For forty years, heparin has been used to temporarily inhibit normal coagulation so as to permit the use of extracorporeal circulation. It has proved effective in preventing gross thrombosis and has not been compromised by changes in adjunctive practices (such as profound hypothermia; circulatory arrest), new pharmacological therapies (such as anesthetics or antibiotics), devices (such as membrane oxygenators), or during use in patients at the extremes of age. Unfortunately, heparin has been and continues to be inefficient in preserving hemostatic function during cardiopulmonary bypass resulting in undesirable bleeding after surgery.
