Urothelial injury to the rabbit bladder from various alkaline and acidic solutions used to dissolve kidney stones.

Different irrigating solutions are used clinically to dissolve uric acid, cystine and struvite stones. These studies were undertaken to assess the toxicity to the rabbit bladder epithelium of several commonly used formulations. Test solutions were infused antegrade through a left ureterotomy overnight. Bladders were removed and routine histological sections made. A pH 7.6 solution of NaHCO3 appeared harmless. The same solution with two per cent acetylcysteine produced slight injury. All pH 4 solutions caused significant damage to the urothelium. Hemiacidrin, which contains magnesium, produced less damage than did other pH 4 solutions without that cation. Our data tend to support Suby's conclusions that addition of magnesium reduces urothelial injury even though the presence of magnesium will slow dissolution of struvite.