Translational Surgery

: 2016  |  Volume : 1  |  Issue : 4  |  Page : 91--94

Extracorporeal shock wave lithotripsy in the treatment of pediatric nephrolithiasis: Comparison of the outcome between preschool and schoolgoing children: A single-center study

Nadeem Iqbal, Salman Assad, Aisha Hasan, Muhammad Usman Shabbir, Taimur Hijazi, Saeed Akhter 
 Department of Urology, Shifa International Hospital, Islamabad, Pakistan

Correspondence Address:
Salman Assad
Department of Urology, Shifa International Hospital, Islamabad 44000


Aim: This study aimed to retrospectively evaluate the effectiveness of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal stones, between preschool and schoolgoing children. Methods: From January 2007 to March 2015, a total of 103 ESWL-treated children were considered for the study. Stone clearance rate, number of retreatment required, complication rate, and ancillary procedures used were evaluated. Results: Of the 103 patients with age limits of 2-14 years, 36 were <5 years (preschool group) and 67 were ≥5 years (schoolgoing group) of age. The mean age and mean stone size in preschool group was 3.26 ± 1.29 years and 0.97 ± 0.25 cm, respectively, whereas in schoolgoing group, it was 10.31 ± 3.01 years and 14 ± 0.68 cm, respectively. The stone-free rate in preschool and schoolgoing group was 34/36 (94.4%) and 57/67 (85%), respectively, with no statistical difference between the two (P = 0.2076). Post-ESWL complications, including hematuria, mild fever, flank pain, steinstrasse requiring ureteroscopy, and sepsis were seen in both preschool and schoolgoing groups, at varying rates that failed to reach statistical significance among the two (P > 0.05). Mean number of shock waves required for stone clearance was significantly less in preschool group (P = 0.0001). Conclusion: ESWL is equally effective for managing nephrolithiasis in both <5-year or ≥5-year aged children.

How to cite this article:
Iqbal N, Assad S, Hasan A, Shabbir MU, Hijazi T, Akhter S. Extracorporeal shock wave lithotripsy in the treatment of pediatric nephrolithiasis: Comparison of the outcome between preschool and schoolgoing children: A single-center study.Transl Surg 2016;1:91-94

How to cite this URL:
Iqbal N, Assad S, Hasan A, Shabbir MU, Hijazi T, Akhter S. Extracorporeal shock wave lithotripsy in the treatment of pediatric nephrolithiasis: Comparison of the outcome between preschool and schoolgoing children: A single-center study. Transl Surg [serial online] 2016 [cited 2021 Sep 26 ];1:91-94
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Extracorporeal shock wave lithotripsy (ESWL) has revolutionized the management of renal stone. Shock wave lithotripsy results in good stone-free rates for stone sizes up to 20 mm. [1],[2] It is a noninvasive, safe, and efficacious procedure in managing renal stones at various locations. [3] ESWL has been used as a therapeutic procedure for pediatric renal stones. [4],[5] Cases with anatomic abnormalities, large-sized stones, and failed minimally invasive procedures need open surgery, while for smaller stones and in patients with no anatomical problems, ESWL has become the procedure of choice for managing the majority of upper urinary tract calculi in children. [6],[7] The excellent results seen in pediatric ESWL could be due to smaller body volume in children, thus receiving better shock wave transmission. Numerous studies have showed an overall stone clearance rate of almost 80%, at 3 months of follow-up, in pediatric group. [8],[9],[10] Yet, the long-term safety of ESWL, for nephrolithiasis, in pediatric population is not yet established. [1]1] One of the post-ESWL complications is steinstrasse, which may occur due to obstructed ureteric fragments. Although ureteral stenting is believed to be useful in preventing complications such as renal colic and obstruction after ESWL, it has no protective role against steinstrasse formation and also does not increase the percentage of stone-free patients. [12] While selecting a suitable management approach for urolithiasis, few factors that need to be considered are the number of stones and their size, composition, location and the presence of hydronephrosis, and anatomical factors such as ureteric anomalies, presence of a solitary kidney, strictures, and obesity. [13],[14] In this study, we retrospectively evaluated and compared the effectiveness of ESWL, in the treatment of renal stones, between preschool and schoolgoing children.


This Ethics Committee-approved retrospective study evaluated the records of a total of 103 patients who received ESWL treatment, for renal stones, between January 2007 and March 2015 at our tertiary care hospital. Of the 103 patients, 36 patients with <5 years (mean age: 3.26 ± 1.29 years) of age were grouped as preschool children and 67 patients with ≥5 years (mean age: 10.31 ± 3.01 years) of age were grouped as schoolgoing children. Written informed consent was obtained from the parents of all the children. All the study patients had received the ESWL treatment from the 4 th generation MODULITH SL X lithotripter (Storz Medical AG, Tδgerwilen, Switzerland). The stone-free rates, number of ESWL sessions required, complication rates, and ancillary procedures used were evaluated in a comparative manner. Exclusion criteria before ESWL treatment consisted of stones of ≥2 cm at its longest diameter, renal scarring and vesicoureteral reflux, urinary tract infection with fever, bleeding diathesis, congenital urinary tract anomalies, and poorly functioning kidneys.

Complete blood counts, urine culture, coagulation profile, plain X-ray of kidney and urinary bladder, ultrasonography, and computed tomography (CT) scan were done for all patients before ESWL session. Patients were placed in the supine position, on the procedure table, for all the cases. Frequency of shock wave delivery was set at 90/min, approximately. Energy level used was 2-4, which was set in such a way that the initial 500 shocks were delivered at an energy level of 2 and the following 2000-3000 shocks at energy levels of 3 and 4. Target depth (cushion height) was adjustable between 5 and 15 cm and the width of focus was kept at 0.7 cm. Mean procedure time was kept at 45 min per session. General anesthesia was used in most of the cases. Ketamine was used in those cases where dissociated analgesia seemed sufficient (children older than 10 years who seemed cooperative during the procedure). Repeat sessions, when required, were done after 3 weeks of the last ESWL session. Fragmentation and localization of the stone was assessed using ultrasound and fluoroscopy. Hydration status was maintained by infusing intravenous fluid throughout the procedure. Posttreatment, the patients were maintained in the supine position and were kept under observation until they regained complete consciousness and no evidence of hematuria, which was for about 2-3 h in all the cases. All cases in the study were attended as day case. After ESWL, parents were instructed to maintain an adequate fluid intake for their children and report back immediately if there is fever, colicky pain, hematuria, or passage of stones in urine. The maximum number of sessions done in both preschool and schoolgoing children was kept to three, and those who did not become stone-free after the three sessions were scheduled for percutaneous nephrolithotomy. The criterion for successful ESWL was the absence of any visible stone on plain radiography or stones smaller than 4 mm on ultrasound or X-ray kidney, ureter, and bladder (KUB), done after ESWL. Statistical analysis was done using SPSS software version 16 (IBM Corporation, NY, USA). Results were expressed as mean ± standard deviation for quantitative variables such as age and stone size, and as rate (%) for stone-free rates and complications. Fischer's exact test and unpaired sample t-test were used to compute P values.


A total of 103 patients; 36 (<5 years) and 67 (≥5 years), were included in the study [Table 1]. In preschool group, the mean age was 3.2 ± 1.2 years, mean stone size was 0.97 ± 0.25 cm, and stone-free rate was 34/36 (94.4%). Of the 36 patients in the preschool group, 29 (80.6%) patients received one session of ESWL while the remaining 7 (19.4%) patients received two sessions [Table 2]. Post-ESWL complications in preschool group included hematuria in 1/36 (2.8%), mild fever in 2/36 (5.6%), flank pain in 2/36 (5.6%), steinstrasse requiring ureteroscopy in 2/36 (5.6%), and sepsis in 1/36 (2.8%) patients [Table 3]. In schoolgoing children, the mean age was 10.3 ± 3.0 years, mean stone size was 1.14 ± 0.68 cm, and stone-free rate was 57/67 (85%). With regard to number of ESWL sessions received by children in schoolgoing group, 48 (71.6%) patients received one session, 16 (23.9%) patients received two sessions, and 3 (4.5%) patients received three sessions. Post-ESWL complications in schoolgoing children included hematuria in 5/67 (7.5%), mild fever in 2/67 (2.98%), flank pain in 5/67 (7.5%), steinstrasse requiring ureteroscopy in 1/67 (1.5%), and sepsis in 3/67 (4.5%) patients [Table 3]. Statistically, no significant difference was observed in complication rates between the assessed two groups (P > 0.05). Similarly, there was no significant difference in stone-free rates among the groups (P = 0.2076). However, the mean number of shock waves required for stone clearance was less in preschool group, compared to schoolgoing group, that managed to reach high statistical significance (P = 0.0001).{Table 1}{Table 2}{Table 3}


The present study retrospectively analyzed the safety and efficacy of ESWL in managing pediatric nephrolithiasis in 103 children. The overall stone clearance rate obtained in this study was 34/36 (94.4%) in preschool group and 57/67 (85%) in schoolgoing group ≥5 years. Our reported stone clearance rate for children <5 years of age was considerably higher compared to previous reports by Brinkmann et al. [15] (83%) and Rizvi et al. [16] (84.2%), which is close to that reported by Rodrigues Netto et al. [17] (97.6%). In this study, we reported the required number of ESWL sessions as one session in 29 (80.6%) and two sessions in 7 (19.4%) children of <5 years of age, compared to one session in 48 (71.6%), two sessions in 16 (23.9%), and three sessions in 3 (4.5%) children of ≥5 years of age. This rate of repeat ESWL session rates is less than those reported by Onal et al. [18] and Elsobky et al., [19] who documented 39% and 64% repeat ESWL session rates, respectively. The mean number of shock waves per session was 2539.14 ± 603.57. A mean stone clearance rate of 89% was observed for mean stone size of 0.9 cm through paired sample test. In the present study, for stones ≤10 mm/1 cm, the stone-free rate was 91.66% (22/24 children stone free) for preschool group and 93.18% (41/44 children stone free) for schoolgoing group, as compared to 92% reported by Elsobky et al. and 97% by Ather and Noor. [19],[20] For stones ≥10 mm (1-2 cm), the stone-free rate reported in this study was 100% for preschool group and 69.56% for schoolgoing group, as compared to 76% reported by Elsobky et al. [19] and 88% by Ather and Noor. [20] In the study by Jee NY et al. [21] , complications were seen in three patients (5.5%); two patients had developed steinstrasse (one from each group), and one patient, in the group of children older than 7 years, had developed acute pyelonephritis.

In our study, the post-ESWL complications included hematuria in 1 (2.8%) and 5 (7.46%), mild fever in 2 (5.6%) and 2 (2.98%), flank pain in 2 (5.6%) and 5 (7.46%), steinstrasse requiring ureteroscopy in 2 (5.6%) and 1 (1.5%), and sepsis in 1 (2.8%) and 3 (4.5%) patients in preschool and schoolgoing groups, respectively. This list of complications were in conjunction with Kotb et al. and Lottmann et al., who reported similar findings. [10],[22] In addition to the above list, Muslumanoglu et al. reported peri-renal or subcapsular hematoma which was not seen in the current study. [23] Hematuria was seen in 5 (19.2%) and 4 (21%) patients and fever was seen in 4 (15.3%) and 6 (31.5%) patients among preschool and schoolgoing groups, respectively, in studies by Kotb et al. and Lottmann et al. Stamatiou et al. had slightly higher complication rates which might have been due to a slightly higher mean size of stone in their groups as compared to ours. [24] In the study by Joon et al., complications were seen in three patients (5.5%); two patients had developed steinstrasse (one from each group), and one patient, in the group of children older than 7 years, had developed acute pyelonephritis. [21]

In the clinical community, there is a concern regarding shock waves being delivered to immature kidney, in pediatric group. [25] It is believed that the harmful effects of shock waves during ESWL can be minimized only by decreasing the number and energy of shock waves. [26] Many studies have documented no deleterious effects of ESWL on healthy kidneys. [22],[27],[28] However, a young kidney is still at a greater risk of reduced glomerular filtration rate and renal plasma flow, on a long-term basis, after ESWL treatment. [29] Although further long-term data are still awaited, it would seem prudent to shock the pediatric kidney with minimum possible dose of shock waves. The availability of ultrasonography and fluoroscopy, for stone localization and stone fragmentation monitoring, has greatly helped in decreasing the dose of harmful shock waves. Some studies have demonstrated an overall success of ESWL in managing renal calculi in children. According to them, younger children have higher stone-free rates, with fewer ESWL sessions, as compared to older children. [30]

There are a few limitations in the present study: (1) We did not analyze the stones' morphology, (2) The stone composition was done only in some patients who experienced recurrent stones, and (3) CT scan was not performed to determine the stone-free status, instead only ultrasound KUB and X-ray KUB were performed.


There is no significant difference in the complication and stone-free rates between preschool and schoolgoing groups, who underwent ESWL for nephrolithiasis. Therefore, it can be concluded that the ESWL treatment is equally effective for nephrolithiasis management in children of both <5 years and ≥5 years of age.

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