Outcomes of fluoroscopy-free retrograde intrarenal surgery and predictive factors of stone-free

Objective: To evaluate the outcomes of flouroscopy-free retrograde intrarenal surgery (ffRIRS) and to investigate the factors that may affect stone-free rate. Materials and methods: The charts of patients who underwent ffRIRS between January 2017 and August 2019 were reviewed retrospectively. Patients with missing preoperative imaging and patients with kidney anomalies were excluded from the study. Age, gender, stone size, stone localization, stone density, laterality, operation time, stone-free rate, complications and auxiliary procedures were recorded and analyzed. Results: Study group involved 44 (43.1%) female and 58 (56.8%) male patients. Stone-free rate in a single-session ffRIRS were found to be correlated with stone localization (p = 0.003), stone volume (p = 0.004), and stone density (p = 0.009) but not with age (p = 0.950). Patients with multiple calyceal stones and a stone burden over 520 mm3 were found to be less stone-free. The complication rate in female gender (n = 7) was significantly higher compared to male (n = 1) (p = 0.011). No major complications such as ureteral injury or avulsion were observed. Overall, 13 patients (12.7%) needed auxiliary procedures. The operation time seemed to be affected by stone size and gender (p = 0.005; p = 0.044, respectively). Conclusions: Stone-free rate in ffRIRS were found to be affected by stone density, size, and localization. Patients with multiple caliceal stones and high stone burden (< 520 mm3) have been found to have low stone-free rate, so one can speculate that having fluoroscopy assistance in RIRS might help us to improve surgical success.

External validation of the T.O.HO. score as predictor of success after retrograde intrarenal surgery

Background To assess the effectiveness of T.O.HO. (Tallness, Occupied lesion, Houndsfield unit evaluation) score in predicting the retrograde intrarenal surgery (RIRS) success and to validate this scoring system. Methods The age, sex, previous stone surgery, hospitalization, surgery duration, postoperative complication, stone length, stone location, stone density, stone number, lateralization, presence of hydronephrosis, and presence of preoperative stent datas of 518 patients who underwent RIRS in our clinic between January 2013 and January 2021 were retrospectively assessed. The patients were divided into two groups as successful and unsuccessful. The T.O.HO scores of all patients were calculated. Results The success rate was 72.5%. Compared to the unsuccessful group, stone length and stone density were lower, surgery duration was shorter and there were less lower pole stones in the successful group (p<0.001). No significant difference was found between the two groups in terms of the other parameters. The T.O.HO. score was significantly lower in the successful group compared to the unsuccessful group (p<0.001). According to the multivariate logistic regression analysis, stone length (OR: 0.905; 95% Cl: 0.866-0.946; p<0.001), lower pole location (OR: 0.546; 95% Cl: 0.013-0.296; p<0.001), stone density (OR: 0.999; 95% Cl: 0.998-1; p=0.044) and the T.O.HO. score (OR: 0.684; 95%Cl: 0.554-0.844; p<0.001) were found as the independent risk factors for RIRS success. ROC curve analysis showed that the T.O.HO. score could predict the RIRS success with 7.5 cut-off point (AUC:0.799, CI: 0.76–0.839; p<0.001). Conclusion The T.O.HO. score can predict RIRS success with a high rate of accuracy.