Different failure rates of insertion of 10/12-Fr ureteral access sheaths during retrograde intrarenal surgery in patients with and without stones

Abstract

Purpose The aim of this study was to compare the failure rates of insertion of a 10/12-Fr ureteral access sheath (UAS) during retrograde intrarenal surgery (RIRS) in cases with and without stones and to analyze the risk factors for UAS insertion failure. Materials and Methods A total of 640 RIRS cases (538 with and 102 without stones) were evaluated. The primary outcome of interest was the failure rate of insertion of a 10/12-Fr UAS. Associated risk factors were assessed using univariate and multivariate logistic regression analyses. Propensity score (PS) matching and inverse probability of treatment weighting (IPTW) were used to ensure the robustness of the results. Results The overall failure rate of 10/12-Fr UAS insertion in the cases without stones was significantly higher than that in the cases with stones (39.2% vs. 7.2%; p<0.001), and was approximately 2.5 to 4 times higher after PS matching and IPTW. Multivariate logistic analyses showed that being in the group without stones and younger age were independent significant risk factors for insertion failure in both the PS-matched cohort (odds ratio [OR], 5.43; 95% confidence interval [CI], 2.16–13.6; and OR, 1.04; 95% CI, 1.01–1.07) and the IPTW-adjusted cohort (OR, 1.82; 95% CI, 1.14–2.90; and OR, 1.03; 95% CI, 1.01–1.04). Conclusions The incidence of 10/12-Fr UAS insertion failure during RIRS was higher in cases without stones than in those with stones. These results provide valuable information for surgeons to use during informed consent discussions with patients undergoing RIRS, especially patients without stones.

The Efficacy and Safety of Radiation-Free Retrograde Intrarenal Surgery: A Prospective Multicenter-Based, Randomized, Controlled Trial

“…For the RF group, RIRS was performed with first-look ureteroscopy using a semirigid ureteroscope under general anesthesia in all cases. 14 A hydrophilic guidewire was advanced to the ureter through the semirigid ureteroscope in the lithotomy position, following which the semirigid ureteroscope was advanced to the upper ureter or renal pelvis and the ureteral length was measured. After a hydrophilic guidewire was left in the renal pelvis as a safety wire, a superstiff guidewire (Amplatz Super Stiff, Boston Scientific, Malborough, Massachusetts) was placed and a UAS was inserted along the superstiff guidewire under direct vision of a semirigid ureteroscope introduced beside the UAS into the bladder to observe whether the UAS was properly inserted through the ureteral orifice without twisting in the bladder.…”

Editorial Comment to Evaluation of ureteral injuries caused by ureteral access sheath insertion during ureteroscopic lithotripsy

“…Recently, Waseda et al reported that the different failure rates of insertion of 10/12-Fr access sheaths in patients with and without stones. 3 A total of 640 Japanese patients including 538 stone cases and 102 non-stones cases were examined. All of them were not pre-stented.…”

Impact of Preoperative Ureteral Stenting in Retrograde Intrarenal Surgery for Urolithiasis

“…RIRS requires repetitive scope insertion to fragment and extract urinary stones; thus, to aid access to the proximal ureter and renal pelvis and to lower intrarenal pressure, a ureteral access sheath (UAS) is widely used during RIRS. However, sometimes ureteral access is not possible-previous studies have reported 8.8% to 20% failure rates for UAS insertion [6]. For these failed cases, or when a tight ureter is expected, double-J ureteral stent insertion is recommended [7], because ureteral stenting induces passive dilation of the ureter, which facilitates passage of the UAS and ureterorenoscope [8].…”