RESUMEN
Chronic compression of the left common iliac vein (CIV) by the right common iliac artery (CIA) or May-Thurner syndrome is rare and could be challenging to diagnose. The phenomenon results in chronic left lower extremity vein thrombosis. In this report, we present a 33-year-old female with pain and swelling in her left inner thigh for 2 days. She denied any systemic signs or any remarkable past medical history. Doppler ultrasonography revealed large blood clots extending from the left femoral and great saphenous veins to the upper part of the external iliac vein, causing a nearly complete obstruction. CT venography showed compression of the left CIV near the confluence by the right CIA and the lumbar vertebrae L4. She was managed by catheter-directed thrombolysis with alteplase via a superior vena cava catheter. Subsequently, a left CIV self-expanding stent was successfully placed. Follow-up demonstrated a positive outcome without any complications.