Abstract: Implants containing a reasonably biocompatible fabric, which is to be exposed to blood flow after implantation, are rendered biocompatible and substantially impervious to blood, by applying a collagen composition containing soluble collagen, and preferably also collagen fibers, to the fabric in such a manner that the collagen composition penetrates into the interstitial spaces of the fabric. The fabric retaining collagen composition is then incubated at elevated temperature for sufficient time to form collagen fibers from the soluble collagen. Thereafter, the implant is dried. The steps of applying collagen composition, incubating and drying are repeated approximately two to four times. The implants, particularly when they comprise tubular vascular grafts, are tested for porosity by placing a pressurized column of aqueous solution, such as saline, into their interior.

Abstract: A heart valve prosthesis and method for replacement of the same are disclosed. The prosthesis includes a sewing ring for permanent attachment to heart tissue, and a valve assembly which is replaceably mounted within the sewing ring in a spaced-apart relationship to define a cylindrical cutting path therebetween. The valve assembly is attached to the sewing ring by interconnecting sutures, but the cylindrical cutting path is otherwise devoid of structure which projects therebetween. Thus, replacement of the valve assembly can be accomplished by insertion of a cutting member, such as a thin scalpel blade, within the cylindrical cutting path, thereby simultaneously facilitating severing of the interconnecting sutures and any tissue ingrowth which may have formed between the sewing ring and valve assembly as the blade is worked around through the cutting path.

Abstract: A mechanical heart valve prosthesis has an annular base which defines a passageway for blood flow, and a pair of valve leaflets hingedly mounted within the annular base for regulating direction of the blood flow. The hinge mechanism includes camming indentations or hinge cavities located substantially in the corners of the valve leaflets at least on one side of each leaflet, and a plurality of camming or hinge pins which protrude radially inwardly from the annular base to engage both sides of the leaflets. Each of the hinge cavities is engaged by one hinge pin. During operation, the valve leaflets undergo certain wobbling or walking motion relative to the hinge pins whereby the hinged surfaces are continuously wiped to minimize the possibility for formation of incipient blood clots.

Abstract: A "tissue valve type" heart valve prosthesis is disclosed which has a biocompatible plastic sewing ring adapted to be surgically implanted into the mitral, aortic or tricuspid annulus of the human heart. The sewing ring has internal square threads and a biocompatible fabric mesh or cloth is embedded into the sewing ring so that the cloth can be fully wrapped around the sewing ring covering all of its plastic surfaces except for the internally protruding threads. A biocompatible plastic stent support ring has externally disposed threads to lock with the threads of the sewing ring in approximately one turn, or less. The stent support ring also embeds a biocompatible fabric mesh which can be wrapped around the stent support ring to cover all of its plastic surfaces, except for the protruding threads, and to form a cloth pocket wherein a solid stent is mounted. A porcine trileaflet valve is mounted to the stent.

Abstract: A "tissue valve type" heart valve prosthesis is disclosed which has a biocompatible plastic sewing ring adapted to be surgically implanted into the mitral, aortic or tricuspid annulus of the human heart. The sewing ring has internal square threads and a biocompatible fabric mesh or cloth is embedded into the sewing ring so that the cloth can be fully wrapped around the sewing ring covering all of its plastic surfaces except for the internally protruding threads. A biocompatible plastic stent support ring has externally disposed threads to lock with the threads of the sewing ring in approximately one turn, or less. The stent support ring also embeds a biocompatible fabric mesh which can be wrapped around the stent support ring to cover all of its plastic surfaces, except for the protruding threads, and to form a cloth pocket wherein a solid stent is mounted. A porcine trileaflet valve is mounted to the stent.