Outcomes in Retrograde Intrarenal Surgery: A Three Year Retrospective Study

Background: Retrograde intrarenal surgery (RIRS) has become an established minimally invasive treatment for renal calculi. However, stone burden, location, and density may significantly influence outcomes. This study evaluated the efficacy, safety, and predictors of stone-free status following RIRS in a large tertiary-care cohort. Methods: A retrospective analysis was performed on 350 patients who underwent RIRS for renal calculi at Gauhati Medical College and Hospital between 2022 and 2025. Demographic, radiological, and perioperative variables were analyzed. Stone size, location, multiplicity, and Hounsfield unit (HU) density were assessed as predictors of outcome. Stone-free status was defined as complete clearance or residual fragments 20 mm (OR 0.34, p < 0.01), multiple stones (OR 0.60, p = 0.02), lower-pole location (OR 0.59, p = 0.03), and higher stone density (OR 0.91 per 100 HU increase, p = 0.004) independently predicted lower stone-free rates. Mean operative time increased with stone size (p < 0.001). Perioperative complications occurred in 12% of patients, with major complications in less than 1%. Conclusion: RIRS is a safe and effective modality for renal stone management, achieving high stone-free rates with minimal morbidity. Stone size, density, multiplicity, and lower-pole location are key determinants of surgical success and should be considered during preoperative planning and patient counseling.