Morphologic observations on heart valve prostheses made of fascia lata.

A cooperative, international study permitted morphologic observations on 58 fascia lata heart valve prosthese. Thirty-nine had been in position less than a year, the remainder for periods up to 50 months. The fascial cusps, no matter whether free or stent mounted, underwent changes that included death of the original fascia and vacuolar, degenerative changes if a valve had been in situ more than 3 years. Formation of a pseudointima on a cusp's surface caused it to shrink. The rate of progression and severity of the changes varied from prosthesis to prosthesis. Severe cusp shrinkage caused valve incompetence. That seemed particularly likely in mitral and tricuspid prostheses and explains why their use has been abandoned. Clinically, fascia lata aortic valves function satisfactorily for several years. However, their long-term value is still uncertain. Morphologically, the specter of late calcification and other degenerative changes haunt their use until more, from long-term survivors, are available for study.