Ultralow Radiation Exposure During Flexible Ureteroscopy in Patients With Nephrolithiasis—How Far Can We Go?

Abstract

To evaluate the feasibility and clinical performance of a novel surgeon technique and protocol targeting ultralow fluoroscopy usage in retrograde intrarenal surgery (RIRS). All RIRS procedures between 2009 and 2015 for 10- to 20-mm renal calculi performed by the same 2 experienced urologists were eligible. All procedures were performed using a highly standardized step-by-step RIRS technique. This technique was modified by the ultralow radiation exposure RIRS protocol; herein, as much as possible of the standardized steps were performed without radiation control targeting ultralow fluoroscopy usage. Primary end points were fluoroscopy time and dose area product. Secondary end points were stone-free rate (SFR) and intraoperative complications according to Satava classification. End points were evaluated using scatter plots and linear regression model. Overall, 174 procedures were assessed. Over the study period, fluoroscopy time and dose area product could be reduced from 167.7 s/318.4 cGy/cm2 in 2009 to 7.4 s/6.4 cGy/cm2 in 2015 (P <.001). SFR (66.7% in 2009; 100% in 2015) and complications (Satava 1 and 2: 28.5% and 4.8%, respectively) improved P <.1), and the surgical duration was reduced (91 minutes and 65 minutes, respectively, P <.001). Our findings revealed a continuous reduction of the amount of radiation used by the implementation of a novel ultralow X-ray usage protocol. SFR, complications, and surgical duration all improved, demonstrating that the novel protocol is as effective as current methods. Exposure to ionizing radiation can be significantly reduced if the presented protocol is followed strictly.