Dosing Variability and Clinical Outcomes of Oxybutynin: A Pediatric Cohort of Patients With Neurogenic Bladder.

Background: Despite the therapeutic advancements of the last several decades, neurogenic bladder remains a significant source of morbidity for patients with a spinal pathology. Oxybutynin is a mainstay of treatment in pediatric populations despite significant side effects and highly variable bioavailability. Objectives: To characterize the use of oxybutynin in a cohort of pediatric patients with neurogenic bladder. Methods: Retrospective data were collected of dosing, drug interactions, and urodynamics parameters in the 100 consecutive patients in a spinal differences clinic who had an appointment between October 7, 2015, and December 30, 2015. In addition to descriptive statistics, a linear regression model of oxybutynin dose versus age and sex was developed to examine the impact of age on dosing variability. Results: One hundred patients (52% female) with a median age of 6.8 years were included. The median daily dose of oxybutynin was 0.36 mg/kg (interquartile range, 0.28-0.54 mg/kg). Of the 48 patients with a recent urodynamics study, 13 had a detrusor leak point pressure (DLPP) greater than the typical cutoff of 40 cm H2O, indicating a need for management escalation. However, of these 13 patients, 38% were already on or exceeding oxybutynin's maximum recommended dose. Conclusion: The wide dosing variability and high DLPPs despite maximal dosing indicate a need for further investigation of oxybutynin's bioavailability in this population compared to its side effects and clinical outcomes. If variability in response to the medication is due to differences in bioavailability, then a precision-dosing model based on patient genomics could be developed for oxybutynin.

More Than Dysuria: Corynebacterial Encrusted Cystitis.

Corynebacterium species, typically considered contaminants in urine culture, can cause encrusted cystitis (EC), a form of chronic urinary tract infection causing pain, bladder necrosis, renal failure, and death. Delayed diagnosis is common due to its rarity and the fastidious nature of Corynebacterium urealyticum. Reported mostly in elderly and immunocompromised patients, EC is rare in pediatric patients. A female adolescent on high dose steroids developed persistent dysuria after urinary catheterization. Abnormal bladder ultrasound and characteristic cystoscopy led to the diagnosis of EC. Appropriate treatment instituted 4 months from onset of dysuria led to an excellent response.

Second Reported Case of Pediatric Bladder Alveolar Soft Part Sarcoma as Secondary Malignancy After Prior Cytotoxic Chemotherapy.

Alveolar soft part sarcoma (ASPS) is a rare malignancy with high rates of metastasis at presentation, defined by an unclear cellular origin and a unique unbalanced ASPSCR1-TFE3 translocation (der(17)t(X:17)(p11:q25)).1 ASPS is insensitive to chemotherapy and has been reported to involve the bladder only twice in the pediatric literature; once as a primary malignancy,2 and once as a secondary malignancy after cytotoxic chemotherapy.3 Herein, we report the third case of pediatric bladder ASPS in a female patient who received cytotoxic chemotherapy for low-risk neuroblastoma. This would represent the second case of pediatric bladder ASPS as a secondary malignancy after prior chemotherapy.

Bladder Recurrence of Clear Cell Sarcoma of the Kidney Seven Years After Initial Presentation.

Clear cell sarcoma of the kidney (CCSK) is the second most common pediatric renal malignancy after Wilms tumor. CCSK has the potential to metastasize to distant sites and was historically known as the bone metastasizing renal tumor. We report an exceedingly rare case of a bladder recurrence of CCSK. Our patient presented with gross hematuria 7 years after initial complete response. He was found to have a large sessile bladder tumor and underwent a partial cystectomy with right pelvic lymph node dissection. Final pathology was metastatic CCSK.

First-ever Reported Obstructing Ureteral Nephrogenic Adenoma in a Child and Subsequent Robotic-assisted Laparoscopic Ileal Ureter.

To report the first known case of a completely intracorporeal robotic-assisted laparoscopic ileal ureter in the pediatric population, a 12-year-old boy with near-complete replacement of his right ureter with nephrogenic adenoma and resulting debilitating renal colic. Intracorporeal robotic-assisted laparoscopic ileal ureter was performed without complication. A detailed description of our surgical technique is included. The patient had improvement in hydronephrosis and complete resolution of renal colic symptoms with minimal incisional length compared to traditional laparotomy. Intracorporeal robotic-assisted laparoscopic ileal ureter provides the benefits of minimally invasive surgery when complete ureteral replacement is needed.

Urethral mobilization for distal and mid shaft hypospadias with chordee.

PURPOSE: Many options are available for repairing mid shaft to distal hypospadias. Reported complications include poor cosmesis, persistent chordee, meatal stenosis and fistula. We hypothesized that advancing the intact native urethra would facilitate chordee correction and minimize complications. MATERIALS AND METHODS: We retrospectively reviewed our records of all 248 hypospadias repairs done from July 2003 to May 2009 and identified patients younger than 18 years with distal or mid shaft hypospadias who underwent repair by urethral mobilization. The outcomes recorded were patient satisfaction, bladder scan volume, and the rate of fistula, meatal stenosis or other complications. RESULTS: Of the patients 83 met study inclusion criteria, including 5 (6%) treated with previous failed hypospadias operations. The hypospadias site was the distal, mid shaft and megameatal intact prepuce variant in 69 (83.1%), 11 (13.3%) and 3 patients (3.6%), respectively. Chordee was present in 80 patients (96.4%). The mean degree of chordee was 61.5 degrees, mean age at operation was 35.7 months and mean followup was 18 months (range 0.25 to 79). Of parental responses 94% were pleased or very pleased. Mean bladder volume on bladder scan was 9.7 ml (range 0 to 81). Fistula developed in 1 patient (1.2%). There were no meatal stenosis cases. CONCLUSIONS: Urethral mobilization results in excellent cosmesis and a low complication rate. This technique is especially well suited to patients with prior operations or deficient preputial skin. Using the native urethra with its blood supply is our preferred method of repairing distal and mid shaft hypospadias with chordee.

Biofeedback therapy for dysfunctional voiding in children.

The past decade has seen a dramatic shift in the management of lower urinary tract dysfunction, including dysfunctional voiding, in children. Once treated primarily with medication, dysfunctional voiding now is managed successfully in most cases with noninvasive evaluations and biofeedback-based pelvic floor muscle retraining. Introduced in 1979, biofeedback initially was expensive and labor intensive, requiring inpatient treatment. The use of animated computer games has expedited results, allowing excellent resolution of dysfunctional voiding and coexisting conditions such as vesicoureteral reflux and constipation with outpatient treatment. Morbidity from medications and surgical procedures has been reduced at centers using biofeedback. Future goals of biofeedback therapy should include further refinements in technique and increasing access to care.