Tissue valves.

The search for an ideal replacement for diseased intracardiac valves has resulted in the use of many tissue valves, including homografts, heterografts and valves of autologous and heterologous fascia lata and of pericardium. Operative mortality in experienced hands has been comparable to that of other operations using prosthetic valves. Sterilization and preservation techniques probably render the graft nonviable in all instances. Although early function has been satisfactory, late deterioration of leaflet tissue has led to valve failure in a high percentage of cases. At present, glutaraldehyde-prepared heterografts and fresh antibiotic-sterilized homografts appear to have the longest durability of the various tissue grafts used for valve replacement. The primary advantage of tissue valves has been the essential elimination of thromboembolic complications, and the primary problems have been infectious endocarditis and late graft deterioration.