Urolithiasis In Children Research Articles

Is oxidative stress related to childhood urolithiasis?

Urolithiasis is a common condition in pediatric populations in Turkey. The role of oxidative stress in renal stone formation in pediatric patients has not been reported to date. The aim of this study was to assess oxidative stress in childhood urolithiasis. Seventy-four children diagnosed with urolithiasis and 72 healthy control subjects were enrolled in the study. Kidney stone formers were evaluated by analysis of metabolic conditions related to urolithiasis, such as hypercalciuria, hyperoxaluria, hypocitraturia and hyperuricosuria. Urine total antioxidant status (TAS), and total oxidant status (TOS) were measured, and oxidative stress index (OSI) was calculated as an indicator of the degree of oxidative stress. Among the stone formers, metabolic analyses revealed that 30 % had hypercalciuria, 45 % had hypocitraturia, 6 % had hyperoxaluria and 40 % had hyperuricosuria. Elevated levels of the renal tubular damage marker urinary N-acetyl- beta-D-glucosaminidase (NAG) was elevated in 25 % of the patient group, but microalbuminuria was not detected. Total oxidant status and total antioxidant status were significantly higher in stone formers than in the controls (p = 0.023 and 0.004, respectively). In addition, urinary NAG was significantly correlated with TOS (r = 0.427, p = 0.019). The results of this study show that oxidative stress may play an important role in the pathogenesis of pediatric stone formers.

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.

Uric acid excretion in rotavirus gastro-enteritis

Background: Urate urolithiasis in children has been reported in Japan in association with rotavirus (RV) gastro-enteritis (GE).Aims: To test the hypothesis that children with RV GE have an increased risk of hyperuricosuria compared with GE presumably caused by other viruses.Objectives: Prospective analytic cohort study of urinary uric acid excretion in children presenting with GE between 1 January 2011 and 31 May 2012.Methods: Two groups were compared: group R (RV GE) and group N (with presumed other viral causes of GE). Serum urea, creatinine (Scr), uric acid (Sur) and urinary uric acid were compared with creatinine (Uur/Ucr) ratio, fractional excretion of uric acid (FEur) and uric acid for creatinine clearance between the two groups.Results: A total of 87 Emirati children were enrolled in the study. Group R included 46 children (mean age 25 months) and group N 41 children (mean age 43 months). There was no significant difference between the two groups in the blood levels of urea, creatinine, uric acid, nor in urinary pH and specific gravity. Urinary uric acid excretion measured by Uur/Ucr ratio, uric acid for creatinine clearance and FEur was not significantly different between the two groups.Conclusion: There was no significant difference in uric acid levels and uric acid excretion between patients with RV GE and those with other presumed viral causes of GE. Further studies with larger sample sizes including children with more severe dehydration and a prolonged course of GE are needed.

Kids with stones—data on causes and treatment safety

Two retrospective studies published recently in The Journal of Urology add to the body of evidence on paediatric upper-tract stone disease. The first study shows that obesity is not a significant risk factor for urolithiasis in children, whereas the second confirms the use of percutaneous nephrolithotomy (PCNL) as a safe and effective treatment modality.

E35 The new surgical treatment method of staghorn urolithiasis in children

E35 The new surgical treatment method of staghorn urolithiasis in children

Urolithiasis in Children with Acute Lymphoblastic Leukemia

Background: Urinary tract lithiasis(UTL) requires careful intervention, especially when associated with other diseases. The purpose of this study was to assess the outcome of symptomatic UTL in children with acute lymphoblastic leukemia (ALL) and to evaluate its correlation with the anti-neoplastic treatment phase and drugs, and to assess the need for intervention, results, complications and follow-up. Procedure: The charts of 350 patients with ALL (1990-2008) were retrospectively evaluated. Signs and symptoms, methods of diagnosis, complications, treatment approach, resolution, anti-leukemic treatment phase when the UTL was diagnosed, drugs used and interference on ALL treatment were recorded. Results: A total of 12/350 patients (3.4%) had UTL (14 stones). The median age was 7.6 years. Pain was present in 60%, hematuria in 20% and both in 20%. The median stone size was 4mm (3- 13.8mm). Three patients required hospitalization (pain) and one had chemotherapy discontinued due to severe hematuria and blood support. At the time of diagnosis of UTL, four patients were in the induction phase with corticosteroids, four were in the maintenance phase with corticosteroids, two were in the maintenance phase without corticosteroids, and one had a recurrence after therapy, and two were off-therapy. 11/13 episodes of UTL had spontaneous resolution, two underwent successful extracorporeal shockwave lithotripsy, and one patient remains with an asymptomatic stone. Conclusions: 3.4% of children with ALL presented symptomatic UTL. While the majority of cases have been resolved spontaneously, hospitalization and delay in chemotherapy have increased morbidity in these children.

526 Prevalence and temporal trends in admissions for urolithiasis in children

526 Prevalence and temporal trends in admissions for urolithiasis in children

Idiopathic urolithiasis in Tunisian children: A report of 134 cases

We evaluated the metabolic and the nutritional aspects of 134 urolithiasis children in order to outline the characteristics of idiopathic urolithiasis in children. This prospective study group of 134 children (56 females, 78 males) with renal calculi was evaluated. The age range of the patients was six months to 16 years. A dietary survey was performed on every child. All patients were investigated with respect to stone localization and serum and urine risk factors. Statistical analysis of data was carried out using software SPSS 11.0 for Windows. Hypercalciuria was the most common risk factor detected in this group (28.3%). A decrease of water intake was noted in all age groups, especially in the rural area (549.6 mL/day vs. 1150.6 mL/day), and there was an increase in animal protein intake in 17 cases (mean: 1.9 g/kg). In addition, increased intake of starchy foods and food with high oxalate content (sorgum) were detected in the ten to 16 years age group (51%) of our study. Calcium oxalate monohydrate represents the principal component of idiopathic stone (58.2%), which is more frequent in children (68%) than in infants (51.7%) (P <0.02). The major etiology of idiopathic urolithiasis highlights the influence of dietary habit in stone formers in our country. The increased occurrence of calcium oxalate stones in school age children confirms the change in the etiology of urolithiasis according to age.

Is Urolithiasis in Children Associated With Obesity or Malnutrition?

Although it is known that obesity predisposes to urolithiasis, a tendency for malnutrition in children with urolithiasis owing to recurrent urinary infections and abdominal pain also makes sense. In this study, we aimed to determine the nutritional status of infants and children with urolithiasis, and to observe whether obesity or malnutrition is more prevalent in that population. One hundred eighty-seven children aged 4 months to 17 years (mean, 4.9 ± 4.4 years) with urolithiasis, and 278 age- and sex-matched children without any chronic diseases were included. Anthropometric evaluations, including weight and height standard deviation score (SDS), body mass index, and triceps and subscapular skinfold thickness (SFT), were performed. Mean weight SDSs of the patients was statistically lower than that of the control subjects (P < .0001). Malnutrition rate was statistically higher in the patients with urolithiasis when evaluated according to weight SDS and percentiles of body mass index and SFT. When the age factor was taken into account, the percentage of malnutrition, determined by the percentiles of triceps and subscapular SFT measurements, was found to be higher in children younger than 2 years. Short stature was more prevalent in older children. Malnutrition among children with urolithiasis is not as rare as thought previously. A careful anthropometric evaluation should be included in the clinical assessment of those children.

Current management of paediatric urolithiasis

We aimed to review a current management of paediatric nephrolithiasis. The current literature, including our own experience on the treatment of paediatric nephrolithiasis was reviewed by MEDLINE/PubMed search. We have used in our search following keywords: urolithiasis, nephrolithiasis, paediatrics, surgical treatment, conservative management, ESWL, ureteroscopy, and open renal surgery. The search was limited to the English language literature during the period of time from 1990 to 2011. All papers were reviewed independently by all co-authors and only the manuscripts directly related to the reviewed subjects were included into the current review. Due to the high incidence of predisposing factors for urolithiasis in children and high stone recurrence rates, every child with urinary stone should be given a complete metabolic evaluation. Most stones in children can be managed by ESWL and endoscopic techniques. Paediatric stone disease is an important clinical problem in paediatric urology practice. Because of its recurrent nature, every effort should be made to discover the underlying metabolic abnormality so that it can be treated appropriately. Obtaining a stone-free state with interventional management and close follow-up are of utmost importance.

Pediatric Urinary Stone Composition in the United States

The incidence of urolithiasis in children is increasing. However, stone composition studies in this population are limited. We sought to determine the effects of age, gender and geographical location on urinary stone composition in the United States pediatric population. We obtained composition analyses for all urinary stones submitted to a reference laboratory between 2000 and 2009. Stones were excluded if the patient was younger than 1 year or older than 18 years. Stone composition was determined by Fourier transform infrared spectroscopy. Logistic regression analysis was performed to determine associations between stone composition frequency and age, gender and geographical region. A total of 5,245 stones were included in our analysis. Calcium was found in 89.2% of stones. The percentage of stones containing calcium oxalate increased, while magnesium ammonium phosphate and ammonium acid urate containing stones decreased with age. Calcium oxalate and magnesium ammonium phosphate containing stones were more common in females, while uric acid stones were more common in males. Additionally, significant differences in stone composition frequency were noted between males and females in specific age groups and between age groups within the same gender. Geographical distribution was not significantly associated with stone composition. This series is the largest analysis to date of urinary stone composition in the pediatric population in the United States. Age and gender were significantly associated with stone composition, while geographical region was not significantly associated with stone composition.

Flexible Ureteroscopy in Children with von Willebrand Disease

Treatment options for urolithiasis include shockwave lithotripsy (SWL), percutaneous nephrostolithotomy (PCNL), and ureteroscopy. While these treatment options are becoming the standard of care in the pediatric population, children with a bleeding dyscrasia must be approached differently. We report our flexible ureteroscopic experience in children with von Willebrand disease (vWd). A review of a prospectively maintained database of stone patients was performed. Children with a bleeding diathesis were identified. Stone burden, operative access, intraoperative complications, postoperative complications, stone-free status, and perioperative medical management were evaluated. During a 7-year period, a total of five children with a bleeding disorder underwent 7 ureteroscopic and 10 cystoscopic procedures for urinary calculi. The mean patient age was 72.4 months (range 49-123 mos) at the time of the procedure. There were three boys and two girls. Mean follow-up was 29.7 months (range 8-79 mos). Mean stone burden was 6.1 mm (range 3-14 mm) with an average of 1.3 stones per patient. Four patients were known to have vWd before surgical intervention and were pretreated with desmopressin acetate. The remaining patient was found to have vWd based on significant bleeding after ureteral stent placement. No ureters were actively dilated. Flexible ureteroscopy was performed in all cases regardless of stone location. Stone clearance was 100% (7/7). Complications occurred in 6% of procedures (1/17). Ureteroscopy is a safe and efficacious modality in the management of urolithiasis in children with a bleeding abnormality. Perioperative medical management of the bleeding diathesis may help reduce complications.

Pediatric urolithiasis: causative factors, diagnosis and medical management

Childhood urolithiasis is associated with considerable morbidity and recurrence. Many risk factors--including those metabolic, genetic, anatomic, dietary and environmental in nature--have been identified in children with urinary tract calculi. As pediatric urolithiasis with a metabolic etiology is the most common disease, evaluating the metabolic risk factors in patients is necessary to both effectively treat current stones and prevent recurrence. We discuss causative risk factors of pediatric urolithiasis, as well as the diagnostic and therapeutic approaches.

Influence of Overweight on 24-Hour Urine Chemistry Studies and Recurrent Urolithiasis in Children

PurposeWe investigated the influence of overweight on 24-hour urine chemistry studies and recurrent urolithiasis (UL) in children.Materials and MethodsA retrospective cohort study was designed to assess children who presented with UL at a pediatric institution between 1985 and 2010. We calculated body mass index percentile (BMIp) adjusted for gender and age according to the 2007 Korean Children and Adolescents Growth Chart and stratified the children into 3 BMI categories: lower body weight (LBW, BMIp≤10), normal BW (NBW, 10<BMIp<85), and upper BW (UBW, BMIp≥85). Twenty-four hour urine chemistry studies (urine volume, creatinine, calcium, oxalate, citrate, and pH) were compared between the 3 BMIp groups. Univariate and multivariate analyses were performed to assess independent risk factors for stone recurrence.ResultsA total of 125 patients were included. The age of the patients in the NBW group was older than that of patients in the LBW group, but 24-hour urine chemistry studies did not differ significantly between the three groups. Mean urine citrate levels were lower (0.273±0.218 mg/mg/d vs. 0.429±0.299 mg/mg/d, p<0.05) and the incidence of hypocitraturia was higher (81.5% vs. 45.7%, p<0.05)) in the recurrent stone former group. In the univariate analysis, hypocitraturia and acidic urinary pH were risk factors, but in the multivariate analysis, only hypocitraturia was a risk factor for stone recurrence (hazard ratio, 3.647; 95% confidence interval, 1.047 to 12.703). In the Kaplan-Meier curve, the hypocitraturia group showed higher recurrence than did the normocitraturia group (p<0.05).ConclusionsUnlike in adults, in children, overweight adjusted for gender and age was not associated with 24-hour urine chemistry studies and was not a risk factor for recurrent UL. Hypocitraturia was the only risk factor for UL in children.

Clinical and Biological Characteristics of Childhood Urolithiasis in Tunisia: A Study of 300 Cases

Clinical and Biological Characteristics of Childhood Urolithiasis in Tunisia: A Study of 300 Cases

Enigma of uric acid stones associated with rotavirus-associated gastroenteritis

Sirs,We are grateful to Dr. Fujieda for suggesting anotherpossibility as the cause for uric acid stones associated withrotavirus-associated gastroenteritis [1].The pathogenesis of urate stone formation in children withhuman rotavirus (HRV)-associated gastroenteritis, which wasmainly reported from Japan, remains unknown. As formationof urolithiasis consisting of urate, which is rarely seen inchildren, is generally associated with increased urinaryexcretion of uric acid, previous reports have proposed severalpossibilities of hyperuricuria being the cause.Possible causes of hyperuricuria in this condition include:1. Hyperuricemia due to massive breakdown of intestinalcells due to HRV [2]2. Severe dehydration caused by HRV infection [2]3. Renal hypouricemia associated with mutation of humanurate transporter 1 (URAT1) gene [3]Fujieda et al. [1] suggest another intriguing hypothesis thatHRVmightinfectnotonlysmallintestinalcells,butalsorenaltubularcells,whichleadstoincreasedurinaryconcentrationofuric acid in conjunction with increased excretion of beta-2-microglobulin and N-acetyl-β-glucosaminidaseHowever, none of the possibilities mentioned above hasclearly answered the following questions:1. Why is this condition reported mainly in Japan?2. Do other viruses causing gastroenteritis, such asnorovirus or adenovirus infect renal tubular cells?3. Is an infection of the renal epithelial cells exclusivelycharacteristic of HRV?4. Why do most of the children with HRV-associatedgastroenteritis not have the complication of urateurolithiasis?Until these questions have been clarified, the pathogenesisof urolithiasis in children with HRV-associated gastroenteritiswill remain enigmatic.References

Clinical and Biological Characteristics of Childhood Urolithiasis in Tunisia: A Study of 300 Cases

Clinical and Biological Characteristics of Childhood Urolithiasis in Tunisia: A Study of 300 Cases

Treatment of pediatric urolithiasis: how small is “small enough”?

“Big” scars for stone removal are only needed in unusual circumstances. This is true given the fact that technology is fast evolving and instruments becoming smaller and smaller. The management of urolithiasis in children has undergone a paradigm shift in the past decade. Management of pediatric urolithiasis necessitates a balance between stone clearance and morbidity related to the procedure. A variety of treatment options are available, which include shock wave lithotripsy (SWL), percutaneous Nephrolithotomy (PCNL), and retrograde intra renal surgery (RIRS) and open surgery. Concerns regarding endourologic treatment include eVect on the renal development and function, the side eVects of radiation, and the implications of residual stones. Children with pediatric urolithiasis need to be worked up metabolically to prevent recurrence. The treatment options should be chosen with prudence, as each of the treatment options has its share of problems. SWL has been the treatment of choice for renal calculi less than 15 mm in size. The stone-free rates range from 68 to 84% [1]. In our study, ESWL was found to be safe and eVective in children as was in adults for solitary renal and upper ureteric stones less than 2 cm in size. We found that children required fewer and lower energy shock waves to achieve equivalent results. Considering that long-term data are awaited regarding functional consequences of shock waves on pediatric kidneys, it would be prudent to shock these kidneys as little as possible. In this context, we feel to minimize the “shock loss,” and optimizing the number and energy of shock waves, the patient should be given optimum anaesthesia with the use of ultrasound and Xuoroscopy for localizing and monitoring of stone fragmentation [2]. PCNL remains the most eVective option for treating large stones in this age group. The obvious downside of this approach is the potential for life-threatening complications such as bleeding; hence, surgeon experience is paramount in deciding the number and site of access. Stone-free rates of more than 90% have been shown in pediatric age group [3]. Percutaneous Nephrolithotomy has been described even in children as small as 11 months, having complex calyceal stones and/or staghorn calculi. The method to gain access, ultrasound or Xuoroscopy, is a matter of experience and personal preference. Ultrasound oVers the advantage of visualization of spleen and liver and avoids injury. It also minimizes radiation to these kids. The key to success in PCNL in these small patients is staging the procedure if required, miniaturization of instruments, and using ultrasound as the method of achieving access. PCNL oVers a good clearance rates with acceptable morbidity. Miniaturization of instruments particularly smaller nephroscopes and newer energy sources will decrease the morbidity of PCNL. The question is how small is small enough! In this regard, in our opinion, microperc is the “new kid on the block.” It has a role to play in percutaneous management of these small patients. Essentially, “microperc” involves performing the procedure through the eye of the needle. The microoptics of 0.9 mm diameter are used. The assembly has a integrated light head inserted through the working sheath of the needle, and PCNL can be done through the same needle sheath with a 3-way needle allowing irrigation, passage of Xexible telescope and a laser Wbre [4]. Although investigational, larger multicentre trials that are already underway will prove its utility. M. Desai (&) Nadiad, India e-mail: mrdesai@mpuh.org

Association Between Body Mass Index and Urolithiasis in Children

The prevalence of obesity and urolithiasis in children has increased with time. We evaluated the relationship between body mass and urolithiasis in children. We performed a matched case-control study in a network of 30 primary care pediatric practices. Cases included subjects with ICD-9 codes for urolithiasis and controls were matched on age, duration of observation before the index date and clinical practice. Age and sex specific body mass index z scores at the time of the stone episode were calculated. Continuous body mass index z scores and clinical weight categories were evaluated with covariates, including race, ethnicity, gender and payer status. The OR and 95% CI were calculated using multivariate conditional logistic regression. We identified 110 cases and 396 matched controls, of whom 1.9% and 4.3% were overweight, and 3.7% and 4.5% were obese, respectively. On multivariate conditional logistic regression analysis the continuous body mass index z score (OR 0.84, 95% CI 0.63-1.12, p = 0.18), overweight status (OR 0.13, 95% CI 0.01-1.18) and obese status (OR 0.18, 95% CI 0.02-1.40) were not associated with urolithiasis. However, black race (OR 0.35, 95% CI 0.15-0.85) and Medicaid payer status (OR 0.47, 95% CI 0.24-0.93) were associated with a significant decrease in the odds of urolithiasis. High body mass was not associated with urolithiasis in our primary care pediatric practice network. However, black race and Medicaid payer status were associated with decreased odds of urolithiasis.

Assessment of recoverability of kidney function in children with obstructive calcular anuria: Multicenter study

Objective Urolithiasis in children can cause considerable morbidity. Our aim was to evaluate the impact of intervention on the recoverability of kidney functions. Materials and Methods This prospective study included 93 children (66 boys and 27 girls) with median age of 3 years (range 0–14). Inclusion criteria were presence of anuria, oliguria, serum creatinine >2 mg% and/or hyperkalemia ≥ 6 mmol/L. The mean duration of anuria or oliguria was (mean ± SE) 5.3 ± 0.4 days. On presentation, mean plasma creatinine was 6.5 ± 0.29 mg/dl with a mean estimated glomerular filtration rate (eGFR) of 14 ml/min and creatinine clearance (CC) of 8.24 ml/min. Dialysis was performed in 21 (22.6%) patients. When condition allowed, emergency surgery was performed. Results Mean follow up was 1.5 years with compliance of 82%. At the end of treatment, 83% of patients had complete clearance of calculi. Mean plasma creatinine after treatment was 3.3 ± 0.35 mg/dl with an average GFR of 24.5 ml/min. After treatment renal function returned to normal in 57%, improved in 27% and deteriorated in 16% of children. Renal function recoverability rate was 94.6%. Chronic renal failure developed in 3 (3.2%) patients and 2 (2.2%) patients died. When absolute plasma creatinine concentration [P cr] improved 20–50% the eGFR and CC were doubled, and when improved 50–70% eGFR and CC tripled. Beyond 70% improvement in [P cr], eGFR and CC improved 7–8 times. Using Spearman’s correlation, the mode of presentation and the type of management had a significant correlation with renal function outcome ( P = 0.019 and 0.013 respectively). Conclusion Urgent management of calcular anuria both medically and surgically is the cornerstone for favorable outcome. The mode of presentation and the type of management are significant factors affecting final renal function outcome.