Perirenal urinary extravasation associated with urethral valves in infants.

We present 7 cases of urethral valves and perirenal urinary extravasation, and review 37 cases reported previously in the literature. The extravasation usually is from the kidney (66 per cent) and often is associated with reflux (70 per cent). It appears to be a pressure-related phenomenon. Although the mortality associated with the condition is significant (32 per cent) renal function is usually preserved. Prompt treatment with correction of metabolic acidosis, and decompression of the tense abdomen and the urinary tract is recommended.