May-Thurner Syndrome: An Unusual Case of Unilateral Severe Deep Vein Thrombosis in a Middle-Aged Women.

A 50-year-old female presented with a 10-day history of progressive swelling and pain in the left lower extremity, ultimately diagnosed with deep vein thrombosis (DVT) and May-Thurner Syndrome (MTS). Initial ultrasound indicated thrombosis involving the left external iliac, femoral, and popliteal veins, among others. Blood tests revealed normocytic anemia, but thrombophilia screening and other blood markers were normal. Computed tomography angiography (CTA) identified compression of the left common iliac vein (LCIV) by the right common iliac artery (RCIA), leading to thrombus formation. Initial management included anticoagulation with enoxaparin and iron supplementation. Interventional radiology was consulted, and an inferior vena cava (IVC) filter was placed. Through popliteal vein access, catheter-directed thrombolysis with Actilyse significantly reduced the thrombus burden. Venoplasty with a 12 mm balloon was performed to relieve the stenosis in the LCIV; however, recurrent stenosis required stent implantation. Post-stenting venography showed complete resolution of the stenosis and restored blood flow. This case illustrates the critical role of multimodal management in treating complex DVT with MTS, including anticoagulation, thrombolysis, and stent placement.