MXPA97003260A - Endovascular device for aneuri protection - Google Patents

Abstract

The present invention relates to a prosthesis for imparting structural integrity to a blood vessel having an aneurysm defining an aneurysmal sac, comprising: a) a longitudinal member having a surface, a first end, a second end and an inner surface defining a longitudinal orifice to allow the passage of a fluid in motion having a velocity, the inner surface provided with means for increasing the velocity of the fluid passing through the longitudinal orifice, and b) a plurality of openings in fluid communication with the external surface and the longitudinal orifice, the openings are sized and arranged to allow blood to be drawn from the aneurysmal sac into the longitudinal orifice.

Description

ENDOVASCULAR DEVICE FOR ANEURISM PROTECTION FIELD AND BACKGROUND OF THE INVENTION The present invention relates to devices that are implanted within a body conduit of a living animal or a human being to impart structural integrity. In particular, the present invention relates to intravascular devices for delivery or implantation in a blood vessel having an aneurysm without many of the disadvantages and damaging characteristics of known devices. Aneurysm is a phenomenon in which the wall of a blood vessel, typically an artery, is abnormally dilated due to weakening of the vessel wall. This presents damage since the blood pressure inside the vessel could cause the vessel to rupture. A conventional approach to treat aneurysms is to use intravascular prostheses. Intravascular implants having a narrowed diameter for delivery through a blood vessel and an expanded diameter for applying a radially outwardly extending force to treat the aneurysm in a blood vessel are known in the art. These implants are usually covered with a cover, for example, Teflon or Dacron and serve to replace the aneurysmal wall of the blood vessel and relieve pressure on the aneurysmal wall by isolating the blood flow within the vessel. A disadvantage of those devices of the prior art is that the poor apposition of the prosthesis to the walls of the vessel being treated may allow blood to flow between the prosthesis and the aneurysm. This blood can create pressure on the aneurysmal wall in an amount sufficient to break the vessel at the weakened point of the aneurysm. A conventional approach to treating this problem is to insert an implant-like insert into the two ends of the prosthesis in an attempt to push the prosthesis against the vessel wall to create a more airtight seal between the prosthesis and the vessel wall that is trying. A disadvantage of this approach is that the introduction of the implants requires that the additional pressure be applied to the area being treated with the possibility that the pressure could cause damage to the vessel being treated. Another disadvantage of this approach is that in this procedure blood can leak into the aneurysmal sac. Therefore, it would be highly desirable to have a prosthesis to impart structural integrity to a blood vessel having an aneurysm that minimizes the risk of blood pressure in the aneurysmal sac.

OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION It is an object of this invention to provide a prosthesis for imparting structural integrity to a blood vessel having an aneurysm that minimizes the risk of blood leaking into the aneurysmal sac and maintaining pressure thereon. . It is another object of the invention to provide a prosthesis part for imparting structural integrity to a blood vessel having an aneurysm that minimizes the risk of blood seeping into and pressurizing the aneurysmal sac. It is even another object of this invention to provide a prosthesis for imparting structural integrity to a blood vessel having an aneurysm, comprising: a) a longitudinal member having an external surface, a first end, a second end and an internal surface that defines a longitudinal orifice, the inner surface provided with means for increasing the velocity of a fluid passing through the longitudinal orifice; and b) a plurality of openings in the fluid communication with the outer surface and the longitudinal hole.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a longitudinal side view of a blood vessel with an aneurysm; Fig. 2 shows a longitudinal side view of a conventional prosthesis with implants applied to its two ends applied to the blood vessel as shown in Fig. 1; Fig. 3 shows a longitudinal side view of a prosthesis constructed in accordance with the invention applied to the blood vessel of FIG. 1; Fig. 4 shows a longitudinal side view of a prosthesis constructed in accordance with the invention applied to the blood vessel of FIG. 1 after the aneurysmal sac has been suctioned in contact with the prosthesis; and Fig. 5 shows an alternative embodiment of a prosthesis constructed in accordance with the invention applied to the blood vessel of FIG. 1 after the aneurysmal sac has been suctioned in contact with the prosthesis.

DETAILED DESCRIPTION OF THE INVENTION Fig. 1 shows a blood vessel with an aneurysm 2. Fig. 2 shows a conventional prosthesis 3 placed at the site of the aneurysm 2. The less than optimum apposition of the prosthesis 3 to the inner wall 4 of the blood vessel 1 allows the blood 5 to leak or drain into the aneurysmal sac (" AS ") 6 which is the space 6 between the aneurysm 2 and the outer wall 7 of the prosthesis 3. Fig. 2 shows a conventional method for increasing the seal between the outer surface 7 of the conventional prosthesis 3 and the outer wall 4 of the blood vessel 1. After the prosthesis has been placed in the site of the aneurysm 2, the inserts 8 and 8 'were inserted into the ends 9 and 10 of the conventional prosthesis 3. The implants 8 and 8' apply pressure to the ends 9 and 8. 10 forcing them into close contact with the inner wall 4 of the blood vessel 1. A disadvantage of this procedure is that the pressure required could result in damage to the blood vessel 1. Another disadvantage is that the possibility remains that the blood 5 can still be filtered into the aneurysmal sac 6 due to an inadequate seal between the outer wall 7 of the prosthesis 3 and the aneurysm 2. Fig. 3 shows a prosthesis 1 1 constructed according to this invention placed in a blood vessel 1. The prosthesis 1 1 comprises a longitudinal member 12 having an external surface 16, a first end 14 and a second end 15. The internal surface 16 defines a longitudinal hole 17. The internal surface 16 is provided with means 18 for increasing the speed of the blood 5 flowing through the longitudinal orifice 17. In a preferred embodiment these means 18 are a tapered tapering as shown in Figs. 3, 4 and 5. If the velocity of a fluid that moves increases for any reason, the static pressure of the fluid decreases. This reduction in static pressure with the speed that increases is known as the Venturi effect. The effect can be demonstrated very easily. If two sheets of paper are kept parallel to one another and the velocity of the air layer between them increases, for example by blowing, it is observed that the two sheets move towards each other. This is because the static pressure between the two sheets is reduced compared to the surrounding atmospheric pressure.

As shown in Figs. 3, 4 and 5. The internal surface of the apparatus of this invention is provided with a uniformly tapered constriction or passage 18. The presence of this narrowing causes the velocity of the blood 5 to increase which is accompanied by a drop in pressure static The structure is similar to a hydrodynamic plane, i.e. the shape of the cross section of a hydrofoil, which has a greater curvature on the main surface than a second main surface. When a fluid, such as water, moves relative to that object, the flow velocity is greater over the surface of greater curvature. The resulting pressure difference between the more curved surface and the less curved surface gives rise to the suction. A plurality of openings 19 19 are in fluid communication with the outer surface 13 and the longitudinal hole 17 to allow blood 5 to flow from the aneurysmal sac 6 into the longitudinal hole 17. FIG. 4 shows that blood 5 flows in the direction of arrow 20, the blood 5 that may have been collected in the aneurysmal sac 6 is withdrawn or sucked into the longitudinal hole 17 through the openings 19. The inner wall 4 of the blood vessel 1 is withdrawn towards the external surface 13 of the prosthesis 1 1 due to the decreased static pressure within the longitudinal hole 17 resulting from the increase in the velocity of the moving blood 5 caused by the constriction 18. Therefore, the internal pressure on the aneurysmal sac 6 is decreased.

Fig. 5 shows an alternative embodiment of the invention wherein the outer surface 13 is parallel to the inner surface.

Claims (2)

1 . A prosthesis for imparting structural integrity to a blood vessel having an aneurysm, comprising: a) a longitudinal member having an external surface, a first end, a second end and an internal surface defining a longitudinal hole, the inner surface provided with means for increasing the velocity of the fluid passing through the longitudinal orifice; and b) a plurality of openings in fluid communication with the outer surface and the longitudinal hole.

2. The apparatus of claim 1, wherein the means is a uniformly tapered constriction.