The First 100 Cases of Endoscopic Combined Intrarenal Surgery in Korea: Matched Cohort Analyses versus Shock-Wave Lithotripsy

Abstract

Purpose: This study presents our initial experience with endoscopic combined intrarenal surgery (ECIRS) for large renal stones and compares the results of a propensity score-matched cohort of patients undergoing shock-wave lithotripsy (SWL).

Materials and methods: A total of 100 adults underwent ECIRS for renal stones between August 2017 and January 2019. For comparison, 2172 patients who underwent a first session of SWL between January 2005 and May 2018 were included in the SWL cohort. Propensity score matching was performed using maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) scores. Stone-free rate (SFR) and success rate were compared between ECIRS and SWL.

Results: In the ECIRS group, the mean MSL, mean MSD, and mean SHI were 28.7±15.2 mm, 1013.9±360.0 Hounsfield units (HU), 209.4±104.0 HU, respectively. The SFR was 70%, and the success rate was 82.0% in this group. Although the ECIRS group had larger, harder, and more homogeneous stones than the SWL group, ECIRS showed a higher SFR and success rate than SWL. After propensity-score matching, SFR and success rate remained higher with ECIRS than with SWL (both, p<0.001). In multivariate logistic regression, smaller stone size [odds ratio (OR): 0.947, 95% confidence interval (CI): 0.913-0.979, p=0.002] and lower Seoul National University Renal Stone Complexity score (OR: 0.759, 95% CI: 0.610-0.935, p=0.011) were independent predictors of successful ECIRS.

Conclusion: ECIRS showed a higher SFR and success rate than SWL for large renal stones. Smaller stone size and lower complexity of stones were associated with a higher likelihood of successful ECIRS.