May-Thurner Syndrome

This is an anatomic variant whereby the L common iliac vein is compressed between the R common iliac artery and the vertebral body underneath, and is associated with unprovoked large L iliac vein DVTs, especially in women ages 20-50.  It is important to recognize because they are often refractory to anticoagulation alone, and may require IR catheter-directed thrombolysis and angioplasty/stent.

(Chanu Rhee MD, 9/17/10)