Management of pediatric urolithiasis in Pakistan: experience with 1,440 children. J Urol. 2003;169:634-637. [PMID: 12544331 DOI: 10.1016/s0022-5347(05)63979-1]

Contemporary minimal invasıve surgical management of stones in children

Objective

Pediatric urolithiasis has been more common over the past 20 years, and urologists have unique challenges in managing it surgically because this particular demographic is recognized as one of the high-risk categories for stone recurrence. Given this reality, care focuses on maintaining renal function, achieving total stone-free status, and most importantly avoiding stone recurrences. In this presented article, we aimed to make a comprehensive review of the current minimally invasive treatment of pediatric kidney stone disease.

Methods

We evaluated the results of 74 studies following a comprehensive PubMed search till February 2023. This article was written by making use of current urology guidelines.

Results

Considering the reported occurrence of metabolic issues in up to 50% of cases in addition to the anatomic anomalies (about 30% of cases), the treatment of pediatric urolithiasis necessitates a full metabolic and urological examination on an individual basis. Timely management of metabolic imbalances and obstructive diseases is necessary. In addition to encouraging proper fluid consumption, it is advisable to improve urine volume and consider using medical therapeutics to raise urinary citrate levels. The location, content, and size of the stone(s), the morphology of the collecting system, the presence of urinary tract infection, as well as the presence of any obstruction, should all be taken into consideration while deciding on the best surgical procedure.

Conclusion

All modern endourological methods are now used in the safe and efficient care of pediatric urolithiasis as a consequence of the obvious advancements in instrument technology and expanding expertise derived from adult patients. Other minimally invasive procedures, such as ureterorenoscopy and percutaneous nephrolithotomy, require more expertise and can be successfully applied with careful management for an excellent stone-free rate with minimal morbidity. Of these procedures, shock wave lithotripsy is still the first choice in the majority of cases with upper tract calculi. Open surgery will still be the therapy of choice for pediatric patients with complicated and big stones as well as anatomical anomalies.

Minipercutaneous Nephrolithotomy in the Management of Large and Complex Renal Calculi in Children: How Effective Is It?

Purpose: To evaluate the efficacy and safety of minipercutaneous nephrolithotomy (PCNL) in the management of large and complex calculi in children. Patients and Methods: From May 2017 to April 2021, a total of 41 pediatric cases were diagnosed with large/complex renal stones (partial-total staghorn) and following a detailed biochemical evaluation and thorough radiological examination (plain abdominal radiograph, urinary ultrasound, noncontrast and/or computed tomography), all cases underwent mini-PCNL procedure for the minimal invasive management of these calculi. Preoperative, intraoperative, and postoperative data were analyzed and reported in detail. Results: A total of 41 procedures were performed in 26 boys and 15 girls (male/female = 1.73). While the age of the kids ranged from 2.5 to 10 years (mean 6.74 ± 2.76), mean size of the stones was 16.28 ± 3.43 mm (range 11-24) with a mean stone density value of 816 HU (range 550-1350). Evaluation of the success rates in terms of complete stone clearance on postoperative day 1 revealed that while 73.2% (30/41), residual fragments have been noted in 11 cases (26.8%). Size of the residual fragments ranged from 2 to 7 mm (mean 4.3). Of those children, 10 cases required flexible ureteroscopy for stone removal, and in 1 case, placement of Double-J was adequate for spontaneous passage. During a 3-month follow-up, the stone-free rate (SFR) increased to 100% without any residual fragment left. Conclusions: Mini-PCNL with holmium laser lithotripsy is an effective and safe treatment alternative in the minimal invasive management of large/complex kidney stones in children with high SFRs.

Primary hyperoxaluria: Comprehensive mutation screening of the disease causing genes and spectrum of disease-associated pathogenic variants

The primary hyperoxalurias are rare disorders of glyoxylate metabolism. Accurate diagnosis is essential for therapeutic and management strategies. We conducted a molecular study on patients suffering from recurrent calcium-oxalate stones and nephrocalcinosis and screened primary hyperoxaluria causing genes in a large cohort of early-onset cases. Disease-associated pathogenic-variants were defined as missense, nonsense, frameshift-indels, and splice-site variants with a reported minor allele frequency <1% in controls. We found pathogenic-variants in 34% of the cases. Variants in the AGXT gene causing PH-I were identified in 81% of the mutation positive cases. PH-II-associated variants in the GRHPR gene are found in 15% of the pediatric PH-positive population. Only 3% of the PH-positive cases have pathogenic-variants in the HOGA1 gene, responsible to cause PH-III. A population-specific AGXT gene variant c.1049G>A; p.Gly350Asp accounts for 22% of the PH-I-positive patients. Pathogenicity of the identified variants was evaluated by in-silico tools and ACMG guidelines. We have devised a rapid and low-cost approach for the screening of PH by using targeted-NGS highlighting the importance of an accurate and cost-effective screening platform. This is the largest study in Pakistani pediatric patients from South-Asian region that also expands the mutation spectrum of the three known genes.

HOGA1 gene pathogenic variants in primary hyperoxaluria type III: Spectrum of pathogenic sequence variants, and phenotypic association

Primary hyperoxalurias (PH) are a group of rare heterogeneous disorders characterized by deficiencies in glyoxylate metabolism. To date, three genes have been identified to cause three types of PH (I, II, and III). The HOGA1 gene caused type III in around 10% of the PH cases. Disease-associated pathogenic variants have been reported from several populations and a comprehensive spectrum of these mutations and genotype-phenotype correlation has never been presented. In this study, we describe new cases of the HOGA1 gene pathogenic variants identified in our population. We report the first case of ESKD with successful kidney transplantation with 5 years of follow-up. Furthermore, a comprehensive overview of PH type III associated HOGA1 gene variants was carried out. Compiling the data from the literature, we reviewed 57 distinct HOGA1 gene pathogenic variants in 175 patients worldwide. The majority of reported variants are missense variants that predicted a loss of function mechanism as the underlying pathology. There has been evidence of the presence of founder mutations in several populations like Europeans, Ashkenazi Jews, Arab, and Chinese populations. No significant genotype-phenotype correlation was identified concerning the ages of onset of the disease and biochemical and metabolic parameters. Nephrocalcinosis was rare in patients with disease-associated variants. Most of the patients were presented with urolithiasis early in life; only five cases reported disease progression after the second decade of life. The establishment of impairment of renal function in 8% of all the reported cases makes this type a relatively severe form of primary hyperoxaluria, not a benign etiology as suggested previously.

Successful management of ectopic kidney stones in a patient with situs inversus totalis: a rare case report

Background

Situs inversus totalis is a very rare congenital anatomical variation, in which all thoracic and abdominal organs are right-left inverted. This condition is associated with an increased risk of organ malformations including ectopic kidney, which is a very rare combination.

Case presentation

A 56-year-old male presented with colicky left iliac pain associated with nausea, vomiting, and irritative lower urinary symptoms. The patient has a medical history of recurrent lower urinary infections and a family history of situs inversus totalis. Radiological images demonstrated dextrocardia, situs inversus totalis of all the abdominal organs, and an ectopic pelvic kidney on the left side, with 4 stones inside it. Left nephrectomy was performed due to extensive renal damage. At discharge and during follow-up, the patient's condition was satisfactory and stable.

Conclusions

The ectopic kidney may present diagnostic and therapeutic challenges when associated with situs inversus.

Treatment outcomes of bladder stones in children with intact bladders in developing countries: A systematic review of >1000 cases on behalf of the European Association of Urology Bladder Stones Guideline panel

INTRODUCTION

Bladder stones (BS) are still endemic in children in developing nations and account for a high volume of paediatric urology workload in these areas. The aim of this systematic review is to comparatively assess the benefits and risks of minimally invasive and open surgical interventions for the treatment of bladder stones in children.

METHODS

This systematic review was conducted in accordance with Cochrane Guidance. Database searches (January 1970- March 2021) were screened, abstracted, and assessed for risk of bias for comparative randomised controlled trials (RCTs) and non-randomised studies (NRSs) with >10 patients per group. Open cystolithotomy (CL), transurethral cystolithotripsy (TUCL), percutaneous cystolithotripsy (PCCL), extracorporeal shock wave lithotripsy (ESWL) and laparoscopic cystolithotomy (LapCL) were evaluated.

RESULTS

In total, 3040 abstracts were screened, and 8 studies were included. There were 7 retrospective non-randomised studies (NRS's) and 1 quasi-RCT with 1034 eligible patients (CL: n=637, TUCL: n=196, PCCL: n=138, ESWL: n=63, LapCL n=0). Stone free rate (SFR) was given in 7 studies and measured 100%, 86.6%-100%, and 100% for CL, TUCL and PCCL respectively. CL was associated with a longer duration of inpatient stay than PCCL and TUCL (p<0.05). One NRS showed that SFR was significantly lower after 1 session with outpatient ESWL (47.6%) compared to TUCL (93.5%) and CL (100%) (p<0.01 and p<0.01 respectively). One RCT compared TUCL with laser versus TUCL with pneumatic lithotripsy and found that procedure duration was shorter with laser for stones <1.5cm (n=25, p=0.04).

CONCLUSION

In conclusion, CL, TUCL and PCCL have comparable SFRs but ESWL is less effective for treating stones in paediatric patients. CL has the longest duration of inpatient stay. Information gathered from this systematic review will enable paediatric urologists to comparatively assess the risks and benefits of all urological modalities when considering surgical intervention for bladder stones.

Percutaneous nephrolithotomy in children

INTRODUCTION

The high success rates of percutaneous nephrolithotomy (PCNL) in the clearance of large renal calculi has made it a primary mode of surgical management in adults. Similarly, in children too PCNL has been gaining ground and the indications for the same are on the rise. We retrospectively evaluated the safety and efficacy of this technique, in children below 18 years of age.

MATERIALS AND METHODS

We retrospectively reviewed the inpatient, outpatient records, imaging films of all children with renal stones undergoing PCNL at our hospital.

RESULTS

During the study period, 123 children underwent 129 PCNL at our centre for renal calculi. The mean age was 11.06 years and 87 (70.73%) of the children were males. The size of the stones varied from 15 to 37 mms in the longest diameter. A complete staghorn was noted in six (4.65%) and a partial staghorn in nine (6.97%) children. Supine PCNL was performed in 21 (16.2%) children and remaining 102 (83.7%) children underwent PCNL in prone position. The mean drop in haemoglobin was 1.24 gm%. Stone clearance was achieved in 122 (94.5%) children. Post-operatively four (3.1%) children needed blood transfusions due to excessive bleeding.

CONCLUSIONS

Refinements in percutaneous access techniques, miniaturization of instruments, and technologic advances in energy sources for lithotripsy have led to improvement of outcomes and have lowered the morbidity rates in children following PCNL. It is a safe and effective means of clearing large volumes of renal calculi with minimal morbidity.

Which Endoscopic Methods in Prepubertal Patients with 10-20 mm Bladder Stones: Transurethral Cystolithotripsy or Percutaneous Cystolithotripsy?

BACKGROUND

The aim of this study was to evaluate the efficacy and safety of transurethral cystolithotripsy(TUC) and percutaneous cystolithotripsy(PCC) in prepubertal patients with 10-20 mm bladder stones.

MATERIALS AND METHODS

The files of patients the age of 12 and under who were admitted our clinic for bladder stones from January 2007 to January 2021 were reviewed retrospectively. Inclusion criteria were patients who were 12 years of age and under with 10-20 mm bladder stones, and who underwent endoscopic surgery(TUC or PCC). None of the patients had prior bladder or stone surgery. The patients were divided into two groups(Group 1:PCC group, and Group 2:TUC group) and collected data(preoperative, intraoperative, and postoperative characteristics) were compared between the groups.

RESULTS

This present study was enrolled 51 patients(21 patients in Group 1 and 30 patients in Group 2).The mean ages of the groups were similar (Group 1:4.7±3.6; Group 2:4.6±3.2; p:0.936). The mean stone size was 15.8±3.5 in Group 1, and 12.1±2.4 mm in Group 2. It was higher in the PCC group than TUC group(p<0.001). The operative time was lower in Group 1 than Group 2(36.4±12.9 min vs. 42.7±16.3 min, respectively), but there was no statistically significance difference between the groups (p:0.117).We achieved SFR for all the patients in both groups. Complications were observed in four (7.7%) cases. One female patient was in Group 1 and three male patients were in Group 2. There was no difference for complication rates between the groups(p:0.634).

CONCLUSIONS

Endoscopic surgeries have almost become a routine method in the treatment of bladder stones. Despite larger stone size, PCC provides similar SFR compared with TUC along with a tendency of shorter operative time. However, the use of the TUC method in toddler males could increase the risk of postoperative urinary retention. Hence, stone size and patient age should be considered in the selection of a surgical approach.

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.

Open pyelolithotomy in an ectopic kidney: A case report

Renal ectopia with stone is a rare case with no specific reported incidence rate. The treatment of kidney stone in ectopic kidneys poses a challenge to urologists. A 48-year-old male presenting with colicky pain on the right flank since one year ago. CT urography revealed an right-crossed renal ectopia and hyperdense lesions (25 × 20 mm and 10 × 10 mm) in the ureteropelvic junction of the right kidney. Under general anesthesia, we performed open pyelolithotomy for the patient and removed two stones completely. Open surgery could be the choice for patients with complex stone burden and associated renal anomalies such as ectopic kidney.

Management of staghorn stones in special situations

Staghorn stones have always been a challenge for urologists, especially in some special situations, such as horseshoe kidney, ectopic kidney, paediatric kidney, and solitary kidney. The treatment of these staghorn stones must be aggressive because they can lead to renal function loss and serious complications. The gold-standard management for staghorn stones is surgical treatment with the aim of clearing the stones and preserving renal function. Treatment methods for staghorn stones have developed rapidly, such as extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy and laparoscopy and open surgery. Whether the standard procedures for staghorn stones can also apply to these stones in special situations is still not agreed upon. The decision should be made individually according to the circumstances of the patient. In this review, we evaluates the previous studies and comments on the management of staghorn stones under special situations in the hope of guiding the optimal choice for urologists.

Efficacy of extracorporeal shockwave lithotripsy with furosemide and hydration in renal stone management: A randomised controlled trial

Objective: To assess the effect of diuretics (furosemide) administered before extracorporeal shockwave lithotripsy (ESWL) followed by continuous infusion of 0.9% NaCl during the ESWL in patients with renal stones. Patients and methods: A tertiary care teaching hospital-based prospective randomised controlled trial was conducted from July 2015 to June 2017, including 714 patients who underwent ESWL. The patients were randomised in two groups: in Group-A, patients received 40 mg furosemide 30 min before each ESWL session and 1000 mL 0.9% NaCl intravenous hydration during the procedure. In Group-B, the patients only received 0.9% NaCl. All patients were followed-up every 2 weeks for 3 months with X-ray and ultrasonography of the kidney, ureter and bladder. Patients without a radio-opaque stone at follow-up were classified as successes. Results: After 2 months, the stone-free rate (SFR) was much higher in Group-A, at 77.0% vs 65.3% (P < 0.001). Further, for patients aged ≤40 years, the SFR was significantly higher in Group-A than Group-B, at 89.2% vs 71.4% (P < 0.001). The mean (SD) age of the patients was 34.4 (8.23) years. Amongst them, 441 (61.8%) were male and 273 (38.2%) were female. The mean (SD) stone size was 1.42 (0.21) cm in Group-A and 1.40 (0.20) cm in Group-B. Conclusion: We conclude that the efficacy of diuretics (furosemide) along with hydration is superior to hydration alone during ESWL for renal stone clearance. Abbreviations: BMI: body mass index; KUB: kidney, ureter and bladder; OPD: Outpatient Department; ESWL: extracorporeal shockwave lithotripsy; SFR, stone-free rate.

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.

Update on Surgical Management of Pediatric Urolithiasis

Urolithiasis has always been a fascinating disease, even more so in children. There are many intriguing facets to this pathology. This article is a nonsystematic review to provide an update on the surgical management of pediatric urolithiasis. It highlights the pros and cons of various minimally invasive surgical options such as extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), laparoscopy, and robotics. This article also describes the various intracorporeal disintegration technologies available to fragment the stone, including the newer advancements in laser technology. It also emphasizes the cost considerations especially with reference to the emerging economies. Thus, this manuscript guides how to select the least-invasive option for an individual patient, considering age and gender; stone size, location, and composition; and facilities and expertise available.

Pediatric urolithiasis in Morocco: Composition of 432 urinary calculi analyzed by infrared spectroscopy

PURPOSE

Incidence of pediatric urolithiasis is decreasing in most developing countries where endemic bladder stones are less prevalent than in the past years. In parallel, stone composition has changed. Only few data are available in North Africa, except for Tunisia. We report stone composition in the Moroccan pediatric population.

MATERIAL AND METHODS

Composition of 432 stones from children (302 boys, 130 girls) was determined by infrared spectroscopy. The samples were collected during the period 1999-2016. Stone morphology, which is an important aspect for etiology was determined by examination of each stone under a stereomicroscope. Stone composition was compared to patients' age and gender.

RESULTS

The global male-to-female ratio was 2.32. Regarding stone composition, calcium oxalate was the main component in 51.6% of the stones, followed by struvite (18.1%), ammonium urate (9.5%) and carbapatite (9%). Significant differences were found between males and females: calcium oxalate accounted for 72.3% of stones in girls and 42.7% in boys (P<10^-6); conversely, struvite was more frequent in boys than in girls (22.2 vs 8.5%, P<10^-4). The same was found for calcium phosphate stones (11.9% in boys; 4.6% in girls, P<0.05). Stone morphology helped us for detecting several pathological conditions: type Ic whewellite stones, as a marker for primary hyperoxaluria, was found in 17.6% of stones and type IIId ammonium urate stones, suggestive for infectious diarrhea, was identified in 20.1% of all stones.

CONCLUSION

This is the largest series of pediatric stones in Morocco studied by infrared analysis and morphological examination.

LEVEL OF EVIDENCE

3.

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.

Endemic bladder calculi in children

Urinary calculi are being recognized more frequently in children and the urinary bladder is the most common site for stone formation in the lower urinary tract. Bladder calculi are grouped into three basic categories: primary idiopathic/endemic, secondary, and migrant. The incidence of vesical calculi has declined significantly in the last 70 years in developed nations owing to improvements in nutrition and socioeconomic conditions, but it is still high in developing nations. Primary idiopathic/endemic bladder calculi typically occur in children, in the absence of urinary tract infection (UTI), urinary stasis, or foreign body, and diet lacking in animal proteins is the major contributor factor. Comprehensive preventive and treatment strategies are critical for improving the quality of life of diseased children, in addition to helping to eradicate, or at least decrease, the incidence of endemic bladder calculi in developing nations.

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.

Risk factors for formation of steinstrasse after extracorporeal shock wave lithotripsy for pediatric renal calculi: a multivariate analysis model

OBJECTIVES

To define various stone, renal and therapy factors that could affect steinstrasse (SS) formation after extracorporeal shock wave lithotripsy (SWL) for pediatric kidney stones. Thus, SS could be anticipated and prophylactically avoided

METHODS

From January 1999 through December 2012, 317 children underwent SWL with Dornier Lithotripter S for the treatment of renal stones. Univariate and multivariate statistical analyses of patients, stones and therapy characteristics in relation to the incidence of SS were performed to detect the factors that had a significant impact on SS formation.

RESULTS

The overall incidence of SS was 8.5%. The steinstrasse was in the pelvic ureter in 74.1% of the cases, lumbar ureter in 18.5% and iliac ureter in 7.4%. Steinstrasse incidence significantly correlated with stone size, site and age of child. Steinstrasse was more common with increasing stone length and stones located in renal pelvis or upper calyx with the age below 4 years. A statistical model was constructed to estimate the risk of steinstrasse formation accurately. The equation for logistic regression is Z = -4.758 + B for age + B for size stone X length in mm + B for stone site.

CONCLUSIONS

The stone size, site and age are the most important risk factors responsible for SS formation in children. Our regression analysis model can help with prospective identification of children who will be at risk of SS formation. Those children at high risk of SS formation should be closely monitored or treated by endoscopic maneuvers from the start.

Endoscopic cystolithotomy by mini nephroscope: a preliminary study

OBJECTIVE

To introduce a novel endoscopic surgical technique with mini-nephroscope by suprapubic transvesical route for cystolithotripsy in children.

MATERIAL AND METHODS

This was a non-randomized study with a series of 12 boys, between February 2012 and September 2013. Demographic, operative, and postoperative data were recorded. Our new endoscopic surgery technique could be performed in all patients. Complications were noted.

RESULTS

Mean age was 35.1 ± 8.6 months (19-46 months), the average stone size was 16.5 ± 5.2 mm (10-20 mm). Mean operation time was 28.9 min (21-40), and mean hospital stay was 2.2 (2-3) days. In all procedures, stones were successfully fragmented and extracted by the new surgical technique. There was no intraoperative and/or postoperative complication or urethral stricture during follow-up period. In stone analyses, the main components were ammonium acid urate, calcium oxalate, and struvite.

CONCLUSIONS

The new endoscopic surgery technique is safe and effective for bladder stones in children. Thus, our technique can be a strong candidate for an alternative treatment of childhood bladder stones.

Does previous open nephrolithotomy affect the outcomes and complications of percutaneous nephrolithotomy in children?

OBJECTIVE

To analyze the success and complication rates of percutaneous nephrolithotomy (PCNL) performed in pediatric patients and to compare outcomes of the patients undergoing primary PCNL with those of patients who had undergone previous open nephrolithotomy.

MATERIALS AND METHODS

Between 2000 and 2011, PNL procedures were performed in 123 renal units (RU) of 111 children. We compared RU on which previous open surgery had been performed (group 1 RU = 26) on the same kidney with RU that had not been involved in previous surgery (group 2 RU = 97). Patient characteristics, pre- and postoperative hematocrit and creatinin levels, operative time, fluoroscopic screening time, stone free rate, complications and hospitalization time were documented and compared.

RESULTS

There were no significant differences between the groups in sex, stone burden, pre- and postoperative hematocrit levels. Mean age and pre- and postoperative creatinin levels were significantly higher in group 1 (p < 0.05). Mean operative time, fluoroscopic screening time and hospitalization times were similar in each group (p > 0.05). The stone free rates after PCNL were 65.4% in group 1 and 81.4% in group 2 (p > 0.05). Multiple access rate was higher in group 1; however, this was not statistically significant (27% vs. 15%, p > 0.05).

CONCLUSION

PCNL can be performed in pediatric patients who have previously undergone open nephrolithotomy but the success rates may be lower and risk of bowel injury higher. NCCT should be considered preoperatively for patients who have previously undergone open renal surgeries to investigate the presence of retrorenal colons. Our study includes relatively few patients with a history of open surgery and we believe that additional clinical studies with larger numbers of patients are needed to confirm our initial findings.

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.

Evolution of pediatric urology at sindh institute of urology and transplantation

Sindh Institute of Urology and Transplantation was started in 1972 as an eight bedded department of genitourinary surgery in a government hospital by its pioneer and present director Syed Adib ul Hassan Rizvi. Responding to the socioeconomic dynamics and the needs of the patient population the facility grew into the largest tertiary care Urology, Nephrology, and Transplant center of south Asia. One of the salient components has been the evolution of the Department of Pediatric Urology, which in itself has shown a tremendous growth into an internationally recognized center for pediatric urology services taking care of all aspects including center of excellence for pediatric stone disease. The guiding mission of this institute remains to provide free medical services at zero cost without any discrimination to all who come to its doorstep and matching with high standard of care without compromising their dignity and self-respect. This institute highlights the fact that lack of resources is no excuse and is a role model for developing countries, where national and international support, motivation, and cooperation can offer more advanced and better quality medical services to our children.

Treatment of renal stones with flexible ureteroscopy in preschool age children

The aim of the study is to evaluate the efficacy and safety of retrograde intrarenal surgery (RIRS) to treat renal stones in preschool age (<7 years) children. From September 2005 to May 2013, a total of 65 children (31 boys and 34 girls) with 72 renal stones were treated using RIRS. Patients were considered stone-free when the absence of residual fragments was observed on imaging studies. In the presence of residual calculi >4 mm, a second-stage RIRS was performed. The pre-operative, operative and post-operative data of the patients were retrospectively analyzed. A total of 65 patients with a mean age of 4.31 ± 1.99 years (6 months-7 years) were included in the present study. The mean stone size was 14.66 ± 6.12 mm (7-30 mm). The mean operative time was 46.47 ± 18.27 min. In 5 (7.69%) patients, the initial procedure failed to reach the renal collecting system and ended with the insertion of a pigtail stent. The stone-free rates were 83.07 and 92.3% after the first and second procedures, respectively. Complications were observed in 18 (27.7%) patients and classified according to the Clavien system. Post-operative hematuria (Clavien I) occurred in 6 (9.2%) patients, post-operative urinary tract infection with fever (Clavien II) was observed in 10 (15.4%) patients, and ureteral wall injury (Clavien III) was noted in 2 (3%) patients. RIRS is an effective and safe procedure that can be used to manage renal stones in preschool age children.

What changed in the management of pediatric stones after the introduction of minimally invasive procedures? A single-center experience over 24 years

OBJECTIVE

To assess the impact of new technology on the management of pediatric urolithiasis by analyzing our local practice over the past 24 years, and determining the role of open surgery at the present time.

METHODS

We retrospectively reviewed the charts of 768 children (783 procedures) who underwent surgical treatment for urolithiasis between June 1987 and October 2010. Data were analyzed with respect to patient characteristics and changing patterns of treatment with time. We compared the type of procedures performed between four time periods: the first was before ESWL, the second was after the introduction of ESWL, the third was after introduction of PCNL, and the fourth was our experienced period with a pediatric urologist.

RESULTS

The mean age of the children was 7.50 years (range 9 months-17 years). There were 495 renal, 228 ureteral, 21 bladder, 11 urethral stones, and the remaining 13 had stones in multiple locations. Of the 783 procedures performed, 75.9% were open surgery during the first period (1987-1992), 29.7% during the second period (1993-1998), 6.1% during the third period (1999-2004) and 0.2% during the fourth period (2005-2010). The number of children who underwent urinary stone treatment increased significantly (p = 0.001) and the age of the children at the time of surgery decreased (9.09-6.08 years) (p = 0.001) with time.

CONCLUSION

The majority of stones in children can be managed using endourological procedures. Additionally, technological advances and improved surgical skills have greatly reduced the number of children requiring open surgery, which is mainly used for those with complex urinary calculi presenting with anatomic abnormalities. Minimally invasive techniques allow us to treat stones at an earlier age.

The importance of instrument type in paediatric percutaneous nephrolithotomy

We reported our experience with percutaneous nephrolithotomy in children and compared the outcomes, including the morbidity and success rates, regarding the instruments of different sizes. One hundred and seventy-three paediatric patients, who underwent percutaneous nephrolithotomy in our clinic between 1999 and 2013, were assessed. According to the size of instruments used during surgery, three different groups were formed and the pre- and postopeartive outcomes were compared between the groups. 76 girls and 97 boys with a mean age of 9.24 (≤ 17) years were assessed. Stone-free rates were 75.6 % in group 1 (n = 82) using 17 F nephroscope, 79.4 % in group 2 (n = 73) using 24 F nephroscope and 72.2 % in group 3 (n = 18) using 26 F nephroscope. Postoperative fever was seen in four, five and one patient in group 1, 2 and 3, respectively. Urinary infection was seen in one patient in group 1 and four patients in group 2. Mean haematocrit drop and stone burden were significantly lesser in group 1. No significant difference was seen in the duration of nephrostomy and hospitalization between the groups. The success rates obtained in the groups using different instrument types (paediatric or adult) were similar. However, age, weight, height, stone burden and bleeding were significantly lesser in group 1 that used paediatric type of instrument. As the most frequent complication of PNL, bleeding seems to be associated with stone burden, the diameter of dilatation and the calibre of instrument. To decrease the particular complications, paediatric type of instruments are convenient and do not affect the success.

Factors affecting complication rates of percutaneous nephrolithotomy in children: results of a multi-institutional retrospective analysis by the Turkish pediatric urology society

PURPOSE

We assessed factors affecting complication rates of percutaneous nephrolithotomy in children.

MATERIALS AND METHODS

We retrospectively evaluated data on 1,205 renal units in 1,157 children treated with percutaneous nephrolithotomy at 16 Turkish centers between 1991 and 2012. Of the patients 28.3% had a history of urolithiasis. Complications were evaluated according to the Satava classification system and modified Clavien grading system. Univariate and multivariate analyses were done to determine predictive factors affecting complication rates.

RESULTS

A total of 515 females and 642 males were studied. Mean ± SD patient age was 8.8 ± 4.7 years (range 4 months to 17 years). Mean ± SD stone size, operative time and postoperative hospital stay were 4.09 ± 4.06 cm(2), 93.5 ± 48.6 minutes and 5.1 ± 3.3 days, respectively. Postoperative stone-free rate was 81.6%. A total of 359 complications occurred in 334 renal units (27.7%). Complications were intraoperative in 118 cases and postoperative in 241. While univariate analysis revealed that stone history, positive urine culture, operative time, length of hospitalization, treatment success, punctured calyx and location of the stone significantly affected the complication rates (p <0.05), operative time, sheath size, mid calyceal puncture and partial staghorn formation were the statistically significant parameters affecting complication rates on multivariate logistic regression analysis.

CONCLUSIONS

Percutaneous nephrolithotomy is the treatment of choice for most renal calculi in children. The technique is effective and safe in children, with a high success rate and a low rate of major complications. The significant factors identified should be considered by clinicians to decrease associated complication rates.

Cystoscopically guided percutaneous suprapubic cystolitholapaxy in children

PURPOSE

To evaluate the safety and efficacy of endoscopically guided percutaneous suprapubic artery forceps litholapaxy for pediatric vesical and posterior urethral stone <1 cm in diameter.

MATERIALS AND METHODS

A retrospective series study of 73 children (68 boys and 5 girls) with vesical and urethral stones less than 1 cm in diameter with an average age of 3.5 years (range 1-9 years) were included in this study. Cases with previous suprapubic surgery, stones of more than 1 cm in diameter, multiple bladder or urethral stone, anterior urethral stones and cases with neurological or anatomical abnormalities were excluded from our study. The bladder was filled and punctured suprapubically by an artery forceps under the vision of the pediatric cystoscopy then the stone is completely crushed. All intraoperative and postoperative complications were recorded. The stone-free rate status was evaluated 2 weeks postoperatively using plain X-ray/ultrasonography.

RESULTS

All cases were successful, and the stones were completely crushed to smaller insignificant fragments in a single session. No intraoperative bladder perforation or bleeding was recorded. The mean operative time was 12.5 min (ranging from 9 to 17 min). There were no postoperative complications apart from 2 cases of persistent suprapubic leakage postoperatively for 24 h and the leakage stopped after 48 h with the insertion of 8 Fr Foley catheter. In all cases, no significant stone fragments were found 2 weeks postoperatively.

CONCLUSION

Our technique for management of pediatric vesical and posterior urethral stone less than 1 cm is an easy and safe with no intraoperative or postoperative significant complications.

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.

Percutaneous nephrolithotomy in children with cystine stone: long-term outcomes from a single institution

PURPOSE

We determined the effectiveness of percutaneous nephrolithotomy in children with cystine stones and present the long-term outcomes.

MATERIALS AND METHODS

We reviewed the data of 65 renal units in 51 children who underwent percutaneous nephrolithotomy for cystine stones between 2000 and 2012. Of the patients 19 (37%) had undergone ipsilateral renal surgery and 11 (22%) had undergone extracorporeal shock wave lithotripsy. Children were designated as being stone-free or having residual stone (any evidence of persistent stone fragments irrespective of size). Medical treatment with α-mercaptopropionylglycine, potassium citrate or potassium sodium hydrogen citrate was recommended for all patients after stone analysis.

RESULTS

Median stone burden was 3.3 cm(2) (range 1 to 13) and median patient age was 6 years (1 to 17). Stone-free status was achieved in 41 renal units (63.1%). Stone-free status was increased to 73.8% with additional endoscopic procedures. The remaining patients with residual stones were followed. Complication rate was 15.4%. A total of 35 children (68.6%) receiving regular medical treatment were followed for a median of 95 months (range 6 to 136). The recurrence rate for children achieving stone-free status was 31.2%, and the regrowth rate for children with residual stones was 29.4%.

CONCLUSIONS

Percutaneous nephrolithotomy is a safe and effective treatment for children with cystine stones. Our high recurrence and regrowth rates emphasize that our treatment schedule is inadequate to prevent recurrent cystine calculi. Additional investigation is needed to determine the optimal medical therapy for preventing recurrence and regrowth of cystine stones.

[A different approach to the percutaneous nephrostomy by urologists]

INTRODUCTION

Percutaneous nephrostomy (PCN) tube placement is generally performed in radiologic departments worldwide. However, there are a few urologist-directed studies about PCN performed with ultrasound guidance. Needle direction using a convex abdominal ultrasound probe might be difficult in unexperienced hands. In order to perform this procedure easily, we propose that a probe placed on flank or intercostal region and a long grooved needle director that never allows needle movement would be useful. We considered a transrectal ultrasound (TRUS) probe was suitable to resolve this issue.

MATERIAL AND METHOD

From January 2007 to April 2011, a total of 113 percutaneous renal access (PRA) were performed using a TRUS probe in 102 patients, aged 20 to 84 years old. Because of the insufficient imaging capability of the TRUS probe in obese patients whose body mass index (BMI) greater than 30kg/m(2) were excluded. Forty two PRA were performed under local anesthesia and this group was named local anesthesia (LA) group. Seventy one PRA were performed for nephrostomy insertion under local anesthesia supplemented by deep sedation and this cluster was named deep sedation (DS) group.

RESULTS

Targeted calyx puncture and guide wire placement was performed in all patients (100%) but success rate of tube insertion in each group was different. Successful PCN insertion rate was 69.1% (29 of 42 cases) in LA group and 95.8% (68 of 71 cases) in DS group. No major vascular injury and/or adjacent organ injury to bowel, liver, spleen or lung was seen in any patient.

CONCLUSION

Guidance of TRUS probe, deep sedation, and modified dilators may offer a high success rate to the urologists with little experience in PCN insertion which they would find it difficult to perform.

Predictive factors and management of steinstrasse after shock wave lithotripsy in pediatric urolithiasis--a multivariate analysis study

OBJECTIVE

To define the predictive factors for the formation of steinstrasse (SS) after shock wave lithotripsy (SWL) and determine the treatment strategies for this complication in pediatric urolithiasis.

METHODS

We retrospectively reviewed the data of 341 renal units (RUs) treated with SWL for urolithiasis. The stone location, stone burden, auxiliary procedures, energy level, and number of shock waves were recorded. Statistical analysis was performed to detect the predictive factors for the formation of SS. In addition, the treatment of children with SS was evaluated.

RESULTS

The mean age of the children was 8.31 years (range 1-17). Episodes of SS developed in 26 RUs (7.6%). Of the 26 RUs, 20 (77%) were localized in the lower, 5 (19%) in the upper, and 1 (4%) in multiple locations in the ureter. The stone burden was the only statistically significant factor predicting the formation of SS on logistic regression analysis (P = .001). Of the 26 RUs, 17 (65.4%) were successfully managed by repeat SWL monotherapy, 4 (15.4%) were managed with ureteroscopy after failure of SWL, 1 (3.8%) was managed by ureteroscopy monotherapy, and 4 (15.4%) were monitored with conservative management with antispasmodic drug plus hydration therapy. The mean number of SWL sessions was 1.72.

CONCLUSION

The incidence of SS development in children after SWL treatment was similar to that in adult series. Our results suggest that the stone burden is a significant predictive factor for the development of SS after SWL in pediatric urolithiasis. Most children with SS could be easily and safely treated by repeat SWL.

The management of staghorn calculi in children

OBJECTIVES

To review reports focusing on the surgical treatment of staghorn stones in children, as despite all the improvements in the surgical treatment of paediatric urolithiasis the management of staghorn calculi still represents a challenging problem in urology practice.

METHODS

To evaluate current knowledge about treating staghorn calculi in children, we searched PubMed for relevant articles published between 1991 and 2011, using a combination of related keywords, i.e. staghorn stone, child, kidney calculi, surgical treatment, electrohydraulic shockwave therapy (ESWL), percutaneous nephrolithotomy (PCNL), and open surgery. Reports relating to the treatment of paediatric stone disease in general (open surgery, PCNL, ESWL) were also searched with the same method. Additional references were obtained from the reference list of full-text reports.

RESULTS

Although open surgery had been widely used in the past for treating such stones in children, currently it has only limited indications in highly selected patients. Current published data clearly indicate that, in experienced hands, both PCNL and ESWL are now effective methods for treating staghorn calculi in children.

CONCLUSIONS

Due to advanced techniques and instrumentation, it is now possible to successfully treat staghorn calculi in children, with very limited safety concerns. Currently, while PCNL is recommended as the first-line surgical treatment, ESWL, open surgery and/or combined methods are valuable but secondary options in the treatment of paediatric staghorn calculi.

Percutaneous nephrolithotomy in infants: evaluation of a single-center experience

OBJECTIVE

To evaluate the efficacy and safety of percutaneous nephrolithotomy (PCNL) in infants (<3 years) with renal calculi.

METHODS

From November 2005 to August 2010, 20 renal units with calculi in 19 infants (13 boys and 6 girls) were treated with PCNL at our institution. Mean age of infants was 20.6 months (range, 7-36 months), the mean stone size was 2.2 cm (range, 1.9-3.1 cm). All PCNL procedures were performed with 14 to 16F percutaneous access and 8/9.8F rigid ureteroscope. Stones were fragmented with a pneumatic lithotripter and evacuated.

RESULTS

Mean operative time was 77.5 minutes (range, 35-120 minutes). Stones were completely removed in 85% of kidneys (17 of 20 kidneys) after the first session and 95% (19 of 20 kidneys) after a second look PCNL procedure. No patients required a blood transfusion. Evaluation of the renal function before and after the PCNL procedure demonstrated the stabilization of corresponding glomerular filtration rate in the treated kidney (48.2 ± 3.7 vs 50.4 ± 5.2 mL/min; P = .22).

CONCLUSION

When performed by experienced endourologists, PCNL is a safe and effective procedure in infants for the removal of renal calculi.

Treatment of renal stones in infants: comparing extracorporeal shock wave lithotripsy and mini-percutaneous nephrolithotomy

The objective of the study is to compare the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) and mini-percutaneous nephrolithotomy (MPCNL) in treating renal stones sizing 15-25 mm in infants <3 years. Forty-six infants with renal stones sizing 15-30 mm were treated by either ESWL (22 renal units in 22 infants) using Dornier compact delta lithotripter or MPCNL (25 renal units in 24 infants) using 14F-18F renal access under general anesthesia. The operation time, stone-free rate, re-treatment rate, and complications between the two groups were compared with the χ(2), Mann-Whitney U, and Student's t tests. No significant differences in mean age and stone size were observed between the two groups. The 1- and 3-month postoperative stone-free rates were 84 and 96% in MPCNL group and were 31.8 and 86.4% in ESWL group. The re-treatment and complication rates were significantly higher in ESWL group than in MPCNL group (50 vs. 12%, P = 0.004; 16.0 vs. 45.5%, P = 0.028). The stone recurrence rate was similar between the two groups. No significant changes of serum creatinine (Cr) level and glomerular filtration rate were observed in both groups. In conclusion, MPCNL is an effective and feasible alternative monotherapy for large renal stones (15-25 mm) in infants, with a higher stone-free rate and a lower complication rate when compared with ESWL.

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.