Comparative evaluation of flexible and navigable suction sheath (FANS), percutaneous nephrostomy (PCN), and conventional ureteral access sheath (UAS) during retrograde intrarenal surgery: a randomized controlled trial.

PURPOSE: Optimizing drainage during retrograde intrarenal surgery (RIRS) is crucial for procedural efficacy and safety. Flexible and navigable suction ureteral access sheath (FANS) offers active intrarenal suction without external access, while percutaneous nephrostomy (PCN) provides reliable but invasive drainage. This study compared the efficacy and safety of FANS versus PCN tube drainage during RIRS as compared to conventional ureteral access sheath (UAS).

METHODS

This randomized controlled trial included 217 adult patients with renal stones (14-27 mm) undergoing RIRS. Patients were randomized into three groups: (UAS, n = 72), PCN (n = 72), and FANS (n = 73). Outcomes assessed included operative time, stone-free rate (SFR), complications, and postoperative recovery.

RESULTS

SFR was significantly higher with PCN (97.2%) and FANS (98.6%) versus UAS (81.9%; p < 0.001). The mean operative time was shorter with PCN (48 ± 14 min) than UAS (58 ± 13 min) and FANS (58 ± 11 min; p < 0.001). Loin/suprapubic pain and hematuria were more frequent with UAS, whereas infectious and major complications were infrequent and similar. On stepwise multivariable analysis, lower Hounsfield units and use of PCN (OR 7.756, 95% CI 1.655-36.346) or FANS (OR 17.25, 95% CI 2.156-138.024) independently predicted stone-free status.

CONCLUSIONS

PCN and FANS are both effective and safe drainage strategies during RIRS and outperform conventional UAS in SFR. FANS provides a minimally invasive, entirely endoscopic alternative to PCN with comparable safety and efficacy.