Abstract: Disclosed is a controlled autolysis method for making biological tissue substantially acellular by exposing the biological material, prior to any fixation thereof, to at least one buffered solution having a pH in the range from about 5.0 to 8.0 and a temperature in the range from about 12.degree. C. to 30.degree. C. for a sufficient period of time to render at least one region of the biological material substantially acellular while substantially preserving the structural integrity and non-cellular structural components of the biological material. Also disclosed is a method of making a bioprosthetic heart valve using biological material that has been treated by controlled autolysis and a method of treating a mammal having a defective heart valve using a bioprosthetic heart valve made, in part, by controlled autolysis.

Abstract: Disclosed is a controlled autolysis method for making biological tissue substantially acellular by exposing the biological material, prior to any fixation thereof, to at least one buffered solution having a pH in the range from about 5.0 to 8.0 and a temperature in the range from about 12.degree. C. to 30.degree. C. for a sufficient period of time to render at least one region of the biological material substantially acellular while substantially preserving the structural integrity and non-cellular structural components of the biological material. Also disclosed is a method of making a bioprosthetic heart valve using biological material that has been treated by controlled autolysis and a method of treating a mammal having a defective heart valve using a bioprosthetic heart valve made, in part, by controlled autolysis.

Abstract: Disclosed is a controlled autolysis method for making biological tissue substantially acellular by exposing the biological material, prior to any fixation thereof, to at least one buffered solution having a pH in the range from about 5.0 to 8.0 and a temperature in the range from about 12.degree. C. to 30.degree. C. for a sufficient period of time to render at least one region of the biological material substantially acellular while substantially preserving the structural integrity and non-cellular structural components of the biological material. Also disclosed is a method of making a bioprosthetic heart valve using biological material that has been treated by controlled autolysis and a method of treating a mammal having a defective heart valve using a bioprosthetic heart valve made, in part, by controlled autolysis.

Abstract: An arrangement for preparing natural tissue in the form of a heart valve, vessel or the like for implantation in which tanning fluid under pressure is applied to a portion of the tissue so as to cause said tissue to assume substantially its natural configuration, while additional tanning fluid is applied to the remainder of the tissue, said tanning fluid being so applied for a time sufficient to cause the tissue to become fixed, and, for vessels or the like, a guide may engage the tissue during fixation, whereby said tissue maintains substantially the configuration of the guide.

Abstract: An arrangement for preparing natural tissue in the form of a heart valve, vessel or the like for implantation in which tanning fluid under pressure is applied to a portion of the tissue so as to cause said tissue to assume substantially its natural configuration, while additional tanning fluid is applied to the remainder of the tissue, said tanning fluid being so applied for a time sufficient to cause the tissue to become fixed, and, for vessels or the like, a guide may engage the tissue during fixation, whereby said tissue maintains substantially the configuration of the guide.

Abstract: An arrangement for preparing natural tissue in the form of a heart valve, vessel or the like for implantation in which alternately tanning fluid under pressure is applied to a portion of the tissue so as to cause said tissue to assume substantially its natural configuration, and the pressure is relieved so as to result in a flexing of the tissue, while additional tanning fluid is applied to the remainder of the tissue, said tanning fluid being so applied for a time sufficient to cause the tissue to become fixed.

Abstract: A heart valve stent that includes an annular framework, preferably of bendable material, having three rounded apexes interconnected by support arms curved to incline away from the apexes. Additional support arms are included parallel to and axially beyond the first support arms. For use in the mitral position, the framework is circumscribed by an outer ring, which receives an annular element of felt or other suitable material. The heart valve is positioned on the stent, with its marginal portions overlapping it and affixed to it by sutures.

Abstract: An arrangement for preparing natural tissue in the form of a heart valve, vessel or the like for implantation in which tanning fluid under pressure is applied to a portion of the tissue so as to cause said tissue to assume substantially its natural configuration, while additional tanning fluid is applied to the remainder of the tissue, said tanning fluid being so applied for a time sufficient to cause the tissue to become fixed, and, for vessels or the like, a guide may engage the tissue during fixation, whereby said tissue maintains substantially the configuration of the guide.