Urolithiasis in children: medical approach

Emergency department utilization patterns for pediatric urinary stone patients in the United States

BACKGROUND

The prevalence of pediatric urolithiasis has increased rapidly, leading to more emergency department (ED) visits across the United States.

OBJECTIVE

The purpose of this study was to determine emergency care practices for children and adolescents with urinary stones and characteristics associated with management.

METHODS

We performed a cross-sectional study of the 2021 Nationwide Emergency Department Sample to identify pediatric patients (≤21 years) presenting to an ED in the United States with a primary diagnosis of urinary stone disease. The primary outcome was patient disposition. Multivariable logistic regression was used to identify patient and hospital characteristics associated with hospital admission. Imaging utilization was a secondary outcome of the study.

RESULTS

There were 57 pediatric ED visits for urinary stone disease per 100,000 population in the study (mean age 17.7 years; 59.6 % female). Most patients (91.2 %) were treated and discharged, while 6.9 % were admitted to the same hospital. Computed tomography was the primary imaging modality (60.2 %), with utilization increasing with age. Considerable variability in disposition and imaging utilization was observed, with hospital admission rates ranging from 1.3 % to 55.1 % and CT use from 1.7 % to 77.5 % among patient and hospital subgroups.

CONCLUSIONS

This study reveals a high rate of pediatric urinary stone presentations to United States EDs. Significant variations in disposition and imaging utilization across different patient and hospital characteristics highlight the need for standardized, evidence-based approaches to pediatric urinary stone care.

Risk factors for recurrence in pediatric urinary stone disease

BACKGROUND

Children's urinary system stones may develop from environmental, metabolic, anatomical, and other causes. Our objective is to determine the recurrence and prognosis, demographic, clinical, and etiological characteristics of children with urolithiasis.

METHODS

Medical records of patients were evaluated retrospectively. Patients' demographic data and medical history, serum/urine biochemical and metabolic analysis, blood gas analysis, stone analysis, imaging findings, and medical/surgical treatments were recorded.

RESULTS

The study included 364 patients (male 187). Median age at diagnosis was 2.83 (IQR 0.83-8.08) years. The most common complaints were urinary tract infection (23%) and urine discoloration (12%). Sixty-two percent had a family history of stone disease. At least one metabolic disorder was found in 120 (88%) of 137 patients having all metabolic analyses: hypercalciuria was found in 45%, hypocitraturia in 39%, and hyperoxaluria in 37%. Anatomical abnormalities were detected in 18% of patients. Of 58 stones analyzed, 65.5% were calcium and 20.6% were cystine stones. Stone recurrence rate was 15% (55/364). Older age (> 5 years), family history of stone disease, stone size (≥ 5 mm), and urinary system anatomical abnormalities were significantly associated with stone recurrence (p = 0.027, p = 0.031, p < 0.001, and p < 0.001, respectively). In adjusted logistic regression analysis, stone size ≥ 5 mm (OR 4.85, 95% CI 2.53-9.3), presence of urinary system anatomical abnormalities (OR 2.89, 95% CI 1.44-5.78), and family history of stone disease (OR 2.41, 95% CI 1.19-4.86) had increased recurrence rate.

CONCLUSIONS

All children with urolithiasis should be evaluated for factors affecting stone recurrence. Children at higher risk of recurrence need to be followed carefully.

Review of childhood genetic nephrolithiasis and nephrocalcinosis

Nephrolithiasis (NL) is a common condition worldwide. The incidence of NL and nephrocalcinosis (NC) has been increasing, along with their associated morbidity and economic burden. The etiology of NL and NC is multifactorial and includes both environmental components and genetic components, with multiple studies showing high heritability. Causative gene variants have been detected in up to 32% of children with NL and NC. Children with NL and NC are genotypically heterogenous, but often phenotypically relatively homogenous, and there are subsequently little data on the predictors of genetic childhood NL and NC. Most genetic diseases associated with NL and NC are secondary to hypercalciuria, including those secondary to hypercalcemia, renal phosphate wasting, renal magnesium wasting, distal renal tubular acidosis (RTA), proximal tubulopathies, mixed or variable tubulopathies, Bartter syndrome, hyperaldosteronism and pseudohyperaldosteronism, and hyperparathyroidism and hypoparathyroidism. The remaining minority of genetic diseases associated with NL and NC are secondary to hyperoxaluria, cystinuria, hyperuricosuria, xanthinuria, other metabolic disorders, and multifactorial etiologies. Genome-wide association studies (GWAS) in adults have identified multiple polygenic traits associated with NL and NC, often involving genes that are involved in calcium, phosphorus, magnesium, and vitamin D homeostasis. Compared to adults, there is a relative paucity of studies in children with NL and NC. This review aims to focus on the genetic component of NL and NC in children.

Paediatric Renal Stone Management in Africa: A Scoping Review and Analysis of Current Practices

Renal stones are solid deposits formed from minerals and salts that develop within the kidneys and urinary tract. While the condition is more common among adults, children and even infants can also be affected. There is an increasing incidence of paediatric renal stones in Africa alongside multiple challenges faced in managing the condition. This scoping review aimed to provide an overview of the management modalities of paediatric renal stones in Africa. This study utilised Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. A systematic search was conducted in three electronic databases: PubMed, African Journal Online (AJOL), and Google Scholar, with 1,180 articles curated. After extensive examination, 10 articles satisfied the inclusion criteria. The review found that calcium oxalate stones were the most prevalent type, accounting for 34.03% of cases, followed by whewellite stones and ammonium urate stones. The most frequent location for stones was the kidney, and the most common symptom was pain. Abdominopelvic ultrasound was the most frequently utilised investigation. Of the 886 patients managed for renal stones, 75.4% were managed surgically, 2.9% medically, and 21.7% spontaneously resolved without intervention. This review identifies opportunities for improving the management of paediatric renal stones in Africa, including the need for standardised diagnostic and treatment protocols and the development of evidence-based guidelines tailored to the African context. Overall, this scoping review provides valuable insights into the patterns and management of paediatric renal stones in Africa and highlights the need for further research to improve the management of this condition in the region.

Calcium Carbonate Urolithiasis in a Pediatric Patient: A Case Report

Urinary stones composed of calcium carbonate are extremely rare, accounting for 0.01%-1.4% of urolithiasis (UL) cases. Urolithiasis is an infrequent condition in the pediatric population worldwide and in Mexico; nevertheless, the incidence in the Yucatán Peninsula is higher than that reported in other areas of Mexico and the world. Urolithiasis is the second most common urinary disease among pediatrics in the Yucatán Peninsula, which makes it an endemic region for this disease. We describe the case of a five-year-old male from the southeast region of Mexico who presented with signs and symptoms of urinary tract infection (UTI) and was diagnosed with bilateral staghorn stones of calcium carbonate, successfully treated by mini endoscopic combined intra-renal surgery, and dietary adjustments to prevent recurrence.

Urinary stone disease in Syrian children

BACKGROUND

Pediatric urinary stone disease (USD) is a costly medical problem. This study aims to assess the clinical characteristics and outcomes of common and rare causes of pediatric USD.

METHODS

A retrospective descriptive cohort study included all children < 13 years of age with confirmed USD admitted to the Children's University Hospital in Damascus, Syria, from January 2013 to December 2019. The study sample was divided into two groups based on etiologies: common and rare causes groups.

RESULTS

We evaluated 235 patients; 147 of them were males, and the male-to-female ratio was 1.7:1. The common causes group consisted of 203 patients (mean age 3.52 ± 3.66 years) and mainly included metabolic disorders (45.5%) and anatomical abnormalities (22.3%), while the rare causes group included 32 cases (mean age 4.93 ± 4.08 years), 12 patients with uric acid stones (37.5%), 7 patients with cystinuria (21.9%), and primary hyperoxaluria in 5 patients (15.6%). In addition, 39.6% of study patients were born to consanguineous marriages. Sixty-two patients developed AKI, and eleven patients had chronic kidney disease (CKD). Patients with rare causes were more likely to have AKI, CKD, bilateral stones, and recurrent stones (P-value < 0.05). Stone analysis was performed on 83 patients, and the main stone types were calcium oxalate (34.9%), uric acid (14.4%), and struvite stones (12%). Surgery was the most performed treatment in 101 patients (56.7%).

CONCLUSION

Patients with rare causes of pediatric USD are at a higher risk for severe complications and require early diagnosis and management. The high rate of uric acid stones in our society requires further evaluation for possible underlying causes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Urolithiasis in patients with inflammatory bowel disease: A systematic review and meta-analysis of 13,339,065 individuals

BACKGROUND

This study aimed to summarize the current literature regarding the prevalence of renal stones in patients with inflammatory bowel disease (IBD). Moreover, we aimed to evaluate the risk factors of urolithiasis in patients with IBD and the difference between patients with IBD and healthy controls in terms of urinary profile.

METHODS

On February 23, 2022, a computerized search was conducted on PubMed, OVID via MEDLINE, Web of Science, and Scopus using relevant keywords. Three independent reviewers performed 2-stage screening and data extraction. The National Institutes of Health tools were employed for quality assessment. Review Manager 5.4 software was used to calculate the mean difference (MD) between IBD patients and non-IBD in terms of urine profile using the Inverse-variance model and to estimate the odds ratio of reported risk factors for renal stones with the Generic Inverse-Variance model.

RESULTS

Thirty-two articles (n = 13,339,065 patients) were included. The overall prevalence of renal stones in patients with IBD was 6.3%, 95% Confidence interval (4.8%-8.3%). The prevalence of urolithiasis was more common in Chron's disease vs Ulcerative colitis (7.9% vs 5.6%) and in old studies (1964-2009) than in more recent studies (2010-2022) (7.3% vs 5.2%), respectively. Compared to non-IBD patients, patients with IBD were associated with significantly lower urine volume (MD = -518.84 mL/day, P < .00001), calcium 24-hour urine (MD = -28.46 mg/day, P < .0001), citrate 24-hour urine (MD = -144.35 mg/day, P < .00001), sodium 24-hour urine (MD = -23.72 mg/day, P = .04), and magnesium 24-hour urine (MD = -33.25 mg/day, P < .00001).

CONCLUSION

The overall prevalence of renal stones in patients with IBD was comparable to the general population. Patients with Chron's disease were associated with a higher prevalence of urolithiasis compared to Ulcerative colitis. Drugs that induce renal calculi should be stopped in high-risk patients.

An atypical presentation of urolithiasis with pyonephrosis in a child: A case report

<b>Background:</b> Childhood urolithiasis is previously rare but increasingly recognized nowadays. Presentation varies, and often children, do not present with the classical symptoms commonly seen in adults.<br /> <b>Case report:</b> This case was initially presented to the emergency department with atypical symptoms of nephrolithiasis. Therefore, he was treated for acute appendicitis before an ultrasound abdomen revealed there is gross hydronephrosis, which is secondary to pelvic-ureteric junction obstruction. CT abdomen was then proceeded, found right nephrolithiasis and vesicoureteric calculus with right hydroureter and gross hydronephrosis. Retrograde pyelography (RPG), ureteroscopy (URS), and insertion of the stent for right pelvic-ureteric junction obstruction were performed and subsequently, he developed complications.<br /> <b>Conclusion: </b>The initial presentation of this case is common however not a classical presentation of renal stone. Therefore, evaluation of the symptoms and initial investigations should be done properly, so that we will not miss this common disease with the rare presentation, especially in children.

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.

Shockwaves and the Rolling Stones: An Overview of Pediatric Stone Disease

Urinary stone disease is a common problem in adults, with an estimated 10% to 20% lifetime risk of developing a stone and an annual incidence of almost 1%. In contrast, in children, even though the incidence appears to be increasing, urinary tract stones are a rare problem, with an estimated incidence of approximately 5 to 36 per 100,000 children. Consequently, typical complications of rare diseases, such as delayed diagnosis, lack of awareness, and specialist knowledge, as well as difficulties accessing specific treatments also affect children with stone disease. Indeed, because stone disease is such a common problem in adults, frequently, it is adult practitioners who will first be asked to manage affected children. Yet, there are unique aspects to pediatric urolithiasis such that treatment practices common in adults cannot necessarily be transferred to children. Here, we review the epidemiology, etiology, presentation, investigation, and management of pediatric stone disease; we highlight those aspects that separate its management from that in adults and make a case for a specialized, multidisciplinary approach to pediatric stone disease.

Dietary management of hypocitraturia in children with urolithiasis: results from a systematic review

PURPOSE

Hypocitraturia is a low urinary excretion of citrate and a well-known risk factor for kidney stone development in children. This systematic review aimed to evaluate the dietary management of hypocitraturia in children with urolithiasis.

METHODS

Literature search was performed on 30th September 2022 using Embase, PubMed, and Cochrane Central Controlled Register of Trials. Studies were included if children with stones and hypocitraturia were managed with diet supplements.

RESULTS

Six papers were included. Four studies evaluated the role of oral potassium citrate associated with high fluid intake on stone resolution and recurrence. Two studies assessed the impact of oral potassium citrate on long-term stone recurrence after percutaneous nephrolithotomy and shock wave lithotripsy. All studies demonstrated that the association of potassium citrate and high fluid intake was well tolerated with no side effects and restored normal urine citrate excretion, allowed a reduction in stone size, and, following definitive treatments, was associated with a lower rate of stone regrowth and recurrence compared with controls. These effects were demonstrated across all pediatric ages.

CONCLUSIONS

Our review infers that oral potassium citrate and high fluid assumption are safe and effective in restoring urine citrate excretion, treating and preventing stone recurrence with no serious adverse events, and should probably be the first-line treatment of pediatric patients with asymptomatic stones and hypocitraturia.

Diagnosis and Management of Nephrolithiasis in Children

The incidence of kidney stones in children is increasing. Approximately two-thirds of pediatric cases have a predisposing cause. Children with recurrent kidney stones have an increased higher risk of developing chronic kidney. A complete metabolic workup should be performed. Ultrasound examination is the initial imaging modality recommended for all children with suspected nephrolithiasis. A general dietary recommendation includes high fluid consumption, dietary salt restriction, and increased intake of vegetables and fruits. Depending on size and location of the stone, surgical intervention may be necessary. Multidisciplinary management is key to successful treatment and prevention.

Do dietary factors play a role in infantile urolithiasis?

BACKGROUND

Urolithiasis is a significant cause of morbidity that may be diagnosed at a young age. However, there is little research on the role of nutrition in pediatric urolithiasis, and research on the infantile period is extremely rare. The aim of this study is to investigate the effect of dietary factors on those diagnosed with "idiopathic" infantile urolithiasis.

METHOD

The study group included 44 infants without a proven etiological factor for urolithiasis. The control group consisted of 60 fully healthy infants of matched age and gender. The parents and caregivers of each infant in the patient and control groups were carefully questioned by the same researcher for their dietary characteristics.

RESULT

The duration of formula usage and daily volume of formula were statistically higher in the study group than the control group (p = 0.041 and p = 0.003, respectively). The urolithiasis group consumed significantly more cow's milk and dairy products (p = 0.033 and p = 0.001). There was no statistically meaningful difference between the two groups in terms of starting age for free water and salty food, as well as daily water intake.

CONCLUSION

We concluded that dietary conditions could also be a risk factor for idiopathic urolithiasis. We believe that nutritional factors for infantile urolithiasis should be better described, in addition to genetic, anatomical, and metabolic factors. A higher resolution version of the Graphical abstract is available as Supplementary information.

Diet, Fluid Intake, Urine Output and Urinary Sodium/Potassium Ratios in Children With Urolithiasis

We performed a cross-sectional study on 25 children (17 boys) with urolithiasis with normal glomerular functions at a tertiary care teaching hospital between March, 2018 to March, 2019. Dietary assessment showed that caloric intake was below recommended dietary allowance (RDA) in 68% patients while the median protein intake was 34.3% more. The fluid intake was below the recommended standards in 56%, and 48% of the children had urine output below 1.5 mL/kg/hour. The urinary sodium was elevated in 96% of the children, urinary potassium was low in 40%, and hypercalciuria was seen in 28%. While metabolic causes predominate in childhood urolithiasis, other factors like dietary changes, liberal fluid and low sodium intake are advised for prevention of recurrences as they have a contributory role too.

Retrograde Intrarenal Surgery (RIRS) for upper urinary tract stones in children below 12 years of age: A single centre experience

OBJECTIVE

Retrograde Intra Renal Surgery (RIRS) is a minimally invasive surgical modality for the treatment of renal stones. We evaluated the efficacy of RIRS in children below aged 12 years of age in the form of stone-free rate (SFR), complications and the feasibility of the procedure.

MATERIALS AND METHODS

This retrospective study included all children ≤ 12 years of age, with upper urinary tract stones single or multiple ≤ 15 mm in size who underwent RIRS between February 2019 to November 2021. RIRS was performed with 7.5 Fr flexible ureterorenoscope over the guidewire, the stones were dusted with Laser and the ureteral stent was left after RIRS. All patients had the post-procedure stent removed within 3 weeks after checking for residual stones with X-ray and ultrasonography of Kidney-Ureter-Bladder (USG-KUB). Follow-up USG KUB was done at 4 months.

RESULTS

15 patients included in our study met the inclusion criteria. The mean age was 8.7 ± 2.8 years, the mean stone size was 11.26 ± 2.14 mm and 26.6 % had multiple stones. Retrograde access failure was noted in 36.3 % in non stented patients. The mean operative time was 72.6 ± 20 minutes, fluoroscopy time was 4.4 ± 0.9 minutes and the mean LASER time was 26 ± 3.9 minutes. The mean hospital stay was 2.8 ± 0.9 days. Ureteral access sheath (UAS) was used in one patient. Conversion to mini PCNL was done in one pre stented patient due to access failure and one patient had a second look RIRS for residual stone. No major complications were noted except onr patient who had sepsis. The stone-free rates were 93.3% after primary RIRS and 100% after second look RIRS.

CONCLUSIONS

RIRS is a feasible, safe procedure for pediatric upper urinary stones with excellent stone-free rates and a low rate of complications.

Comparison of infants and children with urolithiasis: a large case series

We evaluated the demographic features, etiologic risk factors, treatment strategies, and outcome of the infants and children with urolithiasis (UL). A retrospective multicenter study was conducted including 23 Pediatric Nephrology centers in Turkey. The medical records of 2513 children with UL were reviewed. One thousand, three hundred and four boys and 1209 girls (1.1:1) were reported. The mean age at diagnosis was 39.5 ± 35 months (0.4-231 months), and 1262 patients (50.2%) were in the first year of life (infants). Most of the cases with infantile UL were diagnosed incidentally. Microlithiasis (< 3 mm) was found in 794 patients (31.6%), and 64.5% of the patients with microlithiasis were infants. Stones were located in the pelvis-calyces in 63.2% (n: 1530) of the cases. The most common stone type was calcium oxalate (64.6%). Hypocitraturia was the most common metabolic risk factor (MRF) in children older than 12 months, but in infancy, hypercalciuria was more common. Fifty-five percent of the patients had received at least one medical treatment, mostly potassium citrate. At the end of a year's follow-up, most of the patients with microlithiasis (85%) showed spontaneous remission. The rate of spontaneous stone resolution in infants was higher than in children. Spontaneous remission rate was higher in cases with MRF ( - ) stones than in MRF ( +) stones. However, remission rate with medical treatment was higher in cases with MRF ( +) stones. This study represents the results of a large series of infants and children with UL and showed that there are several differences such as underlying metabolic and anatomic abnormalities, clinical course, and stone remission rates between infants and children with urinary stone disease.

Hyperuricosuria and hypercalciuria, probable etiologies of functional abdominal pain: A case-control study

BACKGROUND

Functional abdominal pain (FAP) is a common complaint causing several referrals to pediatricians. On the other hand, the most common presentation of hyperuricosuria and also hypercalciuria is chronic/recurrent abdominal pain. Therefore, a hypothesis has been raised; abdominal pain due to hyperuricosuria and/or hypercalciuria may be misdiagnosed as FAP. The current study has aimed to respond to this theory.

MATERIALS AND METHODS

This is a case-control study conducted on children diagnosed with FAP based on Rome IV criteria and age-matched normal controls. Blood and random urine samples were taken from healthy children and those with FAP. Random urine samples were examined for calcium, uric acid, oxalate, and creatinine concentrations. Random urine calcium to urine creatinine above 0.2 mg/mg was considered hypercalciuria and random urine uric acid above 0.56 mg/dl, GFR as hyperuricosuria. The data were analyzed using logistic models.

RESULTS

Hypercalciuric children had a significantly lower chance of FAP (odds ratio [OR] =0.425, 95% confidence interval [CI] =0.204-0.886). Although an inverse association was seen between hyperuricosuria and FAP (OR = 0.693, 95% CI = 0.395-1.214), it was not statistically significant. In stratified analyses by gender for both hyperuricosuria and hypercalciuria, a marginal inverse significant association was seen in male gender (P < 0.1).

CONCLUSION

Our study showed that hypercalciuria is significantly in inverse association with FAP but not hyperuricosuria. Therefore, these disorders, particularly hyperuricosuria may not be considered as the possible causes of FAP. Further studies with larger sample size for providing more reliable evidence are recommended.

Clinical Features and Surgical Outcomes of the Children With Urolithiasis at a Tertiary Care Hospital: First Report From Somalia

INTRODUCTION

There are very few studies regarding pediatric urolithiasis (PU) reported from Africa, and to date, no data have been presented from Somalia. This study evaluated the sociodemographic and radiological characteristics, treatment, and outcome data of the PU patients treated at Somalia's only tertiary care center.

METHOD

The data of all patients diagnosed with urolithiasis during a 6-year period were reviewed. Only pediatric (age <18) urolithiasis patients were included. Demographic parameters, radiological features, stone characteristics, treatment, and outcome data were collected and analyzed.

RESULTS

Overall, 227 (127 male, 100 female) patients were included. The rate of PU was 8.1%. The mean patient age was 12.7 ± 3.2. More than two-thirds of the patients (n = 161, 70.9%) were adolescents. The stones were located in the kidney in 50.7%, the ureter in 33%, and the bladder in 14.5%. Distal ureteral stones (36%) accounted for the majority of ureteral stones, followed by the ureterovesical junction (26.7%) and proximal ureteral (24%) stones. The mean stone size was 16.2 mm. Most (42.3%) stones had a 10-20 mm diameter, while 23.3% were sized between 6 and 10 mm. Renal insufficiency was present in 5.3%. Among 227 patients, 101 (44.5%) underwent minimally invasive procedures including ureterorenoscopic lithotripsy (n = 40, 18%), retrograde intrarenal surgery (n = 30, 13.2%) and percutaneous nephrolithotomy (n = 31, 14%). Open pyelolithotomy was the most common surgery performed (n = 53, 22.3%). Surgical site infection developed following 3.5% of the open surgery cases. The stone-free rate was 91.3%. It was significantly higher in open cases (98%) compared to the cases performed via a minimally invasive approach (83%) (p = 0.02).

CONCLUSION

In Somalia, PU is more common than in many other countries. Open surgery continues to be the primary treatment modality for children with urolithiasis due to the restricted endourology resources. However, minimally invasive approaches have evolved over the last years.

Twinkle artifact in renal ultrasound, is it a solid point for the diagnosis of renal stone in children?

Background: Twinkle artifact, also known as color Doppler comet-tail artifact, occurs behind very strong, granular, and irregular reflecting interfaces such as crystals, stones, or calcification. This is visualized as a random mixture of red and blue pixels in the high-frequency shift spectrum located deep to the interface. Study results have suggested that the sonographic twinkling artifact may aid in the detection of renal stones with a variety of reference standard imaging modalities, including abdominal radiography, excretory urography, gray-scale sonography, and CT. Material and methods: Our retrospective observational study included children who had undergone abdomen/renal ultrasound for kidneys stones in our radiology department between 2013 and 2019. Presence of the twinkle artifact, and stone numbers and sizes were documented. CT examinations done <3 months prior to or after US were retrospectively assessed to confirm the presence of kidney stones as a reference standard. Results: Thirty-three abdominal renal US scans of 33 patients (21 males, 12 females) fulfilled the entry criteria. The interval between the US and CT was <3 months for all patients. The median overall age of the patients was 4 years (IQR: 3.125, range: 1- 165 months), The median number of days between the US and CT was 13 (IQR: 26, range: 0-81 days). US detected 33 hyperechoic foci suspected to be stones; 26 were confirmed as true positive (i.e. showed the twinkle artifact and were seen in CT), 4 were false positive (showed the twinkle artifact but were not seen in CT), and 3 were false negative (did not show the twinkle artifact but were seen in CT). The overall median stone size was 2 mm in the right kidney, and 5 mm in the left kidney (IQR: 6,11 mm), respectively. Twinkle artifact sensitivity was found to be 89.7% (95% CI 39.574%-90%). The twinkle artifact was assessed in all true-positive stones, determining a relatively high PPV of 26/29 (86.7%) for the twinkle artifact. The twinkle artifact was not dependent on stone size. Specificity for the twinkle artifact could not be calculated due to a lack of true negatives. Conclusion: The twinkle artifact is a sensitive US tool for detecting pediatric kidney and ureter stones, but with a small risk of false positive findings.

Ureterolithiasis in Adolescents: A Case Report

A 13-year-old patient presented to the emergency department with a history of abdominal pain and right flank pain. Two days before, she was evaluated at her pediatrician's office and was diagnosed with acute gastroenteritis and sent home. In the emergency department, the patient was diagnosed with ureterolithiasis after a physical examination, laboratory work, and imaging findings. She was treated successfully with conservative medical management. Symptomatic presentation of ureterolithiasis can include abdominal pain, flank pain, hematuria, dysuria, urgency, nausea, and vomiting. Nurse practitioners need to recognize nonspecific symptoms of ureterolithiasis for accurate diagnosis and treatment. Risk factors, signs and symptoms, prevention, and treatment options for ureterolithiasis are discussed.

Metabolic and Clinical Characteristics of Children with Urolithiasis from Southern India

OBJECTIVE

To study the etiological profile and patterns of clinical presentations of urolithiasis (UL) in children.

METHODS

This observational study included patients <18 y with UL, who were referred to the pediatric nephrology clinic. Clinical features, family history, consanguinity and estimated glomerular filtration rate (eGFR) at presentation and follow-up were recorded. The children were evaluated using relevant blood and urine investigations.

RESULTS

A total of 72 children with UL were evaluated for the study. The etiology of UL (n = 72) included hyperoxaluria (n = 25; 34.7%), idiopathic hypercalciuria (n = 21; 29.2%), idiopathic hyperuricosuria (n = 3; 4.2%), cystinuria (n = 3; 4.2%), urate transporter defect (n = 2; 2.8%) and mixed stones (predominant component calcium oxalate) (n = 9; 12.5%). No etiology was detected in 4 cases (5.5%). Common presenting complaints included flank pain (n = 41; 56.7%), hematuria (n = 29; 40.3%), urinary tract infection (UTI) (n = 29; 40.3%) and vomiting (n = 11; 15.3%). The median age of presentation was 60 (36, 96) mo. Family history and consanguinity were present in 30 cases (41.7%) and 28 cases (38.9%) respectively. Stone analysis was done in 20 cases, of which 9 cases were mixed stones (predominant calcium oxalate) and 6 were calcium oxalate stones.

CONCLUSIONS

Among children with urolithiasis, hyperoxaluria, idiopathic hypercalciuria, idiopathic hyperuricosuria, and cystinuria were the predominant identifiable entities, together accounting for 72% of cases; and renal colic, hematuria and UTI were the commonest clinical complaints.

Extracorporeal Shock Wave Lithotripsy and Combined Therapy in Children: Efficacy and Long-Term Results

Background: Extracorporeal shock wave lithotripsy (ESWL) is nowadays the first choice for the treatment of upper urinary tract stones smaller than 2 cm, considering its low complications and high success rate. Aim: To present an update of the current situation of ESWL treatment and to analyse our series of patients and the efficacy of combined lithiasis treatment in different locations and sizes. Patients and Method: Retrospective study including patients with urolithiasis treated with ESWL between 2007 and 2019. Collected data included: gender and age at treatment, presentation symptoms, imaging studies, stone location and size, complications and stone clearance. Success was defined as stone-free status or the presence of clinically insignificant residual fragments (<4 mm after 3 months follow-up). Patients with residual stones larger than 4 mm after 3 months were programmed for another ESWL session or received a combined sandwich therapy, followed by URS or percutaneous approach. Results: Between 2007 and 2019, 37 patients presented a total of 41 lithiasis episodes that were treated with ESWL sessions. Median age at first procedure was 9 years old (1-17) and median follow-up time was 6 years (3-12). Stones were located in the renal pelvis, followed by the lower, middle and upper calyx, proximal ureter, and 51% of our patients had multiple lithiasis. Median stone size was 12 mm (5-45), the main component being calcium oxalate (34%). During immediate postoperative period, 8 patients (19%) presented complications: renal colic, hematuria and urinary tract infection. After the first ESWL, 41% of the patients (n = 17) were stone-free. Out of the 24 residual lithiasis episodes (58%), three patients (7%) underwent a second ESWL session. In the remaining 19 patients, ESWL was combined with URS or percutaneous approach to achieve complete stone clearance. Overall stone free status after combined therapy was 95% (n = 39). Conclusion: These data support that ESWL is an effective minimally invasive technique, with low cost and morbidity, reproducible and safe for the treatment of stone disease in children. Even though lithiasis size seems to be a significant factor in ESWL success, in combination with other lithotripsy procedures it can reach very high rates of stone clearance.

Evaluation of Preoperative Tamsulosin Role in Facilitating Ureteral Orifice Navigation for School-Age Pediatric Ureteroscopy

Purpose

To address whether preoperative tamsulosin increases the rate of successful ureteral orifice navigation for ureteroscopy (URS) without prestenting in school-age pediatric patients.

Methods

We retrospectively reviewed all pediatric patients who had undergone ureteroscopy (URS) at our institution from 2013 to 2020. Patients were divided into two groups: those who had received tamsulosin 0.4 mg daily ≥48 hours preoperatively and those who had not. Statistical analysis was done using independent-sample t-tests and Mann–Whitney U tests for continuous variables, and χ² and Fisher’s exact tests were used for categorical variables. Multivariate analysis was done using binary logistic regression test.

Results

Overall, successful ureteral orifice navigation occurred in 44 of 50 patients (88%) who had received tamsulosin and 17 of 26 (65.4%) who had not (p=0.019). On further subanalysis based on stone location and instrumentation used, successful ureteral orifice navigation had occurred in 21 of 24 patients (87.5%) in the tamsulosin group and one of five (20%) in the no-tamsulosin group for semirigid ureteroscopy for mid–distal ureterolithiasis (p=0.007). For proximal ureteral and renal stones, successful ureteral orifice navigation with a flexible ureteroscope or ureteral access sheath had occurred in 23 of 26 patients (88.5%) in the tamsulosin group and 16 of 21 (76.2%) in the no-tamsulosin group (p=0.437). Multivariate analysis showed no significant difference between success rates in the two groups after controlling for patient weight, height, BMI, and stone location. We did not observe any adverse effects from tamsulosin.

Conclusion

This is the first study to evaluate preoperative tamsulosin on successful ureteral orifice navigation in school-age pediatric patients. Although not reaching statistical significance, further evaluation should be done on larger cohorts. Patient height was found to be an independent predictor of successful ureteral orifice navigation.

Idiopathic Osteoporosis and Nephrolithiasis: Two Sides of the Same Coin?

Idiopathic osteoporosis and nephrolithiasis are formidable health problems showing a progressive increase in their incidence and prevalence in the last decades. These temporal trends were observed in both pediatric and adult populations worldwide. Epidemiological and experimental studies indicate that both disorders show several common pathogenic environmental and genetic factors. In this review, we analyzed the clinical characteristics common to the two disorders and the state-of-the-art knowledge regarding the genetic predisposition and the environmental factors recognized as triggers in adult and pediatric ages. As a result of this work, we propose to consider idiopathic nephrolithiasis and osteoporosis as two possible expressions of a unique clinical syndrome. Accordingly, the clinical approach to both disorders should be modified in order to program an efficient primary and secondary prevention strategy.

Prevention of recurrent urinary stone disease

PURPOSE OF REVIEW

Urinary stone disease (USD) is increasing in prevalence and recurrence is common. In pediatrics, most stones are composed primarily of calcium with the highest incidence observed in adolescents. Given the morbidity associated with USD, an in depth review of current management strategies is of paramount importance to highlight the data supporting the recommended treatments and the knowledge gaps which still exist.

RECENT FINDINGS

Several interventions for the management of recurrent calcium USD in children have been recommended based on primarily adult studies. These interventions include modification of diet and fluid intake in addition to the utilization of medications such as thiazide diuretics and citrates when supportive care is inadequate. Overall there is conflicting data in the adult literature which is further complicated by our attempts to extrapolate these data to children.

SUMMARY

Based on the currently available literature the management of USD in pediatrics should be individualized to each patient and focused on the particular metabolic risk factors that are identified during the course of their evaluation. Several interventions may be required or trialed in a particular patient to show an effect. Well designed trials to assess the efficacy of each intervention in the pediatric population are needed.

Educational review: role of the pediatric nephrologists in the work-up and management of kidney stones

BACKGROUND

The incidence of nephrolithiasis in children and adolescents is increasing and appears to double every 10 years. The most important role of the pediatric nephrologist is to diagnose and modify various metabolic and non-metabolic risk factors, as well as prevent long-term complications especially in the case of recurrent nephrolithiasis.

OBJECTIVE

The purpose of this review is to summarize the existing literature on the etiology and management of pediatric nephrolithiasis.

RESULTS

The incidence of kidney stones is increasing; dietary and environmental factors are probably the main causes for this increased incidence. In most pediatric patients, the etiology for the kidney stones can be identified. Metabolic factors, such as hypercalciuria and hypocitraturia, urinary tract infection, and urinary stasis, constitute leading causes. Herein, we review the etiologies, diagnostic work-up, and treatment options for the most prevalent causes of kidney stones. The detrimental effects of excessive dietary sodium, reduced fluid intake, and the benefits of plant-based over animal-based protein consumption on urinary crystal formation are discussed. We also review the long-term complications.

CONCLUSIONS

Pediatric nephrologists have an important role in the diagnostic work-up and prevention of recurring nephrolithiasis.

Formation of a calcium oxalate urethral stone in a 3-year-old boy due to hypocitraturia

INTRODUCTION

Urolithiasis in children is often due to metabolic abnormalities (e.g. hypocitraturia) and hence recurs frequently.

CASE PRESENTATION

A 3-year-old boy presented with gross hematuria. Computed tomography detected a urethral calculus. The calculus was removed surgically. The stone was composed of calcium oxalate. Although oxalate and uric acid levels in the urine were within normal ranges, urine calcium was moderately elevated and urine citrate was substantially low. Urinalyses of the parents revealed that the father had acidic hypocitraturic urine, containing oxalate crystals, and the mother had hypercalciuria. Administration of oral citrate acid normalized urine citrate levels and eliminated the oxalate crystals, from the boy and his father.

CONCLUSION

Although preventing urolithiasis using oral citrate is common in the adult population, this preventive measure is not well recognized in children, thus warranting further study.

Post-renal transplant urolithiasis in children: an increasingly diagnosed complication: a retrospective cohort study

OBJECTIVE

Urolithiasis in renal transplant (RTx) recipients is a potential cause of allograft loss if obstruction is untreated. It is not clear if paediatric transplant recipients are following the global trend for increased prevalence of urolithiasis over time.

DESIGN/SETTING/PATIENTS

A retrospective chart review was undertaken to evaluate the frequency, risk factors and characteristics of post-RTx urolithiasis over two decades (1995-2016), in a tertiary Australian paediatric hospital.

RESULTS

Stones were diagnosed in 8 of 142 (5.6%) recipients, 6 of whom were transplanted in the latter decade. All patients were male, with a median age 4.9 years and median weight 11.8 kg. Presentation was with haematuria (n=4), pain (n=2), dysuria (n=2), stone passage (n=1) and asymptomatic (n=1). Time to presentation was bimodal; three stones were identified in the initial 3 months post RTx and the remainder after 31-53 months. Two stones were in association with retained suture material and two patients had recurrent urinary tract infections. The average stone size was 8.4 mm. Five stones were analysed; all contained calcium oxalate, three were mixed, including one with uric acid. Five (83.3%) children had hypercalciuria but none had hypercalcaemia. Cystolithotripsy was the the most common treatment (n=5), in combination with citrate supplementation. No graft was lost due to stones.

CONCLUSIONS

Calculi occur with increasing frequency after renal transplantation. Clinicians need a high index of suspicion as symptoms may be atypical in this population. The cause for the increased frequency of stones in transplant recipients is not clear but is in keeping with the increase seen in the general paediatric population.

Drug-Induced Urolithiasis in Pediatric Patients

Drug-induced nephrolithiasis is a rare condition in children. The involved drugs may be divided into two different categories according to the mechanism involved in calculi formation. The first one includes poorly soluble drugs that favor the crystallization and calculi formation. The second category includes drugs that enhance calculi formation through their metabolic effects. The diagnosis of these specific calculi depends on a detailed medical history, associated comorbidities and the patient's history of drug consumption. There are several risk factors associated with drug-induced stones, such as high dose of consumed drugs and long duration of treatment. Moreover, there are some specific risk factors, including urinary pH and the amount of fluid consumed by children. There are limited data regarding pediatric lithogenic drugs, and hence, our aim was to perform a comprehensive review of the literature to summarize these drugs and identify the possible mechanisms involved in calculi formation and discuss the management and preventive measures for these calculi.

Cystine Urolithiasis in Early Childhood

Urolithiasis in children is rare with reported incidence of 1.8 per 1000 children. A metabolic cause is identifiable in 40-50% of children with stones and is considered when multiple, recurrent and bilateral. Cystinuria is an important preventable cause of urolithiasis. We present an infant with recurrent gross hematuria due to cystine urolithiasis for its rarity.

Acoustic shadowing in pediatric kidney stone ultrasound: a retrospective study with non-enhanced computed tomography as reference standard

BACKGROUND

The usefulness of acoustic shadowing as a feature of pediatric kidney stone ultrasound (US) may be underestimated.

OBJECTIVE

The hypothesis was that the majority of stones in children have acoustic shadowing and that its specificity is high (>90%) in pediatric kidney stones.

MATERIALS AND METHODS

Our retrospective observational study included children who had undergone abdominal non-enhanced computed tomography (CT) for kidney stones in a pediatric renal stone referral centre between 2015 and 2016. US examinations prior to CT were retrospectively assessed for US features such as acoustic shadowing, twinkle artifact and stone size. These features were compared to CT as reference standard.

RESULTS

Thirty-one patients (median age: 13 years, range: 1-17 years) with 77 suspected kidney stones were included. The median stone size was 5 mm (interquartile range [IQR]: 5 mm). For acoustic shadowing, sensitivity was 70% (95% confidence interval [CI] 56-80%) and specificity was 100% (95% CI 56-100%). All kidney stones with a diameter ≥9 mm demonstrated shadowing. Sensitivity for twinkle artifact was 88% (95% CI 72-96%), but specificity for twinkle artifact could not be calculated due to the lack of true negatives. All false-positive stones on US demonstrated twinkle artifact, but none showed shadowing.

CONCLUSION

Acoustic shadowing was demonstrated in the majority of pediatric kidney stones. Specificity was high, but this was not significant. Twinkle artifact is a sensitive US tool for detecting (pediatric) kidney calculi, but with a risk of false-positive findings.

Nephrocalcinosis and Nephrolithiasis in X-Linked Hypophosphatemic Rickets: Diagnostic Imaging and Risk Factors

Context

Nephrocalcinosis (NC) and nephrolithiasis (NL) are described in hypophosphatemic rickets, but data regarding their prevalence rates and the presence of metabolic risk factors in X-linked hypophosphatemic rickets (XLH) are scarce.

Objective

To determine the prevalence rates of NC and NL and their risk factors in patients with XLH with confirmed PHEX mutations.

Methods

Renal ultrasonography (US) and CT were performed in 16 children and 23 adults. The images were evaluated by two blinded radiologists specializing in US and two specializing in CT. Confirmation of NC was determined with a positive result on both US and CT, whereas the diagnosis of NL was confirmed by CT alone. The presence of hypercalciuria, hypocitraturia, and hyperoxaluria was determined from 24-hour urinary samples from each patient. The glomerular filtration rate was estimated.

Results

NC was identified in 15 patients (38.4%), and stratification by age group showed a higher prevalence of NC in children than in adults (56.2% vs 26.1%). CT identified NL in four adults (10.2%). Patients in the pediatric group required intensive use of phosphate, started treatment earlier, and presented greater phosphaturia than those in the adult group (P < 0.01). In addition to hyperphosphaturia, which was present in all patients with XLH, hypocitraturia was the most common metabolic factor (28.2%), whereas hypercalciuria occurred in two patients (5.1%). None had hyperoxaluria. Most patients had normal renal function.

Conclusions

NC was more prevalent than NL. The main metabolic factor was hyperphosphaturia, and intensive phosphate treatment appears to be a worsening factor for kidney calcification.

Update on Dent Disease

Dent disease is an X-linked form of chronic kidney disease characterized by hypercalciuria, low molecular weight proteinuria, nephrocalcinosis, and proximal tubular dysfunction. Clinical presentation is highly variable. Male patients may present with early-onset rickets, recurrent nephrolithiasis, or insidiously with asymptomatic proteinuria or chronic kidney disease. Mutations in both the CLCN5 and OCRL1 genes have been associated with the Dent phenotype and are now classified as Dent-1 and Dent-2, respectively. This article describes the clinical presentation, laboratory evaluation, genetics, pathophysiology, management, and future therapies of Dent disease.

Confounding risk factors and preventative measures driving nephrolithiasis global makeup

Nephrolithiasis is increasing in developed and developing countries at an alarming rate. With the global spike in kidney stone diseases, it is crucial to determine what risk factors are influencing the current global landscape for kidney stones. Our aims for this review are: to identity and analyze the four categories of risk factors in contributing to the global scale of stone formation: lifestyle, genetics, diet, and environment; and discuss preventative measures for kidney stone formation. We also performed data search through the published scientific literature, i.e., PubMed^® and found that there is a significant link between lifestyle and obesity with cases of calcium stones. Food and Agriculture Organization of the United Nations and World Health Organization factor indicators for dietary intake and obesity, along with climate data were used to create the projected total risk world map model for nephrolithiasis risk. Complete global analyses of nephrolithiasis deplete of generalizations is nearly insurmountable due to limited sources of medical and demographic information, but we hope this review can provide further elucidation into confounding risk factors and preventative measures for global nephrolithiasis analysis.

CLINICAL-EPIDEMIOLOGICAL PROFILE OF 106 PEDIATRIC PACIENTS WITH UROLITHIASIS IN RIO DE JANEIRO, BRAZIL

Objective:

To describe the frequency, clinical profile and treatment of patients with urolithiasis in the Pediatric Nephrology Department of a public state hospital in Rio de Janeiro, Brazil.

Methods:

Retrospective study. Data from pediatric patients (age: 1 month - 18 years) with urolithiasis admitted between January/2012 and December/2014 were reviewed from hospital charts. The studied variables were: demographic and anthropometric data, clinical status, family history of urolithiasis, urinary tract infection and use of lithogenic drugs, diagnostic procedures, associated abnormalities, metabolic disorders, treatment and recurrence.

Results:

The frequency of urolithiasis was 13.6%. Main characteristics of the patients: male gender, white race, eutrophy, aged between 5 and 10 years, family history of urolithiasis, previous urinary infection and spontaneous stone passage. Abdominal and flank pain and macroscopic hematuria were the most common complaints. The most frequent metabolic disorders were hypercalciuria, hyperuricosuria and hypocitraturia. Hypocitraturia was associated with previous urinary infection (p=0.004). Abdomen/urinary tract ultrasonography was the most commonly used diagnostic test. Hydronephrosis occurred in 54.4% of the cases, 81.1% of the stones were in the kidneys, and bilateral stones were associated to a family history of urolithiasis (p=0.030). Recurrence rate was 29.3% (most patients had a metabolic disorder). In 12.3%, the patients underwent lithotripsy, 24.5% were surgically treated (mainly pyelolithotomy), and only 7.6% had their stones analyzed (calcium oxalate was the main finding in the examined stones).

Conclusions:

The frequency of urolithiasis in these pediatric patients was similar to that reported by the literature. A metabolic evaluation is required and the composition of stones should be better evaluated.

Pediatric Stone Disease

Once considered rare, pediatric nephrolithiasis has become a critical field of study in the last decade due to the rapid increase in incidence. Understanding the changing epidemiology and lifelong implications of pediatric stone disease is critically important to effectively manage the individual patient as well as identify risk factors for childhood onset that could be modified. Determining the role of diagnostic imaging in children is a unique challenge as limiting radiation and imaging stewardship should be priorities. Approaches to management have also changed, as technology continues to evolve and both medical and surgical options expand.

Treatment of upper urinary tract stones with flexible ureteroscopy in children

INTRODUCTION

This single-centre, retrospective study aimed to assess the efficacy and safety of flexible ureteroscopy (FURS) combined with holmium laser lithotripsy in treating children with upper urinary tract stones.

METHODS

From June 2014 to October 2015, a total of 100 children (74 boys and 26 girls) with upper urinary tract stones were treated using FURS. A 4.7 Fr double-J stent was placed two weeks before operation. Patients were considered stone-free when the absence of residual fragments was observed on imaging studies. The preoperative, operative, and postoperative data of the patients were retrospectively analyzed.

RESULTS

A total of 100 pediatric patients with a mean age of 3.51±1.82 years underwent 131 FURS and holmium laser lithotripsy. Mean stone diameter was 1.49±0.92 cm. Average operation time was 30.8 minutes (range 15-60). The laser power was controlled between 18 and 32 W, and the energy maintained between 0.6 and 0.8 J at any time; laser frequency was controlled between 30 and 40 Hz. Complications were observed in 69 (69.0 %) patients and classified according to the Clavien system. Postoperative hematuria (Clavien I) occurred in 64 (64.0 %) patients. Postoperative urinary tract infection with fever (Clavien II) was observed in 8/113 (7.1%) patients. No ureteral perforation and mucosa avulsion occurred. The overall stone-free rate of single operation was 89/100 (89%). Stone diameter and staghorn calculi were significantly associated with stone-free rate.

CONCLUSIONS

FURS and holmium laser lithotripsy is effective and safe in treating children with upper urinary tract stones.

Management of Hematuria in Children

Purpose of Review

This paper provides a review of the diagnostic evaluation of both microscopic and gross hematuria, as well as an update on the pathogenesis, clinical features, and treatment strategies for several diseases of the kidneys and urinary tract in which hematuria is a prominent finding. The goal is to provide pediatric providers with a framework through which appropriate and expeditious referral to subspecialty care may be made for definitive treatment.

Recent Findings

Although there has been great heterogeneity in published treatment strategies for many causes of hematuria, the Kidney Diseases Improving Global Outcomes (KDIGO) initiative has recently set forth guidelines for glomerular diseases in particular to provide evidence-based strategies for treatment. In addition, recent advances in the understanding of molecular pathogenesis and long-term clinical outcomes for other non-glomerular diseases has led to updates in treatment strategies summarized in this review.

Summary

As the pediatric primary care provider is often the first point of contact for children with microscopic or gross hematuria, updated knowledge as to the epidemiology and management of several of the various causes of hematuria will improve the care of children by both avoiding extraneous testing and interventions and implementing definitive care (either by expectant management and reassurance or by subspecialty referral) in a timely manner.

Urolithiasis in the pediatric population - current opinion on epidemiology, patophysiology, diagnostic evaluation and treatment

Urolithiasis, a condition in which calculi are found in the urinary tract, has been known for centuries. Although the disease was considered casuistic in the pediatric population, its prevalence is rising among both children and infants. The occurrence of the disease is greater in developed countries, therefore urolithiasis should be considered a lifestyle disease. Its etiopathogenesis has not yet been well understood. Kidney stone formation is influenced by factors such as climate, eating habits, profession, fluid intake, genetic predisposition, urinary tract infections and malformations of the urinary tract. Calculi are usually composed of mixed mineral substances. Only about 30% are made up of one chemical substance, calcium oxalate being the most common. Urolithiasis can be asymptomatic and accidentally diagnosed. Abdominal pain is the most common clinical symptom, however disease presentation among infants is nonspecific. Hematuria is a common clinical finding. Ultrasonography is the most important diagnostic tool in the diagnosis of kidney stone disease. Metabolic evaluation is required in every case of urolithiasis in the pediatric population, as metabolic disorders can be found in the majority of cases in this age group. The spontaneous passage of calculi less than 6mm in diameter is likely. Invasive treatment should be carried out if stones exceed 6mm in diameter or fail to expulse spontaneously. Prophylactic treatment includes adequate fluid intake, healthy eating habits and physical activity to maintain a healthy weight. Urolithiasis is a recurrent disease, therefore long-term treatment, prophylaxis and a lasting change in dietary habits are essential.

Experience of a Tertiary-Level Urology Center in the Clinical Urological Events of Rare and Very Rare Incidence. VI. Unusual Events in Urolithiasis: 1. Long-Standing Urethral Stones without Underlying Anatomical Abnormalities in Male Children

OBJECTIVES

The study aimed to present our center's experience with long-standing urethral stones in male children with normal urethra.

MATERIALS AND METHODS

Retrospective search of our center data was done for the cases of long-standing urethral stones with normal urethra in male children during the period July 2001 - June 2016. Demographic and clinical data were studied.

RESULTS

Of more than 54,000 urolithiasis procedures, 17 male children (0.031%) were operated for long-standing urethral stones with normal urethra. In 14 cases (82.4%), residence was rural and parental education levels were low or none. All children were regularly prompted voiding with a history of difficulty or dysuria. All the stones lodged in the posterior urethra with an approximate mean duration of 2 months. The mean stone size of 11.29 ± 3.88 mm and rough surfaces in 88.2% of cases represented the main predisposing factors. Major complications included rectal prolapse in 1 case and vesicoureteral reflux in 3 cases. Endoscopic push-back was followed by disintegration in 76.5% or cystolithotomy in 17.7%, while it failed in 1 case that was treated by cystolithotomy.

CONCLUSIONS

Long-standing urethral stones in male children with normal urethra are very rare misdiagnoses. Stone topography and sociocultural factors predisposed to their lodgments and negligence. Endoscopic treatment is the best approach.

MOnitored supplementation of VItamin D in preterm infants (MOSVID trial): study protocol for a randomised controlled trial

Background

The pivotal role of vitamin D (vit D) in skeletal health is well known. Neonatal vit D storage at birth is dependent on maternal levels, and newborns receive 50–70% of their mother’s 25-hydroxyvitamin D [25(OH)D]. Deficiency of vit D can lead to prematurity bone disease, with an incidence of up to 55% in infants weighing < 1000 g. The aim of this study is to assess the effectiveness of monitored supplementation of vit D in a population of preterm infants.

Methods/design

Preterm infants born at 24–32 weeks of gestation will be recruited within the first 7 days of life. Depending on the type of feeding, and after reaching partial enteral feeding or at 7 days of life, vit D supplementation will consist of 500 IU and an additional 150–300 IU/kg included in human milk fortifiers (if fed exclusively with breast milk) or 190 IU/kg in milk formulas. Subjects will be randomised to either monitored (with an option of dose modification based on 25(OH)D levels as per protocol) or standard therapy up to 52 weeks of post-conceptional age (PCA). The primary outcome measure will be the number of neonates with deficiency or excess levels of 25(OH)D at 40  ±2 weeks of PCA. Additional 25(OH)D levels will be measured at birth, at 4 and 8 weeks of age, and/or at 35 and 52  ±2 weeks of PCA. Secondary objectives will include the incidence of osteopenia, nephrocalcinosis and nephrolithiasis. Serum parameters of calcium phosphorus metabolism will also be measured.

Discussion

Despite multiple years of research and numerous publications, there is still a lack of consensus in regard to how much vit D infants should receive and how long they should receive it. Because 80% of calcium and phosphorus placental transfer occurs between 24 and 40 weeks of gestation, preterm infants are especially prone to adverse effects of vit D insufficiency. However, both inadequate and excessive amounts of vit D may be unsafe and lead to serious health issues. The results of our study may shed new light on these concerns and contribute to optimising vit D supplementation.

Trial registration

ClinicalTrials.gov, NCT03087149. Registered on 15 March 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2141-y) contains supplementary material, which is available to authorized users.

Silodosin in the treatment of distal ureteric stones in children: A prospective, randomised, placebo-controlled study

Objectives

To evaluate the possible role of silodosin (a highly selective α_1A-adrenoceptor antagonist) in facilitating the passage of distal ureteric stones (DUS) in children, as the role of α-blockers as medical expulsive therapy is well known in adults.

Patients and methods

In all, 40 paediatric patients (27 boys and 13 girls) diagnosed with unilateral, single, radiopaque DUS of <10 mm were included in the study. Their mean (SD, range) age was 8.1 (2.7, 5–17) years. The patients were randomly divided into two groups: Group A, received silodosin 4 mg as a single bedtime dose; and Group B, received placebo as a single bedtime dose. Ibuprofen was prescribed to both groups on-demand for pain episode relief. Patients were followed up biweekly for 4 weeks. The stone expulsion time and rate, pain episodes, analgesic use, and any adverse effects were recorded.

Results

The mean (SD) stone size in Group A was 6.6 (1.7) mm and in Group B was 6.7 (1.4) mm (P = 0.4). Two patients were lost to follow-up (one from each group), and one patient in Group A refused to complete the study. The stone-free rate at end of the 4-week treatment period was 88.8% in Group A vs 73.6% in Group B (P = 0.4). The mean (SD) stone expulsion time was 7.0 (4.3) vs 10.4 (4.7) days in groups A and B, respectively (P = 0.02). The mean (SD) number of pain episodes requiring ibuprofen was 2.3 (1.4) vs 4.7 (2.6) episodes in groups A and B, respectively (P < 0.001). Adverse effects (headache and dizziness) were recorded in three patients (16.7%) in Group A, which were mild and none of them discontinued treatment, whilst no adverse effects were recorded in Group B.

Conclusions

The data in the present study show that silodosin can be safely used in the treatment of DUS in children for decreasing time to stone expulsion, pain episodes, and analgesic requirement.

Laparoscopic ureterocalicostomy for ureteropelvic junction obstruction in a 10-year-old female patient: a case report

BACKGROUND

Ureterocalicostomy is indicated mainly in cases with failed pyeloplasty or with a completely intrarenal pelvis. While there have been several case series reported in adults, laparoscopic ureterocalicostomy in pediatric cases has rarely been reported. We report a case of pure laparoscopic ureterocalicostomy for ureteropelvic junction obstruction in an Asian female child.

CASE PRESENTATION

A 10-year-old female patient was referred to our hospital due to right high-grade hydronephrosis and a right renal stone, which was detected due to hematuria. Laparoscopic pyelolithotomy and ureterocalicostomy were indicated because of the completely intrarenal pelvis with thinning of the cortex, especially at the lower calyx. A transperitoneal approach was implemented in a lateral flank position with four trocars. After exposing the renal hilum, the renal stone was extracted without lithotripsy by making a small longitudinal incision at the ureteropelvic junction. Then, the ureter was transected, and the renal pelvis was closed. A 2-cm incision was made at the lower calyx. Uretero-caliceal anastomosis was completed in a running fashion using 5-0 absorbable sutures. The operation time was 379 min. The postoperative course was uneventful. Postoperative imaging studies showed marked improvement of the right hydronephrosis.

CONCLUSION

Laparoscopic ureterocalicostomy is a safe and feasible treatment for selected patients with complicated ureteropelvic junction obstruction, even in the pediatric population.

What do we know about pediatric renal microlithiasis?

Renal or calyceal microlithiasis is a common disorder with increasing prevalence especially in infants and younger children. The main presenting symptoms and the underlying metabolic abnormalities of renal microlithiasis are similar to renal stone. Although renal microlithiasis is considered as a main problem of the health system with diverse etiologies, our information about its natural course is very limited. Hence, further investigations to make an appropriate clinical approach to this entity is mandatory. Also, general practitioners, pediatricians, nephrologists and urologists have to be well educated regarding renal microlithiasis for early diagnosis, appropriate evaluation and proper management of this entity. In this review study, we focused on collection of the present information about different aspects of renal microlithiasis in children.

Herbal remedies for urinary stones used in India and China: A review

ETHANOPHARMACOLOGICAL RELEVANCE

The process of formation or appearance of a urinary stone anywhere in the renal tract is known as urolithiasis. It is a longstanding health problem, known to exist since early age of civilization. Records about symptoms, signs and treatment strategies of urinary stones diseases are found in the several ancient texts of traditional medicines such as Ayurveda, Traditional Chinese Medicine (TCM), Siddha and Unani. In Ayurveda, urolithiasis has been considered as one of the eight most troublesome diseases. Ayurvedic management and cure of urinary stone involves herbal formulas, alkaline liquids and surgical procedures. Whereas, TCM recommends polyherbal drugs, acupuncture and mexibustion for treatment of the urinary stones. Among these therapies, herbal remedies are in practice till today for the treatment and cure urinary stone diseases.

MATERIALS AND METHODS

A comprehensive review of the scientific literature about pathophysiology of urinary stones and antiurolithiatic plants was undertaken using the following bibliographic databases: MEDLINE/PubMed, Scopus, Web of Knowledge and Google Scholar. The search was conducted from publications from all years until Dec., 2015 by combination of the search terms and Boolean operators; 'urinary stone' OR 'kidney stone' AND 'plant' OR 'medicine' OR 'antiurolithiatic plants'. Outputs were restricted to those completed studies only published in English. In this review, literatures about plants which are used as diuretic and/or in treatment urinary tract infections have not also been considered. The Plant List and Royal Botanical Garden, Kew databases were used to authenticate botanical names of plants. Books and monographs published in English were used to collect information about historical records of antiurolithiatic plants.

RESULTS

Recent pharmacological interventions accredited ancient antiurolithiatic claims to several plants and their formulations. The majority of antiurolithiatic plants were found to either dissolve the stones or inhibit the process of urinary stone formation. Plants such as Phyllanthus niruri L. and Elymus repens (L.) Gould, as well as herbal products including 'Wu-Ling-San' formula, 'Cystone' and 'Herbmed' have been proved their utility as promising antiurolithiatic medicines in the different phases of clinical trials. In addition, some of the isolated phytochemicals such as berberine, lupeol, khelin, visnagin, 7-hydroxy-2',4',5'-trimethoxyisoflavone and 7-hydroxy-4'-methoxyisoflavone were reported to have potent antiurolithiatic activity.

CONCLUSION

In ancient medicinal texts, antiurolithiatic potential has been ascribed to several plants and their formulations. Present scientific studies provide scientific evidences for few of these claims however, they are insufficient to establish many of these plants and herbal formulations as therapeutic remedies for the treatment and management of urinary stones. Conversely, findings of pre-clinical and clinical studies about some plants and herbal formulations are promising, which underlines the utility of herbal remedies as alternative medicines for the treatment and management of urinary stones in the future.

Pediatric urolithiasis associated with acute gastroenteritis: an inpatient database study in Japan

Pediatric urolithiasis associated with acute gastroenteritis (AGE) has not been systematically investigated, including its prevalence, risk estimate, and outcome. Using a national inpatient database in Japan, we searched for children (≤59 months old) who were hospitalized for AGE and those complicated by urolithiasis over a 24-month period. We found 23 cases of urolithiasis among 62,800 children who were hospitalized for AGE (3.7 cases/10,000 AGE admissions). AGE was associated with an increased risk of urolithiasis (odds ratio 2.01; p = 0.015). The patients' mean age was 24 months and there was male dominance. Four patients had chronic medical conditions, including two with renal conditions. None of the patients had congenital metabolic disorders. Nine patients had causative agents for AGE, including rotavirus (n = 5), norovirus (n = 2), and bacteria (n = 2). Two patients required placement of a nephrostomy tube and the remaining 21 patients were discharged without invasive procedures.

CONCLUSION

Childhood AGE is associated with a twofold risk of urolithiasis in a hospitalized cohort, but the absolute risk is low. Our study shows that AGE-related urolithiasis occurs through a variety of pathogens, and the outcomes of patients are favorable, which is in contrast to previous reports. What is Known: • There are several sporadic reports of pediatric urolithiasis associated with acute gastroenteritis (AGE), predominantly from Japan. • The epidemiology of AGE-related urolithiasis is however unclear. What is New: • AGE is associated with a two-fold risk of urolithiasis in a hospitalized cohort, with its absolute risk of 3.7 cases/10,000 AGE admissions.

Why we need a higher suspicion index of urolithiasis in children

BACKGROUND

Most children with symptoms of urolithiasis and urinary solute excretion abnormalities leading to stone formation have no calculi revealed by ultrasound or X-ray plain film ("occult urolithiasis"). This covers a large group of children presenting with common symptoms such as abdominal pain, hematuria, and dysuria, often faced by general practitioners and pediatricians. However, half or more of children with urolithiasis could present with abdominal/flank pain without specific urinary symptoms.

STUDY DESIGN

We review the current evidence about prevalence, clinical presentation, and radiological detection of overt and "occult" urolithiasis in children, aiming to give readers the instruments to suspect and diagnose urolithiasis while avoiding cost-ineffective and undue diagnostic procedures.

CONCLUSIONS

It is important to investigate for urolithiasis first by ultrasound and, in specific cases, by urinary metabolic and different imaging studies in the following groups: 1) in children with non-glomerular hematuria or/and dysuria not presenting inflammation of external genitalia; 2) in children with acute/sub-acute or infrequent recurrent abdominal pain and family history of urolithiasis in first or second degree relatives or being at higher risk of developing stones although hematuria and dysuria are lacking; 3) in children under 8 years old, even though pain is central or diffuse to the whole abdomen; and 4) in children presenting risk factors or conditions predisposing to urolithiasis. Finally, it seems reasonable to repeat ultrasound 1-2 years later also in children with "occult" urolithiasis and high risk of developing stones to detect any (re-)appearance of calculi.