Blood Vessel Bridging Device

Abstract

A blood vessel bridging device to be surgically implanted between two blood vessels to prevent partial occlusion of one by the other. The device comprises a generally U-shaped molded body of, e.g., Dacron reinforced silicone rubber having flattened bearing portions at both ends thereof and a generally U-shaped cross-section at its mid portion to cradle the overlying blood vessel.

Description

BACKGROUND OF THE INVENTION

The present invention relates to surgical devices and more particularly to a device for surgical implantation for prevention of partial occlusion of blood vessels at points where one crosses over another.

In a study of thrombotic and static venous diseases of the lower extremities it has been found that a preponderance of problems occur on the left side and it has been observed that many of these are apparently caused by venous adhesions and outflow obstruction produced by compression of the left common iliac vein at the point where the right common iliac artery crosses over it. The statistical significance of primary disease occuring in the left leg is overwhelming, with thrombophlebitis occuring twice as frequently on the left, ileofemoral thrombosis having a similar predominance, and lymphedema praecox having a 80 percent occurence on the left. This juncture of stasis has also been implicated as a frequent source for pulmonary emboli. These diseases, of course, take a fantastic toll in clinical morbidity and mortality. Dissections in unselected autopsies show an average adult incidence of 24 percent of intimal bands or adhesions at this point. Yet, in fetal and new born dissections virtually no such adhesions exist. It has, therefore, been theorized that the pulsating artery lying in substantial contact with the vein induces an intimal thickening and thrombosis and surgery has in the past been utilized to attempt to correct such problems. Up until the present invention, however, surgeons have suffered from an inability to prevent recurrent arterial compression following an initial restoration by surgery. It is toward that problem that the present invention is directed.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to provide a surgically implantable device which will prevent recurrence of venous stasis at the point where the right common iliac artery crosses over the left common iliac vein. The present invention provides a device which is a generally U-shaped molded body of semi-rigid material having a flattened bearing portion at both ends thereof. The center portion of the body is also generally U-shaped in cross-section taken perpendicular to the longitudinal axis of the body and acts to cradle the overlying blood vessel and prevents contact between the pair of vessels. The bearing portions of the device serve to support the overlying blood vessel and prevent pressure from being exerted on any confined area of the underlying vessel by the overlying one. The device has been designed specifically for the point at which the right common iliac artery crosses over the left common iliac vein. Clinical evidence indicates efficacy of the device for the purpose for which it was designed.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be better understood by reference to the following detailed description when read in connection with the accompanying drawings wherein:

FIG. 1 is a view in prespective of a bridging device made in accordance with the present invention;

FIG. 2 is a side elevational view of the device shown in FIG. 1;

FIG. 3 is an end view in elevation of the device shown in FIGS. 1 and 2;

FIG. 4 is a vertical cross-sectional view of the device shown in FIGS. 1-3 taken along the line 4--4 of FIG. 2;

FIG. 5 is an anatomical sketch showing positioning of the device of FIGS. 1-4 within a human body;

FIG. 6 is a view in perspective of a modified form of the device, and

FIG. 7 is an anatomical sketch showing positioning of the device of FIG. 6 within a human body.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the figures thereof there is shown in FIGS. 1-4 a molded body of semi-rigid material which constitutes the present invention. The term "semi-rigid" as used herein means a material of sufficient rigidity to retain its shape under stress from the pulsing of arteries into which it is to be placed in contact but capable of flexing to prevent anatomical damage to portions of the body adjacent to the device in the event of severe stresses. The material, of course, must be substantially inert with respect to the body in which it is being implanted. A preferred material is Dacron fabric reinforced silicone rubber.

As may be seen from FIGS. 1-4 the body has a generally U-shaped configuration along its longitudinal axis and in addition has a generally U-shaped configuration in its midsection as may be seen more clearly from the cross-section in FIG. 4. The opposite ends of the body are flattened to provide footplates or bearing portions 11 and 12 and preferably an elongated stripe 13 of radio-paque material is provided along the length of the device to allow visual inspection by X-ray of placement of the device subsequent to surgery.

The anatomical sketch shown in FIG. 5 shows placement of the device as shown in FIGS. 1-4. The aorta is indicated by the numeral 14 and branches into right and left iliac arteries 15 and 16, respectively. The vena cava 17 is similarly fed by the right and left iliac veins 18 and 19, respectively. Since the aorta lies to the left of the vena cava the right iliac artery 15 must cross over the left iliac vein 19. Iliac venous compression is caused by pressure exerted by the artery 15 on the vein 19. The body 20 of the present invention is interposed between the artery and vein at that point. The bearing portions 11 and 12 of the device are sutured to the prevertebral fascia at the iliac venous crotch and the left superior iliocaval border. The right iliac artery is cradled between the upturned edges of the center portion of the device to thereby hold it in position. The longitudinal U-shaped of the center portion of the device serves as a bridge over the left iliac vein to thereby eliminate pressure on the vein by the artery. The device also acts as a spacer to prevent any adhesion between the vein and the artery. The inherent rigidity of the device provided, for example, by the silicone rubber and the fabric reinforcement thereof from which the device is preferably manufactured, serves to maintain the relationship.

In about 20 percent of the cases in which iliac venous compression occurs the right iliac artery tends to run parallel to the right iliac vein at the iliac venous crotch thus preventing placement of the bearing portion on the prevertebral fascia in the crotch. In such instances it is preferable to have a device shaped such as the modification 20' shown in FIG. 6 in which the bearing portion 11' at one end of the device is made substantially wider than the body of the device instead of substantially the same width of the device as is shown in FIGS. 1-4. Placement of the device 20' in a human body is shown in the anatomical sketch of FIG. 7. The wide bearing portion 11' can then overly the right iliac vein and bear on fascia at both sides thereof or at least spread any pressure exerted on the device by the right iliac artery over a much wider area thereby preventing adhesions. Obviously it is desirable for the widened bearing portion 11' to have a curvature corresponding to the curvature of the right iliac vein to minimize pressure on the right iliac vein and flattened footplates provided at each end of the bearing portion 11'.

In the preferred operative technique for implanting the device of the present invention the aortic bifurcation is exposed through a midline transabdominal incision. The distal aorta and the right common iliac artery are mobilized and retracted to the left. Elevation of the artery permits lysis of fibrous adhesions surrounding the left iliac vein and characteristically allows the previously flattened vein to assume a substantially circular configuration. Minimal posterior dissection is required. The prevertebral fascia at the iliac venous crotch and the left superior ileocaval border is then exposed and the device is temporarily positioned with its footplates on these cleared areas to allow ajustments to insure gentle arterial bridging. When alignment is deemed proper sutures are placed into the fascia with the device removed and the free suture ends are then passed through each respective footplate. After the device is securely positioned the peritoneum is closed over the vessels and the abdomen is closed.

It should be realized that although the description of a preferred embodiments refers only to a device for bridging the left iliac vein, similar devices utilizing the same principles may be used in other portions of the human body or in animal bodies if similar conditions exist. It will also be obvious to those skilled in the art that some modifications and variations of the device may be made without departing from the spirit and scope of the invention; therefore, it is to be understood that within the scope of the amended claims the invention may be practiced otherwise than as specifically described.

Claims

That which is claimed is:

1. A blood vessel bridging device for surgical implantation between a juxtaposed pair of blood vessels to prevent compression of one of said vessles by the other, comprising a molded body of semi-rigid material substantially inert to the animal body having a generally U-shaped configuration along the longitudinal axis thereof with a flattened bearing portion at both ends thereof; the center portion of said body being also generally U-shaped in a cross-section taken perpendicular to the longitudinal axis of said body to thereby cradle the overlying blood vessel and prevent contact between said pair of vessels.

2. A blood vessel bridging device as defined in claim 1 wherein both of said bearing portions are of substantially the same width as the remainder of said device.

3. A blood vessel bridging device as defined in claim 2 wherein said device is fabric reinforced silicone rubber.

4. A blood vessel bridging device as defined in claim 3 wherein a stripe of radiopaque material is molded integrally therewith along the length thereof.

5. A blood vessel bridging device as defined in claim 1 wherein at least one of said bearing portions is substantially wider than the remainder of said body.

6. A blood vessel bridging device as defined in claim 5 wherein said device is fabric reinforced silicone rubber.

7. A blood vessel bridging device as defined in claim 6 wherein a stripe of radiopaque material is molded integrally therewith along the length thereof.

8. The combination of a pair of juxtaposed blood vessels in an animal body, the blood vessels comprising a first vessel and a second vessel and a blood vessel bridging device to be implanted between the first and second vessel, the device comprising a molded body of semi-rigid material substantially inert to said body having a generally U-shaped configuration along the longitudinal axis thereof with a flattened bearing portion at both ends thereof; the center portion of said body being also generally U-shaped in a cross-section taken perpendicular to the portion of the longitudinal configuration along the longitudinal axis abutting the first vessel and spaced from the second vessel thereby to cradle the first vessel and preventing contact between said pair of vessels.