May-Thurner Syndrome

May-Thurner Syndrome

In medicine, May–Thurner syndrome is classically a rare condition in which compression of the common venous outflow tract of the left lower extremity may cause discomfort, swelling, or blood clots, called deep venous thrombosis (DVT), in the iliofemoral vein. The specific problem is compression of the left common iliac vein by the overlying right common iliac artery. This leads to pooling or stasis of blood, predisposing the individual to the formation of blood clots. May–Thurner syndrome is therefore more common in the left leg as the artery acutely overlaps the left iliac vein. In the 21st century the May–Thurner syndrome definition has been expanded to a broader disease profile known as nonthrombotic iliac vein lesions (NIVL) which can involve both the right and left iliac veins as well as multiple other named venous segments. This syndrome frequently manifests as pain when the limb is dependent and/or significant swelling of the whole limb.