Extracorporeal shockwave lithotripsy for renal stones in pediatric patients: A multivariate analysis model for estimating the stone‐free probability

Abstract

Abbreviations & Acronyms CT = computed tomography KUB = plain X-ray of kidney, ureter and bladder NCCT = non-contrast computed tomography PNL = percutaneous nephrolithotomy RUS = renal ultrasonography SWL = shockwave lithotripsy URS = ureteroscopy Objectives: To define factors affecting the stone-free rate of extracorporeal shockwave lithotripsy in the treatment of pediatric renal calculi, and to establish a regression model for pretreatment prediction of stone-free probability. Methods: From January 1999 through February 2012, 207 children with mean age 6.4 Ϯ 3.8 years underwent shockwave lithotripsy with Dornier Lithotripter S for treatment of renal stones. The stone-free rate was evaluated 3 months after the last shockwave lithotripsy session with non-contrast computed tomography. Treatment success was defined as complete clearance of the stones with no residual fragments. Multivariate logistic regression analysis was used to identify independent risk factors and to predict the probability of being stone free. Results: The mean length of the stone was 11.6 Ϯ 4 mm. The stone-free rate was 71%. Independent factors that adversely affect stone-free rate were increasing stone length and calyceal site of the stone. Relative risks for not being free of stones were 1.123 for stone length, 2.673 for stones in the upper or middle calyx and 4.208 for lower calyx stones. Conclusion: Stone length and location are prognostic factors determining stone-free rate after shockwave lithotripsy for renal calculi in pediatric patients. Based on our analysis, shockwave lithotripsy should be recommended for renal pelvis stones up to 24 mm, upper or middle calyceal stones up to 15 mm and lower calyceal stones up to 11 mm.

Evaluation of Extracorporeal Shock Wave Lithotripsy (ESWL): Efficacy in Treatment of Urinary System Stones

“…According to the recommendations of the El-Nahas et al ( 17 ), ESWL should be recommended for renal stones localized in the renal pyelon up to 24 mm for the upper or middle stones to 15 mm, and lower stones with size up to 11 mm.…”

Extracorporeal Shock Wave Lithotripsy Treatment for Renal and Ureteral Stones in Duhok City

“…Size of stone, its position and localization as well as ages of patients and sometimes patients' region are prognostic factors that determine the level of disintegration of stone after using ESWL in pediatric patients. According to the analysis of [13], ESWL should be recommended for renal pylon stones up to 24 mm for the upper or middle calyx to 15 mm, and lower calyx to 11 mm. Although the composition of stone is independent variable that can be useful for predicting the success of ESWL, for most stones is difficult to predict the sensitivity of breaking by the X-ray prior to ESWL.…”

Risk factors for formation of steinstrasse after extracorporeal shock wave lithotripsy for pediatric renal calculi: a multivariate analysis model

“…Successful SWL in children was first published in 1986 [4]. Since then several reports showed safety and stone-free rates comparable to those of adults [5][6][7].…”