Clot Mayhem: A Case of May-Thurner Syndrome.

May-Thurner syndrome (MTS), also known as the iliac vein compression syndrome, is an anatomic anomaly in which the compression of the left common iliac vein by an overlying right common iliac artery leads to blood stasis, which predisposes to deep venous thrombosis (DVT) in the iliofemoral venous system. We present a case of a female with a history of DVT and currently on warfarin with a therapeutic international normalized ratio (INR), admitted with left leg swelling, redness, and intractable pain. Venous Doppler scan confirmed a massive DVT from the level of the left common femoral vein to the popliteal vein. The clot recurred after an unsuccessful trial of argatroban, in-line pharmacokinetic thrombolysis with local catheter-based alteplase infusion, and interventional radiology (IR)-guided mechanical thrombectomy. Subsequently, the patient was diagnosed as MTS with overlying left common iliac vein compression, as evident on venous Doppler ultrasound. She was managed successfully by venous stent placement and ongoing systemic anticoagulation with fondaparinux.