May-Thurner syndrome is caused by blockade of local venous flow due to local vascular intimal proliferation, caused by repeated pulsatile compression of the iliac or iliofemoral vein between the iliac artery and the lumbar spine. In this case, we confirmed May-Thurner syndrome using lower extremity computed tomographic angiography and venography. However, on venography, it was impossible to distinguish the left iliac vein from the collateral vein; a thrombus was also seen, although some of the thrombus was not seen clearly. These problems were overcome with use of intravascular ultrasound. We report on intravascular ultrasound guided treatment of May-Thurner syndrome.

May-Thurner syndrome is associated with deep vein thrombosis resulting from chronic compression of the iliac vein against the lumbar vertebrae caused by the overlying common iliac artery. Stent insertion into the compressed lesion is used in treatment of May-Thurner syndrome. Various complications can occur during angioplasty while using a stent. Among these complications, shrinkage of the vein below the stent, a rare complication, was observed in our hospital during treatment of a patient with May-Thurner syndrome. Different complications can occur when venous angioplasty is performed, unlike that when arterial angioplasty is performed.