It is important to consider<unk>  in patients who have no other obvious reason for hypercoagulability and who present with left lower extremity thrombosis. To rule out other causes for hypercoagulation, it<unk>  be appropriate to check the antithrombin, protein C, protein S, factor V Leiden, prothrombin G20210A, and antiphospholipid antibodies. Venography will demonstrate the classical syndrome when causing deep venous thrombosis.<unk>  in the broader disease profile known as nonthrombotic iliac vein lesions (NIVLs) exists in the symptomatic ambulatory patient and these lesions are usually not seen by venography. Morphologically, intravascular ultrasound (IVUS) has emerged as the best current tool in the broader sense. Functional testing such as duplex ultrasound, venous and interstitial pressure measurement and plethysmography<unk>  sometimes be beneficial. Compression of the left common iliac vein<unk>  be seen on pelvic CT.
May–Thurner syndrome
Van Wyk and Grumbach syndrome
Helsmoortel-Van der Aa syndrome
Wells-Jankovic syndrome
Jeavons syndrome
Crome syndrome
Bogart–Bacall syndrome
Keutel syndrome