Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Heart valve – Having rigid or semirigid pivoting occluder
Patent
1993-02-09
1995-04-11
Isabella, David
Prosthesis (i.e., artificial body members), parts thereof, or ai
Heart valve
Having rigid or semirigid pivoting occluder
137527, A61F 224
Patent
active
054053811
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a heart valve prosthesis having an annular valve body and two leaflets which are disposed in said member and, by means of a hinge mechanism, are pivotable between an open position and a closed position.
No conventional heart valve prosthesis meets all the requirements made on such products, which have to function in an extremely reliable manner and withstand the constant wear caused by the heart beats.
Since heart valve prostheses, hereinafter referred to as heart valves, are implanted in a very sensitive and `cramped` space of the body, it is imperative that they do not damage or get tangled up in the surrounding tissue. Many of today's heart valves suffer from the inconvenience that either the leaflets proper or projections on the annulus protrude too far, so that the risk of surrounding tissue interfering with the valve function is imminent, especially if the valve is used in the mitral position. Projections on the annulus may further hinder the surgeon when implanting the heart valve.
To emulate the function of the natural heart valve, a prosthesis should preferably have a central flow. It should in addition open and close rapidly and quietly, have an insignificant resistance against flow in the forward direction, and cause a minimum of turbulence. The artificial heart valve must of course be biocompatible, i.e. acceptable to the body, and be thrombo-resistant, i.e. not cause or be the residence of thrombosis. From this point of view, it is essential that all surfaces are well flushed by the blood, so that there are no hidden corners where clots may form.
U.S. Pat. No. 4,078,268 discloses a heart valve which has an annulus and two flat, semicircular leaflets. In one embodiment, the hinge is made up of pins projecting from the leaflets and corresponding holes in the annulus. In another embodiment, both the inside of the annulus and the leaflets are formed with projections which make up the hinges of the valve. The downstream side of the annulus is provided with triangular projections on which the leaflets rest when the valve is closed.
U.S. Pat. No. 4,274,437 discloses a heart valve which also has an annulus and two leaflets. These leaflets are sections of a hollow, straight and circular cylinder. The hinge mechanism includes a groove on the inside of the annulus, as well as two projections fitting in the groove and provided one on each leaflet. The projections run freely in the groove, so that the leaflets can rotate in the annulus.
These prior-art valves mainly suffer from the disadvantage that some portions project much too far from the annulus, so that there is a considerable risk that they damage, or are themselves hindered by, the surrounding tissue.
U.S. Pat. No. 4,863,459 discloses another heart valve which has an annulus and two curved semicircular leaflets. This valve has the advantage of not projecting as far as the other two valves described, but it nevertheless has quite a few drawbacks. Above all, it has no central flow and does not close quietly enough.
One object of the invention is to provide a heart valve of this type, which has as low a structural profile as possible, i.e. has a minimum of elements projecting from the annulus, and which will not damage or get tangled up in the surrounding tissue, either in the open or in the closed position. This is achieved by a special design of the leaflets.
Another object of the invention is to provide a heart valve which functions also when mounted in a slightly oblique position relative to the flow direction in the heart. When mounted in this manner, some prior-art heart valves cannot function properly, and as a result one of the leaflets stops working, with disastrous consequences for the patient.
According to the invention, the heart valve prosthesis is characterised in that the leaflets are substantially semicircular, that the leaflets are evenly curved in two perpendicular directions, one direction being perpendicular to the diameter of the semicircle, so as to bulge outward, as seen from the center of the an
REFERENCES:
patent: 4078268 (1978-03-01), Possis
patent: 5002567 (1991-03-01), Bona et al.
patent: 5108425 (1992-04-01), Hwang
patent: 5116366 (1992-05-01), Hwang
patent: 5116367 (1992-05-01), Hwang et al.
patent: 5123920 (1992-06-01), Bokros
patent: 5192313 (1993-03-01), Budd et al.
patent: 5197980 (1993-03-01), Gorshkov et al.
patent: 5236448 (1993-08-01), Angelini et al.
Fossum Laura
Isabella David
LandOfFree
Hinged heart valve prosthesis does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hinged heart valve prosthesis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hinged heart valve prosthesis will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1535609