Chemolysis of residual stone fragments after extensive surgery for staghorn calculi.

Chemical dissolution of residual stone fragments was attempted in twelve instances via nephrostomy tube irrigation. Appropriate solutions containing either hemiacidrin or sodium bicarbonate were used for struvite and uric acid stones, respectively. Precautions were taken to prevent and recognize outflow obstruction and urinary infection. Seventy-five per cent of the stones so treated were completely dissolved, and there were no major complications. The incidence of retained stones, natural history, and indications for chemical dissolution are reviewed.