Percutaneous catheter dissolution of cystine calculi.

In 11 kidneys with presumed cystine stones that were symptomatic and obstructing, percutaneous nephrostomy and stone lavage with either acetylcysteine-bicarbonate solution or tromethamine-E were performed. There were 7 complete stone dissolutions: 2 of 6 attempts with acetylcysteine-bicarbonate alone, 3 of 5 with tromethamine-E, 1 partial with acetylcysteine-bicarbonate, which was completed with tromethamine-E, and 1 proved mixed stone (cystine and calcium phosphate) that required acetylcysteine-bicarbonate and hemiacidrin. In 1 case tromethamine-E irrigation was 97 per cent complete but a few tiny caliceal fragments remained. There were 3 failures of chemolysis: 2 pure cystine stones (1 each acetylcysteine-bicarbonate and tromethamine-E) and 1 mixed calculus with a surface shell of calcium oxalate. Irrigation time was 6 to 42 days for the 7 unoperated kidneys. Tromethamine-E appears to be a more effective agent for cystine stone dissolution. Percutaneous nephrostomy and dissolution are an alternative to an operation in patients with cystine calculous disease.