Management of Nonthrombotic May-Thurner Syndrome

Venous outflow pathology of the lower extremity may be categorized into thrombotic or nonthrombotic etiology. This chapter focuses on the nonthrombotic etiology that results from the compression of the left iliac vein or May-Thurner syndrome (MTS). MTS is an anatomic variant condition associated with venous outflow stenosis due to extrinsic compression of the iliocaval venous segment. The most common cause of the partial obstruction is left iliac vein compression by the overlying right common iliac artery, although other anatomic varieties of MTS do exist. Partial or complete impedance to the venous outflow in the iliocaval venous segment may lead to extensive deep vein thrombosis of the ipsilateral extremity. Clinical presentations may include, but are not limited to, pain, extensive lower-extremity swelling, venous stasis ulcers, and skin discolorations. Treatment is based entirely on the clinical presentation; normally for nonthrombotic MTS, angioplasty and stenting of the diseased iliac vein segment are usually sufficient after defining the location and extent of stenosis. In this review, we (1) describe and define MTS, (2) highlight variable presentations of MTS, and (3) outline the possible management strategies within the current Society for Vascular Surgery updated consensus guidelines. This review contains 3 Figures, 2 Videos, 3 Tables and 66 references Key Words: angioplasty, artery compression, deep venous thrombosis, iliac vein, iliofemoral stenosis, May-Thurner syndrome, spur, stent, venogram, venous hypertension