Preoperative tract dilatation for percutaneous nephrolithotomy

The purpose of this study was to understand the principle of percutaneous nephrolithotomy(PNL), to increase its success rate, and to base the radiologic approach on preoperative interventional tract dilatation. Twenty-six patients(male, 19, female, 7) with staghorn or pelviocalyceal calculi who had undergone PNL were included in this study. After percutaneous nephrostomy(PCN) was performed in each patient, the tract was dilated to 30F with Amplatz dilators using coaxial techniques or a 30F, 10cm high-pressure tract dilatation ballon. One day before the calculi were fragmented and removed by PNL, a 30F Amplatz sheath was inserted under local anesthesia. The time required for tract dilatation, complications, and surgery was analyzed. Percutaneous tract dilatation were successful in all patients, and forceps, a nephrol-ithotome and a nephroscope were successfully introduced into the pelvocalyceal system. The aver-age procedure time was 19.5 minutes;a double J stent was replaced in the pelvocalyceal system of 13 of 26 patients (50%);because of improper catheter direction or/and bleeding, the Amplatz sheath was replaced in three. After PNL, complications involving renal hematoma occurred in one patient. This did not affect the patient's prognosis, however. Owing to its short procedure time and low complication rate, interventional preoperative tract dilatation for PNL is thought to be an effective technique for patients with staghorn or pelvocalceal calculi.=20