The Clinical Efficacy of Dual-Lumen Catheter Technique in Retrograde Intrarenal Surgery for the Management of Nephrolithiasis: A Propensity Score Analysis

Objective: To assess the clinical efficacy of dual-lumen catheter technique in retrograde intrarenal surgery (RIRS) in terms of stone-free rate. Methods: The data of 172 patients who underwent RIRS for renal stones between 2010 and 2017 were retrospectively reviewed. Patients were classified into two groups depending on whether the dual-lumen catheter technique was used (group 1, n = 25) or not (group 2, n = 147) during RIRS. In turn, all patients of group 1 were compared with those of group 2 using propensity score analysis methods. Clinical variables, including post-RIRS residual fragments (RFs) (≥2 mm) and dusts (sandy stones) (≤1 mm), were compared between both groups. Logistic regression analyses were conducted to identify the predictors of postoperative RFs and dusts. Results: According to propensity score analysis, no other clinical variables were significantly different between the two groups, except the dust-free rate was significantly higher in group 1 than in group 2 (92% vs 40%, p < 0.001). In multivariate analysis, the performance of dual-lumen catheter technique was an independent predictor of the absence of dusts after RIRS (odds ratio [OR], 0.040; 95% confidence interval [CI], 0.070-0.220). In addition, on performing multivariate analyses in another matched population, it was found that although the technique adversely affected the removal of RFs (OR, 4.711; 95% CI, 1.203-18.447), it showed an excellent effect on the evacuation of dusts (OR, 0.049; 95% CI, 0.007-0.347). Conclusion: Our analyses suggest that the use of dual-lumen catheter during RIRS can facilitate the evacuation of sandy stones. However, further prospective randomized trials are required to verify the usefulness of this technique in real clinical practice.