Mark C. Adams

THE ROLE OF HYPERCALCIURIA IN A SUBGROUP OF DYSFUNCTIONAL VOIDING SYNDROMES OF CHILDHOOD

PURPOSEnIdiopathic hypercalciuria is believed to be the cause of a variety of urinary tract complaints in clinical pediatrics, including urinary frequency, urgency, and/or dysuria, often associated with gross or microscopic hematuria. In children noncalculous manifestations of idiopathic hypercalciuria are reportedly more common than urolithiasis. We determine the use of the calcium-to-creatinine ratio for the evaluation of different subsets of functional voiding disorders.nnnMATERIALS AND METHODSnWe retrospectively evaluated 288 patients with functional voiding disorders during the last 8 years. Patients presenting with isolated urinary tract infection were not included in the study. A thorough history with emphasis on voiding patterns was elicited and a routine urinalysis was performed in all patients. Patients were divided into 5 groups of 22 with total gross hematuria and dysfunctional voiding pattern, 102 with microhematuria and dysfunctional voiding pattern, 66 with isolated childhood daytime frequency, 45 with the isolated dysuria syndrome and 53 with combined childhood frequency-urgency-dysuria syndrome. The season at presentation was noted to determine a seasonal pattern. In 149 patients urine was evaluated for a spot calcium-to-creatinine ratio.nnnRESULTSnMean age of the 95 (33%) males and 193 (67%) females was 6.1 years (range 2 to 14) and mean duration of symptoms was 10 months (1 week to 10 years). The incidence of idiopathic hypercalciuria was 28% in cases with gross hematuria and dysfunctional voiding, 30% with microscopic hematuria and dysfunctional voiding, 21% with pure childhood daytime frequency, 22% with pure dysuria, and 28% with frequency, urgency and dysuria. The patients were treated predominantly with behavioral therapy, correction of faulty voiding habits, anticholinergics and minor diet modification in some. Mean followup of 6.5 months (range 1 month to 10 years) was available for 153 patients (53%). Resolution of symptoms along with marked improvement in voiding habits was noted in 136 (89%) patients, moderate improvement in 10 (6.5%) and persistent symptoms with minimal improvement in 7 (4.5%). Treatment with thiazides was used in only 6 (2%) patients who had intractable symptoms and a markedly elevated urine calcium-to-creatinine ratio of whom 5 responded favorably.nnnCONCLUSIONSnIdiopathic hypercalciuria may have a significant role in cases of functional voiding disorders. It affects the different subsets of voiding disorders with remarkable consistency but the exact mechanism remains unknown. Although a significant number of patients with voiding dysfunction have an elevated calcium-to-creatinine ratio, the majority respond to standard behavioral therapy and pharmacotherapy in the form of anticholinergics, and treatment directed toward hypercalciuria is not required in most cases.

Long-term urological impact of fetal myelomeningocele closure.

PURPOSEnBetween 1997 and 2002 a large number of fetal myelomeningocele closures were performed at our institution. Previously early reports showed little improvement in neonatal bladder function after fetal back closure. We evaluated the long-term urological impact of this procedure.nnnMATERIALS AND METHODSnUsing a combination of retrospective review and survey questionnaire we reviewed the records of 28 patients in whom fetal myelomeningocele closure was done at our institution between 1997 and 2002. The areas addressed included medical management for neurogenic bladder and bowel, need for lower urinary tract reconstruction and functional bladder assessment by videourodynamics. Parameters after fetal myelomeningocele closure were compared to those of 33 age and sex matched patients with myelomeningocele who underwent standard postnatal closure.nnnRESULTSnWe reviewed the records of 28 patients after fetal myelomeningocele closure. At a mean age of 9.6 years 23 used clean intermittent catheterization to manage the bladder, 24 required a bowel regimen to manage constipation and 6 underwent lower urinary tract reconstruction with enterocystoplasty and a catheterizable bladder channel. Videourodynamics performed in 14 patients at a mean age of 7.4 years revealed decreased bladder capacity in 71%, detrusor overactivity in 35% and increased detrusor pressure in 25%. Compared to age and sex matched children who underwent postnatal closure we noted no significant differences in bladder management, urinary tract surgery or urodynamics.nnnCONCLUSIONSnNeurogenic bowel and bladder management continues to be a significant issue for patients after fetal myelomeningocele closure. After fetal surgery patients should be followed closely, similar to patients who undergo postnatal closure.

A new classification for genital ambiguity and urogenital sinus anomalies.

To describe a new system for classifying genital ambiguity and urogenital sinus abnormalities. Praders classification (which attempts to describe the degree of masculinization) has been used for decades, while the urogenital sinus has generally been described as simply high or low; neither classification fits the spectrum of anomalies, nor do they allow for outcome data research.

Lower Urinary Tract Reconstruction Using Stomach and the Artificial Sphincter

We implanted the artificial urinary sphincter at gastrocystoplasty in 13 male and 5 female patients. The diagnoses were classical bladder exstrophy (8 patients), myelodysplasia (8), cloacal exstrophy (1) and bilateral ectopic ureters (1). Mean patient age was 14.3 years (range 7 to 32.5). Six patients (5 with bladder exstrophy and 1 with clocal exstrophy) had failed bladder neck continence procedures, 3 myelodysplastic patients had failed artificial urinary sphincter placement, and 1 exstrophy patient had failed a Young-Dees bladder neck repair and artificial urinary sphincter placement. The sphincter cuff was placed around the reconstructed bladder neck in these patients, while in the remainder the artificial urinary sphincter was placed around the intact bladder neck. Mean followup was 20.3 months (range 1 to 5). Of the patients 16 (88%) are continent day and night, while 2 are wet. A total of 11 patients (61%) use Valsalvas maneuver alone for voiding and the remainder use Valsalvas maneuver and/or clean intermittent catheterization for bladder evacuation. Complications related to the artificial urinary sphincter were recurrent pump erosion requiring conversion to a Mitrofanoff continent stoma in 1 patient, and mechanical dysfunction requiring pump cuff and reservoir replacement in 3. There were no complications due to infection. Our report demonstrates that the combination of augmentation gastrocystoplasty and an artificial urinary sphincter leads to urinary continence and can allow for spontaneous urination. The rate of infectious complications is not increased when the 2 procedures are combined simultaneously.

Modulation of the Hypoxic Response Following Partial Bladder Outlet Obstruction

PURPOSEnTissue level hypoxia has been noted in animal models of partial bladder outlet obstruction. The key mechanisms linking hypoxia and obstruction induced bladder dysfunction remain unknown. 2-Methoxyestradiol is a natural derivative of 17β-estradiol and is currently used as an oncologic agent for its ability to regulate the hypoxia pathway. We investigated the ability of 2-methoxyestradiol to modulate the hypoxia response in a mouse model of bladder obstruction.nnnMATERIALS AND METHODSnA group of 5 to 6-week-old female C57BL/6 mice underwent oophorectomy and partial bladder outlet obstruction. Obstructed animals received a subcutaneous pellet of cholesterol placebo (7) or 2-methoxyestradiol plus cholesterol (7). Age matched controls underwent oophorectomy only (8). After 4 weeks the bladders of mice with partial bladder outlet obstruction and of unobstructed animals were harvested. Bladder sections (5 μm) were immunostained for Hypoxyprobe™-1, glucose transporter 1 and hypoxia inducible factor-1α. Real-time polymerase chain reaction was performed for hypoxia inducible factor-1α and lysyl oxidase. Statistical analysis was performed using 1-way ANOVA and the Wilcoxon rank sum test.nnnRESULTSnImmunostaining for glucose transporter 1 and Hypoxyprobe-1 revealed the presence of tissue hypoxia after partial bladder outlet obstruction. Immunostaining and real-time polymerase chain reaction demonstrated the up-regulation of hypoxia inducible factor-1α in mice after partial bladder outlet obstruction compared to controls (p = 0.0394). Although not statistically significant, a trend toward lower gene expression of hypoxia inducible factor-1α was seen in mice receiving 2-methoxyestradiol compared to placebo (p = 0.0625). Compared to placebo, 2-methoxyestradiol treatment increased lysyl oxidase expression (p = 0.007).nnnCONCLUSIONSnMurine partial bladder outlet obstruction resulted in hypoxia and up-regulation of the hypoxia inducible factor-1 pathway. Subcutaneous 2-methoxyestradiol administration attenuated this response and may be a viable tool to study the role of hypoxia after partial bladder outlet obstruction.

Inadvertent concentrated epinephrine injection at newborn circumcision: effect and treatment.

Medications are commonly delivered by injection in the practice of urology. In pediatric genital surgery local anesthetics with or without vasoconstrictors are used for penile blocks. Vasoconstrictors may be injected subcutaneously to provide a bloodless field, and normal saline may be injected intracorporeally to assess penile curvature. When used correctly, these agents are safe. However, significant consequences can occur when they are used incorrectly. We describe inadvertent injection of concentrated epinephrine into the penis of a newborn and suggest a plan for treatment.

A Compressible Fluid Power Dynamic Model of a Liquid Propellant Powered Rifle

This paper presents a dynamic model of the interior ballistics of an experimental liquid propellant-powered rifle. The liquid propellant-powered rifle described utilizes a misture of Hydroxyl Ammonium Nitrate (HAN) and hydrocarbon fuel to replace gunpowder typically used in such firearms. The motivation for such a development is to discard the need for a shell casing whereby carrying only propellant and bullets will reduce both the mass and volume per shot carried by the soldier. A first-principles dynamic model of the interior ballistics is derived as a compressible fluid power problem with the chemical liberation of heat within the chamber modeled via a condensed-phase reaction rate law. The model is used to predict the overall performance in terms of ballistic kinetic energy as well as draw design insight regarding the role of friction, chamber geometry, and the profile of chamber pressure with respect to time. Simulation results are presented as well as preliminary experimental results from a proof-of concept device.Copyright