[Dissolution of obstructive uric acid calculi by percutaneous nephrostomy and in situ alkalinization].

Following the introduction of one or two percutaneous nephrostomy drains, 16 obstructive uric acid calculi were treated by perfusion of excretory cavities with 14% sodium bicarbonate solution. Twelve calculi had dissolved within an average of 5 days, 1 required percutaneous lithotripsy because of incomplete dissolution and 3 were unaltered. Success of this treatment appears to be dependent on the total radiotransparency of calculi, a feature difficult to demonstrate. There were no reports of major complications. The only weakly invasive nature of alkalinization in situ makes it a method of choice to be reserved for obstructive calculi, and a therapeutic strategy is proposed.