Is flexible navigable suction ureteral access sheath (FANS) safer and more efficient than conventional sheaths? Italian multicentric experience

Background and Objective The flexible and navigable suction ureteral access sheath (FANS) with continuous flow lithotripsy may improve stone-free rates (SFR) in ureterorenolithotripsy procedures, reducing operative time and the need for fragment extraction. This study aimed to compare the safety and efficacy of FANS versus conventional sheaths in patients undergoing retrograde intrarenal surgery (RIRS) for renal stones. Methods From January to September 2024, patients undergoing RIRS with high-power pulsed lasers (60 W Ho:YAG or 100 W pTm:YAG) were randomized to receive either a conventional sheath (Group 1) or FANS (Group 2). Data on baseline characteristics, operative details, and complications were collected. SFR, defined as the absence of fragments > 3 mm, was assessed with non-contrast CT scans one-month post-surgery. Statistical significance was set at p < 0.05. Results A total of 132 patients were enrolled (70 with conventional sheath, 62 with FANS). The FANS group had shorter operative times (55.25 vs. 61.36 min, p = 0.028), while laser time was similar between groups. Postoperative complications were lower in the FANS group. At one month, the FANS group had a higher SFR (95% vs. 67%, p < 0.005) and fewer re-interventions (p = 0.02). Conclusions FANS significantly improves SFR without increasing postoperative complications postoperative complications or negatively affecting recovery, offering a promising alternative to conventional sheaths in ureterorenolithotripsy procedures. Patient Summary FANS improves kidney stone surgery outcomes, providing better stone removal, fewer complications, and faster recovery compared to the standard tool.