Pressurized iliac artery aneurysm causing atypical May-Thurner syndrome

An 84-year-old man previously treated with endovascular aneurysm repair had enlargement of a right iliac artery aneurysm sac from 3.5 to 4.3 cm over 1 year. Two years later, he presented to the clinic with a weeklong history of severe swelling in his left leg. Computed tomography scan revealed left iliac vein compression by an enlarging, 4.8-cm iliac artery aneurysm sac. Intravascular ultrasound examination confirmed near complete occlusion of the left iliac vein without thrombosis. This was treated with a 16 × 10 mm venous stent and postdilated with a 16 × 20 mm balloon. The patient reported relief of symptoms within 24 hours postoperatively.