Flexible ureteroscopy (F-URS) with suction technology has become a minimally invasive surgery for the management of renal stones. While the Flexible and Navigable Suction Ureteral Access Sheath (FANS) and Direct In-Scope Suction (DISS) ureteroscopes individually have proven benefits and restrictions, there is no dedicated research if integrating both these technologies can complement the limitations of each to improve suction F-URS outcomes. This audit introduces the Flexible Integrated Retrograde Suction-Ureteroscopy Technique (FIRST) procedure, which integrates FANS with a DISS ureteroscope, and compares its outcomes against DISS combined with a conventional ureteral access sheath (C-UAS).
This prospective audit enrolled 64 adult patients undergoing F-URS with a DISS ureteroscope between August 2024 and October 2025 at 2 institutions. Patients were allocated to DISS with FANS (Group 1, n = 37) or DISS with C-UAS (Group 2, n = 27) based on surgeon discretion and device availability. The primary outcome was 30-day stone-free rate (SFR) assessed by non-contrast CT scan (single fragment up to 2 mm). Secondary outcomes included perioperative complications, renal function, and 3-month residual fragment rate, and the surgeon-reported ergonomics of procedures.
Despite significantly greater stone burden in Group 1, the FIRST procedure achieved a superior 30-day SFR of 83.8% versus 70.4% in Group 2, with zero-residual-fragment status in 72.9% versus 48.1% of patients, respectively (p < 0.001). At three months, zero residual fragments were detected in all patients in Group 1 compared to 22.2% in Group 2 (p < 0.01), translating into zero reinterventions in Group 1. Surgeon-reported ergonomics, intraoperative visibility, and simultaneous DISS-laser manipulation were rated significantly superior in Group 1. Overall 30-day complication rates were comparable between groups (18.9% vs. 22.2%), with no high-grade (Clavien ≥ 3) complications and preserved renal function in either cohort.
The FIRST procedure using this integrated suction technique can potentially give 100% SFR with significantly improved ergonomics with negligible complications. These findings support further investigation of the integrated FIRST procedure in routine and anatomically complex renal stone disease.
World journal of urology. 2026 Jun 20*** epublish ***
Vineet Gauhar, Deepak Ragoori, Mallikarjuna Chiruvella, Steffi Kar-Kei Yuen, Olivier Traxer, Bhaskar Somani, Daniele Castellani
Endourology Section of the European Association of Urology, Arnhem, The Netherlands., Department of Urology, Asian Institute of Nephrology and Urology, Hyderabad, India., Endourology Section of the European Association of Urology, Arnhem, The Netherlands. .