Strut fracture in the Björk-Shiley mitral valve prosthesis--two case reports.

Two similar cases of a lethal mechanical complication after mitral valve replacement by a Björk-Shiley prosthesis are reported. In both cases the smaller outlet strut spontaneously fractured at the site of juncture welds. The tilting disc was embolized into the aorta, the patients died of acute congestive heart failure.