Percutaneous nephrolithotomy. With emphasis on large renal stones.

With utilization of safety guide wire, dilator (up to 36F), and Mazzariello-Caprini forceps, percutaneous removal of renal stone was successfully performed in 18 cases, including 5 cases with staghorn calculus, although parts of the staghorn calculus were left in 4 cases. Attempts at stone extraction were performed on the day nephrostomy was made. All of the renal stones excluding staghorn calculi were removed without disruption followed by satisfactory postoperative renal function. Unexpectedly Kocher forceps was found to be a useful and relatively safe instrument for quick fragmentation and removal of staghorn calculi.