Technical procedures
pain
All surgeries were performed with the patient under general anesthesia, in a lithotomy position. The surgeon routinely inserted a single safety guidewire and then positioned the UAS with the guidance of fluoroscopy. In all cases, a Navigator™ HD, with a length of 36 cm and a size of 12–14 Fr, was used to pass distal scopes in all the studied patients. The application was performed within normal movement (neither rapid nor slow), then it either passed smoothly, passed with resistance or did not pass (failed application). It was observed that in patients within the silodosin group, it passed smoothly, and few patients showed minimal resistance during passage and very few patients showed failure application of ureteral access sheath. In the control group, either passage was with resistance or failed application was observed. In case of failed application, a double J stent was applied to those patients and then they were excluded from the study. Following completion of the procedure, the UAS was removed while monitoring with ureteroscopy and for evaluation of the ureteral injuries. The entire surgical procedure was recorded using a video system, and any instances of ureteral wall injury were documented with serial-numbered pictures taken with a ureteroscope. The stones were treated by laser dusting. To minimize the effects of UAS (e.g., pain), all patients received a ureteral double J stent at the end of the operation. After UAS placement, operative notes including operative time, hospital stay and visual analog scale (VAS) measurements of pain severity (ranging from 0 for no pain to 10 for the worst possible pain) were recorded [