Extracorporeal shock wave lithotripsy in children: experience using two second-generation lithotripters

Pediatric Nephrolithiasis

The prevalence of pediatric nephrolithiasis has increased dramatically in the past two decades for reasons that have yet to be fully elucidated. Workup of pediatric kidney stones should include metabolic assessment to identify and address any risk factors predisposing patients to recurrent stone formation, and treatment should aim to facilitate stone clearance while minimizing complications, radiation and anesthetic exposure, and other risks. Treatment methods include observation and supportive therapy, medical expulsive therapy, and surgical intervention, with choice of treatment method determined by clinicians' assessments of stone size, location, anatomic factors, comorbidities, other risk factors, and preferences and goals of patients and their families. Much of the current research into nephrolithiasis is restricted to adult populations, and more data are needed to better understand many aspects of the epidemiology and treatment of pediatric kidney 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.

Paediatric stone management: innovations and standards

PURPOSE OF REVIEW

The aim of this study was to discuss current trends and recent developments in the surgical management of paediatric urolithiasis.

RECENT FINDINGS

Medical expulsive therapy (MET) is considered as an option for the treatment of children with ureter stones. Extracorporeal shockwave lithotripsy (SWL) remains as a first option for majority of kidney stones and upper ureter stones. Advances in endourology have led to increased adoption of retrograde intrarenal surgeries (RIRS) and percutaneous nephrolithotomy (PCNL/mini-PCNL/ultra-mini-PCNL/micro-PCNL).

SUMMARY

Management of paediatric stone disease has developed significantly in the past decade. However, the evidence in the literature remains disproportional to these advances. Well designed multicentric studies are still needed to compare effectiveness and safety of these procedures.

Reprint - Medical and surgical interventions for the treatment of urinary stones in children: A Cochrane Review

INTRODUCTION

We performed systematic review to assess the effects of different medical and surgical management of urinary stones in children.

METHODS

We performed a comprehensive search using multiple databases (MEDLINE, EMBASE, Cochrane Register of Controlled Trials), trials registries (World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov), and abstract proceedings of major urological and pediatric urology meetings, with no restrictions on the language of publication or publication status, up until December 2017. We included all randomized controlled trials (RCTs) and quasi-RCTs. Two review authors independently assessed the eligibility of studies for inclusion, extracted data, and assessed risk of bias in accordance with the Cochrane "Risk of bias" tool. We performed statistical analyses using a random-effects model and assessed the quality of the evidence according to GRADE.

RESULTS

We included 14 studies with a total of 978 randomized participants in our review, informing seven comparisons with shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy (regardless of the type of lithotripsy), open stone surgery, and medical expulsive therapy. There was very low quality of evidence in the most comparisons with regards to the effectiveness and adverse events for the treatment of pediatric upper renal tract stone disease.

CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children. There is a critical need for better-quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Medical and surgical interventions for the treatment of urinary stones in children

BACKGROUND

Urolithiasis is a condition where crystalline mineral deposits (stones) form within the urinary tract. Urinary stones can be located in any part of the urinary tract. Affected children may present with abdominal pain, blood in the urine or signs of infection. Radiological evaluation is used to confirm the diagnosis, to assess the size of the stone, its location, and the degree of possible urinary obstruction.

OBJECTIVES

To assess the effects of different medical and surgical interventions in the treatment of urinary tract stones of the kidney or ureter in children.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid) as well as the World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov. We searched reference lists of retrieved articles and conducted an electronic search for conference abstracts for the years 2012 to 2017. The date of the last search of all electronic databases was 31 December 2017 and we applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs looking at interventions for upper urinary tract stones in children. These included shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy, open surgery and medical expulsion therapy for upper urinary tract stones in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane guidance. Two review authors independently searched and assessed studies for eligibility and conducted data extraction. 'Risk of bias' assessments were completed by three review authors independently. We used Review Manager 5 for data synthesis and analysis. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 14 studies with a total of 978 randomised participants in our review, informing eight comparisons. The studies contributing to most comparisons were at high or unclear risk of bias for most domains.Shock wave lithotripsy versus dissolution therapy for intrarenal stones: based on one study (87 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on stone-free rate (SFR), serious adverse events or complications of treatment and secondary procedures for residual fragments.Slow shock wave lithotripsy versus rapid shock wave lithotripsy for renal stones: based on one study (60 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures for residual fragments.Shock wave lithotripsy versus ureteroscopy with holmium laser or pneumatic lithotripsy for renal and distal ureteric stones: based on three studies (153 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Shock wave lithotripsy versus mini-percutaneous nephrolithotripsy for renal stones: based on one study (212 participants), SWL likely has a lower SFR (RR 0.88, 95% CI 0.80 to 0.97; moderate quality evidence); this corresponds to 113 fewer stone-free patients per 1000 (189 fewer to 28 fewer). SWL may reduce severe adverse events (RR 0.13, 95% CI 0.02 to 0.98; low quality evidence); this corresponds to 66 fewer serious adverse events or complications per 1000 (74 fewer to 2 fewer). Rates of secondary procedures may be higher (RR 2.50, 95% CI 1.01 to 6.20; low-quality evidence); this corresponds to 85 more secondary procedures per 1000 (1 more to 294 more).Percutaneous nephrolithotripsy versus tubeless percutaneous nephrolithotripsy for renal stones: based on one study (23 participants) and consistently very low quality evidence, we are uncertain about the effects of percutaneous nephrolithotripsy on SFR, serious adverse events or complications of treatment and secondary procedures.Percutaneous nephrolithotripsy versus tubeless mini-percutaneous nephrolithotripsy for renal stones: based on one study (70 participants), SFR are likely similar (RR 1.03, 95% CI 0.93 to 1.14; moderate-quality evidence); this corresponds to 28 more per 1,000 (66 fewer to 132 more). We did not find any data relating to serious adverse events. Based on very low quality evidence we are uncertain about secondary procedures.Alpha-blockers versus placebo with or without analgesics for distal ureteric stones: based on six studies (335 participants), alpha-blockers may increase SFR (RR 1.34, 95% CI 1.16 to 1.54; low quality evidence); this corresponds to 199 more stone-free patients per 1000 (94 more to 317 more). Based on very low quality evidence we are uncertain about serious adverse events or complications and secondary procedures.

AUTHORS' CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children.Common reasons why we downgraded our assessments of the quality of evidence were: study limitations (risk of bias), indirectness, and imprecision. These issues make it difficult to draw clinical inferences. It is important that affected individuals, clinicians, and policy-makers are aware of these limitations of the evidence. There is a critical need for better quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Medical and surgical interventions for the treatment of urinary stones in children

BACKGROUND

Urolithiasis is a condition where crystalline mineral deposits (stones) form within the urinary tract. Urinary stones can be located in any part of the urinary tract. Affected children may present with abdominal pain, blood in the urine or signs of infection. Radiological evaluation is used to confirm the diagnosis, to assess the size of the stone, its location, and the degree of possible urinary obstruction.

OBJECTIVES

To assess the effects of different medical and surgical interventions in the treatment of urinary tract stones of the kidney or ureter in children.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid) as well as the World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov. We searched reference lists of retrieved articles and conducted an electronic search for conference abstracts for the years 2012 to 2017. The date of the last search of all electronic databases was 31 December 2017 and we applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs looking at interventions for upper urinary tract stones in children. These included shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy, open surgery and medical expulsion therapy for upper urinary tract stones in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane guidance. Two review authors independently searched and assessed studies for eligibility and conducted data extraction. 'Risk of bias' assessments were completed by three review authors independently. We used Review Manager 5 for data synthesis and analysis. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 14 studies with a total of 978 randomised participants in our review, informing eight comparisons. The studies contributing to most comparisons were at high or unclear risk of bias for most domains.Shock wave lithotripsy versus dissolution therapy for intrarenal stones: based on one study (87 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on stone-free rate (SFR), serious adverse events or complications of treatment and secondary procedures for residual fragments.Slow shock wave lithotripsy versus rapid shock wave lithotripsy for renal stones: based on one study (60 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures for residual fragments.Shock wave lithotripsy versus ureteroscopy with holmium laser or pneumatic lithotripsy for renal and distal ureteric stones: based on three studies (153 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Shock wave lithotripsy versus mini-percutaneous nephrolithotripsy for renal stones: based on one study (212 participants), SWL likely has a lower SFR (RR 0.88, 95% CI 0.80 to 0.97; moderate quality evidence); this corresponds to 113 fewer stone-free patients per 1000 (189 fewer to 28 fewer). SWL may reduce severe adverse events (RR 0.13, 95% CI 0.02 to 0.98; low quality evidence); this corresponds to 66 fewer serious adverse events or complications per 1000 (74 fewer to 2 fewer). Rates of secondary procedures may be higher (RR 2.50, 95% CI 1.01 to 6.20; low-quality evidence); this corresponds to 85 more secondary procedures per 1000 (1 more to 294 more).Percutaneous nephrolithotripsy versus tubeless percutaneous nephrolithotripsy for renal stones: based on one study (23 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Percutaneous nephrolithotripsy versus tubeless mini-percutaneous nephrolithotripsy for renal stones: based on one study (70 participants), SFR are likely similar (RR 1.03, 95% CI 0.93 to 1.14; moderate-quality evidence); this corresponds to 28 more per 1,000 (66 fewer to 132 more). We did not find any data relating to serious adverse events. Based on very low quality evidence we are uncertain about secondary procedures.Alpha-blockers versus placebo with or without analgesics for distal ureteric stones: based on six studies (335 participants), alpha-blockers may increase SFR (RR 1.34, 95% CI 1.16 to 1.54; low quality evidence); this corresponds to 199 more stone-free patients per 1000 (94 more to 317 more). Based on very low quality evidence we are uncertain about serious adverse events or complications and secondary procedures.

AUTHORS' CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children.Common reasons why we downgraded our assessments of the quality of evidence were: study limitations (risk of bias), indirectness, and imprecision. These issues make it difficult to draw clinical inferences. It is important that affected individuals, clinicians, and policy-makers are aware of these limitations of the evidence. There is a critical need for better quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Stones in special situations

There are several special situations in which urinary lithiasis presents management challenges to the urologist. An in-depth knowledge of the pathophysiology, unique anatomy, and treatment options is crucial in order to maintain good health in these patients. In this review, we summarize the current literature on the management of the following scenarios: bladder stones, stones in bowel disease, during pregnancy, in association with renal anomalies, with skeletal deformities, in urinary diversions, and in children.

Outcomes of Shock Wave Lithotripsy and Ureteroscopy for Treatment of Pediatric Urolithiasis

PURPOSE

Shock wave lithotripsy has been commonly used to treat children with renal and ureteral calculi but recently ureteroscopy has been used more frequently. We examined postoperative outcomes from these 2 modalities in children.

MATERIALS AND METHODS

We reviewed linked inpatient, ambulatory surgery and emergency department data from 2007 to 2010 for 5 states to identify pediatric admissions for renal/ureteral calculi treated with shock wave lithotripsy or ureteroscopy. Unplanned readmissions, additional procedures and emergency room visits were extracted. Multivariate logistic regression using generalized estimating equations to adjust for hospital level clustering was performed.

RESULTS

We identified 2,281 admissions (1,087 for shock wave lithotripsy and 1,194 for ureteroscopy). Ages of patients undergoing ureteroscopy and those undergoing shock wave lithotripsy were similar (median 17.0 years for both cohorts, p = 0.001) but patients were more likely to be female (63.4% vs 54.7%, p <0.0001), to be privately insured (69.8% vs 62.2%, p <0.0005) and to have a ureteral stone (81.0% vs 34.8%, p <0.0001). Patients undergoing ureteroscopy demonstrated a lower rate of additional stone related procedures within 12 months (13.6% vs 18.8%, p <0.0007) but a higher rate of readmissions (10.8% vs 6.3%, p <0.0002) and emergency room visits (7.9% vs 4.9%, p <0.0036) within 30 days postoperatively. On multivariable analysis patients undergoing ureteroscopy were nearly twice as likely to visit an emergency room within 30 days of the procedure (OR 1.97, p <0.001) and to be readmitted to inpatient services (OR 1.71, p <0.01).

CONCLUSIONS

Ureteroscopy is now used more commonly than shock wave lithotripsy for initial pediatric stone intervention. Although repeat treatment rates did not differ between procedures, ureteroscopy patients were more likely to be seen at an emergency room or hospitalized within 30 days of the initial procedure.

Contemporary Management of Medium-Sized (10-20 mm) Renal Stones: A Retrospective Multicenter Observational Study

PURPOSE

To evaluate contemporary management approaches to medium-sized (10-20 mm) renal stones.

PATIENTS AND METHODS

A total of 935 patients treated for medium-sized renal stones (10-20 mm) between July 2012 and March 2014 were included in the study program. Contemporary minimally invasive approaches applied in the management of such stones were evaluated and compared.

RESULTS

The cohort consisted of 561 male (60%) and 374 female (40%) patients. Of the 935 patients with medium-sized renal calculi, 535 (57.2%) were treated with shockwave lithotripsy (SWL), 201 (21.4%) with retrograde intrarenal surgery (RIRS), 110 (11.7%) with minimally invasive percutaneous nephrolithotomy (miniperc), and the remaining 89 (11.7%) patients with micropercutaneous nephrolithotomy (microperc). In the SWL group, stones were located mostly in the pelvis (51%), while in the miniperc and microperc groups, they were located mainly in the lower pole (46%, 53%, respectively). Stone-free rates after a single session were 77.2%, 86.1%, 88.8%, and 83.6% in the SWL, RIRS, microperc, and miniperc groups, respectively. Although no serious complications (above Clavien level III) were noted in any of the groups evaluated, Clavien I to II complications were common in the miniperc group.

CONCLUSION

Although SWL is the preferred treatment option for patients with medium-sized (10-20 mm) renal stones, endourologic methods also have been found to have a significant role. Relatively lower complication rates along with higher stone-free status observed with the RIRS technique compared with percutaneous approaches have made this method a valuable option in the management of such stones in recent years.

Recent management of urinary stone disease in a pediatric population

The incidence of stone disease has been increasing and the risk of recurrent stone formation is high in a pediatric population. It is crucial to use the most effective method with the primary goal of complete stone removal to prevent recurrence from residual fragments. While extracorporeal shock wave lithotripsy (ESWL) is still considered first line therapy in many clinics for urinary tract stones in children, endoscopic techniques are widely preferred due to miniaturization of instruments and evolution of surgical techniques. The standard procedures to treat urinary stone disease in children are the same as those used in an adult population. These include ESWL, ureterorenoscopy, percutaneous nephrolithotomy (standard PCNL or mini-perc), laparoscopic and open surgery. ESWL is currently the procedure of choice for treating most upper urinary tract calculi in a pediatric population. In recent years, endourological management of pediatric urinary stone disease is preferred in many centers with increasing experience in endourological techniques and decreasing sizes of surgical equipment. The management of pediatric stone disease has evolved with improvements in the technique and a decrease in the size of surgical instruments. Recently, endoscopic methods have been safely and effectively used in children with minor complications. In this review, we aim to summarize the recent management of urolithiasis in children.

Effect of size and site on the outcome of extracorporeal shock wave lithotripsy of proximal urinary stones in children

OBJECTIVE

To determine the effect of location and size of stones on the outcome of extracorporeal shock wave lithotripsy (ESWL) in children.

PATIENTS AND METHODS

In 2008-2010, 150 children (median age 6.6 years) with radio-opaque ureteric and renal stones measuring ≤4 cm were treated. Exclusion criteria were coagulation disorders, pyelonephritis, distal obstruction, non-functioning kidney and hypertension. ESWL was performed under general anesthesia. Follow up period was 5-22 months.

RESULTS

186 stones were treated: 76 calyceal, 92 pelvic and 18 proximal ureteral. Mean stone size was 1.3 cm. A total of 312 sessions were performed (mean per stone = 1.67 sessions). The mean number of shock waves per session was 2423.68. Overall stone-free rate was 89.24%. Having a calyceal location did not significantly affect the stone-free rate (p = 0.133). The failure rate was significantly higher (66.7%) in stones >3 cm in size (p < 0.001). Complications were encountered in 18 patients; 2 underwent auxillary ureteroscopy and 4 uretrolithotomy for treatment of steinstrasse.

CONCLUSION

ESWL is a safe and effective method for treatment of stones up to 2 cm in children. Rate of auxillary procedures increases in stones >2 cm in size. About 80% of failures were associated with stone size >1.35 cm while 52.3% of completely cleared stones were associated with size <1.35 cm.

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

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.

Treatment of pediatric renal stones in a Western country: a changing pattern

BACKGROUND

Over the last 10years the miniaturization of endoscopic instruments made minimally invasive procedures for kidney stones feasible even in children. The evolution in management of kidney stones in a tertiary care center in Europe is reported.

METHODS

Patients treated in our hospital for kidney stones from 2002 to 2011 were reviewed and group A (2002 to 2006) was compared with group B (2007 to 2011). The therapeutic options offered were Extracorporeal Shock Waves Lithotripsy (ESWL), Retrograde Intrarenal Surgery (RIRS), Percutaneous Lithotripsy (PCNL) and open surgery. Outcome measures were: first treatment chosen, stone free rate after a single procedure, and retreatment. Results were compared by chi-square test, with p <0.05 considered statistically significant.

RESULTS

333 patients, mean age 9.7years, were treated, 161 in group A and 172 in group B. ESWL was the first option in both groups, but decreased by 34% in group B vs A. In contrast, RIRS and PCNL increased by 17% and 16%, respectively, in group B vs group A. Open surgery was never required in primary lithiasis cases without associated malformations.

CONCLUSION

The advent of PCNL and RIRS has significantly changed the pattern of renal stone treatment in the pediatric age group. A progressive increase of endourologic minimally invasive procedures was recorded. Open surgery should be a very rare option.

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.

Advances in the surgical pediatric urologic armamentarium

The surgical armamentarium of the pediatric urologist has changed greatly in the past 2 decades on account of new technology and careful adaptation of minimally invasive techniques in children. Conventional laparoscopy, robotic-assisted laparoscopy, laparoendoscopic single-site surgery, and endourologic surgery have, to varying degrees, provided new approaches to urologic surgery in the pediatric population. This article reviews the technology and adaptations behind these recent advances as well as their current applications in management of urologic disease in children.

Fragmentation without extraction in ureteral stones: outcomes of 238 cases

We aimed to evaluate the success rates, auxiliary procedures and complications after ureteroscopic lithotripsy (URS) during which the fragments left in situ for spontaneous passage after complete disintegration into a acceptable (<4 mm) size. 238 patients with ureteral stones were treated with URS between 2005 and 2011, and disintegrated fragments (<4 mm) were left in situ for spontaneous passage. Patients were followed with radiography for 3 months and evaluated with respect to the success rates (stone-free), auxiliary procedures, complication rates and additional analgesic requirement. The median age was 42.2 ± 13.7 years, and overall stone size was 8.79 ± 2.94 mm. Significantly lower rate of stone-free status was achieved in proximal stones (p < 0.05). A second URS was necessary in 5% (n = 12) of the patients. Double-J catheter placement during initial URS did not cause any change in the rate of secondary URS (p = 0.620). Additional oral or intramuscular analgesia was required in 41% (n = 97) and 25% (n = 59) of the patients, respectively, after discharge. The overall stone-free rate was 95% and mean time to complete clearance was 5 days. Severe colic pain within 24 h was noted in 21 (9%), and transient hydro-ureteronephrosis in 31 (13%) patients, as minor complications. Leaving the fragments (<4 mm) in place for spontaneous passage following a successful disintegration in URS could be a reasonable approach with acceptable and comparable stone-free rates, and this approach appears to give chance of shortening the duration of operation and also avoiding from the potential morbidity of repeated manipulations during the both further disintegration and extraction.

Treatment of Kidney Stones Using Extracorporeal Shock Wave Lithotripsy (ESWL) and Double-J Stent in Infants

Background. Extracorporeal shock wave lithotripsy (ESWL) has progressively acquired popularity as being the gold standard treatment for upper urinary tract lithiasis in infants since 1980. Our aim was to evaluate the outcome of ESWL for kidney stones and the use of double-J stent in infants. Material and Methods. A prospective clinical trial study performed on 50 infants with renal calculi at pelvic admitted in the Urology ward of Shafa Hospital, Sari, Iran, between 2001 and 2010. Main outcome measure of our study was clearing stones after one or more consecutive sessions of ESWL. Results. The study included 50 patients with renal calculi at pelvic. Among them, there were 35 (70%) boys and 15 (30%) girls with the age ranging from 1 to 13 months (mean of 7 month ± 3 days). All of them were treated by standard ESWL using Simons Lithostor plus machine. The stone sizes ranged from 6 mm to 22 mm. Double-J stents were placed in 11 infants (22%) with stones larger than 13 mm. Most of the patients required only one ESWL session. Conclusion. Since there were no complications following ESWL treatment, we can conclude that, in short term, ESWL is an effective and safe treatment modality for renal lithiasis in infants. In addition, we recommend double-J stent in infants with stones larger than 13 mm.

Does child's age affect interval to stone-free status after SWL? A critical analysis

OBJECTIVE

To evaluate the success rates and complications of extracorporeal shock wave lithotripsy (ESWL) in children with renal stones in an age-dependent manner.

METHODS

From 2006 to 2010, 164 children (male/female ratio 1:3) with renal calculi have been treated with ESWL (PiezoLith3000 lithotripter). The children were divided into 2 age groups: group 1, 0-6 years old (n = 133); and group 2, 7-15 years (n = 31). The patient- and treatment-related parameters were recorded for comparative evaluation. The success of ESWL in terms of the stone-free rates, additional procedures, and complications were comparatively evaluated. The data were analyzed statistically.

RESULTS

The mean age of groups 1 and 2 was 28 ± 18 months (range 4-71) and 119 ± 28 months (range 73-178), respectively. Although general anesthesia was used for all patients in group 1, 29% of the patients were treated under neuroleptic anesthesia in group 2. During the 3-month follow-up period, the complete stone-free rate was 94.7% (126 of 133), and treatment was unsuccessful in 7 patients (5.3%) in group 1. The corresponding data were 87% (27 of 31; P = .222) and 4 (13%; P = .089) in group 2. The stone-free rate after the first session was 67.6% (90 of 133) and 38.7% (12 of 31) in groups 1 and 2, respectively (P = .004). The mean number of ESWL sessions applied was 1.6 (range 1-5) and 2.9 (range 1-6) in groups 1 and group 2, respectively (P = .0001). No major complications were noted.

CONCLUSION

Our results have demonstrated that ESWL is highly successful in the management of renal calculi in children. Compared the outcomes by age, the younger children become stone free more quickly than the older children with fewer ESWL sessions.

Clinical practice: surgical approaches to urolithiasis in children

The incidence of urolithiasis in children is increasing. Adequate knowledge of treatment modalities and surgical options is therefore essential for every pediatrician. Surgical approaches to urolithiasis in children continue to evolve with advancements in technology and sophistication of current equipment and techniques. Perhaps the most significant development in new techniques is the advent of robotic-assisted laparoscopy. This review, for the general pediatrician, summarizes the most recent pediatric data and guidelines for surgical approaches to treatment of urolithiasis.

Evaluation of renal function in children undergoing extracorporeal shock wave lithotripsy

PURPOSE

The effect of extracorporeal shock wave lithotripsy on the growing kidneys of young children has always been a concern. We determined whether shock wave lithotripsy causes renal parenchymal scarring or affects glomerular filtration rate in children.

MATERIALS AND METHODS

This prospective study included 100 children with renal stones who presented to the shock wave lithotripsy unit at our institution between March 2005 and March 2008. A total of 28 children had multiple stones in the same kidney. All children with bilateral renal stones had 1 kidney cleared of stones by percutaneous nephrolithotomy before undergoing shock wave lithotripsy. A total of 138 stones were subjected to shock wave lithotripsy. All children underwent radionuclide scan of the renal parenchyma using dimercapto-succinic acid, and glomerular filtration rate was estimated using diethylenetriamine pentaacetic acid before extracorporeal shock wave lithotripsy and 6 months afterward. Children with renal scarring due to previous surgery or vesicoureteral reflux were excluded from the study. The number of shock wave lithotripsy sessions to achieve stone-free status and the dose of shock waves used were recorded for each patient.

RESULTS

No patient demonstrated renal parenchymal scarring on dimercapto-succinic acid scan or any statistically significant change in glomerular filtration rate on diethylenetriamine pentaacetic acid scan up to 6 months after shock wave lithotripsy.

CONCLUSIONS

Shock wave lithotripsy is a safe modality for treating renal calculous disease in children up to 16 years old, with no impact on long-term kidney function.

Contemporary surgical management of pediatric urolithiasis

With miniaturization of instruments and refinement of surgical technique, the management of pediatric stone disease has undergone a dramatic evolution. While shock wave lithotripsy (SWL) is still commonly used to treat upper tract calculi, the use of ureteroscopy (URS) has dramatically increased and is now the procedure of choice for upper tract stone burdens less than 1.5cm at centers with significant experience. Percutaneous nephrolithotomy (PCNL) has replaced open surgical techniques for the treatment of large stone burdens greater than 2cm, with efficacy and complication rates similar to the adult population. Large institutional series demonstrate comparable stone-free and complication rates with SWL, URS, and PCNL, but concerns remain with these techniques regarding renal development and damage to the pediatric urinary tract. Randomized controlled trials comparing the efficacy of SWL and URS for upper tract stone burdens are needed to reach consensus regarding the most effective primary treatment modality in children.

Ureteroscopic surgery for a large upper ureteral stone in an infant with bilateral vesicoureteral reflux

Pediatric urolithiasis is a relatively rare disease that can have lifelong consequences. The management of pediatric urolithiasis should be individualized with careful consideration of the patients' small body sizes, delicate tissues, needs for general anesthesia with every procedure, and risks of long-term complications. Miniaturization of urological instruments has made the treatment of distal ureteral stones by ureteroscopy in children more common, but there are few reports of the ureteroscopic removal of large upper ureteral stones in infants. We present a case of a 10-month-old female who simultaneously underwent ureteroscopic surgery and endoscopic Deflux® injection for treatment of a 22×10 mm unilateral upper ureteral stone and bilateral vesicoureteral reflux. We also review the current treatment options for pediatric urolithiasis.

Comparison of the effectiveness and safety of MPL 9000 and Lithostar Modularis shockwave lithotriptors: treatment results of 263 children

In this study, we aimed to compare the treatment results of two different shock wave lithotripsy (SWL) machines used in the management of pediatric urolithiasis. Between January 1993 and October 2004, Dornier MPL 9000 (electrohydraulic) had been used, and since then Siemens Lithostar Modularis (electromagnetic) has been used. The last evaluation was done 3 months after SWL treatment in terms of the success rate, use of anesthesia and complications. A total of 263 children (171 boys and 92 girls), with an age range of 9 months-14 years (mean age 8.1 +/- 3.8 years) were included in this study. Of the patients treated with the Dornier MPL 9000, 60.1% (173/104) required general anesthesia and 69 needed sedation. In contrast, for all patients treated with the Lithostar Modularis necessitated only sedo-analgesia (90 children). The hospital stay was shorter for Siemens Lithostar Modularis than those of Dornier MPL 9000 (26.2 vs. 35.5 h, P = 0.03). The success rate for the electromagnetic unit (86.5%) was almost identical that achieved with the electrohydraulic unit (85.2%) in the stones for the different location. Success rates were compared for stone burden subsets, the differences were insignificant for both lithotriptors (P > 0.05, for all). The electromagnetic unit had a significantly higher success rate for distal ureteral calculi (86.2 vs. 54.5%, P = 0.034). The efficiency quotients (EQ) for distal ureteral calculi were significantly different in favor of electromagnetic machine (56 vs. 40%). The complication rates for SWL were not significantly different for electrohydraulic and electromagnetic lithotriptors (8.7 and 6.2%, respectively). This study showed that SWL treatment was effective and safe in pediatric urolithiasis using both electrohydraulic and electromagnetic machines. Electromagnetic machine was more effective than electrohydraulic one for distal ureteral calculi. Additionally, the electromagnetic lithotriptor has significant clinical advantages over the electrohydraulic lithotriptor in terms of anesthesia requirements, hospitalization duration and fluoroscopic targeting.

Does the type of lithotripter affect outcomes in children with upper tract urolithiasis?

PURPOSE

To compare the treatment outcome and short-term safety of electrohydraulic and electromagnetic lithotripters in children.

PATIENTS AND METHODS

Comparative analysis of children undergoing shockwave lithotripsy (SWL) with a Dornier MPL 9000 electrohydraulic lithotripter (EHL) and a Siemens Modularis electromagnetic lithotripter (EML) was performed. All SWL treatments were performed by a single operator under the supervision of an admitting urologist. The demographic features, stone, and treatment-related parameters, including complications, were analyzed for both groups. Stone-free (SF) rates, re-treatment rate, and efficiency quotient (EQ) were calculated and compared for the two groups.

RESULTS

Ninety-eight children had SWL for renal and proximal ureteral stones. There were 58 children in the EHL group and 40 in the EML group. There were no statistically significant differences between the groups in terms of age, sex, type of anesthesia, diagnostic modality, site, side, and size of the stones. Number of shockwaves used with EML was greater than with EHL (P < 0.00). SF rate was 95% and 77% for EHL and EML, respectively, with a statistically significant difference (P < 0.00). The re-treatment rate was equal in either group. The complication rate was higher with the EHL compared with the EML, although it did not reach statistical significance. Steinstrasse was the most common complication noted. EQ was 66% for the EHL, in comparison with 53% for the EML.

CONCLUSION

The EHL has a better SF and EQ than the EML; however, short-term safety is marginally better with the EML.

Endourological management of pediatric stone disease: present status

PURPOSE

The incidence of nephrolithiasis in the pediatric population has been steadily increasing. The miniaturization of endoscopic instruments and improvement in imaging modalities have facilitated safe and effective endourological treatment in this patient population. We reviewed the current status of pediatric stone disease management.

MATERIALS AND METHODS

A comprehensive literature review was performed using MEDLINE/PubMed to evaluate the indications, techniques, complications and efficacy of endourological stone management in children.

RESULTS

In the 1980s shock wave lithotripsy revolutionized stone management in children, becoming the procedure of choice for treating upper tract calculi less than 1.5 cm. Percutaneous nephrolithotomy has replaced open surgical techniques for the treatment of stone burdens greater than 1.5 cm with efficacy and complication rates mirroring those in the adult population. However, at an increasing number of centers ureteroscopy is now being performed in cases that previously would have been treated with shock wave lithotripsy or percutaneous nephrolithotomy. Results from recent retrospective series demonstrate that stone-free rates and complication rates with ureteroscopy are comparable to percutaneous nephrolithotomy and shock wave lithotripsy. Although concerns remain with all endoscopic techniques in children regarding damage to the urinary tract and renal development, neither short-term nor long-term adverse effects have been consistently reported.

CONCLUSIONS

Shock wave lithotripsy, percutaneous nephrolithotomy and ureteroscopy are highly effective endourological techniques to treat stone disease in the pediatric population. A lack of prospective randomized trials comparing treatment modalities coupled with a vast disparity in the access to resources worldwide continues to individualize rather than standardize stone treatment in children.

Is extracorporeal shock wave lithotripsy in pediatrics a safe procedure?

Removal of urinary calculi is an essential element in the successful treatment of patients with urinary stone disease. The new generation of lithotriptors allows the treatment without the need for general anesthesia. The patients, often outpatients, have a faster discharge from the hospital with a reduction of hospitalization time and operating costs. Shock wave lithotripsy (SWL) is currently considered a safe technique for treatment of pediatric urinary lithiasias, with a low percentage of complications and subsequent surgical retreatments. But can we define SWL as a safe procedure in pediatrics? Herein, we will review the literature to justify SWL safety in children, focusing on important parameters as the insertion of preoperative stenting, side effects, and complications after the procedure.

Observations on intrarenal geometry of the lower-caliceal system in relation to clearance of stone fragments after extracorporeal shockwave lithotripsy

PURPOSE

To study the intrarenal geometry of the lower-caliceal system in patients with and without residual fragments after extracorporeal shockwave lithotripsy (SWL) and to formulate a summarizing mathematical expression of relevant variables.

PATIENTS AND METHOD

In a series of patients consecutively treated by SWL, we analyzed the geometric anatomy in 47 patients with (group R) and 47 without (group NR) residual fragments in long-term follow-up. A number of distances and angles previously described in the literature were measured, to which was added the distance between the stone-bearing calix and the vertex of the lower renal lip (CL) and the angle (delta) this line formed with a vertical line.

RESULTS

There were significant differences between the groups in terms of infundibular length (P = 0.009), CL (P = 0.0020), and lower-caliceal height, CH (P = 0.0004). The calix width and the various angles did not differ significantly between the groups. The quotient CH/CL was used to calculate cos delta, and a summarizing expression (Index LC) was given the form CH(2)/CL which equals CH x cos delta. This index was significantly different in groups R and NR (P = 0.0036). Approximately 4% of the patients in group NR, compared with 28 percent in group R, had Index LC values >25.

CONCLUSION

Index LC, as an expression of the geometry of the lower-caliceal system, might be useful for simple description of the lower-caliceal anatomy and supportive for decisions on the use of fragment clearance-facilitating procedures or the selection of a more invasive approach than SWL.

Minimally invasive treatment of ureteral calculi in children

A retrospective analysis was done to determine the efficacy of shock wave lithotripsy (SWL) and ureteroscopy in the treatment of paediatric ureteral calculi. We reviewed the records of 67 (35 boys, 32 girls) children (71 ureters) admitted to our clinic for treatment of ureteral calculi during 1990-2005. The initial treatment method was SWL in 80.3% (57 ureters), ureteroscopy in 11.3% (eight ureters) and open surgery in 8.5% (six ureters) of the renal units. The mean age of the patients was 10.67 +/- 4.4(1-16) years. The stone-free rates after SWL for upper, middle and lower ureteral calculi were 74.1, 100 and 75.9%, respectively. Increased stone diameter (P = 0.014) and/or burden (P = 0.002) were found to be significant factors that had an adverse affect on the stone-free rate after SWL while the success rates of SWL were independent of location. Including six patients (seven ureters) with failed SWL, a total of 14 patients (15 renal units) subjected to ureteroscopy for lower ureteral calculi yielded a stone-free rate of 93.3%. Thus, the overall stone-free rates after SWL, ureteroscopy and open surgery were found to be 75.4, 93.3 and 100%, respectively. Depending on the stone burden, SWL might be a good option for initial treatment of most ureteral calculi in children. Ureteroscopy offers a high success rate for lower ureteral calculi, including SWL failures.

Treatment of renal stones in children: a comparison between percutaneous nephrolithotomy and shock wave lithotripsy

PURPOSE

We compared the results of percutaneous nephrolithotomy and shock wave lithotripsy for the treatment of 1 to 2 cm renal stones in children.

MATERIALS AND METHODS

The study included 166 children with renal stones 1 to 2 cm. A total of 75 patients (82 kidneys) were treated with percutaneous nephrolithotomy and 91 (93 kidneys) were treated with shock wave lithotripsy. Mean followup was 31 +/- 10 months (range 6 to 84). Both groups were compared regarding stone-free rate, re-treatment rate, complications and incidence of stone recurrence.

RESULTS

Both groups were comparable regarding preoperative characteristics. Of the units treated with percutaneous nephrolithotomy 4 (4.9%) were associated with minor complications. Stone-free rate after a single session of percutaneous nephrolithotomy was 86.6% (71 units), and the remaining 11 kidneys with residual stones were successfully treated with repeat percutaneous nephrolithotomy in 7 and shock wave lithotripsy in 4. Therefore, a total of 78 units (95%) were stone-free after percutaneous nephrolithotomy monotherapy, and the overall stone-free rate at 3 months was 100%. Of the patients undergoing shock wave lithotripsy 1 (1.1%) had development of steinstrasse and was successfully treated with ureteroscopy. The overall re-treatment rate after shock wave lithotripsy was 55%. A total of 79 units (84.9%) were stone-free after shock wave lithotripsy monotherapy, whereas 7 (7.5%) with no gross response to treatment were treated with percutaneous nephrolithotomy and 7 with insignificant stones less than 4 mm were followed. Therefore, the overall stone-free rate at 3 months was 92.5%. The differences in stone-free rates and re-treatment rates significantly favored percutaneous nephrolithotomy, while the incidence of complications and stone recurrence at last followup were not significantly different between the groups.

CONCLUSIONS

For treatment of 1 to 2 cm renal stones in children percutaneous nephrolithotomy is better than shock wave lithotripsy, yielding higher stone-free and lower re-treatment rates.

Safety and Outcome of Rigid Ureteroscopy for Management of Ureteral Calculi in Children

PURPOSE

To present our experience with ureteroscopy for the treatment of pediatric ureteral calculi.

PATIENTS AND METHODS

The records of 32 children with an average age of 8.7 years (range 2-15 years) treated with rigid ureteroscopy between June 1994 and July 2003 were reviewed. In 33 ureteral units, 8F rigid ureteroscopy was carried out 35 times to treat stone disease. Stones were located in the upper ureter in 2 cases, the middle ureter in 2 cases, and the lower ureter in 29 cases. Stone size ranged from 4 to 15 mm (mean 7 mm). Dilatation of the ureteral orifice was necessary in 10 procedures.

RESULTS

The management of stone in 29 children (90.7%) was straightforward, and a single procedure was sufficient to clear the ureters. In 2 children (6.2%), repeat ureteroscopy was undertaken to render the ureters stone free, and in 1 child (3.1%), it was not possible to remove the stone. Stones were fragmented with pneumatic lithotripsy in 2 cases and with the holmium laser in 9; in the remaining 22 cases, the stones were removed without fragmentation. Intraoperative complications occurred in 3 children (9.3%) and consisted of extravasation (1 patient) and stone migration (2 patients). The early postoperative complications were hematuria in one patient and renal colic in another. Of the patients, 28 were followed 3 to 48 months. No stricture was detected at the site of stone impaction in any patient.

CONCLUSION

In the hands of an experienced surgeon, ureteroscopy can be a safe and efficient treatment for ureteral stones in children.

Factors affecting the success rate of extracorporeal shock wave lithotripsy for renal calculi in children

The aim of the study was to analyse factors affecting the success rate of extracorporeal shock wave lithotripsy (ESWL) in children with renal calculi. We performed a retrospective analysis reviewing records of 85 (40 female, 45 male) children (89 renal units) subjected to ESWL for treatment of renal calculi during 1990-2005 in our department. As 4 patients had bilateral calculi and 19 children (21 renal units) had renal stones at more than one different site, each location was analysed separately for convenience. The mean age of the patients was 10.3+/-4.6 (2-16) years. The stone-free rates for renal pelvis, lower, middle and upper caliceal calculi were 70, 62, 50 and 73%, respectively. A higher rate (33%) of insignificant fragments (< or = 4 mm) was noted for lower pole calculi. Increased stone diameter (P=0.0001) and burden (P=0.04) were found as the most significant factors that adversely affect the stone-free rate for pelvis renalis calculi, whereas an acutely oriented infundibulum and/or a long lower infundibulum (P=0.005) were unfavourable factors for clearance of lower caliceal stones. The stone-free rate in children with multiple calculi was 48%, while 29% of the renal units had retained fragments. ESWL is a good initial option for treatment of most of the renal calculi < 2 cm except in the presence of unfavourable lower caliceal anatomy. Increased stone burden, multiple stones, staghorn calculi, narrow lower infundibulopelvic angle and long lower infundibulum are factors that adversely affect the clearance rate.

Anesthesia for pediatric lithotripsy

SUMMARY BACKGROUND

We describe 7 years experience of providing anesthesia for children undergoing lithotripsy in a hospital without pediatric inpatient facilities. A pediatric team, including anesthetist, pediatric nurse along with the equipment travel across the city with the patient from the children's hospital. As a high incidence of postoperative vomiting and discomfort was observed, the effect of increasing intraoperative analgesia and the use of antiemetic medication was examined.

METHODS

From 1998 to 2004, 69 children (49 boys and 20 girls) were anesthetized for 120 procedures: 67 extracorporeal shock wave lithotripsy (ESWL) and 53 endosurgical procedures, consisting of percutaneous nephrolithotomy (29), ureteroscopic laser lithotripsy (17) and percutaneous bladder litholapaxy (7). The mean age was 5.4 years (10 months to 13 years) and weight 23.7 kg (7.1-59 kg). ESWL was performed initially with a Wolf Piezolith 2300, and after 1999, a Dornier Compact Delta.

RESULTS

Increased administration of intraoperative analgesia resulted in reduced postoperative analgesia requirements in all the groups, with a significant reduction (P < 0.05) in the endosurgical group. Those who required more postoperative analgesia had more vomiting significantly (P < 0.05).

CONCLUSIONS

For ESWL postoperative pain is dependent on the type of lithotriptor and the resultant stone fragment size created. This study suggests that postoperative vomiting could be reduced more effectively by the increased administration of intraoperative analgesia, than by a single intraoperative dose of an antiemetic drug.

PEDIATRIC UROLITHIASIS: 15 YEARS OF LOCAL EXPERIENCE WITH MINIMALLY INVASIVE ENDOUROLOGICAL MANAGEMENT OF PEDIATRIC CALCULI

PURPOSE

We sought to identify whether changes in technology and local practice have improved outcomes in the minimally invasive management of pediatric stone disease.

MATERIALS AND METHODS

We reviewed retrospectively case notes and imaging from 1988 to 2003, noting treatment modality, stone-free rates, ancillary therapy and complications.

RESULTS

A total of 122 children (140 renal units) with a mean age of 7.7 years underwent 209 extracorporeal shock wave lithotripsy (SWL) sessions. Stone size ranged from 6 to 110 mm. Stone-free rates were 84% for cases involving stones smaller than 20 mm, and 54% for those involving stones 20 mm or greater. For complex calculi 40% of patients were stone-free and 45% required ancillary procedures, with an overall complication rate of 26%. A total of 37 children (43 renal units) with a mean age of 6.4 years underwent 46 percutaneous nephrolithotomies (PCNLs). Stone size ranged from 8 to 155 mm. The overall stone-free rate was 79%. Of these patients 34% required ancillary procedures, with a major complication rate of 6%. A total of 35 children (35 renal units) with a mean age of 5.9 years underwent 53 ureteroscopies. Holmium laser was the most effective treatment modality in this group, with a 100% stone-free rate and no complications.

CONCLUSIONS

For most renal stones smaller than 20 mm SWL was the most effective primary treatment modality. There was no statistical difference between the 2 lithotriptors for stone-free or ancillary procedure rate. The stone-free rate was dependent on stone size rather than type of lithotriptor. For renal stones 20 mm or greater and staghorn calculi we switched from SWL to PCNL as primary treatment, as stone-free rates were higher and the ancillary procedure and re-treatment rates were lower with PCNL. Electrohydraulic lithotripsy and pulse dye laser were initially used to treat ureteral stones. However, with the introduction of holmium laser technology we achieved higher stone-free rates and lower complication rates. Holmium laser lithotripsy is now used as a primary treatment modality for ureteral stones.

Percutaneous nephrolithotomy in children before school age: experience of a Pakistani centre

OBJECTIVE

To review our experience of percutaneous nephrolithotomy (PCNL) in children before school age, and determine its efficacy and safety in this age group.

PATIENTS AND METHODS

The records of children aged < or = 5 years undergoing PCNL were reviewed. Variables assessed included stone number, size, location and type. The PCNL puncture site and number were also recorded. We reviewed stone clearance with PCNL, ancillary procedures used, complication rates and follow-up status of the children.

RESULTS

There were 30 renal units in 29 children (median age 3.8 years, range 1.4-5). Because of poor growth the mean (SD) body weight of the children was only 12.2 (2.8) kg, which is near the 50th percentile for children of mean age 3.5 years. The median (range) stone burden was 2.35 (1.3-6) cm; 60% of the patients had single stones while 28% had more than five. There were five staghorn stones. All PCNL was primary and with one puncture, using a 17 F angled nephroscope; stones were fragmented using a pneumatic lithoclast. After PCNL stones were completely cleared in 60% of the renal units, which increased to 100% after combining it with extracorporeal shockwave lithotripsy. The median (range) follow-up was 24.9 (4-51) months; the overall complication rate was 6%. In the long follow-up hypertension was not detected in any child and isotopic renograms in 17 kidneys detected no new scarring or loss of renal function.

CONCLUSION

PCNL is a safe and effective for treating renal stones in very young children.

Extracorporeal shock-wave lithotripsy for treatment of ureteral calculi in paediatric patients

Our objective was to determine the efficacy of extracorporeal shock wave lithotripsy (ESWL) in the treatment of paediatric ureteral calculous disease. We reviewed the records of 41 (23 boys, 18 girls) paediatric patients admitted to our clinic for the treatment of ureteral calculi between between 1989-2001. Patients' age varied between 4-16 years. The majority of the patients, 38 (92.7%) cases were treated initially with ESWL whereas 3 (7.3%) cases were subjected to ureterolithotomy. The mean age of the patients was found as 12.8+/-3.86 (4-16) years. Most calculi were located at either upper or lower ureter. The mean stone burden was 45.16+/-30.65 mm2 and the mean shock wave number per session and power as 2826.72+/-605.18 and 17.69+/-1.11 kV respectively. Minor complications included skin ecchymosis at the site of entry of shock waves in all cases and renal colic that responded to analgesics and emetics in 3 (7.9%) patients. The overall stone-free rate after ESWL was found to be 81.6%. Two (5.3%) cases have residual fragments that escaped to lower calices after lithotripsy for upper ureteral calculi and are still followed. There were 5 (13.2%) failures who were treated with ureterolitotomy for 1 upper and 1 lower ureteral calculi and with ureteroscopy for the rest. It appears that ESWL is still a good option for the initial treatment of most ureteral calculi in children as it is less invasive than ureteroscopy and has a high success rate as a first-line therapy.

Management of pediatric urolithiasis in Pakistan: experience with 1,440 children

PURPOSE

We evaluated the efficacy and safety of different modalities for pediatric urolithiasis in a developing country in 2 eras, namely before and after the advent of minimally invasive surgery.

MATERIALS AND METHODS

We retrospectively reviewed the records of 1,440 children younger than 14 years treated with various modalities during a 14-year period. From 1987 to 1995, 486 and 50 patients were treated with open surgery, and extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc., Marietta, Georgia) and minimally invasive methods, respectively. Between 1996 and 2000, 518 and 386 children were treated with surgery and minimally invasive methods, respectively.

RESULTS

Of the 1,440 children 795 (55.2%) had renal, 198 (13.8%) had ureteral and 447 (31%) had bladder calculi. Of the renal stones 556 (70%), 177 (22%) and 62 (7.8%) were treated with open surgery, ESWL and percutaneous nephrolithotomy, respectively. Of the ureteral calculi 85 (43%), 37 (18.6%) and 76 (38%) were managed by ESWL, ureterorenoscopy and open surgery, respectively. Of the bladder calculi 307 (68%), 77 (17.2%) and 63 (14%) were treated with open vesicolithotomy, transurethral pneumatic cystolithotripsy and ESWL, respectively. The renal stone clearance rate was 98% after open surgery, 84% after ESWL and 68% after percutaneous nephrolithotomy monotherapy at 3 months of followup. Similarly the ureteral stone-free rate was 54% after ESWL and 86.9% after ureterorenoscopy. Of the patients with bladder calculi 48% and 93% become stone-free after ESWL and transurethral pneumatic cystolithotripsy, respectively.

CONCLUSIONS

The use of ESWL, percutaneous nephrolithotomy and ureterorenoscopy has resulted in treating a large number of children with a short hospital stay and early return to school. Open surgery is reserved only for complex stones.

Pediatric urolithiasis: developing nation perspectives

PURPOSE

We evaluated epidemiology, etiology, dietary and urinary risk factors, and the composition of calculi in pediatric stone formers in Pakistan.

MATERIALS AND METHODS

This retrospective study includes 1,440 children treated between 1987 and 2000. Case records were reviewed for demographics, etiology and clinical symptoms. Dietary and urinary risk factors were analyzed prospectively in idiopathic stone formers. Stone composition was analyzed by infrared spectroscopy.

RESULTS

There were 1,075 males and 365 females for a male-to-female ratio of 3:1. The peak age for renal and bladder stones was 6 to 10 and 1 to 5 years, respectively. Overall 795 stones (55%) were renal, 198 (14%) were ureteral and 447 (31%) were vesical. Bladder stones were present in 60% of cases in the mid 1980s but decreased to 15% in the mid 1990s. The clinical symptoms were abdominal pain in 511 patients (51%) and fever in 193 (19.5%). There were anatomical abnormalities in 96 patients (12%), metabolic abnormalities in 206 (25%), infection stones in 60 (7%) and idiopathic stones in 444 (55%). Urinary analysis in idiopathic stone formers revealed hypercalciuria in 17 (11%), hyperoxaluria in 62 (40%), hyperuricosuria in 41 (27%) and hypocitruria in 97 (63%). Diet involved a low intake of protein in 60 cases (44%), calcium in 45 (33%), potassium in 105 (77%) and high oxalate in 75 (55%). The composition was calcium oxalate in 362 stones (47%), ammonium hydrogen urate in 210 (27%) and struvite in 49 (6.4%). Stones recurred in 30 patients (2%).

CONCLUSIONS

The pattern of calculous disease changed from a predominantly lower tract site in the mid 1980s to the upper tract in the mid 1990s. Stone composition, urinary risk factors and dietary analysis suggest that diet, dehydration and poor nutrition are the main causative factors of stone disease.

[Treatment with shock-wave lithotripsy in children: our experience]

OBJECTIVES

To analyze the efficacy and complication rates of extracorporeal shock wave lithotripsy in the paediatric age group.

PATIENTS AND METHODS

From 1989 to 2000, 29 children (mean age 8 years, range 1-14) underwent ESWL for urinary calculi at our institution. A total of forty-four ESWL sessions were performed in 36 calculi and a previous double pigtail stent was inserted in 11 patients. Intravenous anesthesia was used in the vast majority of cases.

RESULTS

Complete removal of all stone fragments was achieved in 24 (66.7%) renal units after a first session, 6 (16.7%) after a second session. The rest of the patients became stone-free after 3 sessions in 3 patients, open lithotomy in 1 patient and ureteroscopy in another patient. In one case a watchful waiting was decided after the failure of the first session of ESWL. Mean hospital stay was 3.2 days (range 1-11) for each session. Complications appeared in 10 patients: 4 had renal colic, 3 haematuria, 2 fever and 1 subcutaneous hematoma.

CONCLUSIONS

ESWL is a safe and effective treatment for paediatric urolithiasis so it should be considered the first-line treatment.