Dana W. Giel

The feasibility and outcome of nephron-sparing surgery for children with bilateral Wilms tumor. The St Jude Children's Research Hospital experience: 1999-2006.

Approximately 5% of children with Wilms tumor present with bilateral disease. The treatment challenge is to achieve a high cure rate while maintaining adequate long‐term renal function. The authors of this report assessed the feasibility and outcome of nephron‐sparing surgery in patients with bilateral Wilms tumor who were treated at a single institution.

Pediatric Urolithiasis—Does Body Mass Index Influence Stone Presentation and Treatment?

PURPOSE Pediatric obesity is a major public health concern in the United States. We investigated the association of body mass index with presentation and outcome in children with urolithiasis. MATERIALS AND METHODS We identified all patients 2 to 18 years old at our institution with a radiographically confirmed first renal or ureteral stone between January 2003 and June 2008. Data abstracted included demographics, stone characteristics, treatment and metabolic evaluation. Patients were stratified into 3 body mass index categories, including lower (10th percentile or less for age), normal (10th to 85th percentile) and upper (85th percentile or greater) percentile body weight. RESULTS Of the children 62 boys (55.4%) and 50 girls (44.6%) were evaluable. Mean age at diagnosis was 11.8 years. Body mass index stratification showed lower percentile body weight in 11 patients (9.8%), normal percentile body weight in 55 (49.1%) and upper percentile body weight in 46 (41.1%). Mean stone diameter was 5.0 mm. Of the stones 31 (27.7%) were in the kidney or ureteropelvic junction and 81 (72.3%) were in the ureter. Surgery was done in 87 patients (78.9%) and stone clearance was accomplished by 1 (69.0%) or 2 (31.0%) procedures in all. Lower percentile body weight patients presented earlier than normal and upper percentile body weight patients (9.0 vs 12.2 and 12.0 years, respectively, p = 0.04). Neither stone size nor the number of procedures required for stone clearance differed significantly by body mass index. CONCLUSIONS Upper percentile body weight was not associated with earlier stone development, larger stones or the need for multiple surgical procedures. In lower percentile body weight patients symptomatic renal stones developed significantly earlier than in normal or upper percentile body weight patients. Stone size and the surgical intervention rate were similar regardless of body mass index. Further research may identify potential factors predisposing children with lower percentile body weight to early stone development.

Endoscopic Deflux® injection for pediatric transplant reflux: A feasible alternative to open ureteral reimplant

OBJECTIVE Pediatric renal transplantation is frequently performed using a freely refluxing vesicoureteral anastomosis. The resulting vesicoureteral reflux (VUR) may increase the morbidity of urinary tract infections (UTIs) that commonly occur in this setting, yet open surgical correction of the refluxing anastomosis can prove difficult. We report our experience using endoscopic injection of dextranomer/hyaluronic acid (Deflux) to correct transplant VUR. MATERIALS AND METHODS We retrospectively reviewed the charts of patients treated with endoscopic injection of Deflux (Q-Med, Uppsala, Sweden) for VUR into their renal allograft. Indications for inclusion in the study were renal allograft transplantation for primary end-stage renal disease, radiographically proven VUR into the allograft, normal voiding history, and at least one documented febrile UTI. Preoperative and postoperative images, including voiding cystourethrogram and allograft ultrasound, were compared. Location of the transplant orifice and volume of Deflux were recorded. Clinical outcomes, including documented UTI and changes in serum creatinine following treatment, were also assessed. RESULTS Eight patients were identified who were treated for transplant VUR, with a total of nine transplant ureters injected. Mean patient age at time of injection was 11.6 years (range: 7-19 years). Post-injection voiding cystourethrograms and allograft ultrasound were available for all patients. Following treatment, four ureters demonstrated resolution of VUR and one ureter demonstrated improvement to grade 1 VUR. The remaining four ureters demonstrated no change in VUR grade. No patients showed any change in their serum creatinine, and no episodes of transplant pyelonephritis have occurred during the follow-up period. Mean post-injection follow-up has been 17.3 months (range 9-26 months). CONCLUSION Initial results demonstrate that endoscopic treatment with Deflux is feasible and may provide a less invasive alternative for treatment of transplant VUR. Further investigation with a larger group of patients and longer follow-up is needed.

Do Overweight and Obese Pediatric Stone Formers Have Differences in Metabolic Abnormalities Compared With Normal-weight Stone Formers?

OBJECTIVE To determine if 24-hour urinary parameters in children with nephrolithiasis across 4 institutions were influenced by body mass index (BMI). MATERIALS AND METHODS The 24-hour urinary parameters obtained from children with nephrolithiasis between 2000 and 2013 were stratified by BMI percentile ≥85th and <85th (overweight and obese patients vs healthy weight, respectively). A total of 206 children were included in the study. Exclusion criteria included patients with a history of spina bifida, neurogenic bladder, and cerebral palsy, and patients on medical treatment before the first 24-hour urine collection. RESULTS Overweight and obese patients consisted of 35.4% of the cohort (n = 73). Metabolic abnormalities were present in 130 children (63.1%). The most common abnormality present in the <85th percentile was hypercalciuria (32.3%), and in the ≥85th percentile, hyperoxaluria (37.0%). Univariable and multivariable analyses revealed that overweight and obese children were more likely to have low urinary volume and elevated uric acid compared to normal-weight children. CONCLUSION Although there is a link between stone formation and BMI in adults, no definitive conclusions have been proven in the pediatric literature. Our study indicates that stone-forming children who are overweight or obese have low urinary volume and elevated uric acid compared to normal-weight stone-forming children.

National multi-institutional cooperative on urolithiasis in children: Age is a significant predictor of urine abnormalities

INTRODUCTION Pediatric nephrolithiasis is a growing problem and prior studies have shown the greatest increase in nephrolithiasis in the adolescent population. Metabolic abnormalities have historically been cited as the primary cause of pediatric nephrolithiasis; however, dietary and other factors such as obesity have also been studied with mixed results. OBJECTIVE We reviewed the charts of pediatric patients with a history of nephrolithiasis to determine the number and types of metabolic abnormalities present on 24-h urine analysis. STUDY DESIGN We retrospectively reviewed the charts of all pediatric patients with a history of nephrolithiasis from 1999-2013 across four different institutions. The subjects were excluded if they had a history of spina bifida, neurogenic bladder, cerebral palsy, isolated bladder stones, or if they were on medical therapy for nephrolithiasis before the first 24-h urine collection. RESULTS There were 206 subjects included in the analysis with an average age of 13 (±3.9) years. The patients were stratified into two age groups based on an apparent bimodal distribution of metabolic abnormalities, ≤10 years and >10 years of age. Metabolic abnormalities were present in 130 children (63.1%) and there was a difference between the groups, with children ≤10 years more likely to have a metabolic abnormality compared with those >10 years of age (75% vs. 60.6%, p = 0.0443) on univariate analysis. In children ≤10 years hypercalciuria was the most common disorder present (48.4%), and in children >10 years hypocitraturia was the most common disorder present (26.1%). Children ≤10 years of age were more likely to have normal volume (p = 0.006), elevated urinary oxalate (p = 0.0351), elevated urinary calcium (p < 0.001), elevated supersaturation of calcium phosphate (p < 0.001), and elevated supersaturation of calcium oxalate (p = 0.002). On multivariate analysis, children ≤10 years of age were more likely to have normal volume, hyperoxaluria, elevated supersaturation of calcium phosphate and a trend towards hypercalciuria (Table). DISCUSSION Our study reveals that younger children are more likely to have a metabolic abnormality present on 24-h urine analysis. This has important implications when deciding on treatment options, with younger children potentially requiring more aggressive management with medical therapy. Older children were more likely to have low urinary volume and their most common metabolic abnormality was hypocitraturia. Although dietary factors have not been established as the definitive reason behind the rising incidence of nephrolithiasis in the adolescent population, older children may benefit more from diet modification with a strong focus on increasing volume intake. CONCLUSION We found differences in younger compared with older age groups in terms of the number and types of metabolic disorders present. Children ≤10 years of age were more likely to have a metabolic disorder including elevations in calcium, oxalate and supersaturation of calcium phosphate, while children >10 years of age were more likely to have low urinary volume. These differences have important implications for future investigative studies on the rising incidence as well as the best course of treatment for children with nephrolithiasis.

Health Disparities in the Appropriate Management of Cryptorchidism

Objective To assess regional practices in management of cryptorchidism with regard to timely fixation by the current recommended age of 18 months. Study design A retrospective study was performed. Charts of all patients who underwent surgical correction for cryptorchidism by a pediatric general surgeon or urologist within a tertiary pediatric hospital in an urban setting were systematically reviewed. Results We identified 1209 patients with cryptorchidism. The median age of surgical correction was 3.7 years (IQR: 1.4, 7.7); only 27% of patients had surgical correction before 18 months of age. Forty‐six percent of our patients were white, 40% were African American, and 8% were Hispanic. African American and Hispanic patients were less likely to undergo timely repair (P = .01), as were those with public or no insurance (P < .0001). A majority (72%) of patients had no diagnostic imaging prior to surgery. A majority of patients had palpable testes at operation (85%) and underwent inguinal orchiopexy (76%); 82% were operated on by a pediatric urologist. Only 35 patients (3%) experienced a complication; those repaired late were significantly less likely to develop a complication (P = .03). There were no differences in age at time of surgery by surgeon type. Conclusions A majority of our patients were not referred for surgical intervention in a timely manner, which may reflect poor access to care in our region. Public and self‐pay insurance status was associated with delayed repair. Education of community physicians and families could be potentially beneficial.

Hydronephrosis After Pyeloplasty: “Will It Go Away?”

OBJECTIVE To identify attributes of pediatric patients with hydronephrosis due to ureteropelvic junction obstruction and of their surgical encounters which are predictive of resolution of dilatation in order to provide more effective counseling about expected outcomes. This study was inspired by the suggestion in recent literature that greater than 20% improvement in anteroposterior diameter (APD) of the renal pelvis after pyeloplasty is indicative of resolution of obstruction. The remaining dilatation, however, is often distressing to caregivers, and there are no data to guide clinicians in counseling about its likelihood to resolve. METHODS We retrospectively reviewed children who underwent surgery at our institution for ureteropelvic junction obstruction between 1/01/2010 and 6/30/2017. APD of the pre- (preAPD) and postoperative (postAPD) renal pelves were documented. In children with more than 1 postoperative ultrasound, lastAPD was the measurement on their most recent study. Appropriate statistical tests examined the effects of clinical and surgical variables on hydronephrosis resolution. RESULTS PostAPD and lastAPD were obtained at medians of 3 months and 1.9 years after surgery, and were 0 cm in 12 of 105 (11.5%) and 9 of 65 (13.8%) patients, respectively. None of the variables analyzed significantly impacted complete resolution at either time point. Of those that did not resolve, 80.6% (75/93) showed greater than 20% improvement in APD; however, 3 of these children required reoperation due to secondary obstruction. In our study, no one with APD reduction greater than 43% required reintervention. CONCLUSION Complete resolution of hydronephrosis is uncommon and unpredictable. All caregivers should be counseled to expect dilatation to persist after obstruction is corrected.

1201 DOES THE MECHANISM OF INJURY IN PEDIATRIC BLUNT TRAUMA PATIENTS CORRELATE WITH THE SEVERITY OF GENITOURINARY ORGAN INJURY

INTRODUCTION Blunt abdominal trauma can result in injury to genitourinary (GU) organs. Children may be more susceptible to some GU injuries due to anatomic differences compared to adults. Mechanism of injury (MOI) has been thought to relate to both the likelihood and severity of GU injury in children, although this has not definitively been proven. Our purpose was to determine if MOI has any correlation to the severity of GU injury in children treated at our institution. MATERIALS AND METHODS We reviewed records of all pediatric blunt trauma patients presenting to our institution from January 2005-December 2010 using the LeBonheur Childrens Hospital Trauma Registry. All patients with GU injuries were included in this study. Data collected included demographic information, MOI, type and grade of GU injury, associated injuries, and clinical outcome. Continuous variables were tested with ANOVA and categorical variables were tested with chi-square test. RESULTS Records of 5151 children with blunt trauma were reviewed; 76 patients were found to have GU organ injury. There were 47 males (61.8%) and 29 females (38.2%). Categories of MOI included motor vehicle accident, sports injury, bicycle accident, all-terrain vehicle accident (ATV), pedestrian struck accident, falls, and animal injury. MOI did not have any statistically significant association with the severity of GU organ injury (p = 0.5159). In addition, there was no association between MOI and either gender or side of injury. There was a statistically significant association between MOI and patient age (p = 0.04); older pediatric patients were more likely to experience GU injury due to sports injury and ATV accidents, where as younger patients were more likely to experience GU injury due to pedestrian struck, bicycle accidents or animal bite. CONCLUSIONS Although specific MOI would seem to relate to presence and severity of injury in children, MOI alone does not correlate with the severity of GU organ injury in our pediatric trauma population. Age of pediatric patients is associated with the type of MOI that results in GU organ injury. The possibility of GU injury should be considered in all symptomatic pediatric patients with clinically significant blunt trauma regardless of the exact MOI.