Predicting childhood chronic kidney disease severity in infants with posterior urethral valve: a critical analysis of creatinine values in the first year of life.

BACKGROUND: Posterior urethral valve (PUV) is a leading cause of chronic kidney failure in children. Studies have shown that a creatinine nadir above historical cutoff values of 0.8 or 1.0 mg/dL correlates with worse kidney outcomes. The ability to use nadir creatinine more discriminately as a test of kidney outcomes is otherwise limited. METHODS: We performed a retrospective review of 102 infants treated with primary valve ablation prior to 1 year of age. Patient factors including creatinine at presentation (Cr-P), nadir within 6 weeks after ablation (Cr-6 W), and nadir within 1 year after ablation (Cr-1Y) were assessed as predictors of final chronic kidney disease (CKD) severity. An optimal threshold for four CKD levels was defined in incremental fashion using binary outcome with receiver operating characteristic (ROC). Multivariable logistic regression models compared Cr-P, Cr-6 W, and Cr-1Y while adjusting for patient factors. RESULTS: Boys were ablated at mean age of 36.3 days and followed for 6.6 years (± 3.7). When compared to other demographics, only creatinine remained independently predictive of CKD outcomes on multivariable analysis. ROC analysis demonstrated excellent diagnostic accuracy for Cr-6 W and Cr-1Y (p < 0.001) and acceptable accuracy for Cr-P (p < 0.005). Using the Cr-6 W and Cr-1Y models, high sensitivity and specificity creatinine nadir cutoffs were determined to predict each CKD outcome. CONCLUSIONS: The severity of childhood CKD can be predicted with high accuracy using the creatinine nadir within 6 weeks of ablation. The cutoff values described can be incorporated into a clinical setting for patient counseling and individual risk stratification.

Early Detection of Ureteropelvic Junction Obstruction Using Signal Analysis and Machine Learning: A Dynamic Solution to a Dynamic Problem.

PURPOSE: We sought to define features that describe the dynamic information in diuresis renograms for the early detection of clinically significant hydronephrosis caused by ureteropelvic junction obstruction. MATERIALS AND METHODS: We studied the diuresis renogram of 55 patients with a mean ± SD age of 75 ± 66 days who had congenital hydronephrosis at initial presentation. Five patients had bilaterally affected kidneys for a total of 60 diuresis renograms. Surgery was performed on 35 kidneys. We extracted 45 features based on curve shape and wavelet analysis from the drainage curves recorded after furosemide administration. The optimal features were selected as the combination that maximized the ROC AUC obtained from a linear support vector machine classifier trained to classify patients as with or without obstruction. Using these optimal features we performed leave 1 out cross validation to estimate the accuracy, sensitivity and specificity of our framework. Results were compared to those obtained using post-diuresis drainage half-time and the percent of clearance after 30 minutes. RESULTS: Our framework had 93% accuracy, including 91% sensitivity and 96% specificity, to predict surgical cases. This was a significant improvement over the same accuracy of 82%, including 71% sensitivity and 96% specificity obtained from half-time and 30-minute clearance using the optimal thresholds of 24.57 minutes and 55.77%, respectively. CONCLUSIONS: Our machine learning framework significantly improved the diagnostic accuracy of clinically significant hydronephrosis compared to half-time and 30-minute clearance. This aids in the clinical decision making process by offering a tool for earlier detection of severe cases and it has the potential to reduce the number of diuresis renograms required for diagnosis.

Prediction of Clinical Outcomes in Prenatal Hydronephrosis: Importance of Gravity Assisted Drainage.

PURPOSE: In infants with SFU (Society for Fetal Urology) grade 3-4 congenital hydronephrosis, 99mTc-mercaptoacetyltriglycine diuretic renography assesses differential function and drainage half-time. We routinely also include the percent of radiotracer drained after 30 minutes of diuresis as well as after 15 minutes with the patient in the upright position. We investigated whether any 1 or more of these parameters on initial diuretic renography predicts persistent or worsening drainage parameters. MATERIALS AND METHODS: Infants 6 months or younger with grade 3-4 congenital hydronephrosis who presented between January 2009 and December 2014 were identified from billing data and included in analysis if they underwent at least 1 baseline diuretic renography. Those with structural anomalies were excluded from study. Baseline and followup differential function, diuresis half-time, clearance at 30 minutes and clearance with the patient upright were abstracted and comparisons were made between those with initially indeterminate diuresis half-time who underwent pyeloplasty vs those showing spontaneous improvement. RESULTS: A total of 74 patients (82 renal units) with presumed ureteropelvic junction obstruction met inclusion/exclusion criteria. All 10 renal units with initial diuresis half-time less than 5 minutes resolved spontaneously and all 25 renal units with initial diuresis half-time greater than 75 minutes underwent pyeloplasty. Therefore, we defined the indeterminate group as the 47 renal units with initial half-time between 5 and 75 minutes. Of those 47 renal units with indeterminate initial diuresis half-time 23 (47%) underwent pyeloplasty and 25 (53%) resolved spontaneously. Indications for pyeloplasty included worsening in 17 cases, persistent obstruction in 4 and urinary tract infection in 1. Among renal units with indeterminate drainage clearance while upright and clearance at 30 minutes were the only variables that differed significantly between surgical cases and those that resolved spontaneously. CONCLUSIONS: Radiotracer clearance with the patient upright and clearance at 30 minutes are more predictive of surgical management than diuresis half-time or differential function for renal units with indeterminate drainage. They should be included in the standard assessment of ureteropelvic junction obstruction.

Understanding clinic options for overactive bladder.

Overactive bladder (OAB) is a symptom complex of urinary frequency, nocturia and urgency with or without urgency incontinence that adversely impacts patient's quality of life. Conservative management begins in the outpatient clinic, often with significant improvement and patient satisfaction. In this review we will discuss the evaluation of OAB and review treatment options focusing on behavioral modification, medical therapy, and neuromodulation. These treatment options are offered in a stepwise fashion, remembering that more than one may be needed and can be used concomitantly.

Posterior urethral morphology on initial voiding cystourethrogram correlates to early renal outcomes in infants with posterior urethral valves.

INTRODUCTION: Posterior urethral valves (PUV) is a leading cause of chronic renal failure in childhood. Bladder and posterior urethral deformity in infants with PUV are highly variable on initial voiding cystourethrogram (VCUG). Some types of deformity may be more important than others in determining the severity of the condition. Identification of specific VCUG features may allow for a simple, early screening assessment for patients. OBJECTIVE: Determine whether morphologic features on the initial VCUG correlate to renal outcomes as measured by the creatinine nadir in the first year after ablation. METHODS: Children with PUV treated by primary valve ablation before 12 months old and followed >1 year were identified. Initial diagnostic VCUG was evaluated for the bladder height to width ratio (HW-B), posterior urethral height to width ratio (HW-PU), and posterior-anterior urethral ratio (PA-UR). A trabeculation grade was assigned by three pediatric urologists, and reflux was noted. Univariable analyses with chi-square and t-test were used to compare bladder and posterior urethral morphology factors among those who obtained a creatinine nadir <0.8 or ≥0.8 mg/dL in the first year after ablation. Linear regression was performed to correlate morphology values with true creatinine nadir. RESULTS: A total of 120 boys were ablated at mean age of 40.5 days (range 0-342) and followed for 5.9 years (± 3.85). Among these, 21 (17.5%) had a creatinine nadir ≥0.8 mg/dL. Mean overall HW-B and mean PA-UR were not significantly different between those with creatinine nadir <0.8 versus ≥0.8 mg/dL. Bladder trabeculation grade was not associated with creatinine nadir. For the entire cohort, only the difference in HW-PU was statistically significant between creatinine nadir groups with a much higher ratio among those with a nadir ≥0.8 (p < 0.001). Linear regression demonstrated a significant positive correlation between the HW-PU and creatinine nadir (R 2 = 0.097, p = 0.002). The presence of bilateral reflux is significantly associated with creatinine nadir ≥0.8 mg/dL (p = 0.001). DISCUSSION: We investigate for the first time the association of morphology features on the initial VCUG with renal outcome in PUV patients. Posterior urethral deformity as quantified by a higher HW-PU ratio is significantly correlated with a higher creatinine nadir, whereas measured bladder morphology metrics are not. HW-PU may be an indirect measure of the severity of obstruction in posterior urethral valves. CONCLUSION: The HW-PU appears to be a meaningful early morphologic metric for renal outcome.

Opioid utilization is minimal after outpatient pediatric urologic surgery.

INTRODUCTION: There are no guidelines for opioid use after pediatric urologic surgery, and it is unknown to what extent prescriptions written for these patients may be contributing to the opioid epidemic in the United States. We sought to characterize opioid utilization in a prospective fashion following outpatient pediatric urologic surgery at our institution. MATERIALS AND METHODS: After obtainingapproval from the Institutional Review Board, we prospectively recruited pediatric patients undergoing outpatient urologic surgery. All patients and families were counseled regarding appropriate use of over-the-counter pain medications as first-line agents, with opioids for breakthrough pain only. All patients received an opioid prescription (ORx), which we attempted to standardize to 10 doses. Parents were provided with a log for keeping track of pain medication administration. Postoperative surveys were sent at various time points after surgery to assess utilization of pain medications at home. We quantified unused opioids prescribed and evaluated factors potentially associated with opioid use. RESULTS: Two hundred and two patients were recruited. All patients were male, with a median age of 2.7 years (interquartile range (IQR) 5.5, range 0.5-17.9 years). One hundred and fifty-four children underwent penile surgery, 22 underwent scrotal surgery, and 27 underwent inguinal surgery. Nearly half of our study patients were black, 33.2% were white, 12.9% were Latino, and 4.0% were Asian. The median number of doses prescribed was 10 (IQR 0, range 4.0-20.8). Postoperative surveys were completed by 80.7% of study patients. The median number of opioid doses used was 0 (IQR 2), whereas the mean was 1.28 (standard deviation (SD) 1.98). None of the factors evaluated (including patient age, surgery type, perioperative pain management techniques, length of surgery, and insurance type) were associated with the amount of opioid used at home after surgery, as utilization was equally low across all groups. DISCUSSION AND CONCLUSIONS: Ensuring adequate postoperative pain control for children is critical, yet it is also important to minimize excess ORx. We found that the majority of pediatric patients used 0-2 doses of prescription pain medication after discharge following outpatient urologic surgery, representing a small percentage of the total prescribed amount. Low utilization was seen irrespective of patient age, procedure, and perioperative factors. These data can be used to guide perioperative patient and family counseling and to guide future efforts to standardize ORx following outpatient pediatric urologic surgery.