The Risk Factors Analysis Of Rirs And Constructio N And Evaluation Of A New Modified S.T.O.N.E. Scoring System

Objective: To investigate the risk factors affecting stone removal status and develop a new modified S.T.O.N.E.renal stone scoring system by which estimating and predicting stone-free rate after retrograde intrarenal surgery combined with holmium laser lithotripsy.Methods: The clinical data of 280 patients with renal calculi who was tread by RIRS combined with holmium laser lithotripsy in the department of urology of our hospital from January 1,2016 to December 30,2017 were retrospectively analyzed,including 202 patients were finally enrolled into the study cohort according to the inclusion and exclusion criteria.By collecting the general clinical data,stone characteristics,renal anatomy and perioperative data and then the quantitative data is analyzed by independent sample t test between stone-free group and residual group.while categorical data was used to analyze by Chi-square test.Univariate analysis and further multivariate Logistic regression were used to analyze the independent risk factors affecting stone clearance.Based on independent risk factors of calculus clearance and previous literatures,a new modified S.T.O.N.E.scoring system was developed and Preoperative stone characteristics of the patients were scored by the scoring system.Correlation analysis was conducted on the correlation between the new modified S.T.O.N.E.scoring system and operation and postoperative hospitalization time.The sensitivity and specificity of the new modified S.T.O.N.E.score in predicting stone clearance were tested by drawing the subject operating characteristic curve.Results: A total of 202 patients were included in this study,the SFR on postoperative day1 in the present cohort was 65.8%(133/202),and the final SFR after 1 month was 77.7%(157of 202).Cumulative stone diameter(P < 0.001),Topography(P=0.011),stone density(P<0.001)and Renal infundibulopelelvic Angle(P=0.003)were independent risk factors affecting stone removal.There was a statistical significance between the new modified S.T.O.N.E.score and the status of calculus clearance(P<0.001),and there was a certain correlation between new modified S.T.O.N.E.score and the operation time and postoperative hospitalization days(the correlation coefficients were 0.396(P<0.001)and 0.282(< 0.001),respectively).The total points were divided into simple stones(4-6points),medium complex stones(7-9 points)and complex stones(10-13 points)and the corresponding SFR were 91.2%,63.9% and 47.1%,respectively.The AUC under the ROC of the new modified S.T.O.N.E.score,R.I.R.S.score and RUSS score were0.781(95%CI: 0.708-0.854),0.728(95%CI: 0.661-0.788)and 0.712(95%CI:0.625-0.799),respectively.The area under the curve of the new modified S.T.O.N.E.score and RUSS score was compared(Z=2.429,P=0.015),which was statistically significant.Conclusion: Cumulative stone diameter(P < 0.001),Topography(P=0.011),stone density(P<0.001)and Renal Infundibulopelvic Angle(P=0.003)were independent risk factors affecting stone removal.The new modified S.T.O.N.E.scoring system could predict the SFR after RIRS surgery,which contributes to clinical decision-making and academic communication.However,it still needs to be further validated by large samples from multiple centers.