Retrograde nephrostomy for stone removal: combined cystoscopic/percutaneous technique.

The retrograde percutaneous nephrostomy, a new technique for access to the urinary tract for stone removal, involves cystoscopic placement of a 9 French catheter into a selected minor calix, through which a sheathed 20- or 21-gauge needle is then advanced to exit at the skin. The tract is then dilated over this needle. This technique has been used successfully in 38 patients with only three complications. The technique is more reliable and less time-consuming than the standard antegrade percutaneous approach, particularly in the nondilated pelvicaliceal system. However, to avoid damage to the liver, spleen, or pleural cavity, care must be taken to ensure that the needle does not exit in a cranial direction.