Double venous compression due to duplicated inferior vena cava-induced right common iliac vein thrombosis.

Venous compression syndromes are caused by extrinsic venous compression of anatomical structures, such as the adjacent arteries and bones. Chronic venous compression and pulsative vibratory arterial pressure accelerate the development of deep vein thrombosis. Herein, we report the first case of double venous compressions due to a duplicated inferior vena cava-induced right-sided common iliac vein thrombosis. The thrombus was induced by left-sided inferior vena cava entrapment and right-sided common iliac vein compression, resembling nutcracker syndrome and May-Thurner syndrome, respectively. Bypass flow of the right inferior vena cava rendered the right lower extremity asymptomatic. Once daily anticoagulation edoxaban was effective. Congenital venous anomalies and bypass formations should be considered when a common iliac vein thrombus without symptoms in the lower extremities is observed, and a lifelong periodical follow-up is mandatory, even after remission.