Heparin-induced thrombocytopenia and vascular surgery.
Heparin-induced thrombocytopenia (HIT) is of special interest to vascular surgeons as heparin is the predominant anticoagulant used before, during, and after vascular surgery. Further, the prothrombotic nature of this antibody-mediated disorder leads to a high frequency of limb ischemia due to large arterial occlusion by platelet-rich ("white") clots or because of extensive venous thrombosis involving large veins and small venules. This latter syndrome has been associated with coumarin anticoagulation of HIT-associated deep-vein thrombosis (coumarin-induced venous limb gangrene). Non-heparin anticoagulants, such as the direct thrombin inhibitors (lepirudin, argatroban), may be needed for intraoperative management of a patient with suspected acute HIT who requires vascular surgery. The transience of HIT antibodies provides a rationale for intraoperative use of heparin in a patient who has recovered from HIT and in whom HIT antibodies are no longer detectable.
Warkentin
T E
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Department of Pathology and Molecular Medicine, and Department of Medicine, McMaster University, and the Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada. twarken@mcmaster.ca
D000208:Acute Disease; D000925:Anticoagulants / Q000009:adverse effects*; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D007511:Ischemia / Q000209:etiology; D007866:Leg / Q000098:blood supply; D011183:Postoperative Complications / Q000139:chemically induced*; D013921:Thrombocytopenia / Q000139:chemically induced*; D013997:Time Factors; D014656:Vascular Surgical Procedures
D000925:Anticoagulants; D006493:Heparin