This patient presented with extensive left lower limb DVT that extended into the pelvis. CT abdomen/pelvis demonstrated compression of the left common iliac vein by the overlying right common iliac artery, consistent with May-Thurner syndrome.
May-Thurner syndrome is deep venous thrombosis resulting from chronic compression of the left common iliac vein (CIV) against the lumbar vertebrae by the overlying right common iliac artery (CIA). Although both left and right CIVs lie deep to the right common iliac artery, the left CIV has a more transverse course and is predisposed to compression whereas the right CIV ascends more vertically and is therefore not similarly predisposed. First line treatment is with thrombolysis and stenting, which removes the clot and relieves the compression to prevent recurrence.
Reference: Radiopaedia.orgCredit: Dr Donna D'Souza