Cardiac valve prosthesis with valve flaps of biological tissue

Claim 1

A cardiac valve prosthesis which includes valve flaps of biological tissue and which operates regularly and reliably for long implant periods while minimizing the possibilities of formation of blood clots and thromboembolisms in the flow of blood, comprising: an annular frame through which blood can flow in the implant of the prosthesis, including a stent with a tubular body the wall of which has a ring of first apertures and which has first and second end edges which, in the implanted position of the prosthesis, are respectively upstream and downstream relative to the direction of free flow of the blood through the prosthesis, said tubular body also having integral appendages which project from said second edge in an axial direction relative to the tubular body and each of which has respective second apertures located adjacent its free end, and a covering of biocompatible textile wrapped completely over the stent, the covering having associated therewith first suture stitches at least some of which extend through said first ring of apertures to attach said covering to said stent; a valve sleeve of biological tissue including a radially outer sheet and a radially inner sheet of biological tissue formed into a tube and connected together by second suture stitches, wherein said radially outer tubular sheet has a shape which substantially reproduces the shape of said stent and is insertable thereinto, and wherein said radially inner tubular sheet has an end collar portion with an edge portion turned outwardly of said frame in correspondence with said first edge of said stent, and a plurality of valve flaps with free edges projecting inwardly of said frame and intended to be forced apart by the blood flow through the prosthesis in one direction and to prevent the blood flow in the opposite direction, said free edges being brought into mutually mating position by the pressure exerted in the blood itself; and third suture stitches extending through said second apertures in said appendages of said stent and connecting said outer sleeve to said frame, fourth suture stitches connecting said outer end of said collar portion to the covering of said adjacent biocompatible textile, and fifth suture stitches connecting said radially outer sheet to the covering of the biocompatible textile adjacent said second edge of said stent wherein said fifth suture stitches are the sole means for connecting said radially outer sheet to said frame.