Lethal blockage of a Bjørk-Shiley artificial heart valve caused by strut fracture--the metallurgical aspect.

The fracture of the outlet strut of a Bjørk-Shiley artificial heart valve implanted in a 21 year old man lead--6 years after the operation--to the valve disc jamming closed with a resulting lethal heart failure and circulation standstill. The probable cause of the valve strut fracture could be determined by metallurgical/metallographical investigation of the material and the production methods.