[In situ dissolution of uric acid obstructive calculi].

The dissolution of uric acid calculi can be obtained by per os or parenteral alkalinization, but this method cannot be used in case of obstructive calculi. With 3 patients, whose urinary tract was obstructed by a radio-transparent calculi at the pyelo-ureteral junction, the ureteral probe setting by endoscopic way permitted to realize the in situ alkalinization. After 5 to 11 days of treatment, the calculi have been completely dissolved. A patient also presented a slightly radio-opaque lithiasis, but it remained still. The in situ alkalinization is an effective and non invasive treatment in case of obstructive uric acid calculi, and completes the release of the urinary tract logically by ureteral probe setting.