Outcomes of retrograde intrarenal surgery in renal calculi of varying size

INTRODUCTION: Technological advancements have made it possible to attempt retrograde intrarenal surgery (RIRS) in patients with large renal calculi. The objective of this study was to compare the intraoperative adverse events, postoperative complications and stone free rates (SFR) of RIRS in patients with renal calculi of varying sizes. METHODS: Patients who underwent RIRS for renal calculi between January 2016 and June 2020 were categorized into six size groups according to the longest dimension or cumulative measurement of the longest dimension of calculi as follows: Group 1 (1–9 mm), Group 2 (10–19 mm), Group 3 (20–29 mm), Group 4 (30–39 mm), Group 5 (40–49 mm) and Group 6 (≥50 mm). All the patients were followed up for a period of 6 months post treatment completion and the outcomes of interest were computed and compared. RESULTS: Two hundred and ten patients were included in the analysis. Intraoperative adverse events were noted in 9.5%, 8%, 16.9%, 9.1%, 6.7% and 28.6% of the patients in groups 1–6, respectively (P = 0.453). The postoperative complications were noted in 4.8%, 5.3%, 6.8%, 15.2%, 26.7% and 42.9% of patients in groups 1–6, respectively (P = 0.024). The final SFRs were 95.2%, 100%, 96.6%, 90.9%, 86.7% and 71.4% in groups 1–6, respectively (P = 0.012). CONCLUSIONS: RIRS is an effective treatment option for the management of renal stones, including those larger than 20 mm in size. We noted a size dependent increase in the postoperative complications and a reduction in the SFRs. The majority of the postoperative complications were low grade and no stone related events occurred in the patients who were managed conservatively for residual stones after surgery, on the short term follow up.