Safety and efficacy of flexible and navigable suction combined with retrograde flexible ureteroscopy in the management of infectious stones.

Objective: To compare the safety and efficacy of flexible and navigable suction (FANS) ureteral access sheath-assisted retrograde intrarenal surgery (FANS-RIRS) for infectious versus non-infectious stones.

Methods: A retrospective study of 274 patients treated with FANS-RIRS (November 2023–December 2024). Patients were stratified postoperatively into groups based on stone composition. The infectious stone group ( = 61) comprised stones containing at least one of the following components: magnesium ammonium phosphate hexahydrate (struvite), carbonate apatite, or ammonium urate, either as pure or mixed compositions. The non-infectious stone group ( = 213) included other stone types such as metabolic stones, those associated with genetic abnormalities, and drug-induced stones. Outcomes included infectious complications (SIRS/sepsis), stone-free rate (SFR), operative time, and postoperative complications. Statistical analysis used t-tests, Mann-Whitney U, and chi-square tests.

Results: No sepsis occurred in either group. Immediate SFR was comparable (90.2% vs. 92.1%,  = 0.638), with residual stones in infectious cases primarily in lower-pole calyces or diverticula. Infectious stones showed higher preoperative urine culture positivity (32.8% vs. 20.6%,  = 0.046), but no differences in operative time, hospital stay, or complications.

Conclusion: FANS-RIRS for infectious stones demonstrated comparable postoperative infection rates to non-infectious stones, proving safe and effective. However, postoperative antimicrobial stewardship and regular surveillance remained paramount for infectious stone management.