External Validation of the S.T.O.N.E. Score in Predicting Stone-Free Status After Rigid Ureteroscopic Lithotripsy
Received 28 January 2021
Accepted for publication 8 March 2021
Published 23 March 2021 Volume 2021:13 Pages 147—154
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 3
Editor who approved publication: Dr Jan Colli
Noppavut Sirirak, Premsant Sangkum, Yada Phengsalae, Wisoot Kongchareonsombat, Charoen Leenanupunth, Wattanachai Ratanapornsompong, Chinnakhet Ketsuwan
Division of Urology, Department of Surgery, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, 10400, Thailand
Correspondence: Chinnakhet Ketsuwan Tel +66-2-2011536
Email [email protected]
Background: The Size, Topography, Obstruction, Number, and Evaluation of Hounsfield units (S.T.O.N.E.) scoring system has been proposed as a novel prognostic surgical classification for urolithiasis in predicting success rate and complications.
Objective: We carried out an externally validated S.T.O.N.E. score on rigid ureteroscopic lithotripsy (rURS).
Materials and Methods: The data of patients who had undergone rURS between 2012 and 2019 at a tertiary referral center were audited retrospectively. The S.T.O.N.E. score was calculated based on factors determined through preoperative computed tomography images and was analyzed in association with stone-free rate (SFR), operating time, surgical complications, and length of stay (LOS).
Results: A total of 155 patients were included in the study with a median stone size of 10 mm (7– 12) and a median S.T.O.N.E. score of 9 (8– 10). The overall SFR was 89.68%. SFRs were 100.0%, 97.83%, and 77.42% in low (5), moderate (6– 9), and high (10– 13) score groups, respectively. The S.T.O.N.E. score (p = 0.002) and stone size (p = 0.037) were predictive factors for SFR in multivariate analysis. Moreover, there was a significant correlation between the S.T.O.N.E. score and operative time, LOS, and presence of complications (r = 0.22, p = 0.006; r = 0.30, p < 0.001; and r = 0.27, p < 0.001, respectively). The area under the curve of the receiving operator characteristics’ curve for the S.T.O.N.E. score was 0.815.
Conclusion: The S.T.O.N.E. scoring system is simple and effective in predicting postoperative outcomes; therefore, this score would be a valuable tool in clinical planning for every patient who undergoes rURS.
Keywords: ureteroscopy, S.T.O.N.E. score, stone-free rate
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]