Urothelial injury to the rabbit bladder from alkaline irrigants useful in the treatment of uric acid stones.

Irrigation of the urinary tract with alkaline solutions may be used appropriately in some clinical situations to dissolve uric acid stones. Since in vitro studies have suggested that tham-E (pH 10.6) is somewhat more effective than tham (pH 8.6) in promoting dissolution of uric acid, these studies were undertaken to assess the relative toxicities of these two irrigating solutions to the urothelium. Rabbit bladders were irrigated antegrade via a ureterotomy for twenty hours. Tham E produced considerably more mucosal injury than did tham (p = 0.0001). The minimal advantage in rapidity of stone dissolution offered by tham E over tham is more than offset by the considerably increased potential for toxic side effects. The results suggest tham and not tham E should be used for irrigation to dissolve uric acid stones.