Abstract / Summary
To evaluate the impact of preoperative waiting time (PWT) on surgical and renal functional outcomes after elective semi-rigid ureterorenoscopy (URS) and to determine whether these effects differ between elderly and younger patients. We retrospectively reviewed 377 adults who underwent elective semi-rigid URS for ureteral or renal pelvic stones between 2019 and 2023. Patients were stratified into younger (< 65 years; n = 278) and elderly (≥ 65 years; n = 99) groups. PWT was defined as the interval between diagnostic computed tomography and surgery. The primary surgical outcome was successful standard-caliber URS, defined as successful stone access and completion of laser lithotripsy using the standard 9.5-Fr ureterorenoscope. Renal outcomes were assessed by postoperative changes in serum creatinine and estimated glomerular filtration rate (eGFR). Successful standard-caliber URS was achieved in 263 patients (69.8%), with no statistically significant difference between the groups (70.1% vs. 68.7%, p = 0.886). In the main multivariable model, PWT ≥ 7 days (adjusted OR 3.73, 95% CI 2.18–6.36; p < 0.001) and higher hydronephrosis grade (adjusted OR 1.64, 95% CI 1.24–2.17; p = 0.001) were associated with successful standard-caliber URS, whereas periureteral stranding (adjusted OR 0.35, 95% CI 0.20–0.59; p < 0.001), proximal stone location (adjusted OR 0.44, 95% CI 0.27–0.73; p = 0.001), and greater renal parenchymal thickness (adjusted OR 0.93 per mm, 95% CI 0.89–0.98; p = 0.004) were associated with lower procedural success. The association between PWT and procedural success was also observed in sensitivity analyses. PWT was not associated with postoperative changes in serum creatinine or eGFR, and no interaction was detected between age group and PWT regarding surgical or renal functional outcomes. No statistically significant differences were observed in surgical or short-term renal functional outcomes between elderly and younger patients undergoing elective semi-rigid URS. A PWT of ≥ 7 days was associated with successful standard-caliber URS, but this finding should not be interpreted as evidence that delaying surgery improves outcomes. No association was observed between PWT and postoperative changes in global renal function indices, although these measures may be insensitive to unilateral functional changes. No age × PWT interaction was detected.