RIRS with flexible vacuum-assisted UAS versus MPCNL for impacted upper ureteral stones: a prospective, randomized controlled study.

To observe the efficacy and safety of retrograde intrarenal surgery (RIRS) combined with flexible vacuum-assisted ureteral access sheath (FV-UAS) and minimally invasive percutaneous nephrolithotomy (MPCNL) in patients with impacted upper ureteral stones (IUUS). The study included 189 patients, of which 95 were included in the FV-UAS group and 94 in the MPCNL group. The primary study outcome was the stone-free rates (SFRs) on the first postoperative day. Secondary outcomes included the total SFRs 1 month postoperatively, operative time, reduction in hemoglobin levels, length of postoperative hospital stay, improvement in the quality of life as measured by the QoL score, incidence of ureteral stricture at 3 months postoperatively, and any surgery-related complications. There was no obvious difference between two groups in patients' demographics and preoperative clinical characteristics (P > 0.05). The mean decrease in hemoglobin was significantly lower in the FV-UAS group than in the MPCNL group (5.1 vs. 14.7 g/L, P < 0.001). Similarly, the FV-UAS group had a shorter average hospital stay than the MPCNL group (2.7 vs. 4.9 days, P < 0.001). However, SFRs at the first postoperative day and 4 weeks postoperatively were statistically similar between the two groups (P > 0.05). QoL improvement, measured by the QoL score, was significantly higher in the FV-UAS group than in the MPCNL group (32.5 vs. 27.1, P < 0.001). At 3 months postoperatively, the difference between two groups in the terms of ureteral stricture was not statistically significant (P > 0.05). Notablely, the overall rate of postoperative complications was markedly lower in the FV-UAS group than in the MPCNL group (P < 0.001). Our study revealed that RIRS with FV-UAS is a promising approach to treat IUUS, achieving satisfactory SFRs compared to MPCNL and notable improvements in QoL with a low complication rate.