Utilization of flexible ureteroscopy in conjunction with flexible and navigable suction ureteral access sheaths for the management of 1-2 cm complex lower calyceal calculi.

purposeTo evaluate the efficacy and safety of flexible ureteroscopy (FURL) combined with flexible and navigable suction ureteral access sheaths (FANS) compared to conventional FURL for treating 1-2 cm complex lower calyceal stones.

methodsA retrospective single-center study was conducted at the Affiliated Hospital of Shandong Second Medical University, analyzing patients treated between July 2023 and February 2025. Inclusion criteria were: (i) preoperative CT diagnosis of 1-2 cm single lower calyceal stones; (ii) preoperative intravenous urography (IVU) identifying direct insertion of minor calyces into the renal pelvis or branched fusion forming major calyceal openings; and (iii) surgeries performed by one fellowship-trained endourologist for procedural standardization. Exclusion criteria included: (i) uncontrolled preoperative urinary tract infections; (ii) significant ureteral strictures; (iii) severe cardiopulmonary dysfunction or coagulation disorders; (iv) unforeseen postoperative events unrelated to the procedure; and (v) incomplete perioperative data. Patients were divided into an intervention group (FURL with FANS) and a control group (standard FURL with conventional ureteral access sheath). Baseline characteristics, stone-free rates, operative time, hospital stay, and postoperative complications were compared using weighted t-tests, Chi-square tests, or Fisher's exact test.

resultsThe study included 69 patients (intervention group, n = 36; control group, n = 33). After inverse probability of treatment weighting(IPTW) adjustment, baseline characteristics, including age, sex, BMI, stone size, and stone density, showed no significant differences between groups (P > 0.05). The intervention group demonstrated a significantly higher stone-free rate (75.5% vs. 48.9%, P = 0.010), defined as residual fragments < 4 mm on CT at postoperative day 30, shorter operative time (63.02 ± 8.17 min vs. 73.92 ± 15.56 min, P < 0.001), shorter hospital stay (3.15 ± 0.46 days vs. 5.16 ± 1.35 days, P < 0.001), and lower incidence of postoperative fever (0% vs. 12.5%, P = 0.047).

conclusionsFURL combined with FANS offers superior efficacy and safety compared to conventional FURL for managing 1-2 cm complex lower calyceal stones. This approach resulted in higher stone-free rates, reduced operative times, shorter hospital stays, and fewer postoperative complications, presenting a promising alternative for this challenging condition. Larger, multicenter studies are needed to confirm these findings.