[Acute thrombosis of pelvic and leg veins in agenesis of the renal segment of the inferior vena cava].

A 19-year-old, otherwise asymptomatic man presented to the hospital of orthopaedic surgery with acute severe pain like lumbago. Symptomatic treatment was performed after extensive orthopaedic diagnostic procedures. On the third day after admission he showed clinical signs of deep vein thrombosis with painful swelling and livid discoloration of both legs. Colour duplex ultrasound revealed complete thrombosis of the leg and pelvic veins bilaterally, but the cranial extent was not clear. Contrast-enhanced helical computer tomography of the abdomen and the pelvis confirmed deep pelvic vein thrombosis and showed extension into the inferior vena cava. Moreover, the study revealed the agenesis of the renal segment of the inferior vena cava with collateral flow through dilated lumbar veins to enlarged azygous and hemiazygous, through vertebral and paravertebral venous plexus. The renals were drained via dilated capsular veins. The agenesis of renal vena cava is a very rare anomaly causing acute thrombosis of the deep leg and pelvic veins. Other risk factors of thromboembolic disease were not found. The patient was treated successfully with systemic thrombolysis. Therefore we used ultra-high streptokinase infusion (9 million units over 6 hours). Colour duplex ultrasound revealed good flow into deep leg and pelvic veins after three cycle of lysis. Magnetic resonance angiography of the abdomen and pelvis was performed to evaluate the successful fibrinolysis with complete recanalisation of the pelvic veins and to demonstrate the venous anatomy. Permanent oral anticoagulation with phenprocoumon is indicated to decrease the high rate of recurrent thrombosis. Compression stockings were prescribed. To prevent thrombosis, additional risk factors like smoking, immobilization and unusual physical activity should be strictly avoided.