Repetitive intraoperative use of recombinant hirudin (Lepirudin) in peripheral vascular surgery with HITT.

Abstract

Heparin induced thrombocytopenia with thrombosis (HITT) is a rare but dangerous complication related to the application of unfractionated heparin or low molecular weight heparin. Due to an antibody dependent in vivo platelet activation, severe thromboembolic episodes may occur. We present the case of a patient with HITT following implantation of an aortobifemoral graft secondary to bilateral common iliac artery stenoses. An arterial clot developed and led to a partial occlusion of the graft to the right external iliac artery. Heparin was replaced by Lepirudin, a recombinant hirudin. A bolus of 0.4 mg/kg body weight was given, thereafter 0.15 mg/kg body weight per hour was administered continuously i.v. to maintain the aPTT 2- to 2.5-fold above the baseline value. The platelet count (minimum 47 G/l) normalised within two days. During thrombectomy of the right common femoral artery we used Lepirudin intraoperatively (bolus injection of 0.2 mg/kg body weight) to prevent any further platelet and coagulation activation during the clamping phase. Six months later the patient underwent two further bypass operations due to severe stenoses of both superficial femoral arteries. Due to the high risk of thromboembolism if HITT recurred, a bolus of 0.2 mg/kg body weight of Lepirudin was given during each intervention. No bleeding complications occurred. In addition Lepirudin appeared to decrease platelet consumption in the absence of active thrombosis. Direct thrombin inhibitors such as Lepirudin possess no heparin-like immunological properties and seem to have become the therapeutic "gold-standard" in patients with HITT. Our experience suggests that the repetitive intraoperative use of Lepirudin is safe and effective.