Treatment of May—Thurner Syndrome with Catheter-Directed Thrombolysis and Stent Placement,Complicated by Heparin-Induced Thrombocytopenia

May—Thurner syndrome is an uncommon process in which the right common iliac artery compresses the left common iliac vein, resulting in left iliofemoral deep vein thrombosis and severe leg edema. We report the case of a 41-year-old female who presented with severe left leg edema present for 1 day. One week earlier she had experienced acute shortness of breath and pleuritic chest pain. Duplex ultrasound revealed a left iliofemoral deep vein thrombosis. A computed tomography (CT) scan performed for abdominal pain revealed thrombosis of the entire left common and external iliac veins. A ventilation—perfusion scan diagnosed a pulmonary embolism. The patient was treated with systemic intravenous heparin and catheter-directed thrombolysis of the iliofemoral deep vein thrombosis. Complete thrombolysis and iliofemoral vein patency was achieved over 5 days. A persistent stenosis in the left common iliac vein consistent with May—Thurner syndrome was alleviated with percutaneous balloon angioplasty and placement of a Wallstent. Heparin therapy was terminated at the time of stenting because of suspected heparin-induced thrombocytopenia. The patient was started on a continuous infusion of 10% dextran 40, and warfarin therapy was initiated. Heparin-induced antibodies were confirmed by a C-14 serotonin release assay. The endovascular reconstruction remains patent 4 months later. Heparin-induced thrombocytopenia complicating endovascular reconstruction of the iliofemoral venous system in a patient with May—Thurner Syndrome is an uncommon occurrence. This case and a review of the literature are discussed.