Pediatrics

Introduction and Objective:  Prenatal hydronephrosis with concomitant hydroureter is an established risk factor for urinary tract infection (UTI); however, the minimum ureteral diameter for hydroureter is not well defined. We evaluated the definition of clinically significant hydroureter, its association with UTI and whether continuous antibiotic prophylaxis (CAP) impacted UTI risk.  

Methods: Patients with prenatal hydronephrosis from seven centers were enrolled into the Society for Fetal Urology Hydronephrosis Registry from 2008-2020. Patients with ureteral measurement on ultrasound were included. Patients with ureterocele, ectopic ureter, neurogenic bladder, posterior urethral valves, horseshoe or solitary kidney, known ureteropelvic junction obstruction, or follow-up <1 month were excluded. Primary outcome was UTI. Analyses were performed using Cox regression.

Results: Of 1406 enrollees, 237 met inclusion criteria. Hydroureter of 7 mm was a significant threshold to differentiate patients at higher UTI risk. Patients with ureters ≥7 mm had almost three times the risk of UTI adjusting for sex, circumcision, CAP, and hydronephrosis grade (HR = 2.7, 95% CI:1.1-6.5, p = 0.03). In patients without vesicoureteral reflux (VUR), ureteral dilation ≥7 mm corresponded with higher UTI risk compared to ureteral diameter <7 mm on multivariable analysis (HR = 4.6, 95% CI: 1.1-19.5, p = 0.04; Figure 1). Conversely, in patients with VUR, ureteral diameter ≥7 mm did not impact UTI risk (HR = 1.1, 95% CI:0.31-3.6, p =0.93). CAP was significantly protective against UTI for patients with hydroureter (HR = 0.50, 95% CI: 0.28-0.87, p = 0.01).

Conclusions: This is the first prospectively collected, multicenter study to show that prenatal hydronephrosis with hydroureter ≥7 mm identifies a high UTI risk group who would benefit from antibiotic prophylaxis. In contrast, patients with prenatal hydronephrosis and non-refluxing hydroureter <7 mm may be managed more conservatively. 

Objectives: Among surgeons, the prevalence of work-related pain and injuries ranges from 30% to 60%. The current literature lacks in specialty-specific prevalence of work-related pain and injuries. Few programs offer formal ergonomic training for surgeons. We sought to identify the prevalence of work-related musculoskeletal injuries among pediatric urologists. Additionally, we sought to offer various exercises to serve as guidelines in preventing these injuries.

Materials and Methods: A 33-question survey was sent to members of the Societies for Pediatric Urology (SPU) to assess the prevalence of work-related musculoskeletal injuries and pain. Questions included severity, location, and type of pain from work-related injuries. Baseline pain and demographic information were collected along with procedures performed, type of practice, length of time in practice, and time spent doing work-related activities. Analyses were conducted using chi-square tests to compare the proportions of these injuries by characteristics of the respondents.

Results: 161 survey responses were received with a response rate of 22%. Of those, 72.7% (117/161) reported experiencing neck, back, shoulder, arm, or other musculoskeletal injuries due to work duties. The most common location of pain/injuries was the neck (64.3%) followed by lower back (42%), upper back (37.5%), and right-hand (21.4%). About half, 51% (57/112), reported mildly disabling injuries from work duties, and 43.8% (49/112) reported mild difficulty sleeping due to work-related pain. No statistical differences were found between those reporting and not reporting injuries by gender, age, years in practice, glove size, baseline pain, operating time, computer time, or procedures performed (open, endoscopic, laparoscopic, robotic). Most, 87.5% (133/152), reported no workplace ergonomic guidelines, and 74.7% (115/154) reported they had never received ergonomic training. The vast majority, 94.1% (144/153), acknowledged they would support ergonomic protocols. 

Conclusions: There is a high prevalence of work-related injuries among pediatric urologists. Few training protocols are currently in place for ergonomics, although there is almost unanimous support for these. Further steps are needed to reduce the number of work-related musculoskeletal injuries and to develop and implement ergonomic training programs tailored to pediatric urologists. We have suggested several different exercises to serve as guidelines in reducing the physical strain of work-related activities.

Objectives: Circumcision is a commonly performed procedure in pediatric patients and is performed globally. Training procedural skills required for circumcision in the simulation environment allows for a learner-centered approach to technical skill acquisition. Accurate representation of mechanical properties of human tissues in synthetic materials used in physical simulator models is important to prevent negative skill transfer. Our objectives were to characterize the mechanical properties of pediatric foreskin tissue donated following pediatric surgical circumcision and develop a simulator model with materials that more closely represented these mechanical properties.

Materials and Methods: IRB approval was obtained through the University of Washington and Seattle Children’s Hospital for evaluation of mechanical properties of pediatric foreskin tissue. Pediatric foreskin tissue was collected at the time of surgical circumcision and subsequently underwent tensile tests. Synthetic materials were tested for comparison of mechanical properties. A 3D printed mold was created based on the size of an approximately six-month-old male pelvis and was used to create the physical circumcision simulator model. Synthetic materials with various additives and material ratios were used to adjust the mechanical properties of the simulator model.

Results: There were 23 donors with age range of 5 months to 4 years old and average age of 12.8 months. The foreskin samples demonstrated a “toe” and “linear” region on stress strain curve whereas the synthetic materials demonstrate a linear relationship between stress and strain. The novel features of the circumcision model include materials based on properties of human foreskin tissue as well as anatomical accuracy using 3D printed molds.

Conclusions: The increased fidelity of this model has the potential to decrease the likelihood of negative skill transfer in the simulation environment and has the potential to be integrated into curricula modules for multiple specialties.

Source of Funding: None

Figure 1. 3D printed molding process for circumcision model.

Objectives: Diagnosis of Multicystic dysplastic kidney (MCDK) can be confirmed with functional renal scans or potentially with follow-up renal ultrasound (RUS) alone. We hypothesized that among patients with unilateral MCDK, undergoing functional renal studies compared to follow-up RUS alone would not affect differences in vesicoureteral reflux (VUR), febrile UTI (fUTI) or chronic kidney disease (CKD).

Methods: This was a retrospective review of patients from 2010 to 2020 with MCDK confirmed by RUS and functional renal studies (RUS+FS), compared to patients with MCDK identified on follow-up RUS alone. Functional studies included dimercaptosuccinic acid (DMSA) and mercaptoacetyltriglycine (MAG-3) scans, with MCDK defined as having less than 1% function. Demographics, VUR, fUTI, and CKD rates were evaluated. Differences between cohorts were evaluated using Pearson X² and Fisher Exact tests. 

Results: 178 patients with MCDK met inclusion criteria: 89 (50.0%) patients underwent RUS+FS and 89 (50.0%) were underwent RUS alone (Table 1). Males who underwent functional studies were significantly more likely to be circumcised than males who did not undergo functional studies (p<0.0001). Overall, 4.5% of patients had contralateral VUR (3.4% in RUS+FS; 5.6% in RUS group). 19.1% had at least one febrile UTI (22.5% in RUS+FS group; 15.7% in RUS group). Four patients (2.2%) developed CKD, all in patients with MCDK confirmed with functional studies. Neither group varied significantly in development of VUR, fUTI, CKD, or requiring continuous antibiotic prophylaxis.

Conclusions: Patients who have unilateral MCDK confirmed by RUS alone do not significantly vary in outcomes of VUR, fUTI or CKD from those who had MCDK confirmed by functional studies. Although circumcised males underwent functional studies at significantly higher rates than uncircumcised males, the overall fUTI rates between both MCDK groups was similar, indicating that circumcision status may not impact development of fUTI in patients with unilateral MCDK. Functional renal scans are not necessary in the evaluation of unilateral MCDK if a follow-up RUS confirms a clinician’s diagnosis.

Objective: Little is known about patients with genitourinary congenitalism (GUC) and how much they utilize the healthcare system. The purpose of this study is to compare healthcare utilization among patients with GUC versus that of the general public in three parameters: care setting, length of stay, and cost of care. 

Materials and Methods: In this retrospective cohort study, we queried the California Office of Statewide Health Planning and Development (OSHPD) database from 1995 to 2017, which captures all patient encounters at California-licensed hospitals, emergency rooms, and ambulatory surgery centers. We identified a GUC cohort by ICD and CPT codes corresponding with spina bifida, hypospadias, disorders of sexual development, prune belly syndrome, bladder exstrophy, posterior urethral valves, and epispadias. For each GUC patient identified, we randomly selected non-GUC patients, frequency matched 5:1 by year of birth and facility type. We used SAS for statistical analysis with a cutoff of p<0.01 for statistical significance.

Results: Our analysis included 2,197,940 encounters (Table 1). The majority of encounters for both GUC patients (49%) and the general population (52%) occurred in the emergency room. Compared to the general population, GUC patients have a greater proportion of inpatient visits versus emergency room and ambulatory surgery center visits (p<0.001). For inpatient encounters, mean length of stay (p<0.001) and cost of care (p<0.001) were both greater among GUC patients compared to the general population. 

Conclusions: GUC patients are more likely than the general population to have an inpatient encounter, with greater length of stay and cost of care for those encounters. Future studies should clarify if heightened inpatient utilization among GUC patients is directly related to the GUC diagnosis itself versus other predictors such as comorbidities.

Introduction:

There is wide variation in continuous antibiotic prophylaxis (CAP) use for patients born with urologic anomalies. Our objective is to determine which subgroups of prenatal hydronephrosis (PHN) and vesicoureteral reflux (VUR) patients benefit from CAP use.

Methods:

We analyzed 1400 patients from the national PHN registry and 607 patients from RIVUR trial. PHN registry patients with isolated hydronephrosis and those with dilated ureter were selected for analysis. RIVUR trial data was stratified into low and high-risk groups based on our previously published criteria. Cox regression was used to determine the benefit from CAP with primary endpoint of UTI.

Results:

PHN Registry:

802 patients had isolated PHN and 237 had ureteral dilation. In isolated PHN, UTI rate was 4.2% compared to 22% in dilated ureter. Among isolated PHN independent predictors of UTI were female sex (HR = 13, p = 0.0001) and intact prepuce (HR = 5.1, p = 0.01). CAP was not protective for the overall isolated PHN population. In PHN patients with dilated ureter, UTI predictors were female sex (HR = 5.1, p = 0.003), intact prepuce (HR = 4.0, p = 0.003), and ureteral diameter ≥7 mm (HR= 2.7, p = 0.03). CAP was protective against UTI for PHN patients with ureteral dilation (HR = 0.50, p = 0.01).

RIVUR Re-analysis:

RIVUR trial was re-analyzed using a risk classification system with 64% low risk and 36% as high risk. Low risk was defined as low-grade VUR, circumcised males or females without constipation. Uncircumcised males, grade IV VUR, or presence of constipation denoted high risk. Among the low-risk group, UTI recurrence was not significantly different between CAP and placebo (HR = 0.71, p = 0.19). In the high-risk group, CAP was protective (31% vs 11.4% UTI rate on CAP) (HR = 0.27, p = 0.001).  

Conclusions:

PHN and VUR patients have a spectrum of risk for UTI and not all patients benefit from CAP. Among PHN patients, CAP is most effective in patients with ureteral dilation, females, and uncircumcised males. In VUR patients, CAP is best targeted to females and uncircumcised males with high-grade VUR and/or bladder and bowel dysfunction.

Objectives: The indications for voiding cystourethrogram (VCUG) were changed with the 2011 American Academy of Pediatrics guidelines, which recommended delaying VCUG until after the second febrile urinary tract infection (UTI). We hypothesized that prevalence of high grade VUR and surgical intervention have increased following publication of the guidelines. 

Methods: Patients with primary VUR were prospectively collected at a single center. The modern cohort was born between 2012-2020 and the historical cohort from 2007-2010. Children with secondary VUR, ureterocele, duplication anomalies, multicystic dysplastic kidney, ectopic ureter were excluded. The two populations were compared based on demographic, VUR characteristics, and the outcomes of UTI development and surgical intervention.  UTI development defined as pyuria and bacteriuria on urinalysis and greater than 50,000 CFU/mL of a single organism. Chi-square and Wilcoxon tests were used for analysis. 

Results: In the modern cohort, 256 patients met inclusion criteria and 73 patients in the historical cohort. Median age at diagnosis did not differ between the two groups (p = 0.16).  No differences were found in circumcision status, race/ethnicity, or median follow-up time between the two groups (median 3.2 years in both, p = 0.85). However, the historical cohort had more female patients (68%, 50/73) compared to modern cohort (50%, 128/256, p = 0.005). The rate of high grade VUR increased from 15% (12/73) in historical cohort to 36% (92/256) in modern cohort (p = 0.002). More patients in the contemporary cohort (20%, 52/256) developed UTI during follow-up compared to historical cohort (6.9%, 5/73) but this was not significant (p = 0.20). In the modern cohort, more patients required surgical intervention (19%, 49/256) compared to historical patients (6.9%, 5/73, p= 0.02). 

Conclusions: We found a greater than two-fold increase in high grade VUR in the modern cohort and a significantly higher number of patients required surgical management compared to our historical cohort. Our results indicate that modern VUR patients have more severe VUR compared to patients seen prior to 2011.  Modern VUR management should account for patients presenting with higher grade VUR and higher risk of UTI. 

Purpose:

        Pediatric nephrolithiasis is a commonly encountered and difficult to manage condition. Although less common in the pediatric population than adults, the reported incidence is increasing over time with reported annual rate increase of 6-10% over the last 20 years ¹ . Current management options include observation, medical expulsive therapy, extracorporeal shockwave lithotripsy (ESWL), ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), and pyelolithotomy. For stones requiring intervention, historically, ESWL has been the primary treatment choice due to its minimally invasive nature. The purpose of this study was to demonstrate the prevalence and characterize the trends in primary treatment choice of pediatric nephrolithiasis. 

Methods:

            We used the IBM MarketScan database to query all patients <18 years of age from 2007 to 2019 with a new diagnosis of nephrolithiasis using International Classification of Disease (ICD)-9/10. Current Procedural Terminology (CPT) Codes were used to define the diagnosis codes and procedure type for ESWL, URS, and PCNL. All treatments within 60 day time windows were considered a single stone event. The first treatment modality was selected as primary and any additional treatments within this window were excluded.

 Results:

From 2007-2019 a total of 130,919 stone events were identified. Total stone rates by year peaked in 2011 at 14,291 and declined to 5,431 most recently in 2019. The proportion of patients receiving any treatment trended downward from 9% to 6.9% during this period. Among those getting stone treatment, rates of ESWL trended downward from 47.7% of all cases in 2007 to 24.6% in 2019. PCNL peaked in 2012 at 10.7% with a recent decline to 1.6%. Rates of URS increased from 52.9% in 2007 to 76.5% more recently in 2019. Notably, PCNL was more common in in age group 0-4 years (47% of all cases) and URS was more common treatment modality in older kids/teens of those getting treatment (61-62.9%).

Conclusions:

Notably, multiple treatment modalities are uncommon and the rates of receiving any treatment are going down over time. With improved endoscopic modalities ESWL rates have decreased over time. Babies and younger children mostly had PCNL and older children/teens had increased rates of URS.

Objectives: Hypospadias is one of the most common congenital malformations encountered by pediatric urologists. There is debate in the literature about which risk factors are predictive for complications in hypospadias repair. We aim to assess which factors may be predictive for postoperative complications.

Materials and Methods: We evaluated a retrospectively maintained hypospadias database of 515 boys undergoing single-stage hypospadias repair at a single institution including four pediatric urologists between 2004 and 2020. We evaluated clinical data including complications, severity, surgeon, type of repair, glans width, degree of ventral chordee, and anesthesia block type (caudal or penile nerve block). Degree of severity was stratified by native meatus location: distal, midshaft, or proximal. Glans width was measured with calipers at the start of surgery. Postoperative complications were defined as meatal stenosis, urethral stricture, urethrocutaneous fistula, persistent penile chordee, and glans dehiscence. We evaluated TIP and MAGPI hypospadias repair. Descriptive statistics and multiple logistic regression were performed using SPSS with p<0.05 being considered statistically significant.

Results: A total of 140 MAGPI repairs for megameatus and the distal-most glanular hypospadias and 375 TIP repairs for more significant hypospadias were recorded. The overall complication rate was 12.4%. The severity of hypospadias was distal in 83.5% of cases, midshaft in 8.2%, and proximal in 8.3%. The complication rate for MAGPI was 5.0%. The complication rate for TIP was 15.2% (11% distal, 11.9% midshaft and 46.5% proximal).  Average follow-up time (TIP+MAGPI) was 7.88 months. 8.4% of boys had chordee 0-30º (complication rate 4.7%), 66.3% had 31-60º (complication rate 8.9%), and 25.3% had 61º+ (complication rate 24.8%).

On multiple logistic regression, glans width (p=.016, 95% CI .646-.957) and location severity (p<.001, 95% CI 1.398-3.357) were found to be independent predictors of complication. Surgeon, repair type, degree of chordee, and block type were not statistically significant predictors.