Background and Objective: This retrospective cohort study aimed to evaluate the safety of stentless flexible ureteroscopy (fURS) using a ureteral access sheath (UAS) for stone management. Patients and Methods: A total of 270 ureteral stentless postoperative patients were analyzed. Stentless indication was characterized by having no ureteral wall or mucosa injury with only slight erosion, < 1-hour operative time, and no endoscopic stone fragments with or without stone dust. Postoperative complications and pain were analyzed for safety measurements. In addition, preoperative and intraoperative risk factors associated with the incidence of systemic inflammatory response syndrome (SIRS) and postoperative pain were evaluated. Results: The most common UAS sizes were 10/12 Fr (69.6%) and 9.5/11.5 Fr (28.1%). The rate of patients who were stone-free was 95.9%. The median operation time was 34 min. Only three grade 1 ureteral injuries occurred intraoperatively. Postoperative SIRS occurred in 8.8% of patients, and postoperative use of analgesics was 35.9%. Only four patients were required to undergo eventual ureteral stenting. Less than 10/12-Fr UAS was the only factor positively associated with preventing postoperative SIRS (odds ratio [OR], 4.733; 95% confidence interval [CI], 1.085–20.644). Older age and preoperative ureteral stenting were positively associated with preventing postoperative pain (OR, 0.970; 95% CI, 0.951–0.990 and OR, 0.427; 95% CI, 0.232–0.786; respectively). Conclusion: Stentless fURS with UAS in stone management was feasible for selected patients. UAS size of < 10/12 Fr, older age, and preoperative stenting are possible keystones to achieving stentless fURS with UAS postoperatively.

中文翻译：

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评估在输尿管通路鞘使用输尿管柔性镜治疗结石治疗后未放置输尿管支架的患者全身炎症反应综合征和术后疼痛的预测因素

背景和目的：这项回顾性队列研究旨在评估使用输尿管通路鞘 (UAS) 进行结石处理的无支架输尿管软镜 (fURS) 的安全性。患者与方法：共分析270例输尿管无支架术后患者。无支架适应症的特点是无输尿管壁或黏膜损伤，仅有轻微糜烂，手术时间<1小时，内镜下无结石碎片伴或不伴石屑。分析术后并发症和疼痛以进行安全性测量。此外，还评估了与全身炎症反应综合征 (SIRS) 和术后疼痛发生率相关的术前和术中危险因素。结果：最常见的 UAS 尺寸为 10/12 Fr (69.6%) 和 9.5/11.5 Fr (28.1%)。患者无结石率为95.9%。中位手术时间为 34 分钟。术中仅发生 3 例 1 级输尿管损伤。术后 SIRS 发生率为 8.8%，术后镇痛剂使用率为 35.9%。只有四名患者需要接受最终的输尿管支架置入术。小于 10/12-Fr UAS 是唯一与预防术后 SIRS 呈正相关的因素（优势比 [OR]，4.733；95% 置信区间 [CI]，1.085-20.644）。年龄较大和术前输尿管支架置入与预防术后疼痛呈正相关（OR，0.970；95% CI，0.951-0.990 和 OR，0.427；95% CI，0.232-0.786；分别）。结论：对于选定的患者，无支架 fURS 联合 UAS 用于结石管理是可行的。UAS 大小 < 10/12 Fr，年龄较大，