repairing an aneurysm More particularly, but not exclusively, it relates to a device for repairing an arterial aneurysm, especially in the human aorta It further relates to a method for repairing an arterial aneurysm.

An aneurysm is a weakening and ballooning of a blood vessel, which irreversibly stretches and further weakens the wall of the vessel It may particularly affect the aorta, the main artery leaving the heart, especially at a point below the renal arteries, which supply the kidneys, and above where the aorta diverges to form the two iliac arteries The aneurysm may enlarge and, in time, rupture, which is usually fatal Approximately 5000 operations to repair aneurysms are currently performed in the UK each year The present invention will hereinafter be described, by way of example, with reference to aortic aneurysms However, other arteries may require repair in an analogous fashion and the device is equally applicable thereto.

Hitherto, conventional surgery to repair an aneurysm has required opening the abdomen of a patient and sewing a Dacron (Dacron is a Registered Trade Mark) tube into the lumen of the aneurysm This operation is performed when an aneurysm has reached a size at which the risk of rupture outweighs the risk of surgery This is a major abdominal operation, which has a significant mortality rate, perhaps approximately 5 % There is also a risk of lesser complications and there is an inevitable prolonged period of hospitalisation and recuperation.

Endovascular repair offers a less invasive method of repairing aneurysms A stent, comprising a compressed Dacron tube supported on a metal frame, is introduced through a cut into a femoral artery in the groin of a patient The stent is advanced up through the femoral and iliac arteries under radiological control, until it is positioned in the aorta above the aneurysm, extending back through the aneurysm into the iliac artery The stent is released and expands, hooking into the walls of the aorta above the aneurysm, and lining the aorta through the aneurysm The sac of the aneurysm is thus excluded and protected from the pressure of circulating blood.

A crossover graft may be provided from one iliac or femoral artery to the other, to restore circulation to both legs.

Alternatively, a Y-shaped stent may be provided, extending into both iliac arteries; optionally, this may be assembled within the aorta from components introduced along both iliac arteries.

3 This procedure entails a shorter stay in hospital and patients may rapidly return to normal activities It is also suitable for use on patients who are not fit enough to undergo conventional abdominal surgery.

However, such stents have significant limitations The stent may dislodge, or it may suffer mechanical failure A relatively long neck of normal, unaffected aorta is required between the renal arteries and the aneurysm, to which the stent may be sealed Failure of the seal can lead to endoleak, the re-establishment of circulating blood flow between the exterior of the stent and the sac of the aneurysm The aneurysm is again under pressure, and the risk of rupture returns Endoleak occurs in around 10 % of patients per annum Furthermore, stents for this purpose are difficult and expensive to manufacture However, they have become the favoured compromise for this problem.

It is therefore an object of the present invention to provide a device which may be used for the rapid and reliable repair of arterial aneurysms, which is suitable for a wider range of configurations of aneurysm and which tends to eliminate or reduce the risks of failure or endoleakage It is a further object of the present invention to provide a method for repairing aneurysms, employing said device.

According to a first aspect of the present invention, there is provided a device for repair of an arterial aneurysm, comprising first balloon means adapted to be deflatably inflatable to adopt a configuration capable both of blocking blood flow along the artery and of providing a form for a required profile for a lumen of the artery, and a second balloon means surrounding the first and capable of being expanded independently of the first balloon means.

4 The device preferably further comprises means to inject a settable medium into said second balloon means.

The medium, when converted to a more solid form, is adapted to fill such voids as are present between the first balloon means and a wall of the aneurysm.

The outer surfaces of the second balloon means may be provided with a thrombogenic surface to promote in-filling of any spaces remaining between the second balloon means and the sac of the aneurysm.

Preferably, said settable medium comprises a silicone material, advantageously a curable silicone material.

Alternatively the settable medium may comprise a plastics resin or elastomer.

The device may further comprise channel means adapted to introduce material into said second balloon means, said channel means comprising a frangible section to allow the channel means to be broken off after use.

Alternatively, the device may be provided with cutting means to sever said channel means.

The cutting means may comprise a guillotine which is adapted to be introduced along the artery.

The second balloon means may comprise a segmented or otherwise internally sub-divided internal structure, to permit better control of its expansion.

Preferably, said first and second balloon means, in deflated form, are introducable to the aneurysm along the lumen of an artery.

Advantageously, there is further provided a guide wire introducable along an artery and the first and second balloon means may enclose said guide wire to follow said guide wire.

Optionally, said balloon means may be mounted on an introducer to aid handling.

Preferably, said device is provided with a channel adapted for introduction of contrast media into the artery upstream of the device, thereby to facilitate location of the device, employing radiological visualisation.

Where the artery is the aorta, this may be used efficiently to locate the device in relation to the renal arteries and the aneurysm.

The device may also be provided with radio-opaque markers to facilitate such location.

Preferably, the device is provided with means to inflate each said balloon means, so adapted that said first balloon means may be inflated to a higher pressure than said second balloon means, thereby resisting any tendency for the second balloon means to constrict the first balloon means, possibly leading to a constricted lumen.

The second balloon means may comprise a material of greater expansibility than that making up the first balloon means, such that it may be expanded by comparatively lower pressure.

The first balloon means may comprise a semi-rigid structure, so configured that said first balloon means may conform in its inflated form to the normal internal calibre of the artery, facilitating the formation of an accurately dimensioned arterial lumen and improving the occlusion of blood flow in the artery.

Advantageously, the device may be provided with a sealing mechanism attached to an upstream end of said second balloon means, adapted to act as a seal between the artery and said second balloon means, such that leakage between the second balloon means and the walls of the sac of the aneurysm is resisted.

Said sealing mechanism may comprise an expansion cuff of metal or plastics material, optionally provided with detent means adapted to engage with the wall of the artery above the aneurysm.

Optionally, the device may also be provided with a second sealing mechanism attached to a downstream end of said second balloon means, adapted to form a seal between said second balloon means and the artery, such that leakage adjacent the lower end of the aneurysm is also resisted.

The device may be provided with cooling means, adapted to cool a fluid which may be circulated through the first balloon means, in order to conduct away any heat generated during solidification of the medium filling the second balloon means.

The device may be provided with means to create a channel between the lumen of the aorta and the second iliac artery not used to introduce the device, thereby avoiding the need to create a cross-graft to allow blood into the second iliac artery.

In a preferred embodiment particularly, but not exclusively, adapted for use in an aortic aneurysm, the device further comprises third balloon means, mounted distally to the first balloon means and adapted to be deflatably inflatable independently thereof The third balloon means may be so mounted to said first balloon means that limited relative movement is possible between the two.

The third balloon means may comprise an elastic material.

This third balloon means may be so locatable as to be capable of occluding the aorta above and adjacent the renal arteries, in which case deflation of the third balloon means may permit occasional resumption of blood flow to the kidneys during longer procedures.

The first balloon means is in this case adapted to occlude the normal aorta only below the renal arteries and provide a form of the required profile for the lumen of the aorta.

According to a second aspect of the present invention, there is provided a method for repairing an arterial aneurysm, comprising the steps of providing a device comprising first balloon means and second balloon means surrounding the first balloon means and capable of being expanded independently thereof, positioning the device so that said first balloon means extends beyond the aneurysm in both directions; inflating said first balloon means to occlude blood flow through the artery; inflating said second balloon means with a settable medium such that it fills such voids as are present between said first balloon means and a wall of the aneurysm; causing said settable medium to set into a solid state; deflating said first balloon means; and withdrawing said first balloon means separately from said second balloon means to form a lumen through the second balloon means.

Preferably, the method comprises the steps of making an incision in an artery, inserting the balloon means through said incision into the artery and passing it along the arterial system to the aneurysm requiring repair.

Advantageously, the method comprises the step of inserting a guide wire into the artery and guiding the balloon means along the artery.

Preferably, said step of inflating said second balloon means employs a settable medium which may comprise a silicone material, a plastics resin or an elastomer.

Alternatively, said settable medium may comprise a medium which is capable of forming a foam.

In a preferred embodiment of the method for repairing an aortic aneurysm, there is provided additionally a third balloon means, mounted distally to the first balloon means and adapted to be deflatably inflatable independently thereof, inflating said third balloon means simultaneously with or prior to the step of inflating said first balloon means, to occlude the aorta above and adjacent the renal arteries.

9 In this case, said third balloon means may be deflated as required to permit occasional resumption of blood flow along the renal arteries to the kidneys.

Alternatively, where said third balloon means is so mounted to said first balloon that limited relative motion is possible between the two, the steps of positioning said first and third balloon means may be carried out sequentially.

In embodiments of the method adapted for repairing an aortic aneurysm, the method preferably comprises the steps of making an incision into a femoral artery in a groin of a patient, inserting the balloon means into the femoral artery through said incision, and passing the device up along the femoral artery and the corresponding iliac artery into the aorta adjacent the aneurysm.

Advantageously, the method further comprises the step of performing a cross-over graft between the femoral arteries in the groin to restore blood supply to both legs.

Alternatively, means may be introduced to penetrate through such parts of the second balloon means and the set medium within as may be occluding blood flow to that iliac artery not employed to introduce the device.

Preferably the method comprises the step of locating the device within the artery using radiological visualisation.

The method may then additionally comprise the step of injecting a contrast medium into the artery through a channel in the device.

Optionally, the step of locating the device within the artery may additionally comprise the visualisation of radio-opaque markers provided within the various elements of the device to visualise their disposition jointly and severally, including their degree of inflation.

The method may comprise the step of sealing between the aorta and said second balloon means.

Optionally, the method may also comprise the step of sealing between the iliac artery and said second balloon means.

Preferably, the method comprises the steps of inflating the first balloon means to a first pressure, and expanding the second balloon means to a pressure no greater than said first pressure, such that said second balloon means does not significantly constrict said first balloon means.

In the case where the settable medium injected into the second balloon means sets in an exothermic reaction, the method may additionally comprise the step of inflating the first balloon means with a cooled fluid, or alternatively of circulating cooled fluid through said first balloon means, to conduct away heat generated during said exothermic reaction.

The method may comprise the steps of providing channel means to fill the second balloon means, and severing said channel means subsequent to the setting of the medium within said second balloon means.

Embodiments of the present invention will now be more particularly described, by way of example and with reference to the accompanying drawings, wherein:

Figure 1 is a schematic view in longitudinal section of a device embodying the invention, in a deflated configuration in place in an aortic aneurysm; Figure 2 is a schematic view in longitudinal section of the same device in an initially inflated configuration; Figure 3 is a schematic view in longitudinal section of the same device in a fully inflated configuration; Figure 4 is a view in longitudinal section of the aortic aneurysm after deployment of the device; Figure 5 is a scrap view in longitudinal section of part of a device embodying the invention; Figure 5 a shows a cross-section of the device shown in Figure 5, taken along the line A-A; Figure 5 b shows a cross-section of the device shown in Figure 5, taken along the line B-B; Figure 6 is a scrap view in longitudinal section of part of another device embodying the invention; Figure 6 a shows a cross-section of the device shown in Figure 6, taken along the line A-A; Figure 6 b shows a cross-section of the device shown in Figure 6, taken along the line B-B; Figure 7 is a view in longitudinal section of an alternative device embodying the invention, in a fully inflated configuration; Figure 8 is a scrap view in longitudinal section of part of a further device embodying the invention; Figure 8 a shows a cross-section of the device of Figure 8, taken along the line A-A; and Figure 8 b shows a cross-section of the device of Figure 8, taken along the line B-B.

Referring now to the drawings, and to Figure 1 in particular, a device 1 embodying the invention is disposed, in a deflated configuration, on a guide wire 2, extending from an iliac artery 4, through the sac 3 of an aortic aneurysm, into a normal part 5 of the aorta, adjacent the renal arteries 6 The device 1 is mounted on an introducer (not shown).

In Figure 2, a first balloon (or "canalisation balloon") 8 of the device 1 has been inflated and is shown in an inflated configuration, occluding the normal part 5 of the aorta, and extending through the sac 3 of the aneurysm to the iliac artery 4 A second balloon (or "cast balloon") 9, mounted around and connected separably to the canalisation balloon 8, remains in a deflated configuration However, a third balloon (or "occlusion balloon") 7 is in an inflated configuration, occluding the normal part 5 of the aorta and also the renal arteries 6.

However, it may optionally be deflated for short periods to re-establish occasional blood flow along the renal arteries 6 to the kidneys, should the procedure be of such duration as to risk kidney damage if they are kept isolated for that long.

In Figure 3, the cast balloon 9 has been filled with a settable medium 10 and is in an expanded configuration, such that it fills the space between the canalisation balloon 8 and the walls of the sac 3 of the aneurysm, conforming to the configuration of both.

13 In Figure 4, the settable medium 10 is shown as a solid mass The canalisation and occlusion balloons 8, 7 are no longer present, having been deflated and withdrawn The filled cast balloon 9 remains, filling the sac 3 of the aneurysm and isolating its weakened walls from the pressure of the blood flow, which passes through the lumen 11 left by the withdrawal of the canalisation balloon 8 A cross-over graft 12 connects the artery 4 to the corresponding artery 4 ' on the opposite side of the body of the patient, to re- establish blood flow to that side of the body, since the cast balloon 9 occludes the artery 41.

Prior to the inflation of the cast balloon 9, the artery 4 ' may be occluded, either temporarily with a balloon or permanently with a plug, introduced from the groin up the artery 41 to a location near the aneurysm This will prevent any debris dislodged by inflation of the cast balloon 9 from passing down the artery 41 to the leg.

Figures 5, 5 a and 5 b show in more detail the configuration of the canalisation balloon 8 and the occlusion balloon 7 in their inflated configuration A channel 13 permits the inflation and deflation of the occlusion balloon 7, independent of the canalisation balloon 8 Another channel 14 may be employed to inject contrast medium into the aorta above the device 1, to aid positioning of the device relative to the renal arteries by radiological visualisation The device is also provided with radiopaque markers built into its structure (not shown) A further channel 15 permits inflation and deflation of the canalisation balloon 8 The guide wire 2 runs through a separate channel 16 passing through both balloons.

Figures 6, 6 a and 6 b show another embodiment of the device 1, in its fully inflated configuration The canalisation balloon 8 and occlusion balloon 7 are fully inflated (details of these balloons are as shown in Figure 5, and are not shown here) The cast balloon 9 is 14 full of settable medium 10 and adopts a configuration conforming to the space between the canalisation balloon 8 and the sac 3 of the aneurysm A channel 17 is provided for injection of the settable medium 10 into the cast balloon 9 A metal or plastics expansion cuff 18 is attached to a top margin of the cast balloon 9, such that it may be expanded to grip the walls of the aorta, anchoring the cast balloon 9, and creating a seal between it and the aorta.

Once the settable medium 10 is in a more solid state, a guillotine may be introduced up the artery 4 and used to cut the channel 17 connected to the cast balloon 9 Alternatively, the channel 17 may be configured to be easily detachable from the cast balloon 9.

Figure 7 shows a further embodiment of the device 1 A single canalisation and occlusion balloon 19 occludes the normal part of the aorta 5 both above and below the renal arteries 6.

This balloon 19 is provided with a waist 20, which may be aligned with the renal arteries 6.

The channel 14 for injection of contrast medium connects to the waist 20 to facilitate accurate location thereof adjacent the renal arteries 6 by means of radiological visualisation.

Figure 8 shows part of an embodiment of the device 1, in which the occlusion balloon 7 is free to move translationally relative to the canalisation balloon 8 The canalisation balloon 8 is mounted coaxially around a duct 21, within which the channel 16 enclosing the guide wire and the channel 13 permitting inflation and deflation of the occlusion balloon 7 may move freely The channel 14 for injection of contrast medium may pass through the canalisation balloon 8, as shown, or may pass through the duct 21 and the occlusion balloon 7, along with the channel 16.

Claims

1 A device for repair of an arterial aneurysm comprising first balloon means adapted to be deflatably inflatable to adopt a configuration capable both of blocking blood flow along the artery and of providing a form for a required profile for a lumen of the artery, and a second balloon means surrounding the first and capable of being expanded independently of the first balloon means.

2 A device as claimed in claim 1, further comprising means to inject a settable medium into said second balloon means.

3 A device as claimed in claim 2, wherein the medium, when converted to a more solid form, is adapted to fill such voids as are present between the first balloon means and a wall of the aneurysm.

4 A device as claimed in any either claim 2 or claim 3, wherein the outer surfaces of the second balloon means are provided with a thrombogenic surface to promote in-filling of any spaces remaining between the second balloon means and the sac of the aneurysm.

A device as claimed in any one of claims 2 to 4, wherein said settable medium comprises a silicone material, advantageously a curable silicone material.

16 6 A device as claimed in any one of claims 2 to 4, wherein the settable medium comprises a plastics resin or elastomer.

7 A device as claimed in any one of claims 2 to 6, further comprising channel means adapted to introduce material into said second balloon means.

8 A device as claimed in claim 7, wherein said channel means comprises a frangible section to allow the channel means to be broken off after use.

9 A device as claimed in claim 7, wherein the device is provided with cutting means to sever said channel means.

A device as claimed in claim 9, wherein the cutting means comprises a guillotine which is adapted to be introduced along the artery.

11 A device as claimed in any one of the preceding claims, wherein the second balloon means comprises a segmented or otherwise internally sub-divided internal structure, to permit better control of its expansion.

12 A device as claimed in any one of the preceding claims, wherein said first and second balloon means, in deflated form, are introducable to the aneurysm along the lumen of an artery.

13 A device as claimed in claim 12, further comprising a guide wire introducable along an artery, said first and second balloon means so enclosing said guide wire as to follow said guide wire.

14 A device as claimed in any one of the preceding claims, further comprising a channel adapted for introduction of contrast media into the artery upstream of the device, whereby to facilitate location of the device employing radiological visualisation.

A device as claimed in any one of the preceding claims, further comprising radio- opaque marker means to facilitate location of the device.

16 A device as claimed in any one of the preceding claims, further comprising means to inflate each said balloon means, so adapted that said first balloon means may be inflated to a higher pressure than said second balloon means, whereby any tendency for the second balloon means to constrict the first balloon means on inflation is resisted.

17 A device as claimed in claim 16, wherein the second balloon means comprises a material of greater expansibility than that making up the first balloon means, such that it may be expanded by comparatively lower pressure.

18 A device as claimed in any one of the preceding claims, wherein the first balloon means comprises a semi-rigid structure, so configured that said first balloon means may conform in its inflated form to the normal internal calibre of the artery, facilitating the formation of an accurately dimensioned arterial lumen and improving the occlusion of blood flow in the artery.

19 A device as claimed in any one of the preceding claims, further comprising a sealing mechanism attached to an upstream end of said second balloon means, adapted to act as a seal between the artery and said second balloon means, such that leakage between the second balloon means and the walls of the sac of the aneurysm is resisted.

A device as claimed in claim 19, wherein the sealing mechanism comprises an expansion cuff of metal or plastics material, optionally provided with detent means adapted to engage with the wall of the artery above the aneurysm.

21 A device as claimed in either claim 19 or claim 20, further comprising a second sealing mechanism attached to a downstream end of the second balloon means, adapted to form a seal between said second balloon means and the artery, such that leakage adjacent the lower end of the aneurysm is also resisted.

22 A device as claimed in any one of claims 2 to 21, further comprising cooling means to cool a fluid which may be circulated through the first balloon means, in order to conduct away any heat generated during solidification of the medium filling the second balloon means.

23 A device as claimed in any one of the preceding claims, further comprising third balloon means, mounted distally to the first balloon means and adapted to be deflatably inflatable independently of the first balloon means.

19 24 A device as claimed in claim 23, wherein said third balloon means is so mounted to said first balloon means that limited relative movement is possible between the two.

A device as claimed in either claim 23 or claim 24, wherein the third balloon means comprises an elastic material.

26 A device as claimed in any one of claims 23 to 25, wherein the artery is the aorta and the third balloon means is so locatable as to be capable of occluding the aorta above and adjacent the renal arteries, whereby deflation of the third balloon means permits occasional resumption of blood flow to the kidneys.

27 A device as claimed in claim 26, wherein said first balloon means is adapted to occlude the normal aorta only below the renal arteries and provide a form of the required profile for the lumen of the aorta.

28 A device for repair of an arterial aneurysm substantially as described herein with reference to the Figures of the accompanying drawings.

29 A method of repairing an arterial aneurysm comprising the steps of providing a device comprising first balloon means and second balloon means surrounding the first balloon means and capable of being expanded independently thereof, positioning the device so that said first balloon means extends beyond the aneurysm in both directions; inflating said first balloon means to occlude blood flow through the artery; inflating said second balloon means with a settable medium such that it fills such voids as are present between said first balloon means and a wall of the aneurysm; causing said settable medium to set into a solid state; deflating said first balloon means; and withdrawing said first balloon means separately from said second balloon means to form a lumen through the second balloon means.

A method as claimed in claim 29, further comprising the steps of making an incision in an artery, inserting the balloon means in deflated condition through said incision into the artery and passing it along the arterial system to the aneurysm requiring repair.

Amendments to the claims have been filed as follows 1 A device for repair of an arterial aneurysm comprising first balloon means adapted to be inflatable to adopt a configuration capable of blocking blood flow along the artery and of providing a form for a required profile for a lumen of the artery, and thereafter to be deflatabie to allow its removal, and a second balloon means surrounding the first and adapted to be expanded independently of the first balloon means and remain in situ after withdrawal separately of the first balloon means.

A device as claimed in any one of claims 2 to 4 wherein said settable medium comprises a silicone material, advantageously a curable silicone material.

6 A device as claimed in any one of claims 2 to 4, wherein the settable medium comprises a plastics resin or elastomer.

11 A device as claimed-in any one of the preceding claims, wherein the second balloon means comprises a segmented or otherwise internally sub-divided internal structure, to permit better control of its expansion.

24 A device as claimed in claim 23, wherein said third balloon means is so mounted to said first balloon means that limited relative movement is possible between the two.