BACKGROUND OF THE INVENTION

Field of the Invention

This application generally relates to a biological valve for the replacement of a venous valve of the deep venous system of the leg or other veins of comparable caliber.

Description of the Related Art

Patients with chronic deep vein insufficiency may require the repair or replacement of at least one of the venous valves of the deep veins of the leg. Also, in some cases the venous valve replacement may involve the iliac veins.

Present therapy involves either the surgical repair of the valve leaflets or external banding of the vein to decrease the diameter and bring the weakened leaflets to a geometry which may allow for improved function. The incompetent venous valves of patients with advanced chronic disease are usually not amenable to repair and may be replaced.

Currently, venous valve replacement and therapy is limited to allograft or cryopreserved valves. Allograft valves are difficult to harvest and cryopreserved valves can elicit a deleterious immune response.

SUMMARY OF EXEMPLARY EMBODIMENTS

In accordance with one embodiment, a monocusp bioprosthetic valve for implantation into a host vein of a subject is described. The bioprosthetic valve comprises biological tissue from a xenogeneic source. The biological tissue comprises a single leaflet from a heart valve and a patch comprising tissue contiguous with the single leaflet. In one aspect of the embodiment, the xenogeneic source is porcine. In a further aspect, the single leaflet is attached to the patch at natural margins of attachment. In a still further aspect, the heart valve is an aortic valve. In such an aspect, the patch may include a segment of the aortic annulus. In the same aspect, the single leaflet may be a noncoronary leaflet. In yet another aspect of the embodiment, the patch has a generally rectangular shape. In a further aspect, the patch has a generally ovoid shape. In a still further aspect, the patch extends circumferentially on either side of the leaflet so as to provide a region for attachment to the host vein. In another aspect, the patch extends axially above and below the leaflet so as to provide a region for attachment to the host vein. In any of these aspects, at least a portion of the patch may be covered with a synthetic fabric. Also, in any of these aspects, the subject may be human.

In accordance with another embodiment, a bioprosthetic valve for implantation into a host vein of a subject consisting essentially of a single leaflet from a xenogeneic heart valve attached at natural margins of attachment to a patch of valve wall tissue from the xenogeneic heart valve is provided. In one aspect of this embodiment, the xenogeneic heart valve is porcine. In a further aspect, the patch extends circumferentially on either side of the leaflet to provide a region for attachment to the host vein. In another aspect, the patch extends axially above and below the leaflet to provide a region for attachment to the host vein. In yet another aspect, the xenogeneic heart valve is an aortic valve. In the preceding aspect, the leaflet may be a noncoronary leaflet.

In accordance with yet another embodiment, a method of manufacturing a replacement venous valve for a subject is described. The method comprises providing a xenogeneic heart valve which has at least one leaflet and a valve wall, and which has been subjected to a fixation treatment. The method further comprises excising a portion of the heart valve. The portion comprises at least a selected leaflet attached at natural margins of attachment to a patch of valve wall tissue, such that said excised portion comprises a single leaflet. In one aspect of the embodiment, the xenogeneic heart valve is porcine. In another aspect, the patch extends circumferentially on either side of the selected leaflet to provide a region for attachment to the host vein. In a further aspect, the patch extends axially above and below the selected leaflet to provide a region for attachment to the host vein. In a still further aspect, the xenogeneic heart valve is an aortic valve. In such an aspect, the selected leaflet may be a noncoronary leaflet. In yet another aspect of the embodiment, the method further comprises cutting through each of the natural commissures and shaving off tissue of any leaflets adjacent to the selected leaflet. In any of these aspects, the subject may be human.

In accordance with a further embodiment, a method of treating a malfunctioning valve in a host vein of a subject is described. The method comprises providing a replacement biological valve comprising a single leaflet from a xenogeneic heart valve attached at natural margins of attachment to a patch of contiguous tissue from the xenogeneic heart valve. The method further comprises inserting said replacement biological valve into said host vein. In one aspect of the embodiment, the method further comprises creating a fenestration in the host vein in the region of the malfunctioning valve, the fenestration having a shape generally corresponding to the patch. In the preceding aspect, the fenestration may be created generally in the region of the malfunctioning valve, generally above the region of the malfunctioning valve, or generally below the region of the malfunctioning valve. In the same aspect, the method may further comprise attaching the replacement biological valve to the host vein at the fenestration. In another aspect, the method further comprises removing at least one leaflet from the malfunctioning valve of the host vein. In a further aspect, the xenogeneic heart valve is a porcine aortic valve. In such an aspect, the single leaflet may be a noncoronary leaflet. In a still further aspect, the leaflet and patch have been subjected to a fixation treatment. In such an aspect, the fixation treatment may include exposing the leaflet and patch to glutaraldehyde solution. In any of these aspects, the subject may be human.

