Yanaral F et al, 2018: Shock-wave Lithotripsy for Pediatric Patients: Which Nomogram Can Better Predict Postoperative Outcomes?
Yanaral F, Ozgor F, Savun M, Agbas A, Akbulut F, Sarilar O.
Department of Urology, Department of Pediatric Nephrology, Haseki Training and Research Hospital, Istanbul, Turkey.
OBJECTIVE: To evaluate and to compare the accuracy of the Onal and Dogan nomograms for prediction of stone-free rate after shock-wave lithotripsy (SWL) in children.
MATERIALS AND METHODS: We retrospectively analyzed the medical records of children <18 years old who had been treated with SWL for kidney stone in our department between January 2014 and December 2016. A single observer reviewed the records and both Onal and Dogan nomograms were calculated and compared with respect to their predictive capability for stone-free status.
RESULTS: A total of 219 patients with a mean age of 82.7 months fulfilled the study inclusion criteria. In patients who were stone free and those with residual stones after completion of the first session, the mean Onal score was 2.83 and 4.12 (P = .01), and the mean Dogan score was 120.87 and 167.44 (P = .01), respectively. In patients who were stone free and those with residual stones after the third session, the mean Onal score was 3.02 and 4.14 (P = .01), respectively. Multivariate regression analysis identified both Onal and Dogan nomograms as independent preoperative factors for SWL outcome in pediatric patients (P = .001 and P = .001).
CONCLUSION: Our study demonstrates that Onal and Dogan nomograms are independent predictors of stone-free rate following SWL in pediatric patients.
Urology. 2018 Jul;117:126-130. doi: 10.1016/j.urology.2018.03.045. Epub 2018 Apr 6.
Prediction of the outcome of SWL has remained a matter of debate over the years. Few attempts have been made to compare predictions made before treatment, with the subsequent outcome. The present report is no exception in this regard; neither is any of the two nomogram articles referred to [1,2]. Both articles show nomograms or scoring tables developed retrospectively at follow-up after treatment.
In the scoring table developed by Onal and co-workers , the stone size, number of stones (= stone burden), location and child’s age (the younger the better) were associated with lower stone clearance. In the nomogram presented by Dogan and co-workers  the major determinants for inferior clearance were stone size, number of stones (=stone burden), previous treatment and child’s age.
In the current article it was noted that stone size (also including multiple stones; stone burden) and low mean age of the child were the most relevant predictors.
Adding different predictive factors to nomograms or scoring systems might demonstrate the total effect that such factors will have on stone clearance. But irrespective of which factors are included in the predictive tools, the prediction will only be very approximate. It also is of note that other important factors are not included, such as the operator’s experience, treatment strategy and post-treatment recommendations. A comparison of different nomograms makes, in my mind, very little sense when considering the dominance of the stone volume /stone burden factor. My major concern is if it at all is necessary with this kind of scoring systems.
Fundamental to successful SWL is the identification of factors that need special attention and considerations during and after the SWL disintegration. When a non-invasive approach is beneficial for the patient and sufficiently gentle to the urinary tract: use that method. If not endoscopy is recommended.
1. Onal B, Tansu N, Demirkesen O, Yalcin V, Huang L, Nguyen HT, Cilento BG, Erozenci A. Nomogram and scoring system for predicting stone-free status after extracorporeal shock wave lithotripsy in children with urolithiasis.
BJU Int. 2013 Feb;111(2):344-52. doi: 10.1111/j.1464-410X.2012.11281.x. Epub 2012 Jun 6.
2. Dogan HS, Altan M, Citamak B, Bozaci AC, Karabulut E, Tekgul S.
A new nomogram for prediction of outcome of pediatric shock-wave lithotripsy.
J Pediatr Urol. 2015 Apr;11(2):84.e1-6. doi: 10.1016/j.jpurol.2015.01.004. Epub 2015 Mar 5