Objective sonographic measurements of renal pelvic diameter and renal parenchymal thickness can identify renal hypofunction and poor drainage in patients with antenatally detected unilateral ureteropelvic junction obstruction.

INTRODUCTION: Hydronephrosis grading systems risk stratify patients with potential ureteropelvic junction obstruction, but only some criteria are measured objectively. Most notably, there is no consensus definition of renal parenchymal thinning. OBJECTIVES: The objective of this study was to assess the association between sonographic measures of renal length, renal pelvic diameter, and renal parenchymal thickness and the outcomes of a)renal hypofunction(differential renal function{DRF} <40%) and b)high-risk renal drainage(T1/2 > 40 min). STUDY DESIGN: An institutional database of patients who had diuretic renograms(DR) for unilateral hydronephrosis was reviewed. Only infants with Society for Fetal Urology(SFU) grades 3/4 hydronephrosis without hydroureter on postnatal sonogram and had a DR within 120 days were included. The following measurement variables were analyzed: anterior posterior renal pelvic diameter(APRPD), renal length(RL), renal parenchymal thickness(PT), minimal renal parenchymal thickness(MPT = shortest distance from mid-pole calyx to parenchymal edge), and renal pyramidal thickness(PyrT). RL, PT, MPT, PyrT measurements were expressed as ratios (hydronephrotic kidney/contralateral kidney). Multivariate logistic regression was performed for each outcome by comparing three separate renal measurement models. Model 1: RLR, APRPD, MPTR; Model 2: RLR, APRPD, PTR, Model 3: RLR, APRPD, PyrTR. Individual performance of variables from the best performing model were assessed via ROC curve analysis. RESULTS: 196 patients were included (107 with SFU grade 3, 89 with SFU grade 4) hydronephrosis. Median patient age was 29[IQR 16,47.2] days. 10% had hypofunction, and 20% had T1/2 > 40 min 90% with hypofunction and 87% with high-risk drainage had SFU4 hydronephrosis. Model 1 exhibited the best performance, but on multivariate analysis, only APRPD and MPTR were independently associated with both outcomes. No other measure of parenchymal thickness reached statistical significance. The odds of hypofunction and high-risk drainage increase 10% per 1 mm increase in APRPD(aOR 1.1 [CI 1.03-1.2], p = 0.005; aOR 1.1 [CI 1.03-1.2], p = 0.003). For every 0.1unit increase in MPTR the odds of hypofunction decrease by 40%(aOR 0.6 [CI 0.4-0.9], p = 0.019); and the odds of high-risk drainage decrease by 30%(aOR 0.7 [CI 0.5-0.9], p = 0.011). Optimal statistical cut-points of APRPD >16 mm and/or MPTR <0.36 identified patients at risk for obstructive parameters on DR. DISCUSSION AND CONCLUSION: Of the sonographic hydronephrosis measurement variables analyzed, only APRPD and MPTR were independently associated with objective definitions of obstruction based on renal function and drainage categories. Patients who maintain APRPD <16 mm and/or MPTR >0.36 can potentially be monitored with renal sonograms as there is >90% chance that they will not have DRF<40% or T1/2 > 40 min.

Hydronephrotic lower moiety of duplex systems: Observations using diuresis renography.

PURPOSE: The purpose of this study is to characterize the prevalence and behavior of hydronephrosis of non-refluxing lower moiety of duplex kidneys using MAG-3 diuresis renography. We compare our data to previous case series and ureteropelvic junction obstruction of single systems. MATERIALS AND METHODS: An IRB-approved database of over 5000 diuresis renograms performed in 2025 patients was queried to identify cases of hydronephrosis of lower moiety of duplex kidneys suspicious for ureteropelvic obstruction, excluding those with hydroureter or reflux. Kidney function and post-furosemide drainage parameters on initial and follow-up diuresis renograms were recorded. Medical records and patient outcomes were reviewed. RESULTS: In total, 19 renal units were identified in 18 patients (11 male, 7 female), age range 0.5 months to 17.8 years, including one patient with bilateral lower moiety hydronephrosis. Initial diuresis renograms in 12 asymptomatic patients (13 renal units) with antenatal hydronephrosis demonstrated varying drainage patterns from normal to obstructed. Follow-up studies showed worsening drainage in 3 patients, who all underwent surgery. Drainage improved in 4 patients and remained unchanged in 5 patients (6 renal units). Of the 6 patients presenting with Dietl's crisis, 5 showed obstructive drainage on initial diuresis renogram, 2/5 with decreased function. All 5 obstructed patients underwent surgery. CONCLUSION: Hydronephrosis of the lower moiety of a duplex system is rare and behaves similarly to single systems. The majority are diagnosed antenatally, display a dynamic nature, and may present with acute obstruction. Diuresis renography is a valuable tool in its evaluation and management.

Initial observational management of hydronephrosis in infants with reduced differential renal function and non-obstructive drainage parameters.

INTRODUCTION: Hydronephrosis secondary to ureteropelvic junction (UPJ) obstruction is a common finding in infants with prenatally-diagnosed hydronephrosis and often results in pyeloplasty due to obstructive drainage parameters and/or renal function compromise. However, little is known regarding the natural history of hydronephrosis with reduced differential renal function (DRF) but non-obstructive drainage. OBJECTIVE: We sought to explore our experience with initial observational management of these patients. STUDY DESIGN: A retrospective review of our institutional database of all diuretic MAG-3 renal scans obtained between 2000 and 2016 was performed. We included patients with antenatally-detected unilateral hydronephrosis ≥ SFU grade 2, first MAG-3 scan prior to 18months of age, DRF <40% and post-furosemide half-time (T1/2) <20 min. Exclusion criteria were: hydroureter, VUR, solitary kidney, duplication anomalies. Outcomes of interest were a progression of T1/2 ≥ 20 min and/or further decline in DRF >5%. RESULTS: Of 704 patients with unilateral hydronephrosis, 91 had DRF≤40%, of which 29 (18 boys, 11 girls) met our inclusion criteria and were followed for a mean of 2.8 years (1.4 months-6.6 years). Mean age at first sonogram was 2.3 months. 2 patients had SFU grade 2, 16 had grade 3, and 9 had grade 4 hydronephrosis, and 2 unknown grade. Median half-time on initial MAG-3 scan across all patients was 10 min (3-20 min). Initial MAG3 scan was performed at a median of 2.3 months of age (0.3-17 months). 22/29 patients had >1 MAG3 scan. Of the 7 remaining, 5 were lost to follow-up and 2 demonstrated improvement in hydronephrosis. Worsening drainage occurred in 10/22(45%), median final T1/2 was 45.5 min 8 of these underwent pyeloplasty and 2 were lost to follow up. 4/22 patients (18%) had progressive decline in DRF (mean 8.3%, range 6-10%). 3/4 maintained non-obstructive drainage patterns and stable/improved hydronephrosis, and 1 underwent pyeloplasty. 13/18 remaining patients had stable DRF and 5 had improvement in DRF. 7(39%) of these underwent surgery for worsening drainage (Summary Figure). Overall, 7/29(24%) patients had sufficient resolution of hydronephrosis to be discharged from our care, 8(28%) are under continued observation, 9(31%) underwent pyeloplasty, and 5(17%) were lost to follow-up. In the observational group [median follow-up 4.5 years (3.7-6.6 years)], all 8 demonstrated improved non-obstructive drainage (T1/2 <20 minutes) and/or improvement in hydronephrosis. 4/10(40%) with DRF <35% underwent pyeloplasty versus 5/19(26%) with DRF 35-40%(p=0.67). CONCLUSION: Initial observational management of unilateral hydronephrosis with reduced DRF and nonobstructive drainage is recommended as most kidneys maintain nonobstructive drainage and do not demonstrate further decline in DRF. Even when DRF decreases, the majority remain non-obstructive. Worsening drainage over time more often leads to the decision for pyeloplasty rather than change in DRF.

Predicting the likelihood of prolongation of half-time among infants with initially indeterminate drainage values: A single-institution retrospective study of 535 patients with ureteropelvic junction obstruction.

INTRODUCTION AND OBJECTIVE: Prior studies have shown a broad half time (T1/2) interval on MAG3 diuresis renography (DR) that is indeterminate for obstruction. We aimed to refine and sub-divide the indeterminate range and associate it with clinically meaningful outcomes: pyeloplasty and pyeloplasty-free survival. METHODS: We identified patients <1.5 years-old at presentation with unilateral, isolated moderate to severe hydronephrosis who underwent DR from 2000 to 2016. A logistic regression model was created using T1/2 to predict surgery. An indeterminate range was defined based on patients with <90% probability of pyeloplasty or resolution. This group was sub-divided into three T1/2 intervals: 5-20, 21-40, and 41-60 min. Endpoints were pyeloplasty and pyeloplasty free survival. Indications for surgery were loss of differential renal function (DRF), worsening T1/2, family preference, and/or pain. RESULTS: Among 2025 patients with DR, 704 met criteria (169 were lost to follow up). Of the remaining 535, 218 had pyeloplasties and 317 did not. The Pyeloplasty group had significantly worse DRF, T1/2 at initial DR, and exited the study earlier, at a median age 1.1years vs 2.3 years (p < 0.001). For all patients with antenatally detected unilateral UPJ obstruction, the odds of undergoing pyeloplasty at any time increased by 1.8 times (p < 0.001 [95% CI: 1.04, 1.08]) per 10 unit increase in T1/2 until T1/2 = 60. However, in patients with intermediate drainage, five year surgery-free survival probability for patients with T1/2 5-20, 21-40, and 41-60 min were 79.7%, 46.7% and 33.3% respectively (χ2 = 41.2, P = <0.001). DISCUSSION: Previous efforts to define indeterminate drainage resulted in ranges for T1/2 that were too broad to be clinically useful. Within our endpoint-defined indeterminate range, our data show that there are significant step offs in 5-year surgery-free survival for patients with T1/2 < 20 min, 21-40 min, and 41-60 min. Although there is a steady decrease in surgery-free survival among patients with a T1/2 of 21-40 min over the first 5 years of life, half can be managed nonoperatively. These patients likely represent the true intermediate risk group and closer follow up is justified. CONCLUSIONS: Initial T1/2 on DR is predictive of future surgery. When drainage is "indeterminate" for obstruction, sub-stratification allows for more accurate prognostication.

Hyaluronidase to reduce a prolapsed incontinent ischemic ileovesicostomy.

Stomal prolapse is a known late complication of urinary diversions commonly used in urology. While rare, it can lead to ischemia, necrosis, and obstruction of the stoma, requiring urgent reduction before formal revision can be undertaken. Several measures can be attempted to reduce the prolapse including manual pressure and topical osmotic agents. One method that has not been reported in the urologic literature is the use of hyaluronidase. Herein, we report the first case in the literature of hyaluronidase usage to assist in reduction of an ischemic and obstructed prolapsed incontinent ileovesicostomy after manual compression failed.

Evaluating compensatory hypertrophy: a growth curve specific for solitary functioning kidneys.

PURPOSE: While compensatory hypertrophy is expected in solitary kidneys, the definition of appropriate hypertrophy remains unclear. The normal renal growth rate in children age 1 to 18 years with 2 kidneys has been defined as 0.28 × age (years) + 6.1. Solitary kidneys appear to grow faster and larger and, thus, require a separate growth curve. MATERIALS AND METHODS: The records of all patients 18 years old or younger with solitary functioning kidneys were reviewed from 2001 to 2011. Exclusion criteria were greater than SFU (Society for Fetal Urology) grade 2 hydronephrosis, posterior urethral valves, vesicoureteral reflux or any ipsilateral obstruction. Ordinary least squares regression modeled the renal length as a function of age by using only the initial sonogram per subject. The distribution of mean kidney length by age was plotted and compared to published normal values. RESULTS: A total of 91 subjects were included in the study. Patients were evenly split by laterality and gender. Multicystic dysplastic kidney comprised 34% and solitary kidneys 66% of subjects. Of these subjects 55% underwent their first sonogram at younger than 1 year old. There were 61 subjects with multiple sonograms but the initial 91 were included in the study. Age was a better predictor of renal length for subjects age 1 year or older (r(2) = 0.7312) than for those younger than 1 year old (r(2) = 0.6138). For children age 1 to 18 years we used the equation, length = 0.38 × age + 7.2. Solitary kidney values were approximately 2 standard deviations greater than normal values. CONCLUSIONS: The equation 0.4 × age (years) + 7 can be used to accurately estimate expected renal length in children (age 1 to 18 years) with solitary kidneys and can be used as a quick reference to evaluate for renal compensatory hypertrophy.

Abdominopelvic ultrasound: a cost-effective way to diagnose solitary kidney.

PURPOSE: Solitary kidneys are detected on approximately 1 of 1,500 prenatal ultrasounds and during evaluation for other urological complaints. Although renal scintigraphy is currently the gold standard for confirming the diagnosis and ruling out renal ectopia, scintigraphy is associated with radiation exposure, placement of an intravenous line and sedation. We hypothesize that ultrasonography alone is sufficient to detect solitary kidneys and that confirmatory renal scintigraphy is unnecessary. MATERIALS AND METHODS: We reviewed the records of children with a solitary kidney who underwent ultrasound and nuclear scintigraphy at our institution from 2001 to 2010. Radiological findings were compared to assess the accuracy of ultrasound in diagnosing solitary kidneys. Costs were calculated based on 2011 Medicare global reimbursement. RESULTS: A total of 25 children met the inclusion criteria of undergoing ultrasound and renal scintigraphy (dimercapto-succinic acid or mercaptoacetyltriglycine scan). The majority of cases were male (16, 64%) and left sided (17, 68%). Median age was 9 days (range 1 day to 11.6 years) at first ultrasound and 4.4 months (3 weeks to 12 years) at first renal scintigraphy. In 24 patients ultrasound correctly diagnosed a solitary kidney as confirmed by nuclear scan. In 1 patient ultrasound suggested a pelvic kidney but repeat ultrasound was negative, as was dimercapto-succinic acid scan. The diagnostic accuracy of ultrasound was 96%. Medicare reimbursement for dimercapto-succinic acid scan (CPT 78700) is $460 to $720 ($222 plus $240 for radiotracer plus $260 for anesthesia, if used). CONCLUSIONS: Our findings suggest that ultrasonography alone is sufficient to make the diagnosis of solitary kidney. Omitting routine renal scintigraphy saves approximately $460 to $720 per case, and avoids radiation and discomfort without sacrificing diagnostic accuracy.

Parental preferences in the management of vesicoureteral reflux.

PURPOSE: Considering that there are few absolute indications for the timing and type of surgical correction of vesicoureteral reflux, we objectively measured parental choice in how the child's vesicoureteral reflux should be managed. MATERIALS AND METHODS: We prospectively identified patients 0 to 18 years old with any grade of newly diagnosed vesicoureteral reflux. All races and genders were included, and non-English speakers were excluded from analysis. Parents were shown a video presented by a professional actor that objectively described vesicoureteral reflux and the 3 treatment modalities of antibiotic prophylaxis, open ureteral reimplantation and endoscopic treatment. Then they completed a questionnaire regarding their preference for initial management, and at hypothetical followup points of 18, 36 and 54 months. Consultation followed with the pediatric urologist who was blinded to the questionnaire results. RESULTS: A total of 86 girls and 15 boys (150 refluxing units) were enrolled in the study. Mean patient age was 2.6 years old. Preferences for initial treatment were antibiotic prophylaxis in 36, endoscopic surgery in 26, open surgery in 11, unsure in 26 and no response in 2. Among those initially selecting antibiotic prophylaxis, after 18 months the preference was for endoscopic treatment, but after 36 and 54 months preferences trended toward open surgery. After consultation with the pediatric urologist 68 parents chose antibiotic prophylaxis. CONCLUSIONS: Our data show that antibiotic prophylaxis is preferred as the initial therapy for vesicoureteral reflux by 35.6% of parents. However, given persistent vesicoureteral reflux, preferences shifted toward surgery. With time the preference for open surgery increased and the preference for endoscopic surgery decreased.

Observation of infants with SFU grades 3-4 hydronephrosis: worsening drainage with serial diuresis renography indicates surgical intervention and helps prevent loss of renal function.

PURPOSE: Early pyeloplasty is indicated for ureteropelvic junction obstruction (UPJ) obstructions with reduced differential renal function (DRF) and/or no drainage on diuretic renography (DR). Optimal management of Society of Fetal Urology (SFU) Grades 3 and 4hydronephrosis with preservation of DRF and indeterminate drainage is less straightforward. We review our experience using serial DR to guide the management of kidneys with high-grade hydronephrosis, emphasizing preservation of DRF. METHODS: After IRB approval we reviewed the charts of 1398 patients <1-year-old referred for prenatal hydronephrosis. Only patients with SFU Grades 3 and 4 hydronephrosis without ureterectasis were included in the study. Initial evaluation included a baseline DR. Follow-up included DR or ultrasound (US). RESULTS: 115 patients (125 kidneys) were eligible for study inclusion. 27 kidneys underwent early surgery (median 64 days) due to reduced DRF and/or severely impaired drainage. 98 kidneys were initially observed. Of these, 21 underwent delayed surgery (median 487 days) due to worsening drainage. Only 2 patients had an irreversible decrease in DRF of >5%. 77 kidneys demonstrated improved drainage and stable DRF. Comparison of observation (n = 77) and surgery groups (n = 48) revealed more kidneys with SFU Grade 3 hydronephrosis in the observation group (p = 0.0001). CONCLUSION: Infants with Grades 3 and 4 hydronephrosis and preserved DRF may be safely followed with serial DR. Patients with SFU Grade 4 hydronephosis are more likely to require surgery. Worsening drainage on serial DR is a useful indicator for surgical intervention which limits the number of pyeloplasties while preserving DRF.

Complications of circumcision.

In the United States, circumcision is a commonly performed procedure. It is a relatively safe procedure with a low overall complication rate. Most complications are minor and can be managed easily. Though uncommon, complications of circumcision do represent a significant percentage of cases seen by pediatric urologists. Often they require surgical correction that results in a significant cost to the health care system. Severe complications are quite rare, but death has been reported as a result in some cases. A thorough and complete preoperative evaluation, focusing on bleeding history and birth history, is imperative. Proper selection of patients based on age and anatomic considerations as well as proper sterile surgical technique are critical to prevent future circumcision-related adverse events.