[Physiopathology of spontaneous extravasation of urine in the upper urinary tract. Apropos of 24 cases].

Extravasation of urine was seen in 24 intravenous pyelograms taken for renal colic during the year 1973-74. A number of the patients presented with an acute abdomen. Extravasation took place of retained urine under pressure in the renal pelvis with leakage either around the clayces, from a fissure in the pelvis or even around the ureter. Extravasations of this type are in general rabsorbed without trace. In 5 cases, operation was necessary to drain a purulent collection which had developed in association with the extravasated urine.