Cardiac valve prosthesis with valve flaps of biological tissue

Abstract

A cardiac valve prosthesis comprises an annular frame and a valve sleeve with a plurality of valve flaps which are forced apart by the blood passing through the prosthesis in one direction and which are mutually coapted by blood flow in the opposite direction. The frame of the prosthesis includes a rigid or semi-rigid stent constituted by a tubular body with a ring of apertures and with first and second end edges which, in the implanted position of the prosthesis, are respectively upstream and downstream with respect to the direction of flow of the blood through the prosthesis. Biocompatible textile completely covers the rigid stent: the covering has associated suture stitches some of which extend through the apertures of the said ring to attach the covering to the stent itself. The valve sleeve includes two sheets of biological tissue sutured together and wound into a tube, the radially outermost one having a shape which substantially reproduces the shape of the stent of the frame and the radially innermost one whereof, carrying the valve flaps, has a collar end portion which can be turned outwardly of the frame at the first end edge of the stent. The valve sleeve is fixed to the frame by further suture stitches, sone of which extend through the apertures in the ends of the appendages of the frame stent. Other suture stitches connect the end edge of the collar end portion of the radially inner sheet to the covering of biocompatible textile.