Factors affecting the outcome of extracorporeal shock wave lithotripsy for unilateral urinary stones in children: a 17-year single-institute experience

Experience of high polymer gel pad assisted ultrasound monitoring in the treatment of infant urolithiasis during extracorporeal shock wave lithotripsy

In the extracorporeal shock wave lithotripsy for infants, we used a medical polymer gel pad to assist ultrasonic positioning, so that the ultrasonic probe could be far away from the shock wave energy field. Although not affecting the ultrasonic positioning and monitoring effect, we discussed the protective effect of this method on the ultrasonic probe. A retrospective analysis was made on 21 infants (0-3 years old) who received ESWL in our hospital from June 2021 to February 2023. After the stones were accurately located by B-ultrasound before surgery, a 4 * 5 * 10 cm medical polymer gel pad was placed between the skin and the ultrasonic probe to keep the ultrasonic probe away from the shock wave energy field. The B-ultrasonic wave source locked the target stone through the gel pad, and the lithotripter Dornier Compact Delta II was used for lithotripsy. The extracorporeal shock wave lithotripsy was completed under the whole process of B-ultrasonic monitoring. All patients completed the surgery under ultrasound monitoring, and there were no abnormalities in the ultrasound probe during the surgery. The average stone size was 0.60 ± 0.21 cm, the surgical time was 39.8 ± 13.8 min, and the total energy of lithotripsy was 7.41 ± 4.35 J. There were no obvious complications in all patients after the surgery. After 2 weeks of ultrasound examination, the success rate of lithotripsy in 21 patients reached 85.7%. We believe that the use of the gel pad increases the distance between the ultrasonic probe and the skin, leaving the probe away from the shock wave energy field, avoiding the damage of the shock wave source to the ultrasonic probe, and does not affect the monitoring effect of ultrasound on stones and the success rate of lithotripsy, which is worthy of further promotion in the field of children's urinary stones.

Which frequency is better for pediatric shock wave lithotripsy? Low intermediate or high: A systematic review and meta-analysis

Background

To explore the optimal frequency for pediatric extracorporeal shock wave lithotripsy (ESWL) in the treatment of upper urinary stones.

Methods

A systematic literature search was undertaken using PubMed, Embase, Web of Science and Cochrane Central Register of Controlled Trials databases to identify eligible studies published before January 2023. Primary outcomes were perioperative efficacy parameters, including ESWL time, anesthesia time for ESWL sessions, success rates after each session, additional interventions needed, and treatment sessions per patient. Secondary outcomes were postoperative complications and efficiency quotient.

Results

Four controlled studies involving 263 pediatric patients were enrolled in our meta-analysis. In the comparison between the low-frequency and intermediate-frequency groups, we observed no significant difference as regards anesthesia time for ESWL session (WMD = −4.98, 95% CI −21.55∼11.58, p = 0.56), success rates after ESWL sessions (first session: OR = 0.02 95%CI −0.12∼0.17, p = 0.74; second session: OR = 1.04 95%CI 0.56∼1.90, p = 0.91; third session: OR = 1.62 95%CI 0.73∼3.60, p = 0.24), treatment sessions needed (WMD = 0.08 95%CI −0.21∼0.36, p = 0.60), additional interventions after ESWL (OR=0.99 95%CI 0.40∼2.47, p = 0.99) and rates of Clavien grade 2 complications (OR = 0.92 95%CI 0.18∼4.69, p = 0.92). However, the intermediate-frequency group may exhibit potential benefits in Clavien grade 1 complications. In the comparison between intermediate-frequency and high-frequency, the eligible studies exhibited higher success rates in the intermediate-frequency group after the first session, the second session and the third session. More sessions may be required in the high-frequency group. With respect to other perioperative, postoperative parameters and major complications, the results were similar.

Conclusions

Intermediate-frequency and low-frequency had similar success rates and seemed to be the optimal frequency for pediatric ESWL. Nevertheless, future large-volume, well-designed RCTs are awaited to confirm and update the findings of this analysis.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022333646.

Can we predict the ancillary treatments after extracorporeal shockwave lithotripsy for renal and upper ureteral stones?

OBJECTIVE

To quantify the predictors for the ancillary treatments after extracorporeal shock wave lithotripsy (SWL) for renal and upper ureteral stones.

MATERIALS AND METHODS

From January 2014 to January 2017, patients undergoing SWL using an electromagnetic lithotripter machine (Compact Delta; Dornier MedTech GmbH, Wessling, Germany) for renal and upper ureteral stones ≤ 20 mm were retrospectively reviewed. All patients underwent CT urography prior to SWL. The cohort was subdivided into three groups according to stone attenuation values in Hounsfield Units (HU). Group I; HU < 500 (n = 20), group II; HU 500-1000 (n = 51) and group III; HU ≥ 1000 (n = 180). The parameters included for multivariate analysis were stone size, location, multiplicity, stone attenuation value, number of shocks and stone clearance rate by 3 months. The ancillary treatments were ureteroscopy (URS), ureteral stenting and hospital readmission for pain or fever.

RESULTS

A total of 251 patients were included in the study. The overall SWL success rate was 92.4%. Mean stone size was 10.9 ± 2.1, 11.6 ± 3 and 11.4 ± 3.6 mm and mean stone attenuation values were 364 ± 125, 811 ± 154 and 1285 ± 171 HU for groups I, II and III respectively. The stone clearance rates by 3 months were 96%, 92% and 88.4% for groups I, II and III respectively. On subgroup analysis, group III required ancillary treatments in 70% of patients whereas group I, II, did not require any ancillary treatments. On multivariate analysis, stone multiplicity, stone location (lower calyceal stones) and HU were independent significant predictors for the need for ancillary treatments after SWL (p values < 0.05).

CONCLUSIONS

Patients with stone attenuation value (HU) > 1000, multiple stones and/or lower calyceal stones have higher risk to necessitate ancillary treatments after SWL. These patients would likely benefit from upfront endoscopic lithotripsy for treating symptomatic renal or upper ureteral stones.

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.

Is there a place for extracorporeal shockwave lithotripsy (ESWL) in the endoscopic era?

This retrospective study aimed to evaluate whether there was still a place for ESWL therapy in the endourological era. From 1988 to 2018, ESWL therapy was performed with 3 successive types of lithotripters in our hospital. From 1988 to 1998, the electrohydraulic lithotripter NS-15 was used, and the electromagnetic lithotripter HK-V was put to use in 1999. Since 2010, the electromagnetic lithotripter HK-Vm has been used. Over the 30-year period, 16,969 urolithiasis patients underwent ESWL therapy, including 124 paediatric cases and 178 special cases. The stone clearance rate (SCR) and postoperative complications in the 3 lithotripter groups were recorded and analysed. The SCR was estimated by ultrasonography or plain X-ray, while the complications were recorded by the modified Clavien grading system. The primary stone clearance rate (pSCR) of ureteral and renal stones was significantly improved in the HK-Vm group compared with the NS-15 and HK-V groups. The final stone clearance rate (fSCR) of lower calyx stones was considerably higher in the HK-Vm group (55.9%) than in the NS-15 (41.1%) and HK-V (44.1%) groups. Most complications were grade I and II, while the incidence of grade III and above complications was less than 3%. Additionally, the fSCR in paediatric and special cases ranged from 66.5% to 83.5%, with no record of severe complications. As our data showed, ESWL was effective and safe for most urolithiasis patients, including paediatric patients and special cases. Therefore, ESWL is still the major treatment option in the current endourological era.

Factors related to the success rate of pediatric extracorporeal shock wave lithotripsy (ESWL) in Cipto Mangunkusumo Hospital: an 8-year single-center experience

Background

ESWL is still considered as the first favorable therapeutic option for urinary stone disease with acceptable effectivity. However, factors associated with favorable outcome have not been widely studied in pediatrics due to the small number of urinary stone prevalence. The aim of this study is to evaluate the factors associated with the success rate of pediatric ESWL in our center according to immediate stone-free rate and 3-month stone-free rates.

Methods

This is a retrospective cohort study of children less than 18 years who had ESWL for urolithiasis from January 2008 until August 2015. Patient’s characteristics including age, gender, BMI, stone location, stone length, stone burden, stone opacity, and number of ESWL sessions were gathered from the medical record. Nutritional status was determined according to the Centers for Disease Control and Prevention BMI curve. The outcome of this study was the factors related to the success rate in pediatric ESWL.

Results

Extracorporeal shock wave lithotripsy was done for 36 patients and 39 renal units (RUs) with mean age of 13.7 ± 4.3 years old, height of 1480 ± 16.0 cm, and BMI of 20.0 ± 3. Of 36 patients included, 39 renoureteral units (RUs) and 46 ESWL sessions were recorded. The mean overall treatment was 1.2 ± 0.5 sessions with mean stone length of 11.1 ± 6.3 mm and stone burden of 116.6 ± 130.3 mm2. Within 3 months of follow-up, we recorded that the overall 3-month success rate was 100%, while the overall 3-month stone-free rate was 66.7%. Stone length (p < 0.001 and p < 0.001), stone perpendicular length (p < 0.001 and p < 0.001), and stone burden (p < 0.001 and p = 0.001) were found to be significantly associated with immediate success and 3-month stone-free status, respectively.

Conclusions

ESWL is an effective and safe modality to treat pediatric urolithiasis cases. Stone length, stone perpendicular length, and stone burden were found to be associated with immediate success and 3-month stone-free status after pediatric ESWL treatment.

Factors to predict shock-wave lithotripsy results in pediatric patients and external validation of a nomogram

OBJECTIVE

To evaluate the accuracy of the Dogan nomogram in predicting stone-free (SF) rate after a single shock wave lithotripsy (SWL) session and evaluate factors that predict SWL results in children.

PATIENTS AND METHODS

The study included 68 patients under 18 years of age who had been treated with SWL for radiopaque upper urinary tract stones in our tertiary centre from January 2010 to December 2016. The median age is 50 (6-207) months and median follow-up period is 9 (4-50) months. Patients with known cystine stone disease, abnormal renal anatomy, urinary diversion and multiple stones located in different calyces were excluded like in the original nomogram study. SF status was evaluated by performing plain abdominal radiography and urinary ultrasonography 2 weeks after each SWL session. Patients who were completely free of stones were considered to be SF. Multiple logistic regression analyses were performed to determine the variables affecting SF status. The bootstrap method with 1,000 replicates was used for the external validity of a nomogram developed by Dogan.

RESULTS

SF rates for each SWL session were determined as 54.4% (37/68) for the first session, 33.3% (7/21) for the second session and 55.6% (5/9) for the third session. Overall, the SF rate was 72.1% (49/68). Multiple logistic regression analysis showed positive and significant correlations of age and stone size with risk of SWL failure. The external calibration plot showed a nearly good validation with Dogan nomogram to predict SWL failure in first session.

CONCLUSION

Our study demonstrates that the Dogan nomogram can be used to predict the SF status after one session of SWL in pediatric patients.

Extracorporeal shock wave lithotripsy in Indian children: Predictors of outcome and validation of pre-treatment nomograms

BACKGROUND

Although multiple variables have been shown to affect outcomes in pediatric lithotripsy (ESWL), there is no consensus on the same. Nomograms combine multiple variables and provide an objective prediction of outcomes. Two nomograms have been previously described and validated in two studies from the same geographical area. External validation in multiple settings is needed, as a nomogram's performance may vary with time, geographical area and clinical scenario.

OBJECTIVES

This study aimed to identify variables influencing pediatric ESWL outcomes, validate published nomograms and describe the clinical and metabolic profile of Indian children treated with ESWL.

DESIGN

This retrospective cohort study included all children who underwent ESWL from 2002 to 2019 at a single centre. ESWL was performed under general anaesthesia. Mid and lower ureteric calculi were treated in prone and the rest in supine position. 1500-2000 shocks were delivered at a voltage of 12-16 kV. Data pertaining to patient characteristics, metabolic evaluation, imaging, ESWL details and post-procedure outcomes were obtained from the hospital information system and these variables, along with Onal and Doğan scores, were correlated with stone clearance. Cut-offs for Onal and Doğan scores were determined using receiver operator characteristic (ROC) curve analysis and compared with area under the curve (AUC). Complications, ancillary procedures and metabolic abnormalities were recorded.

RESULTS

A total of 66 children (76 renal units) were included. Mean age was 5.5 years (Range 6 months-14 years) and median stone size, 12 mm (IQR 9, 15.25). Average treatment sessions were 1.8 ± 0.99. Median shocks in the stone-free group and those who failed treatment were 1750 (IQR 1500, 3000) and 3250 (IQR 1750, 4750) respectively. The remaining variables are depicted in Table 1. The stone free rate was 63.2%. Fragments <4 mm were seen in 19 (25%). Efficacy Quotient was 40. The AUC for Doğan nomogram (cut-off <199.5) was 0.761 while that for Onal nomogram (cut-off <2.5) was 0.762 and 0.771 after one and three shocks respectively. On multivariate analysis, age, multiple calculi, Onal and Doğan scores were predictive of clearance. Doğan score had higher specificity. Complications were seen in 16 (21%) and ancillary procedures needed in 7 (9.2%). Metabolic abnormalities were seen in 84.8%, the commonest being hyperoxaluria. Mixed stones were most frequent.

CONCLUSIONS

Lithotripsy in children is safe and effective. Older age, presence of multiple calculi, higher Onal and Doğan scores are predictive of treatment failure.

Comparison of extracorporeal shockwave lithotripsy and retrograde intrarenal surgery in the treatment of renal pelvic and proximal ureteral stones ≤2 cm in children

Introduction:

We aimed to compare extracorporeal shockwave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS) in pediatric patients with ≤2 cm renal pelvis and proximal ureteral stones.

Methods:

Medical records of 165 pediatric patients who underwent shockwave lithotripsy (SWL) or RIRS for upper urinary system stones up to 2 cm between January 2014 and December 2018 were retrospectively reviewed. After exclusions, the remaining 130 patients included 73 in the SWL group and 57 in the RIRS group. The groups were compared for demographic features, stone characteristics, operative data, success, and complications.

Results:

The mean stone volume was 308 ± 85 (54–800) and 336 ± 96 (60–720) mm³ in SWL and RIRS groups, respectively (P = 0.46). There were no significant differences in success rates (60% vs. 70%, SWL and RIRS), auxiliary treatment rates (16.4% vs. 14%), and complication rates (26% vs. 24.5%). The number of active procedural sessions and number of anesthesia sessions was higher in the RIRS group (P < 0.001 and P < 0.001, respectively), while the procedural time and anesthesia time were higher in the SWL group (P < 0.001 and P < 0.001, respectively). Stone size was found to be an independent success predictive factor for both the treatment modalities.

Conclusions:

Both SWL and RIRS have similar success, complication, and auxiliary treatment rates. RIRS was superior in terms of total procedure and anesthesia durations, while SWL was superior in terms of numbers of anesthesia sessions and active procedure sessions. As both have similar success rates, the more minimally invasive SWL should be chosen for pediatric upper urinary system stones of less than 2 cm size.

Factors Affecting the Outcome of Extracorporeal Shockwave Lithotripsy in Urinary Stone Treatment

Objectives

We sought to evaluate the factors affecting the outcome of extracorporeal shockwave lithotripsy (ESWL) in urinary stone treatment.

Methods

We conducted a retrospective review of 235 adult patients treated with ESWL, for radiopaque renal or ureteric stones between January 2015 and December 2016. Patient's age, sex, stone size, laterality, location, density, skin-to-stone distance (SSD), and presence of double J stent were studied as potential predictors. At the end of three months, the patients were divided into success and failure groups and the significance was determined.

Results

Of the 235 patients (188 males and 47 females) analyzed, ESWL was successful in 79.1%. Univariate analysis of both groups revealed no significant difference in patient's age and stone laterality. Statistically significant differences in gender, stone size, stone site, stone density, SSD, and patients with stents were observed. Statistically significant factors in multivariate logistic regression analysis were sex and stent. Females had three-times higher risk for ESWL failure than males (odds ratio (OR) = 3.213; 95% confidence interval (CI): 1.194-8.645; p = 0.021) and a higher failure rate when a stent was used (OR = 6.358; 95% CI: 2.228-18.143; p = 0.001).

Conclusions

This study revealed that ESWL can treat renal and ureteric stones successfully with an inverse association between outcome and predictors such as stone size and density, SSD, and stent presence. These factors can help us in improving patient selection and ensure better results at lower cost.

Comparison of intermediate- and low-frequency shock wave lithotripsy for pediatric kidney stones

The aim of the study to compare low and intermediate shock wave frequency rates in terms of success and complications for treating pediatric kidney stones. This retrospective study was performed on 58 consecutive pediatric patients (24 girls, 34 boys) who underwent shock wave lithotripsy (SWL) for kidney stones with an electrohydraulic lithotripter between April 2014 and March 2016. In the first year, all children underwent SWL with a frequency of 90 SWs/min as an intermediate frequency (Group 90), and in the second year all children were treated by SWL using 60 SWs/min as a low frequency (Group 60). The mean age of the patients was 5.87 ± 4.5 years. There were no significant differences in age, gender, stone characteristics and SWL energy level between the groups. Stone-free status was achieved in 14, 6 and 4 children in group 60; and in 10, 6 and 4 children in group 90 after one, two and three sessions, respectively. The stone-free rates were 80 and 74.1% after SWL and 90 and 88.9% after additional treatment in groups 60 and 90, respectively. The total median shock pulses were 2000 and 3600 in groups 60 and 90, respectively (p = 0.115). Efficiency quotients were 51.93 and 44.47 in groups 60 and 90, respectively. The mean total anesthesia times and complication rates did not differ between the groups. The low and intermediate frequency of SWL provided similar stone clearance in pediatric renal stones with similar anesthesia times. However, low SWL tended to need fewer shock pulses (2000/3600) for stone clearance, but the trend was not significant.

Comparison of Extracorporeal Shock Wave Lithotripsy for Urolithiasis Between Children and Adults: A Single Centre Study

Objective

To retrospectively evaluate the effectiveness of extracorporeal shock wave lithotripsy (ESWL) for urolithiasis and compare the results between children and adults.

Materials and methods

From January 2011 to January 2015 (four years), ESWL was performed in 104 children and 300 adults for urolithiasis. MODULITH^® SLX-F2 lithotripter (Storz Medical AG, Tägerwilen, Switzerland) equipment was used for ESWL. The stone-free rates, the number of ESWL sessions required, complication rates and ancillary procedures used were evaluated in a comparative manner.

Results

The mean age ± standard deviation (SD) of children was 7.84±4.22 years and of adults was a 40.22±1.57 years. Mean ± SD of the stone size was 1.28±61 cm in the adults while 1.08 ± 0.59 cm in the children. In adults, the complications included steinstrasse in six (1.98%) patients, fever in 15 (4.95%), hematuria in 19 (6.28%) and sepsis in six (1.98%) patients. In children, steinstrasse was observed in two (1.9%), mild fever in two (1.9%), hematuria in six (5.7%) and sepsis was seen in four (3.8%) patients. The overall complication rate in the adults and in the children, it was found to be 46/300 (15%) and in the children, it was seen to be 14/104 (13%). No statistical difference was found in post-ESWL complications between children and adults (P>0.05). Ancillary procedures including double J (DJ) stent were used in 13 (12.5%) children and 87 (29%) adults. There was a better stone clearance rate in children i.e. 79% as compared to 68% in adults (X²: P=0.036).

Conclusion

Children can achieve high stone-free rates after ESWL with a lower need for repeat ancillary procedures as compared to adults. However, there is a difference in the post-ESWL complications between these groups.

[Uretero(reno)scopy: management of complications]

Rigid and flexible uretero(reno)scopy (URS) are safe and effective methods in interventional calculus therapy. Complications are rare and can be avoided in advance in many cases. In ureteroliths, URS has in many cases replaced extracorporeal shock wave lithotripsy (ESWL) as the method of first choice. However, it is important to describe in detail the advantages and disadvantages as well as the risks of the procedure to the patient.

Pediatric extracorporeal shock wave lithotripsy: multi-institutional results

AIM

To evaluate the efficacy, auxiliary procedures and complications of pediatric extracorporeal shock wave lithotripsy (ESWL) performed with electrohydraulic lithotripters.

METHODS

Children with urolithiasis, aged between 0 and 15, were retrospectively evaluated. ESWL was performed by using two different electrohydraulic lithotripters, Elmed Multimed Classic (Elmed Medical Systems, Ankara, Turkey) and E-1000 (EMD Medical Systems, Ankara, Turkey), between January 2008 and December 2012 in four different referral centers in Turkey.

RESULTS

85.5% of patients were stone-free at 3 months. Further ESWL treatment was needed in 33.7% of the cases (one session, n = 55; two sessions, n = 15; three sessions, n = 13). Steinstrasse occurred in 10 patients but 8 of them cleared completely during the follow-up period. Urinary tract infection was detected in 3 (3.9%), fever in 3 (3.9%) and a small subcapsular hematoma in one (1.3%) patient, respectively. When the stones were divided into two groups as those with diameters &lt;10 mm and ≥10 mm, it was found that the stone-free rate was associated with stone diameter, and that the smaller diameters had higher but statistically insignificant stone-free rates (P = 0.196).

CONCLUSION

ESWL yields favorable results with low rates of complication and auxiliary procedures in selected pediatric patients.

Efficacy of extracorporeal shock wave lithotripsy in pediatric and adolescent urolithiasis

PURPOSE

To retrospectively evaluate the efficacy of extracorporeal shock wave lithotripsy (ESWL) by age and current condition as a first-line treatment for pediatric and adolescent urolithiasis.

MATERIALS AND METHODS

The computerized records of 55 children were retrospectively reviewed from March 1991 to July 2007. The children were below 18 years of age and had undergone ESWL monotherapy for urolithiasis. There were 36 boys (65.5%) and 19 girls (34.5%), with a mean age of 8.5 years (range, 0.5-18 years). There were 24 patients aged 7 years or less and 31 patients aged more than 7 years.

RESULTS

The mean size of the stones was 9.48 mm (range, 4-22 mm). The overall success rate of ESWL was 90.9% (50 children). The mean number of ESWL sessions was 2.02 (range, 1-10). The mean number of ESWL sessions for the patient group aged 7 years or less was 1.16 (range, 1-2) and that for the patient group aged more than 7 years was 2.97 (range, 1-10; p=0.037). There was also a statistically significant difference in the mean number of ESWL sessions between the younger and older patients who needed general anesthesia (1.16 vs. 2.2 sessions, respectively; 0.042).

CONCLUSIONS

In the patient group aged 7 years or less, the number of ESWL sessions and the complication rate were comparable with those for endoscopic management. Thus, ESWL is an effective first-line treatment modality for patients aged less than 7 years.