Aortic Valve Replacement as a Trigger of Atypical Hemolytic Uremic Syndrome.

Mechanical hemolysis is a frequent but usually harmless complication of aortic valve replacement. The most common reason is valvular leakage. This report presents atypical hemolytic uremic syndrome (aHUS) as an alternative cause of mechanical hemolysis after this procedure. aHUS is a complement-mediated disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and renal failure. It necessitates immediate specific treatment including plasma exchange or complement inhibition to avoid an adverse outcome. The present case identifies aortic valve replacement as a trigger of aHUS and shows that this disease must be taken into account in the differential diagnosis of hemolysis after valve surgery.