May–Thurner Syndrome: Update and Review

May–Thurner syndrome (MTS) is an anatomically variable condition of venous outflow obstruction caused by extrinsic compression. Although this syndrome is rare, its prevalence is likely underestimated. The pathology of this condition is secondary to a partial obstruction of the common iliac vein by an overlying common iliac artery with subsequent entrapment of the left common iliac vein. Regardless of the mechanism, this causes partial or complete impedance to the iliac vein outflow with subsequent possible obstruction and extensive ipsilateral deep vein thrombosis (DVT) of the ipsilateral extremity. Clinical presentations include, but are not limited to pain, swelling, venous stasis ulcers, and skin discoloration. With extensive DVT, postphlebetic syndrome, with all of its sequelae, may also develop. Treatment is based on the clinical presentation and includes staged thrombolysis with/without prophylactic retrievable inferior vena cava filter placement, followed by angioplasty/stenting of the left iliac vein in MTS patients with extensive DVT. This review highlights the variable presentations of MTS and outlines possible management within the current Society for Vascular Surgery consensus.