Heparin-induced thrombocytopenia and thrombosis in ischemic stroke.

We reviewed the records of all patients who underwent carotid endarterectomy at our institution during the period from January 1970 through December 1986 to determine the frequency of postoperative occlusions and the role of heparin-induced thrombosis in patients with such occlusions. After 2,527 carotid endarterectomies, a total of 19 occlusions occurred in 18 patients. Of these 18 patients, 6 had an associated heparin-induced coagulation disorder, 3 of whom are described in detail. Although heparin is a useful anticoagulant, it may precipitate occlusion of vessels after an endarterectomy procedure, either at the endarterectomy site or elsewhere. Physicians should be aware of the potentially increased risk for embolic or thrombotic cerebrovascular events in patients who receive heparin therapy.