Intraoperative Bivalirudin Use in Patient Undergoing Femoral Endarterectomy with Heparin-Induced Thrombocytopenia: Case Report and Review of the Literature

PURPOSE: To describe the intraoperative use of bivalirudin during lower extremity revascularization in the setting of heparin-induced thrombocytopenia (HIT). CASE SUMMARY: A 65 year-old man presented with left common iliac, external iliac, and femoral artery occlusion necessitating revascularization with left femoral endarterectomy and common and external iliac stent angioplasty. Three months before the femoral endarterectomy, the patient was hospitalized for a coronary artery bypass procedure. During this admission, the patient tested positive for the presence of heparin-PF4 antibody complexes. With the patient's recent history of HIT, bivalirudin was selected as the optimal agent for intraoperative anticoagulation. Bivalirudin was administered as a 50 mg bolus, followed by a continuous infusion initiated at 1.75 mg/kg/hr. Repeated bivalirudin boluses were necessary to maintain an activated clotting time (ACT) necessary for the revascularization procedures and recurrent subacute thrombi despite appropriate ACT values. DISCUSSION: Bivalirudin has been utilized for cardiopulmonary bypass and carotid endarterectomy (CEA), but data for dosing in lower extremity revascularization are lacking. As the risk for thrombosis with HIT continues for months after diagnosis, it is important to elucidate optimal dosing of non-heparin anticoagulant options, such as the direct thrombin inhibitor, bivalirudin. The absence of validated dosing strategies for bivalirudin can result in prolonged operative times, increased risk of bleeding, and inadequate anticoagulation. CONCLUSION: Bivalirudin is an appropriate agent for intraoperative anticoagulation in lower extremity revascularization. However, further investigation into the optimal intraoperative bivalirudin dosing regimen is necessary.