Kidney stone size and hounsfield units predict successful shockwave lithotripsy in children.

OBJECTIVE: To define the preoperative kidney and stones characteristics on noncontrast-enhanced computed tomography that affect the success of extracorporeal shockwave lithotripsy (SWL) for treatment of renal calculi in pediatric patients. MATERIALS AND METHODS: From 2005 to 2011, 57 children (age <16 years) with documented preoperative noncontrast-enhanced computed tomography scans underwent SWL for treatment of renal stones and were included in the present study. Stone size, site, multiplicity, average skin-to-stone distance, stone attenuation value, and kidney morphology were determined from the preoperative noncontrast-enhanced computed tomography scans. Success was defined as radiographically stone-free status at the 3-month follow-up examination after a single lithotripsy session without the need for additional sessions or ancillary procedures. RESULTS: After a single session of SWL, 24 children (42.1%) were stone free on the 3-month follow-up imaging study without the need for additional SWL sessions. Treatment failed in 33 patients (57.9), with residual fragments in 30 children, of whom 29 required repeat SWL, and 3 with stones that were considered unchanged and were finally treated with percutaneous nephrolithotomy. Logistic regression analysis revealed that stone attenuation in Hounsfield units (HU) and stone length were the only significant predictors of success. When the HU were stratified into 2 groups of ≤600 and >600 HU, the SWL success rate was 82.1% and 20%, respectively (P = .023). When length was stratified as ≤12 mm and >12 mm, the stone-free rate was 58.6% and 25.1%, respectively (P = .016). CONCLUSION: Stone attenuation ≤600 HU and stone length ≤12 mm were significant independent predictors of SWL success in children.

Extracorporeal shockwave lithotripsy for renal stones in pediatric patients: a multivariate analysis model for estimating the stone-free probability.

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 ± 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 ± 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.

Are there long-term effects of extracorporeal shockwave lithotripsy in paediatric patients?

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Extracorporeal shockwave lithotripsy is effective for the treatment of paediatric renal stones with favourable short-term safety. Extracorporeal shockwave lithotripsy for treatment of paediatric renal stones is also safe for the kidney and the child on long-term follow-up. OBJECTIVE: To evaluate the long-term effects of extracoporeal shockwave lithotripsy (SWL) for treatment of renal stones in paediatric patients. PATIENTS AND METHODS: A database of paediatric patients who underwent SWL monotherapy for treatment of renal stones from September 1990 through to January 2009 was compiled. This study included only patients with follow-up for more than 2 years. The long-term effects of SWL were evaluated at the last follow-up with measurement of patients' arterial blood pressure, estimation of random blood sugar and urine analysis. The results of diastolic blood pressure were plotted against a standardized age reference curve. The treated kidney was examined by ultrasonography for measurement of renal length and detection of stones. The measured renal lengths were plotted against age-calculated normal renal lengths in healthy individuals. RESULTS: The study included 70 patients (44 boys (63%) and 26 girls) with mean age at the time of SWL 6.5 ± 3.6 years (range 1-14). The mean follow-up period was 5.2 ± 3.6 years (range 2.1-17.5). The mean age at last follow-up was 11.7 ± 5.3 years (range 4.4-27.5). No patients developed hypertension or diabetes. Only one treated kidney was smaller than one standard deviation of the calculated length. The cause of this was obstruction by a stone in the pelvic ureter 3 years after SWL. CONCLUSION: The long-term follow-up after SWL for treatment of renal stones in paediatric patients showed no effect on renal growth and no development of hypertension or diabetes.

Comparison of endourological and open cystolithotomy in the management of bladder stones in children.

PURPOSE: Vesical stones are common in children in developing countries. Cystolithotomy is the traditional treatment but a percutaneous approach has been advocated. The aim of this study was to evaluate retrospectively our experience with percutaneous cystolithotomy, cystolitholapaxy and open cystolithotomy in children with bladder stones. MATERIALS AND METHODS: A total of 107 children (96 boys and 11 girls) with vesical stones were treated at our center between January 1992 and March 2008. Mean patient age at the time of diagnosis was 5 years (range 2 to 15). The patients were stratified retrospectively into 2 groups according to the procedure of stone removal. Group 1 (53 patients) underwent open cystolithotomy, and group 2 (54) underwent endourological treatment via the transurethral route (27) or the suprapubic approach (27). Stone size ranged from 0.7 to 5 cm (mean 2.8). RESULTS: In all cases the stones were removed successfully. Operative time was comparable in both groups. The hospital stay was significantly shorter after endourological procedures compared to open surgery (2.6 vs 4.8 days, p <0.05). In the open surgery group 1 patient had a small intestinal injury that necessitated repair, while in the endourological group 2 patients had urinary extravasation (1 urethral and 1 vesical). There were no early or late complications in group 1. In comparison, 4 patients (7.4%) in group 2 had early complications in the form of persistent urinary leakage from the suprapubic site and 1 patient had a bulbous urethral stricture 1 year after transurethral stone disintegration. CONCLUSIONS: Open and endourological management of vesical stones in children is efficient, with a low incidence of complications. Endourological management offers a shorter hospital stay compared to open surgery. However, open cystolithotomy seems to be safer.