Do High Ventilation Mode Affect the Success Rates of Retrograde Intrarenal Surgery? A Single-Blind Randomized, Prospective, Single-Center Study.

Purpose: Retrograde intrarenal surgery (RIRS) has been accepted as a first-line therapeutic option for kidney stones <2 cm. Renal mobility might be a challenging situation for the surgeon targeting the laser, thereby limiting the renal mobility during surgery might affect the surgical success. The main objective of the present trial was to evaluate the effect of two different ventilation modes on the efficacy and safety of RIRS performed under general anesthesia. Materials and Methods: The patients undergoing RIRS from January 2023 to April 2023 were prospectively enrolled in the trial. In the standard ventilation (SV) mode, the tidal volume was 8 to 10 mL/kg with respirations per minute being 10-15, whereas in the high ventilation (HV) mode the tidal volume was reduced to 6 to 8 mL/kg with the frequency being increased to 15 to 18 respirations/minute. For the purposes of the trial and the randomization, the anesthesiologist was informed about the ventilation mode used, whereas the surgeon was blinded. The surgical success rates and the observed complications were compared between SV and HV modes. Results: A total of 144 patients were enrolled with the mean age 48.78 ± 14.16 years. The mean duration of operation was 62.9 ± 26.3 minutes in the SV group, whereas it was 58.4 ± 20.1 minutes in the HV group ( p  = 0.031). Fragmentation rate of the stones per minute was higher in the HV group with the difference being statistically significant ( p  = 0.003). In the preoperative period, while hematuria was seen at higher rates in the HV group, the difference was not statistically significant ( p  = 0.671). Stone-free rates (Grades A-B-C) and the rates of postoperative complications were comparable between the groups ( p  = 0.605 and p  = 0.676, respectively). Conclusion: Using HV mode during the RIRS decreased the operative time and provided the surgeon with the ability to target the laser more effectively. Surgeons might prefer using the HV mode during RIRS in a mobile kidney to reduce their operative time and perform comfortable surgery. ClinicalTrials.gov: The trial is registered at ClinicalTrials.gov with the registration number of NCT05792670.