Supported and Nonsupported Valve Homografts in Man

Abstract

In terms of valvular insufficiency, there appears to be little difference between stented and unstented orthotopic aortic valve homografts. Inverted aortic valves in the mitral position, however, resulted in mitral insufficiency in 6 of 19 patients who survived operation. In 3 of the 6 patients this was due to particular technical factors. Clinical and catheterization evidence suggests that a greater degree of turbulence and obstruction occurs with stented than with unstented valves. We cannot state with confidence that the aortic homograft in the mitral position offers a real advantage over some forms of prostheses except from the standpoint of embolic complications. The use of aortic valve homografts has been successful in obviating systemic embolism when this has been a problem with prosthetic valves inserted in the mitral area. Histologically, fresh valves show greater cellularity than do frozen valves, particularly in the first 6 months. Later on, both are acellular. Whether or not this has a bearing on the ultimate performance of the valve remains to be seen. We now prefer to use fresh unstented homografts in the aortic position in the typical patient. The use of stented valves in this area seems to offer an advantage when bypass time needs to be short, however, or when there is inherent weakness or enlargement of the aortic root.