FANS-UAS under local anesthesia for urinary stones with high risk-postoperative urosepsis

Background: Nephrolithiasis is a highly prevalent renal disease. Retrograde intrarenal surgery (RIRS) serves as a primary approach for managing urinary stones, yet urinary tract infections may limit its application. Postoperative fever and sepsis resulting from infection represent the most severe complications of RIRS. To investigates the efficacy and safety of flexible and navigable suction ureteral access sheath (FANS-UAS) assisted RIRS under local anesthesia (LA) in reducing postoperative fever rates for stones with high risk of postopeartive urosepsis. Methods: This was a multiple-center single armed trial from May 2024 to March 2025. Patients with urinary stones ≤30 mm and persistent asymptomatic bacteriuria or asymptomatic pyuria after antibiotic therapy were enrolled. Eligible Patients received FANS-UAS assisted RIRS under LA. The primary clinical outcome was the assessment of stone-free rate (SFR) and the incidence of postoperative fever. Secondary outcomes included final SFR, surgery-related complications and evaluation of pain. Results: A total of 395 patients underwent treatment. 318 cases (80.5%) reached immediately stone-free. There were 11 cases (2.8%) of postoperative fever. We observed significant reductions in the mean urinary leukocytes (p < 0.01) and CRP (p < 0.001). Patients experienced transient intraoperative elevation in VAS scores, but the pain reduced after surgery (p < 0.001). Conclusions: We report the results of FANS-UAS assisted RIRS under LA for stones with HR-POU. The outcomes demonstrate that FANS-UAS combined with LA is a feasible stone clearing method for patients with refractory UTIs.