RIRS procedure
After general anesthesia, Firstly semi-rigid ureteroscopy was performed to evalute and actively dilate the ureter before flexible ureteroscopy. Thereafter, a 12/14 Fr ureteral access sheath (UAS) ( Flexor 12/14Fr, Cook Medical Bloomington, IL, USA, Navigator 11/13Fr, Boston Scientific, Natik, MA, USA ) was placed over the guidewire under fluoroscopic guidance. All the RIRS were performed using Flex-X2 or Flex-XC (Karl Storz Endoscope, Germany) through the ureteral access. If UAS can not be placed, double J ureteral catheter was inserted to the kidney collecting system for passive dilatation approximately 1-2 weeks before re-surgery. The stones were fragmented using a 200/273 μm Holmium laser fiber (Dornier Med-Tech GmbH, Medi­las H20, Wessling, Germany). Surgery was concluded after stone-free status (ureteroscopic inspection and fluoroscopy), or detection of bleeding which blocked the surgeon’s view or decision. When the AUS was withdrawn, the ureter was examined with flexible ureteroscopy. If there were any injuries, DJ was applied at the end of the procedure, according to surgeon’s judgment. DJ stent was removed 2-3 weeks after surgery in all patients.
“Stone-free” status was defined as stones of less than 2 mm or no evidence of stones on one-month postoperative CT.