[Thrombosis of renal veins]

According to whether they are acute or progressive, complete or partial, uni- or bilateral, renal venous thromboses have quite various clinical expressions and biological consequences. The diagnosis is readily suggested by acute pain in the side with an increase in the size of one or both kidneys, associated with hematuria, proteinuria, or in case of renal failure, which is characteristic of acute bilateral thrombosis. On the other hand, chronic thrombosis of a renal vein is sometimes suggested only when complications such as pulmonary embolism occur. This explain why it is often discovered on autopsy. The diagnosis is confirmed on the basis of radiology, with ultrasound combined with vascular Doppler becoming increasingly important. Renal venous thrombosis may have various causes: disorders in renal blood flow, especially in the acute forms in newborns; hypercoagulability, in particular in nephrotic syndromes and above all in extramembranous glomerulonephritis; extension of vena cava thrombosis; retroperitoneal diseases involving the renal pedicle or extension of a renal tumor. The treatment of renal vein thrombosis is mainly medical and based on anticoagulants. The role of fibrinolytic treatment is controversial. Surgery is exceptional.