Inferior vena cava agenesis and deep vein thrombosis: 10 patients and review of the literature.

Inferior vena cava agenesis (IVCA) is a rare condition, found in almost 5% of patients under 30 years old with unprovoked deep venous thrombosis (DVT). We describe 10 consecutive patients with IVCA-associated DVT and conducted an extensive literature review to investigate the typical spectrum of IVCA-associated DVT. Among our patients (eight men and two women; mean age, 25 ± 4.5 years), DVT followed intense and unusual (major) physical activity for eight of them. DVT was bilateral in six patients and unilateral in four. Ultrasonography was unable to detect IVCA, which was visualized by computed-tomography scans for seven patients, and magnetic resonance imaging and angiography for 10. Hereditary thrombophilia screening, to detect factor V Leiden or prothrombin gene heterozygosity (G20210A mutation), was positive for only two patients. Wearing elastic stockings and taking an indefinite or long-term vitamin K antagonist were prescribed for all 10 patients and nine complied with the latter. To date, 62 patients with IVCA-associated DVT have been reported in the English literature. Analysis of them and our patients yielded a typical spectrum of IVCA-associated DVT characteristics: IVCA occurs in young adults, particularly males, and is revealed by proximal DVT following major physical exertion. All were treated with a prolonged vitamin K antagonist and advised to wear elastic stockings. No precise duration of anticoagulation has been established.