Pediatric Shock Wave Lithotripsy Research Articles

Complication rate after pediatric shock wave lithotripsy according to Clavien-Dindo grading system: results from a systematic review and meta-analysis of the existing literature.

Shockwave lithotripsy (SWL) is a minimally invasive technique utilized for renal and ureteric stones in children. Despite being considered safe, certain complications have been recorded. We performed this systematic review and meta-analysis to provide a pooled analysis of Clavien-Dindo graded complications after SWL in children. MEDLINE/PubMed, Scopus and Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, were screened from inception to 12/02/2022 by two authors independently. Only randomized controlled trials providing Clavien-Dindo classification or relevant clinical information were considered eligible. Overall complications were calculated using the aggregate number of each complication divided by the total number of patients in studies with data. Pooled analysis revealed that from children treated with SWL, 27.7% [95% CI 13.1-49.4] suffered Clavien I complications, 4.9% [95% CI 3.1-7.6] Clavien II complications, 2.7% [95% CI 1.6-4.7] Clavien III complications, 2.3% [95% CI 1.3-4] Clavien IV complications, while no Clavien V complications were recorded. In total, 28.1% [95% CI 15.6-45.3] of children suffered minor complications (Clavien-Dindo I-II), while 3% [95% CI 1.8-5] major complications (Clavien-Dindo III-V). Pooled analysis revealed that 10.7% [95% CI 3.2-30.1] of patients suffered macroscopic hematuria, 7.3% [95% CI 2.1-22.7] pain, 5.5% [95% CI 3.3-9] steinstrasse, 5.3% [95% CI 3-9.3] fever, 2.2% [95% CI 0.8-5.6] sepsis, 1.1% [95% CI 0.3-3.7] urinoma, 1% [95% CI 0.4-2.7] symptomatic hematoma and 1% [95% CI 0.3-2.7] asymptomatic hematoma. Need for re-treatment was 42.6% [95% CI 31.4-54.7] and need for auxiliary procedures was 11.8% [95% CI 8.5-16.1]. SWL is an irreplaceable tool for treating urolithiasis in children. Although a minimally invasive technique, parents and children should be adequately informed about the risk of minor/major complications.

Shock Wave Lithotripsy in Pediatric Stone Disease: A 15-Year Single-Center Experience with 2 Types of Lithotripters

Introduction and Objectives: We report our experience with pediatric shock wave lithotripsy (SWL) using two types of lithotripters: Dornier HM3 (HM3) and Dornier Lithotripter SII (DLS). Study Design: We retrospectively reviewed the charts of children who underwent SWL between 2002 and 2016. Patients were divided into two groups based on the type of the lithotripter: during 2002–2009, we used the electrohydraulic HM3 lithotripter which was replaced in 2009 with the DLS electromagnetic lithotripter. Clinical and perioperative parameters were compared. Results: Our cohort included 107 children who underwent SWL. Average age was 11.5 ± 5.1 years. Average stone size was 10.6 ± 4.9 mm. HM3 was used in 38% of children and DLS2 in 62% (n = 41 and 66, respectively). There were no significant differences in age, gender, stone size, or location between the groups. The total SFR did not differ statistically between HM3 and DLS (83% vs. 74%, p = 0.35). SFR after one SWL was higher with the HM3 (78% vs. 62%, p = 0.093). Re-treatment rate was 22% and 17% (HM3 vs. DLS, p = 0.61). Complication rates were low, with renal colic being the most common (HM3 10%, DLS 20%, NS). Conclusions: SWL in the pediatric population using the DLS showed good results with low complication rates that are equivalent to the gold standard HM3.

Which frequency is better for pediatric shock wave lithotripsy? Intermediate or low: a prospective randomized study.

Shock wave lithotripsy (SWL) is the first option in the treatment of pediatric kidney stones; however, optimal frequency is still uncertain. The aim of this study was to compare low frequency [60 shocks per minute (SWs/min)] and intermediate frequency [90SWs/min] in terms of lithotripsy success, complications, cardiac arrhythmia, anesthesia time, secondary procedures, and efficiency quotient (EQ) in children. Seventy-eight consecutive children who received SWL for radiopaque renal stones between July 2016 and January 2020 were randomly divided into two groups: Group 60 (SWL frequency: 60 SWs/min) and Group 90 (SWL frequency: 90 SWs/min). After exclusion (remaining 71 children), Group 60 (n = 38) and Group 90 (n = 33) were compared using univariate analysis. The median age of children (37 girls, 34 boys) was 5 (1-16) years. Patient demographics and stone features were similar between the groups. Success rate after the last SWL session was 81.6% (n = 31) for Group 60 and 87.9% (n = 29) for Group 90 (p = 0.527). Stone-free rate after the first, second, and third sessions was 42.1%, 18.4%, and 21.1% for Group 60 and 48.5%, 27.3%, and 12.1% for Group 90, respectively. Additional treatment rate was similar between the groups. In Group 60, the EQ was 57.83, and it was 64.07 in Group 90. Median total anesthesia time was significantly longer in Group 60 (74.5min) than in Group 90 (32min; p < 0.001). Intermediate frequency and low-frequency pediatric SWL have similar success rates; however, intermediate-frequency SWL has a shorter anesthesia time.

A new nomogram for prediction of outcome of pediatric shock-wave lithotripsy

Despite the fact that shock-wave lithotripsy (SWL) remains a very good treatment option for smaller stones, it is being challenged by endourologic treatment modalities, which offer similar or even higher success rates in a shorter time, with minimal morbidity and invasiveness. The present study aimed to bring a new and practical insight in order to predict the outcomes of pediatric SWL and to provide objective information about pediatric SWL outcomes. To design a nomogram for predicting the outcomes of pediatric shock-wave lithotripsy. The study was conducted with a retrospective design and included 402 renal units who underwent SWL between January 2009 and August 2013. Patients with known cystine stone disease and cystinuria, with internal or external urinary diversion, were excluded. Analysis was performed on 383 renal units. Postoperative imaging was performed by plain abdominal graphy and ultrasonography with 3-month intervals. Patients who were completely free of stones were considered to be a success and statistical analysis was done regardingly Multivariate analysis was conducted by logistic regression analysis and a nomogram was developed. The male/female distribution was 216/167, with a mean age of 48 ± 40 months and a mean stone size of 9 ± 3.5 mm. The overall stone-free rate was 70% (270/383) and efficacy quotient was 0.57. Mean follow-up was 11 ± 11 months (3-54 months). The number of shock waves and amplitude of energy were higher in failed cases. Multivariate analysis showed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. A nomogram was developed using these parameters. In this nomogram, the points achieved from each parameter are summed and total points correspond to the risk of failure in percent. A previous nomogram study by Onal et al. showed that younger age (<5 years), smaller stone burden (<1 cm), absence of previous stone treatment history, single stone, pelvis or upper ureter location (in girls) were favorable prognostic factors for successful outcome. As being the first pediatric study, it had some shortcomings. The study included 381 patients within a time period of 16 years. The present study included a similar number of cases within a 4-year period, which may reflect more homogeneity of data collection. Another issue is concern about the practical use of that nomogram. It constitutes two pages, which is a limiting factor for daily use. From a statistical point of view, they performed 200 bootstrapings with the aim of internal validation, which is less than the ideal number of 1000 bootstrapings, which was performed in the present nomogram. The presented nomogram is more practical, in that the pre-operative factors can be placed on the nomogram, the points can be added up and the parents can be given the approximate percentage of predicted stone-free rate after a single session. The expected treatment modality shown to the parents and patients ought to be the least minimally invasive, have the highest success rate, the least complication rate, and show the efficacy in one procedure at a time within the shortest period. However, SWL does not completely meet these criteria. The results gained from the present critical analysis of SWL in children, which was based on a strict definition of success, showed that outcome after a single session is not that good. Therefore, defining the patients who will benefit the most became one of the main issues. A more objective and skeptical look at SWL data enabled a nomogram to be developed that brings a new and practical insight in order to predict the outcomes of pediatric SWL. In most of the pediatric stone cases, SWL is the first-line treatment option. However, it is wise to define the patients who will benefit the most. Therefore, nomograms can be useful for this purpose. The nomogram in the present study revealed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. This nomogram can practically be used to inform the parents, and for proper patient selection for SWL.

Complications and Associated Factors of Pediatric Extracorporeal Shock Wave Lithotripsy

We determined the safety, efficacy and complications of extracorporeal shock wave lithotripsy in managing pediatric urolithiasis and analyzed possible factors affecting the complication rate. We retrospectively reviewed 128 patients younger than 16 years who had undergone extracorporeal shock wave lithotripsy with a Lithostar® lithotripter between January 2000 and December 2010. Stone clearance and complications were assessed at postoperative week 1, and months 1 and 3. Success was defined as no radiological evidence of stone, or fragments 4 mm or less. Treatment failure was analyzed to find any correlation with stone size. Complications were assessed with a specific focus on rehospitalizations during postoperative week 1. The overall success rate was 93.5% (115 of 123 patients). Repeat treatment rate was 56.1% (69 patients). Extracorporeal shock wave lithotripsy failed in 8 children, who subsequently required ancillary procedures. Mean stone size in the treatment failure group was 17.03 mm, compared to 13.04 mm in the successfully treated group. A total of 22 patients (17.8%) had complications in postoperative week 1 but only 19 (15.4%, 12 boys and 7 girls) were rehospitalized at that time. Presence of a metabolic risk factor was the only predictive factor for complications. By comparison, we found a lower success rate and higher ancillary procedure rate in the group with complications. Extracorporeal shock wave lithotripsy is effective for pediatric urolithiasis, with a small but substantial morbidity rate. Parents should be informed about possible rehospitalization following extracorporeal shock wave lithotripsy due to complications independent of stone size.

Pediatric Extracorporeal Shockwave Lithotripsy: Its Efficiency at Various Locations in the Upper Tract

Several reports demonstrated the effectiveness of extracorporeal shockwave lithotripsy (SWL) in the management of pediatric upper tract urolithiasis. The majority of these studies used the stone-free rate as the main indicator for treatment success. Efficacy Quotient (EQ) is an important outcome measure because it not only takes into consideration the stone-free rate, but also includes other undesirable outcomes that increase patient morbidity and utilizes hospital resources. Nevertheless, very few studies reported on the EQ of pediatric SWL at various locations in the upper tract. We retrospectively reviewed the records of 84 children (103 urinary calculi) who were treated with SWL in our institution between 1995 and 2005. There were 84 renal (pelvis, n = 27; upper calyx, n = 13; middle calyx, n = 8; lower calyx, n = 36) and 19 ureteric (upper third, n = 10; middle third, n = 5; lower third n = 4) stones. EQ for renal pelvic stones was 67% compared to 48% for caliceal stones (upper calyx: 52%, middle calyx: 46% and lower calyx: 47%). Overall, the EQ for renal stone was 54% and it was 59% for ureteric stones. This efficiency in the ureter was achieved at the expense of a higher number of shock waves delivered (3606 vs. 2592, P < 0.01). Overall, the stone-free rate was 82% (renal, 81%; ureteric calculi 84%). The only factor that affected the stone-free rate was the size of the stone (33% in stones >2 cm and 87% in stones <2 cm (P < 0.01). The overall retreatment rate was 41% (renal, 40% and ureteric 42%). However, the number of total treatments ranged from 1 to 5 sessions in renal stones and 1 to 2 sessions in ureteric stones. Auxiliary procedures were performed in 9 patients (stenting, n = 3; ureteroscopy, n = 4 and percutaneous nephrolithotomy, n = 2). Pediatric SWL appears to be more efficient in the renal pelvic stones compared to caliceal stones. The efficiency of SWL in the ureter is achieved with a higher number of shock waves delivered. A discussion on the possible future modifications of the definition of EQ, especially in children, is also provided.

Extracorporeal Shockwave Lithotripsy in Pediatrics

Since its introduction in 1980, extracorporeal shockwave lithotripsy (SWL) has become the first therapeutic option in most cases of upper-tract urolithiasis, and the technique has been used for pediatric renal stones since the first report of success in 1986. Lithotripter effectiveness depends on the power expressed at the focal point. Closely correlated with the power is the pain produced by the shockwaves. By reducing the dimensions of the focus, it becomes possible to treat the patient without anesthesia or analgesia but at the cost of a higher re-treatment rate. Older children often tolerate SWL under intravenous sedation, and minimal anesthesia is applicable for most patients treated with second- and third-generation lithotripters. Ureteral stenting before SWL has been controversial. Current data suggest that preoperative stent placement should be reserved for a few specific cases. Stone-free rates in pediatric SWL exceed 70% at 3 months, with the rate reaching 100% in many series. Even the low-birth-weight infant can be treated with a stone-free as high as 100%. How can one explain the good results? Possible explanations include the lesser length of the child's ureter, which partially compensates for the narrower lumen. Moreover, the pediatric ureter is more elastic and distensible, which facilitates passage of stone fragments and prevents impaction. Another factor is shockwave reproduction in the body: there is a 10% to 20% damping of shockwave energy as it travels through 6 cm of body tissue, so the small body volume of the child allows the shockwaves to be transmitted with little loss of energy. There are several concerns regarding the possible detrimental effect of shockwaves on growing kidneys. Various renal injures have been documented with all type of lithotripters. On the other hand, several studies have not shown adverse effects. In general, SWL is considered to be the method of choice for managing the majority of urinary stones in children of all ages. Re-treatments improve the stone-free rate, often raising it to 100%. Among the predictors of success, stone size seems to be the most important. In the absence of guidelines, selecting the appropriate treatment modality for each child requires planning and depends on instrument availability and local expertise.

Critical Prospective Appraisal of Renal Morphology and Function in Children Undergoing Shockwave Lithotripsy and Percutaneous Nephrolithotomy

To assess the effect of shockwave lithotripsy (SWL) and percutaneous nephrolithotomy (PCNL) on renal morphology and function in children undergoing therapy for upper-tract urolithiasis. Fourteen patients less than 13 years of age with renal or upper-ureteral calculi who were found suitable for primary SWL or PCNL were evaluated for alteration of renal morphology and function after treatment. Of the 18 renal units treated, SWL and PCNL were performed in 9 units each. The average stone size was 880.2 mm2 (range 110-3800 mm2; median 660 mm2). All children underwent ultrasonic estimation of renal length and parenchymal thickness, 99m technetium dimercaptosuccinic acid (DMSA) and 99m Tc-ethylene dicystine (EDC) scintigraphy, and glomerular filtration rate (GFR) estimation prior to intervention and at 3 and 6 months of follow-up. Extracorporeal lithotripsy achieved complete clearance in 8 renal units (88%), requiring an average of 6333 shockwaves and an average of 2.2 sessions per renal unit. The efficiency quotient was 42. Percutaneous surgery likewise achieved complete stone clearance in 88% of renal units, with three units requiring more than one tract. Mixed calcium oxalate monohydrate and dihydrate accounted for the majority of the stones. The mean preintervention GFR was 78.3 +/- 14.6 mL/min/1.73 m2 (median 82.5 mL/min/1.73 m2; range 54-98.6 mL/min/1.73 m2), whereas the mean GFR at 3 months was 78.95 +/- 14.4 mL/min/1.73 m2 (median 78.95 mL/min/1.73 m2; range 52-98 mL/min/1.73 m2). A marginal improvement of an average of 0.65 mL/min was noted. Split function EDC scans demonstrated improved drainage in five cases after intervention; the rest were unchanged. Preintervention DMSA scans revealed renal cortical scars in three children. None of the renal units had developed fresh scars at follow-up scans. None of the children developed new-onset hypertension, proteinuria, or alteration in renal size. In the present study, pediatric SWL and PCNL were not found to cause adverse renal morphologic or functional alteration. Stone clearance resulted in marginally improved function and better drainage.