Radiation exposure during retrograde intrarenal surgery (RIRS): a prospective multicenter evaluation.

PURPOSE: Retrograde intrarenal surgery (RIRS) may require extensive X-ray usage. We evaluated the impact of preoperative surgeon briefing regarding the inclusion and evaluation of fluoroscopy time (FT) and dose area product (DAP) in a multicenter study on the applied X-ray usage. METHODS: A prospective multicenter study of 6 tertiary centers was performed. Each center recruited up to 25 prospective patients with renal stones of any size for RIRS. Prior to study´s onset, all surgeons were briefed about hazards of radiation and on strategies to avoid high doses in RIRS. Prospective procedures were compared to past procedures, as baseline data. FT was defined as the primary outcome. Secondary parameters were stone-free rate (SFR), complications according to the Clavien, SATAVA and postureteroscopic lesion scale. Results were analyzed using T test, chi-squared test, univariate analysis and confirmed in a multivariate regression model. RESULTS: 303 patients were included (145 retro- and 158 prospective). Mean FT and DAP were reduced from 130.8 s/565.8 to 77.4 s/357.8 (p < 0.05). SFR was improved from 85.5% to 93% (p < 0.05). Complications did not vary significantly. Neither stone position (p = 0.569), prestenting (p = 0.419), nor surgeons' experience (> 100 RIRS) had a significant impact on FT. Significant univariate parameters were confirmed in a multivariate model, revealing X-ray training to be radiation protective (OR - 44, p = 0.001). CONCLUSIONS: Increased surgeon awareness of X-ray exposure risks has a significant impact on FT and DAP. This "awareness effect" is a simple method to reduce radiation exposure for the patient and OR staff without the procedures´ outcome and safety being affected.