Management of the choked ureter in obstructive renal failure due to uric acid lithiasis

We report on 8 azotemic patients with anuria or progressive oliguria owing to bilateral uric acid lithiasis. In 7 patients the precipitating cause of acute obstructive renal insufficiency was choking of at least 1 distal ureter with numerous small uric acid stones. In 6 of these ureters contrast retrograde ureterography showed relief of obstruction, which was believed to be owing to the stone dissolution properties of the contrast medium used. In situ alkalization via nephrostomy catheters achieved dissolution of obstructing stones in 3 tracts and systemic alkalization dissolved the stones in 3 others. An operation was necessary in 4 cases of large calculi, all of which showed some radiodensity, either because of super added calcification or phosphatic incrustation, rendering dissolution unfeasible. Methods of management of the obstructed tract caused by uric acid stone disease are evaluated and discussed.