Will Flexible and Navigable Suction Sheaths Change the Paradigm of Stone Treatment in the Era of Novel Generation Lasers?

Background: The flexible and navigable suction sheath (FANS) is designed for the effective treatment of renal stones of various sizes. This study aimed to assess and compare the safety and postoperative outcomes at 30 days following FANS treatment for stones smaller and larger than 20 mm. Materials and Methods: From January to December 2024, patients undergoing retrograde intrarenal surgery performed with FANS were prospectively recruited and divided into two groups based on stone diameter (Group 1: DMAX <20 mm, Group 2: DMAX ≥20 mm). Baseline, perioperative, and follow-up characteristics were analyzed. Stone-free rate (SFR) was evaluated with a non-contrast CT scan at 1-month. Statistical analysis was performed using the unpaired Student’s t -test and chi-squared test with Yates’ correction. Results: A total of 140 patients were enrolled, with 77 having stones <20 mm and 63 having stones ≥20 mm. While a significant difference in stone diameters was observed, no discrepancies were noted regarding the mean stone density between the two groups, thus minimizing the potential for bias. No major Clavien-Dindo complications occurred in either group without differences in hospital length of stay, but Group 1 reported lower visual analogue scale pain. No significant differences in Grade A, B, and C SFR (all p > 0.05) and re-intervention ( p = 0.58) were observed, suggesting similar efficacy for both stone sizes. Conclusions: This study demonstrates that the FANS as a valuable tool for enhancing patient safety and outcomes in managing larger stones, achieving adequate SFR, and reducing the need for re-intervention without major complications. In the future, FANS may effectively change the indications for stone’s treatment according to diameter.