Heart valves

“By the 1980s surgeons had two excellent alternatives for patients suffering from serious valvular disease: the mechanical valve or the bioprosthesis. But the two are not interchangeable. Although mechanical valves can last a lifetime, they introduce foreign materials into the body, increasing the risk of sudden blood clots. To minimize this danger, patients must take anti-coagulant drugs for life. Tissue valves, on the other hand, are unlikely to cause clotting problems but have a maximum lifespan of around twenty years. In practice this means that young patients are generally given a mechanical valve, while the elderly are more likely to receive a bioprosthesis. . . . but today’s clinicians do everything in their power to avoid using devices they spent decades perfecting” owing to evolution of “surgical philosophy” deriving from Carpentier’s insight of 1967 that reconstruction of diseased valve is preferable to its replacement (Morris, loc 2568ff.).