[Chemolysis of cystine calculi incarcerated in the ureter by the alkaline organic amine, tromethamine-E].

We dissolved the cystine calculi incarcerated in the ureter by irrigation with tromethamine-E via percutaneous nephrostomy. Case 1: A 25-year-old man with a past history of cystinuria and staghorn calculi in the right kidney, suffered from obstructive renal failure caused by the incarceration of a stone (18 x 15 mm) in the left middle ureter. After recovering promptly from renal failure by left percutaneous nephrostomy, he received continuous irrigation with tromethamine-E through an angiographic catheter percutaneously placed in the ureter. The ureteral calculus was reduced by 70% in size after the irrigation for 35 days, and then extracted percutaneously. Case 2: A 3-year-old child had multiple cystine calculi in the right renal pelvis and ureter. Although a calculus in the renal pelvis was extracted by the percutaneous ultrasound lithotripsy, two calculi incarcerated in the middle ureter were impossible to remove by a percutaneous approach. The irrigation with tromethamine-E was initiated through the catheter placed percutaneously in the right ureter. Both calculi completely dissolved 47 days later. The chemolysis by irrigation with tromethamine-E was greatly valuable in the treatment of cystine calculi. This dissolution could be an alternative to surgery especially in the treatment of ureteral cystine calculi, which might be difficult to be extracted by the percutaneous or transurethral approach.