Impact of ureteral access sheath use on outcomes of flexible ureteroscopy for renal stones

Abstract

Introduction and objective: Improvements in endoscopic technologies have led to an expansion of flexible ureteroscopy indications in the treatment of renal and ureteral stones. Ureteral access sheath (UAS) was introduced in the clinical practice to facilitate endoscopic access into the upper urinary tract, reduce intrarenal pressure during the procedure and allow the extraction of fragments. The objective of this study is to analyze the impact of UAS on the efficacy and safety of flexible ureteroscopy (fURS) for the treatment of renal stones. Material and methods: a prospectively collected database including 251 consecutive patients treated with fURS between January 2018 and November 2022 was analyzed. Patients were divided into two groups: group 1 – without UAS, 21 patients (8.3%) and group 2 – with UAS, 231 patients (91.7%). UAS was used at the surgeon’s discretion and 3 patients (1.2%) underwent a sheathless procedure due to failure of UAS insertion. Data on patients’ preoperative characteristics and fURS efficacy and safety were compared. Results: There were no statistically significant differences in patients’ preoperative characteristics except for stone size and surface, which were significantly larger in group 2 (9.6±4.1 vs 13.8±5.2 mm; р<0.001 and 68.6±74.2 vs 128.3±109.3 mm2, p=0.002, respectively). Operating time was significantly longer in group 2 (33.6±12.9 vs 42.0±12.9 min, p=0.005). Stone-free rate after a single procedure and at 3rd postoperative month was similar between groups (95.2% vs 87%, p=0.486 and 95.2% vs 88.7%, p=0.709, respectively). The intra- and postoperative complication rates were higher for group 1 (4.8% vs 0.8%, р=0.011 and 14.3% vs 12.1%, p=0.062, respectively). Multivariate regression model identified stone surface (р<0.001), number of stones (p=0.005) and calcium oxalate monohydrate stone composition (р=0.005), but not UAS use (p=0.580), as independent predictors for stone-free rate following fURS. Conclusions: The results of this study suggest that UAS use has no impact on the efficacy of fURS and is not associated with an increased rate of intra- and postoperative complications.