Chronic renal vein thrombosis.

Twenty-eight patients with demonstrated chronic renal vein thrombosis were studied. In seven, only small venous channels were involved; in 21, both small and large veins were thrombosed. A constellation of findings occurred with such frequency in these patients that we believe it virtually diagnostic of renal venous obstruction. These findings include the nephrotic syndrome, great variability in proteinuria and glomerular filtration rate, pulmonary embolization, sterile pyuria, hematuria, hyperchloremic acidosis, decreased renal tubular threshold for glucose and increased fibrin degradation products. These findings are an indication for definitive angiographic and biopsy procedures. Prolonged anticoagulant therapy was generally very effective.