Are Two Channels Better than One? A Comparative Study Between Dual-Lumen and Single-Lumen Flexible Ureteroscope in Retrograde Intrarenal Surgery

Objective: To compare perioperative efficiency, stone-free rates, and safety between a dual-lumen and a single-lumen flexible ureteroscope in retrograde intrarenal surgery (RIRS). Materials and Methods: This comparative study included 80 consecutive patients with a single renal stone 1.0–1.5 cm in the pelvicalyceal system treated with RIRS using either a dual-lumen ureteroscope (Group A, n = 40) or a single-lumen ureteroscope (Group B, n = 40). Recorded outcomes included operative and fluoroscopy times, failure of ureteral access sheath (UAS) insertion, surgeon-rated clarity of vision (0–10 scale), stone-free status on non-contrast computed tomography at 30 days, and complications graded by the Clavien–Dindo system and the Post-Ureteroscopy Lesion Scale (PULS). The stone-free rate (SFR) was defined as absolute and relative. Results: Baseline demographics, stone size, and stone location were comparable between groups. Dual-lumen use was associated with shorter operative time (38.6 ± 9.3 vs 52.7 ± 8.1 minutes, p = 0.018), shorter fluoroscopy time (23.6 ± 5.5 vs 34.2 ± 4.7 seconds, p = 0.04), and higher clarity-of-vision scores (8.6 ± 1.35 vs 5.9 ± 1.86, p = 0.035). UAS insertion failed more often with the dual-lumen scope (20.0% vs 10.0%, p = 0.32). One month after evaluation, SFR did not significantly differ between the two groups. Postoperative complications were infrequent (12.5% vs 10.0%, p = 0.72), all were Clavien–Dindo grade I–II, and no PULS grade ≥4 ureteral injuries occurred. Conclusions: Compared with a reusable single-lumen ureteroscope, the dual-lumen device improved operative efficiency in terms of shorter operative and fluoroscopy time and better clarity of vision. These benefits are counterbalanced by a higher UAS insertion failure rate related to the larger outer diameter of the ureteroscope.