Our patient had a clot in the inferior vena cave and May Thurner syndrome. This refers to compression of the iliac vein by the iliac artery causing low flow and a clot. It can occur on the R or L but usually occurs on the L since the vein has to cut to the R to join the IVC. While the R common iliac artery overlies the L iliac vein in 20% of people it is responsible for 2-3% of lower extremity DVTs. It can be diagnosed on ultrasound in only 20% of cases since the veins are so deep. It should be considered especially in women between 20 and 40 with recurrent DVTs, phlegmasia alba dolens or phlegmasia cerulea dolens.
It was first described in 1851 but was more widely recognized in 1957 when an autopsy series found compression of the L iliac vein against the lumbar spine by the R common iliac artery on 22% of cadavers.
Our patient had multiple pulmonary emboli as well as the IVC clot. She was anticoagulated and placed on Xarelto. She had chronic anemia and her hemoglobin trended downward on several occasions but was transfused and mild esophagitis was seen on endoscopy. She was eventually discharged.
In other series, thrombectomy and stent placement were used to treat the syndrome.
Peters M, Syed R, Katz M, et al May-Thurner syndrome: a not so uncommon cause of a common condition. 2012 Pro(Bayl Univ Med Center) Jul;25(3):231-233.
May R, Thurner J. The cause of predominantly sinistral occurrence of thrombosis of the pelvic veins. Angiology 1957;8(5):419-427.
Kivve MR, Ujiki M, et al. Iliac vein compression in an asymptomatic patient population. J Vasc Surg 2004;39(5):937-943.