Prediction of Possible Factors That Affect Stone-Free Rate of Retrograde Intrarenal Surgery; A Multicenter Study

Abstract

Aim: The aim of the study was to evaluate possible factors predicting stone-free status at retrograde intrarenal surgery for renal stones.Materials and Methods: A retrospective multicenter study was performed using data from 513 patients treated between February 2016 and January 2020 at four referral centers in Turkey. The patients were divided into two groups whether they had no residual stone over 3 mm (Group 1) or had residual stones (Group 2). Pre and peroperative parameters were compared in both groups (Table 1). Univariate and multivariate analyzes were performed to identify any factors affecting the stone-free rate (Table 2).Results: Overall stone-free rate was 88.5% (454/513). Lower calyx stones and multipl stones were significantly higher in Group 2 (p=0.006, p=0.02, respectively). Also access sheathless procedure rate was significantly higher and the basket catheter useage rate was significantly lower in Group 2 (p=0.04, p<0.001, respectively) (Table 1). Multiple stone presence and basket catheter usage during the procedure were found as independent factors to predict the stone-free status of Retrograde Intrarenal Surgery according to the results of logistic regression analysis (95%CI 3.3577-0.9999; H-L p= 0.05 and 95%CI 0.4442-0.1290; H-L p< 0.001, respectively) (Table 2).Conclusion:The presence of multiple stones in preoperative imaging and the use of basket catheters peroperatively are independent factors predicting stone-free status in Retrograde Intrarenal Surgery. The presence of multiple stones increases the probability of residual stones after the procedure, while the use of basket catheters is to reduce this possibility.

Keywords

• kidney stone
• retrograde intrarenal surgery
• stone-free