Tip-Flexible Suctioning Ureteral Access Sheath Combined with Flexible Ureteroscope: a single-institution experience including in vitro experiments

Background To evaluate the clinical application value of tip-flexible suctioning ureteral access sheath (TFS-UAS), this study compares the efficacy and safety of TFS-UAS versus traditional ureteral access sheath (T-UAS) in treating unilateral renal or proximal ureteral calculi, and further summarizs the usage strategy of TFS-UAS by synthesizing vitro experiment and surgical best practices. Methods A retrospective analysis was conducted on 196 patients with renal or proximal ureteral calculi treated with FURS and holmium laser lithotripsy at Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. Patients were divided into TFS-UAS and T-UAS groups. Primary data included operative time, immediate SFR (iSFR), and 2-week SFR. Secondary data encompassed changes in blood parameters (leukocytes, hemoglobin, urea nitrogen, creatinine), complications, and hospital stay. Results This retrospective study found that urologists preferred to use TFS-UAS for larger (17.73 ± 7.79 mm vs 12.56 ± 5.14 mm, P  < 0.001), harder (1156.52 ± 420.15 vs. 778.39 ± 513.46 Hounsfield units, P  < 0.001), and more complex (modified STONE score: 10.86 ± 2.51 vs. 7.37 ± 2.28, P  < 0.001) upper urinary tract calculi. No significant differences in operative time or SFR were found between the TFS-UAS and T-UAS groups overall. However, for stones ≥ 15 mm, those that were larger(22.57 ± 6.35 mm vs 18.70 ± 3.82mm, P  = 0.001), harder(1160.76 ± 382.84 vs 896.56 ± 465.33, P  = 0.007), and more complex(modified STONE score: 11.43 ± 2.40 vs 8.63 ± 2.31, P < 0.001), TFS-UAS significantly reduced operative time (53.92 ± 21.77 vs. 65.76 ± 22.43 min, P  < 0.001) and improved iSFR (91.89% vs 73.17%, P  = 0.063), 2-week SFR (81.08% vs. 56.10%, P  = 0.018). Conclusions TFS-UAS combined with FURS significantly improves operative efficiency and SFRs for upper urinary tract calculi ≥ 15 mm, demonstrating clinical advantages. Clinical trial number: not applicable.