Hemolytic Anemia Due to Progressive Enlargement of Silastic Ball Component of Aortic Prosthesis

Abstract

The patient described developed hemolytic anemia following insertion of a Starr-Edwards aortic valve prosthesis. No diastolic murmur was heard and no insufficiency was detected. The hemolytic anemia was progressively more severe and uncompensated despite various medical measures. The anemia was characterized by fragmented erythrocytes in the peripheral blood, reticulocytosis, elevation of plasma heme pigments augmented by exercise, increased fecal urobilinogen, and iron loss in the urine. Studies of chromium-51-tagged erythrocytes indicated an extracorpuscular mechanism of hemolysis. At reoperation the ball component of the prosthesis was found to be enlarged and obstructing blood flow. Chemical analysis of the ball showed significant cholesterol and lipid deposits. The hemolysis disappeared after the prosthesis was replaced with a homograft valve. Ferrokinetic studies showed rapid plasma clearance and incorporation into circulating erythrocytes. Triglycerides were elevated during the period of hemolysis. Red cell membrane lipids were normal.