Retrograde percutaneous nephrostomy.

The percutaneous approach has become an accepted procedure for the removal of kidney stones in the urinary tract. Developed initially from our method of transvenous punch biopsy and transvenous cholangiography, the "inside-out" retrograde nephrostomy technique involves either cystoscopic or fluoroscopic placement of a 9 or 10 French catheter into a selected minor calix, through which a fine 21-gauge needle passes and exists the skin. The tract is then dilated over the needle. Used in over 200 cases without any complications directly attributable to the nephrostomy, the retrograde approach is safer, more reliable, and less time consuming than the previous standard antegrade approach, particularly in the nondilated pelvicalyceal system. Also presented are several new modifications to the original procedure and further technical considerations for operators.