Cross sectional retrospective assessment of safety of retrograde intrarenal surgery with laser lithotripsy in management of upper urinary tract calculi

Context: The utility of Retrograde Intra Renal Surgery (RIRS) with laser lithotripsy has gained wider acceptance in management of upper tract stones. RIRS is associated with fewer complications. This study aims to assess complication rate of RIRS with laser lithotripsy, severity of complication using modified Clavien-Dindo classification system (MCCS), factors predicting complications and grade of complications. Materials and Methods: This was a retrospective cross-sectional study involving 33 patients with a diagnosis of upper tract stone less than 20mm. Patients had retrograde intrarenal surgery with laser lithotripsy for ureteric stone using a semi rigid ureteroscope (9.5Fr Karl Storz) with a Holmium YAG laser machine, in combination with 274um laser fiber, and a flexible ureterorenoscope was used for renal stones with a ureteral access sheath (UAS). Results: Thirty-three patients were involved in this study, with a mean age of 43.70+/- 11.44 years. Males accounted for 18 (54.5%) of the study population. Mean duration of admission was 2.5+/-1.6 days. The median stone size was 10.55(IQR=0.42-85.0), while mean stone density measured in Hounsfield unit (HU), was 817+/-285.5. Intraoperative and postoperative complication rate was 12.1% and 21.2% respectively. Severity of complication using the MCCS include 47.6%,28.6%, 19.0%, 4.8% for grades I, II, III and, IV respectively. Age (p=0,364), gender (p=0.843), stone size (p=0.143) and, ureteric stones or emergency interventions (p=0.151) were not associated with complications or grade of complications. In a multivariate regression analysis, there were no predictors of complications, or grade of complications. Conclusion: The complication rate of RIRS with laser lithotripsy in this study was moderate, with most patient having minor complications Clavien-Dindo I and II.