Severe paravalvular mechanical hemolysis with a normal blood smear

A 74-year-old white female presented with clinical and laboratory evidence of severe hemolysis caused by paravalvular leakage around a prosthetic mitral valve. The unique aspect of her case is the absence of red blood cell fragments in the peripheral smear. Red blood cell transfusions, which averaged three to four units per week, were no longer required after operative repair of the primary suture line. All evidence for hemolysis disappeared; hematologic values returned to normal and remained so during the subsequent six months.