Post-operative thrombotic thrombocytopenic purpura: a review.

Post-operative thrombotic thrombocytopenic purpura (TTP) is a recently recognised life-threatening clinical syndrome with considerable similarity to classic TTP in presentation and response to early treatment with plasma exchange. To date, 29 cases of TTP associated with surgery have been reported. The majority of cases have complicated vascular surgeries, with a few cases seen following gastrointestinal or orthopaedic procedures. Characteristically, patients develop microangiopathic haemolytic anaemia and consumptive thrombocytopenia 5 to 9 days following surgery with variable presence of fever, impaired renal function and altered mental status. The pathogenesis of post-operative TTP is speculative but may involve the release of large amounts of high-molecular-weight von Willebrand factor (vWF) multimers due to endothelial damage resulting from surgery in the setting of marginal levels of vWF-cleaving enzyme. The myriad of common post-surgical complications that may present with clinical manifestations similar to TTP may result in confusion with the potential for delay in the initiation of life-saving plasma-exchange therapy. It is important that physicians be alert to the phenomenon of post-operative TTP so that prompt recognition and treatment will prevent serious morbidity or mortality.