WORKUP	Section 5 of 11
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Lab Studies:

• Serum electrolytes, BUN, creatinine

• Immediately following birth, the infant's serum chemistries are the same as the mother's. In utero, the placenta functions as the major blood filter for the fetus, with waste passed on to the mother. Observing serum chemistries for several days to weeks is important to determine the true status of the newborn's renal function.

• The normal newborn kidney still is undergoing maturation at birth, and infant glomerular filtration rate (GFR) continues to improve during the first several months of life. Because of renal immaturity at birth, the newborn is unable to concentrate urine and is susceptible to dehydration. This defect is exacerbated by renal dysplasia such as that found with PUV.

• As renal maturation continues, the serum creatinine clearance normally improves. If significant renal dysplasia or damage has occurred, the serum creatinine fails to reach a normal level during the first year of life. Serum creatinine levels greater than 0.8 mg/dL during the first year of life have been demonstrated to be associated with poor long-term renal function.

Imaging Studies:

• Renal and bladder sonography

• Every child with antenatal hydronephrosis requires renal and bladder sonography performed in the immediate postnatal period.

• Because newborns commonly have relative hypovolemia during the first few days of life, obtain a repeat sonogram after the first week of life if findings on previous sonography were normal in a child with previously diagnosed antenatal hydronephrosis before making a final determination that the hydronephrosis has resolved (see History).

• Voiding cystourethrography

• The key to the workup of any child with antenatal hydronephrosis is voiding cystourethrography (VCUG). Perform VCUG during voiding and under fluoroscopy, with imaging of the posterior urethra.

• The diagnosis of PUV is indicated by visualization of the valve leaflets. Other clues to the diagnosis are a thickened trabeculated bladder, a dilated or elongated posterior urethra, and a hypertrophied bladder neck (see Images 1-2). Diverticula, cellules, vesicoureteral reflux, and reflux into the ejaculatory ducts secondary to elevated bladder and urethral pressures also may be present (see Image 2).

• Renal scintigraphy

• Although not necessary in every child, renal scintigraphy may be helpful in some cases. If renal dysplasia is suspected, nuclear imaging can determine relative renal function. Some children may have secondary ureterovesical junction obstruction from bladder hypertrophy.

• Tc-dimercaptosuccinic acid (DMSA), glucoheptonate, and/or mercaptoacetyl triglycine (MAG-3) renal scintigraphy are cortical imaging studies that provide information about relative renal function (each kidney relative to the other) and intrarenal function (eg, photopenic areas within the kidney indicate scarring or dysplasia). Additionally, the MAG-3 renal scan with furosemide (Lasix) provides information about renal drainage and possible obstruction.

Other Tests:

• Urodynamic studies

• Urodynamic evaluation provides information about bladder storage and emptying. The mature bladder should store urine at a low pressure and then empty completely at appropriate pressures.

• The term "valve bladder" is used to describe patients with PUV and a fibrotic noncompliant bladder. These patients are at risk of developing hydroureteronephrosis, progressive renal deterioration, recurrent infections, and urinary incontinence that persists in school-aged children.

• Patients with PUV require periodic urodynamic testing throughout childhood because bladder compliance may deteriorate over time.

Procedures:

• Cystoscopy serves both diagnostic and therapeutic functions in these infants. Appropriately infant-sized cystoscopes (<8F) are needed to avoid injury to the urethra.

• Diagnostic cystoscopy: Confirmation with cystoscopy is required in every child in whom PUV is suggested after VCUG. In some, the filling defect observed on VCUG may represent only external sphincter contraction during voiding. In others, the valve leaflets are confirmed.

• Therapeutic cystoscopy (ie, transurethral incision of the PUVs): Multiple techniques have been described for ablating the valves. Disruption of the obstructing membrane by blind passage of a valve hook is now of only historic interest. Currently, valves are disrupted under direct vision by cystoscopy using an endoscopic loop, Bugbee electrocauterization, or laser fulguration. The objective is to relieve the obstruction by cutting the valves at the 12-, 5-, and 7-o'clock positions. Perform this in the least traumatic fashion to avoid secondary urethral stricture or injury to the urethral sphincter mechanism.

• Vesicostomy: In some patients, the urethra may be too small for the available cystoscopic instrumentation. Fortunately, because of continued advancements in pediatric endoscopic equipment, this is an uncommon occurrence. When this situation arises, a temporary vesicostomy is performed.

	TREATMENT	Section 6 of 11
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Medical Care: The medical management of PUV relates to the treatment of the secondary effects of the valves. Adequate care involves a team approach that includes a neonatologist, general pediatrician, pediatric urologist, and pediatric nephrologist. Short-term goals involve treating pulmonary distress, immediate relief of urethral obstruction (placement of 5F feeding tube), and fluid and electrolyte management. In children who survive the pulmonary distress, the long-term issues include treatment of bladder dysfunction and renal insufficiency.

• Renal treatment

• Newborn period: A minority of patients present with bilateral renal dysplasia at birth. In the past, if patients did not die from associated pulmonary insufficiency, they succumbed to progressive renal insufficiency. With recent advances in peritoneal dialysis, some children may be treated successfully from birth. If growth is adequate, renal transplantation is often possible after the first year of life.

• Delayed renal insufficiency: Approximately one third of patients with PUV progress to ESRD and the need for dialysis or transplantation. Progression of ESRD is accelerated at the time of puberty due to the increased metabolic workload placed on the kidneys. Growth in these children may be significantly below the accepted norm for the child's age. Adequate caloric intake and protein nutrition are essential to growth but also may accelerate the rise in serum creatinine. Renal dysfunction can be accelerated by recurrent infections and elevated bladder pressures. Treatment of the lower urinary tract may influence progression of upper tract disease.

• Bladder management

• Newborn period: All male children with antenatal hydronephrosis require VCUG shortly after birth to exclude PUV. While awaiting this study, place a 5F or 8F urethral catheter to allow for bladder drainage. If valves are confirmed, they can be incised within the first few days of life. However, the newborn urethra may be too small to accommodate available equipment. In these individuals, a vesicostomy can be performed as a temporary solution until urethral growth has been adequate to allow transurethral incision. Secondary ureterovesical junction obstruction from bladder hypertrophy is a controversial issue. Supravesical urinary diversion procedures (eg, cutaneous ureterostomies) generally do not offer better upper tract drainage than standard vesicostomy and, theoretically, may increase bladder dysfunction.

• Delayed bladder management: Severe or prolonged urethral obstruction can lead to a fibrotic, poorly compliant bladder. This occurs when the developing bladder is exposed to high pressures from urethral obstruction, leading to increases in bladder collagen deposition and detrusor muscle hypertrophy and hyperplasia. These bladders manifest chronically poor compliance, leading to elevated storage pressures. This, in turn, leads to increased susceptibility to UTIs, hydroureteronephrosis, and diurnal urinary incontinence. Use urodynamic testing to assess bladder compliance. Some patients may respond to anticholinergic medication, such as oxybutynin. Institution of intermittent clean catheterization aids some patients in gaining continence and decreasing upper tract hydroureteronephrosis. In patients who do not gain adequate bladder capacity and compliance with these measures, augmentation cystoplasty may be required.

Surgical Care: Surgical care of the patient with PUV varies according to age, bladder status, and renal status.

• Urinary drainage

• Primary valve ablation: Ideal treatment involves transurethral incision of the PUV during the first few days of life. Current infant resectoscopes are available in size 8F and smaller. The valves can be incised at the 12-, 5-, and 7-o'clock positions with either a cold knife or electrocautery. Some surgeons prefer to leave a catheter in place for 2-3 days after the procedure. The timing of the postoperative VCUG varies and ranges from several days to several months.

• Vesicostomy: When urethral size precludes safe valve ablation, a communicating channel between the bladder and lower abdominal wall (ie, vesicostomy) can be created to provide bladder drainage. Generally, an 18-20F stoma is created approximately midway between the pubis and umbilicus in the midline. Take care to bring the dome of the bladder to the skin and to limit the stomal size to prevent prolapse of bladder urothelium through the vesicostomy. However, formation of too small a stoma results in stomal stenosis and inadequate bladder emptying.

• Cutaneous ureterostomies: Bilateral cutaneous ureterostomies also can be placed to provide for urinary drainage. Techniques for cutaneous ureterostomy include end stomal ureterostomy, loop ureterostomy, Y-ureterostomy (in which the ureter is divided and one end is brought to the skin and the other is reanastomosed in a uretero-ureterostomy), and ring ureterostomy techniques. Potential complications of cutaneous ureterostomies are ureteral devascularization, inadequate drainage, and stomal stenosis.

• Secondary bladder surgery

• Augmentation cystoplasty: Indications for bladder augmentation include inadequately low bladder storage volumes and high bladder pressures despite anticholinergic medication and clean intermittent catheterization. Ileum is used most commonly; however, large bowel, stomach, and ureter also are used, depending on clinical conditions and surgeon preference. Before undertaking the augmentation procedure, seriously consider the ramifications. Undertake augmentation only in patients willing to commit to lifelong intermittent catheterization. The bladder ruptures in approximately 10% of patients. Electrolyte disturbances may be worsened by the placement of intestinal mucosa in contact with urine. Mucus production can be a source of catheter blockage and may be a nidus for stone formation. Finally, the future risk of neoplasia is not yet defined in these patients. Despite these risks, augmentation significantly can improve patient lifestyle and provide for renal protection in selected patients.

• Continent appendicovesicostomy: Also called the Mitrofanoff principle, this procedure involves placement of a nonrefluxing tubular conduit for catheterization between the bladder and skin to provide an alternative channel for catheterization. In children with PUV, institution of intermittent catheterization through a sensate urethra can be difficult. Use of the Mitrofanoff principle provides another channel for catheterization that many patients find more acceptable. The stoma often can be hidden in the umbilicus to provide acceptable cosmesis. The appendix, ureter, and tubularized bowel can be used for formation of this channel.

Consultations: The child with PUV is best cared for using a team approach.

• Pediatrics and neonatology

• The most life-threatening problem in the newborn period is the potential pulmonary hypoplasia related to in utero renal dysfunction.

• With birth, new metabolic demands are made on the infant kidneys.

• Urinary stasis and elevated detrusor pressures are risk factors for urosepsis in the newborn.

• Generally, treatment is coordinated best by establishing a primary pediatrician or pediatric service to coordinate further referrals.

• Additional pediatric subspecialty consultations often include a neonatal intensivist, a pediatric nephrologist, and a pediatric urologist.

• Radiology
  • Establishing the diagnosis is a priority in the newborn period.

  • Obtain VCUG with proper views of the posterior urethra.

  • Other required studies include a renal sonography and, at times, renal scintigraphy.

• Urology
  • In the newborn period, the first treatment intervention is achieving bladder drainage. Catheterization may be difficult or even impossible because of the thickness of the valves or dilation of the posterior urethra with a hypertrophied bladder neck (see Image 1). Cystoscopic visualization with incision of the valves should be accomplished in the first few days of life after the child is metabolically stable.

  • After the initial newborn period and successful bladder drainage, either by valve incision or vesicostomy, long-term urologic care is needed. Renal deterioration secondary to progressive bladder dysfunction requires follow-up care with serial renal sonographic and bladder urodynamic studies. Treatment is based on clinical findings, ranging from annual imaging to pharmaceutical management to bladder reconstruction.

Diet: Dietary restrictions depend on renal status.

• Avoiding progression of renal deterioration while supporting growth requires careful regulation of protein intake, which is best managed under the care of a pediatric nephrologist.

• In the absence of renal insufficiency, no modification of diet is needed.

Activity: Unless complications such as renal insufficiency occur, activity generally can remain unrestricted. Urinary incontinence may present a social barrier. This often can be managed with anticholinergic therapy with or without clean intermittent catheterization.

	MEDICATION	Section 7 of 11
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PUV initially represents a surgical condition. However, long-term treatment often comprises a combination of medical and surgical treatment, primarily directed at the bladder. The primary medications involved in bladder management are anticholinergic medications used to improve bladder compliance. Other medications that may be needed include prophylactic antibiotics and medications for management of renal insufficiency.

Drug Category: Anticholinergic agents -- Used to improve bladder capacity and compliance in the patient with elevated detrusor pressures leading to hydronephrosis, UTI, or incontinence.

Drug Name	Oxybutynin chloride (Ditropan) -- Inexpensive and effective, oxybutynin chloride long has been the first-line anticholinergic. By inhibiting muscarinic action of acetylcholine on smooth muscle, exerts antispasmodic effect on bladder muscle. Its nonselective anticholinergic action increases adverse effects; however, it may produce fewer adverse effects if dosing gradually increased over >2 wk. Available in both 5-mg tab and 5-mg/5-mL elixir. A long-acting 10-mg tab with once-a-day dosing was recently introduced but is expensive and has been approved only for adults.
Adult Dose	5 mg PO tid; increase dose to this level gradually over >2 wk to minimize adverse effects
Pediatric Dose	<5 years: 1 mg per year of age PO bid >5 years: 5 mg PO bid; many patients can tolerate as much as 5 mg PO tid, especially if dosage is increased gradually
Contraindications	Documented hypersensitivity; glaucoma; partial or complete GI obstruction; myasthenia gravis; ulcerative colitis; toxic megacolon
Interactions	CNS effects increase when administered concurrently with other CNS depressants
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Take care in elderly patients, those prone to urinary retention, and those with renal insufficiency; may cause mental status changes, especially in elderly patients; increases risk of heat exhaustion in high environmental temperatures because of blockage of normal sweat mechanisms; may cause blurred vision; adverse effects may be reduced by gradually increasing dosage to desired level

Drug Name	Hyoscyamine sulfate (Levbid, Levsin) -- Works by inhibiting postganglionic cholinergic receptors on smooth muscle cells. Rapidly absorbed and distributed throughout body, including across blood-brain barrier. Half-life is 3.5 h; excreted unchanged in urine. Available in PO, IV, and SL forms; tab generally used for treatment of PUV. Time-release formulation available. Elixir and drops available.
Adult Dose	0.125 mg PO q4h 0.375 mg time-release formulation PO bid as alternative
Pediatric Dose	<2 years: Individualize dose with drops (use with caution); consult package insert for dosage; concentration of drops is 125 mg/mL; may repeat PO q4h prn The following is an approximate dosage guide: 2.3 kg (5 lb): 3 gtt; not to exceed 18 gtt/d 3.4 kg (7.5 lb): 4 gtt; not to exceed 24 gtt/d 5 kg (11 lb): 5 gtt; not to exceed 30 gtt/d 7 kg (15 lb): 6 gtt; not to exceed 36 gtt/d 10 kg (22 lb): 8 gtt; not to exceed 48 gtt/d 15 kg (33 lb): 11 gtt; not to exceed 66 gtt/d 2-12 years: IR tablet or elixir: 0.0625-0.125 mg PO q4h SR tablet: 0.375 mg PO q12h; not to exceed 2 tab qd Elixir: Dosage based on body weight; 1.25 mL (0.03125 mg/0.25 tsp) per 10 kg weight; elixir contains 1.25 mg/5 mL >12 years: Administer as in adults
Contraindications	Documented hypersensitivity; glaucoma; myasthenia gravis; patients at risk for urinary retention or GI obstruction; patients taking other antimuscarinics, amantadine, haloperidol, phenothiazines, MAOIs, TCAs, or some antihistamines
Interactions	Effects decrease when used concurrently with antacids; toxicity increases when used concurrently with phenothiazines, amantadine, haloperidol; MAOIs; TCAs
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Use with caution in children <2 y; may cause heat exhaustion in high environmental temperatures; may produce drowsiness or blurred vision; CNS symptoms (eg, confusion, disorientation) are possible but usually are short-lived after discontinuation

Drug Name	Tolterodine (Detrol) -- A new antimuscarinic drug with more selective receptor profile targeted for detrusor smooth muscle. Used extensively in adults but not approved by FDA for children. In adults, demonstrated equal in efficacy to oxybutynin chloride with significantly fewer adverse effects. Available in 1- and 2-mg tab.
Adult Dose	2 mg PO bid; titrate to this dosage
Pediatric Dose	Not established (experimental studies have used dosages of 0.1 mg/kg PO divided bid)
Contraindications	Documented hypersensitivity; glaucoma; unrelieved bladder outlet obstruction; patients at risk of intestinal obstruction
Interactions	Patients being treated with CYP-3A4 inhibitors (eg, macrolide antibiotics, antifungal agents, cyclosporine) should not receive doses of tolterodine >1 mg bid
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Although more selective than either oxybutynin chloride or hyoscyamine sulfate, may cause similar anticholinergic adverse effects; do not exceed 1 mg bid with hepatic dysfunction

Drug Category: Antibiotics -- Patients with history of recurrent UTI may benefit from antibiotic prophylaxis, especially in the presence of vesicoureteral reflux. The ideal antibiotic for urinary prophylaxis is safe, effective, inexpensive, and has no adverse effects. Although no antimicrobial is ideal, some are preferred in children. Prophylactic dosage is usually one quarter of the therapeutic dose administered once per day. Too high a dose increases adverse effects (eg, GI upset) and may alter fecal flora. Quinolones commonly are used for prophylaxis and treatment in adults; however, they are inappropriate in children because of their potential arthropathic effect on active growth plates. More appropriate antibiotics in children include trimethoprim (TMP), sulfamethoxazole (SMZ), nitrofurantoin, and amoxicillin.

Drug Name	Trimethoprim and sulfamethoxazole (Bactrim, Septra, Cotrim) -- Inhibits bacterial growth by inhibiting synthesis of dihydrofolic acid. TMP alone or in combination with SMZ is the most commonly used antibiotic for both treatment and prophylaxis of UTI. Inexpensive and has minimal adverse effects on bowel and vaginal flora because excreted and concentrated in urine. Pediatric susp (40 mg TMP and 200 mg SMZ per 5 mL) available.
Adult Dose	Treatment: 1 double-strength (ie, 160 mg TMP, 800 mg SMZ) PO bid Prophylaxis: 1 single-strength (ie, 80 mg TMP, 400 mg SMZ) PO qd
Pediatric Dose	<40 kg: Treatment: 8 mg/kg/d (based on TMP component) plus 40 mg/kg/d SMZ PO divided q12h Prophylaxis: One quarter of treatment dose qd >40 kg: Administer as in adults
Contraindications	Documented hypersensitivity; history of megaloblastic anemia caused by folate deficiency; infants <2 mo because of risk of jaundice and hemolytic anemia
Interactions	May increase PT when used with warfarin (perform coagulation tests and adjust dose accordingly); coadministration with dapsone may increase blood levels of both drugs; coadministration of diuretics increases incidence of thrombocytopenia purpura in elderly patients; phenytoin levels may increase with coadministration; may potentiate effects of methotrexate in bone marrow depression; hypoglycemic response to sulfonylureas may increase with coadministration; may increase levels of zidovudine
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Do not use near term in pregnancy because of risk of kernicterus; discontinue at first appearance of rash or sign of adverse reaction; obtain CBCs frequently; discontinue therapy if significant hematologic changes occur; goiter, diuresis, and hypoglycemia may occur with sulfonamides; caution in folate deficiency (eg, individuals with chronic alcoholism, elderly patients, those receiving anticonvulsant therapy, those with malabsorption syndrome); hemolysis may occur in G-6-PD deficiency; patients with AIDS may not tolerate or respond; caution in renal or hepatic impairment (perform urinalyses and renal function tests during therapy); administer fluids to prevent crystalluria and stone formation

Drug Name	Nitrofurantoin (Furadantin, Macrodantin, Macrobid) -- Synthetic nitrofuran that interferes with bacterial carbohydrate metabolism by inhibiting acetylcoenzyme A. Bacteriostatic at low concentrations (5-10 mcg/mL) and bactericidal at higher concentrations. Another common prophylactic antimicrobial agent, which is also excreted in urine, allowing urinary levels to be high while having few effects on fecal flora. Inexpensive and comes in both liquid and tab preparations. Rarely, associated with peripheral neuropathy and pulmonary hypersensitivity. SR formulation available; liquid susp (25 mg/5 mL) also available.
Adult Dose	Treatment: 25-100 mg PO qid SR: 100 mg PO bid Prophylaxis: 25-100 mg PO qd
Pediatric Dose	<1 month: Do not administer (because of risk of hemolytic anemia from immature erythrocyte enzyme systems) 1 month to 12 years: Treatment: 5-7 mg/kg/d PO divided qid Long-term suppression: 1-2 mg/kg/d PO >12 years: Administer as in adults
Contraindications	Documented hypersensitivity; renal insufficiency (<60 mL/min CrCl); anuria; oliguria
Interactions	Anticholinergics may delay gastric emptying and increase absorption, increasing nitrofurantoin bioavailability; antacids made of magnesium salts may decrease effects of nitrofurantoin, decreasing absorption; high doses of probenecid concurrently with nitrofurantoin decrease renal clearance and increase nitrofurantoin toxicity
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Acute, subacute, and chronic pulmonary reactions have been observed (eg, insidious pulmonary fibrosis); these reactions are rare and generally occur in patients receiving therapy >6 mo; other reported reactions include GI upset, hepatitis, and peripheral neuropathy; monitor pulmonary, hepatic, and neurologic status in patients on long-term therapy; nitrofurantoin may cause severe and irreversible peripheral neuropathy that can be fatal; renal impairment, diabetes mellitus, electrolyte imbalance, anemia, and vitamin B deficiency increase risk of adverse effects

Drug Name	Amoxicillin (Trimox, Amoxil) -- Interferes with synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria. Used as prophylaxis in certain oral, gastrointestinal, or genitourinary procedures.
Adult Dose	Treatment: 500 mg PO tid Prophylaxis: 500 mg PO qd
Pediatric Dose	Treatment: 40 mg/kg/d PO divided tid Prophylaxis: 15 mg/kg PO qd
Contraindications	Documented hypersensitivity
Interactions	Allopurinol may increase risk of rash
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal impairment; may cause diarrhea, abdominal cramps, or rash; monitor for bacterial overgrowth or antibiotic-induced candidiasis

	FOLLOW-UP	Section 8 of 11
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Further Outpatient Care:

• PUV is a lifelong disorder that can have a profound effect on the entire urinary tract. As such, patients need periodic long-term urologic follow-up care. The status of the kidneys determines the need for additional specialty follow-up care (eg, with a pediatric nephrologist).

• Resolution of obstruction: Relief of bladder outlet obstruction is the first step in treatment. After incision of the valves, a repeat VCUG or repeat cystoscopy 1-3 months later confirms valve resolution and urethral healing. These patients also may be at risk of subsequent urethral stricture formation; repeat these studies at any point in the future if any recurrent bladder outlet obstruction is indicated.

• Urodynamics: Chronic changes, which can lead to elevated intravesical pressures, may occur in the bladder of patients with PUV. This leads to upper tract changes, urinary incontinence, and recurrent UTI. These patients may need periodic urodynamic studies to determine bladder capacity, compliance, and postvoid residual urine volumes.

• Upper tract changes: Patients may have baseline renal dysplasia. Elevated bladder pressures and recurrent UTI further may compromise renal function. Obtain periodic renal sonography and serum creatinine levels. Severity of the renal and bladder dysfunction determines the frequency of these studies.

• Urinary incontinence: Approximately one third of patients with PUV have problems with diurnal enuresis when older than 5 years. Diurnal enuresis may be caused by the bladder changes that lead to elevated storage pressures and poor emptying. Rarely, sphincteric dysfunction secondary to valve ablation can be present. Treatment includes anticholinergic medication, intermittent catheterization, and in some patients, bladder augmentation.

In/Out Patient Meds:

• Because PUV is a lifelong condition due to an anatomic anomaly, medications may be necessary for years to suppress symptoms of infection or enuresis. All of the medications previously listed are intended for long-term use.

Transfer:

• Newborn care

• In the newborn with PUV, the first step in treatment is relief of bladder outlet obstruction by placement of a urethral catheter.

• Cystoscopic valve ablation or vesicostomy then can be performed when the child is stable.

• Rarely, a urethral catheter cannot be placed because of hypertrophy of the bladder neck (see Image 1). These patients require cystoscopy under anesthesia for catheter placement, suprapubic tube placement, or primary vesicostomy.

• Therefore, care of the newborn is dependent on having adequate instrumentation (eg, pediatric cystoscopic equipment) and expertise (eg, pediatric radiologist, pediatric urologist, pediatric anesthesiologist). If these services are unavailable, place a catheter (if possible) and transfer the child to an appropriate facility.

• Care of the older child

• Care of the older child also requires adequate equipment and expertise.

• Periodic radiologic and urodynamic evaluation is important to monitor the upper urinary tract and bladder changes. These evaluations occur over an extended period of time and rarely constitute an emergency.

• These patients require a timely referral to a center where appropriate services are available.

Deterrence/Prevention:

• Because PUV is a congenital anomaly of unknown origin, it is not preventable. Subsequent renal deterioration and bladder changes can be treated and minimized with adequate follow-up care.

Complications:

• In the newborn
  • Pulmonary hypoplasia secondary to intrauterine renal dysfunction and oligohydramnios is the primary cause of patient death.

  • Other complications of PUV are generally secondary to chronic bladder changes, leading to elevated detrusor pressures.

  • This, in turn, leads to progressive renal damage, infection, and incontinence.

• Renal insufficiency
  • Historically, of those patients with adequate pulmonary function, approximately 25% died of renal insufficiency in the first year of life, 25% died later in childhood, and 50% survived to adulthood with varying degrees of renal function.

  • Today, with the advent of better techniques in the treatment of pediatric renal insufficiency, most of these children can be expected to survive.

  • The goal of treatment is to preserve the maximal obtainable renal function for each patient. This entails aggressive treatment of infections and bladder dysfunction.

• Vesicoureteral reflux
  • Vesicoureteral reflux (VUR) commonly is associated with PUV, being present in as many as one third of patients (see Image 2).

  • VUR in most children is believed to be due to an insufficient intravesical ureter.

  • When associated with PUV, reflux is generally secondary to elevated intravesical pressures.

  • Therefore, the treatment of VUR in patients with PUV involves treatment of intravesical pressures through anticholinergics, timed voiding, double voiding, intermittent catheterization, and at times, bladder augmentation.

• Urinary tract infections
  • Recurrent UTIs are common in patients with PUV.

  • Elevated intravesical pressures predispose patients to infection, possibly by altering urothelial blood flow.

  • Additionally, patients with PUV may have elevated postvoid residual urine volumes, leading to stasis of urine.

  • Dilated upper urinary tracts, with or without VUR, further elevate UTI risk.

  • UTI management is directed at lowering bladder pressures (anticholinergic medication), lowering postvoid residual urine volume (via clean intermittent catheterization), and at times, administering prophylactic antibiotics.

• Urinary incontinence

• The same factors that lead to VUR and UTI also lead to urinary incontinence.

• Correct management of bladder function depends on adequate bladder evaluation with urodynamic studies.

• Lowering bladder pressure, improving bladder compliance, and minimizing postvoid residual urine volume contribute to attainment of urinary continence.

• In some, bladder augmentation may be needed.

Prognosis:

• The prognosis of children with PUV is improving continually.

• In the past, most children were found to have PUV only after presenting with urosepsis or progressive renal insufficiency. Older series demonstrated mortality rates approaching 50% by late adolescence.

• Today, most individuals with PUV are discovered by prenatal sonography exhibiting hydronephrosis.

• Prompt resolution of bladder obstruction, aggressive treatment of bladder dysfunction, and improved surgical techniques have lowered the neonatal mortality rate to less than 3%.

• Approximately one third of patients progress to renal insufficiency in their lifetimes. Improved dialysis and transplantation techniques have significantly improved not only the mortality rate for these children but also their quality of life.

• Additionally, medical and surgical management can achieve urinary continence in nearly all patients.

Patient Education:

• PUV is a lifelong condition requiring continued medical management. Because of this, both the physician and family must understand the potential long-term complication of renal deterioration if bladder function is not treated adequately.

• Patients and families need realistic expectations regarding continence. While achievable in nearly all of these patients, continence is often dependent upon adherence to a timed voiding schedule and intermittent catheterization.

• Patients and families also need to realize that medications, such as anticholinergics and suppressive antibiotics, are for control of the symptoms of PUV and are not curative.

• For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center. Also, see eMedicine's patient education article Bladder Control Problems.

	MISCELLANEOUS	Section 9 of 11
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Medical/Legal Pitfalls:

• Several publications have recently suggested aggressive evaluation of pediatric UTIs. Often, a UTI may be the only sign of significant underlying urologic pathology. While most patients with PUV are identified because of abnormal findings on prenatal sonography, a significant number present later in life with symptoms of UTI or diurnal enuresis recurring or persisting in children older than 5 years. Because of this, the author recommends that any male child older than 5 years with a documented UTI or diurnal enuresis undergo renal and bladder sonography and VCUG.

Special Concerns:

• The primary special concerns involved with patients with PUV pertain to the issues of upper urinary tract preservation, UTI, and diurnal urinary incontinence, all of which are secondary to decreased bladder compliance.

• Remember that PUV is a dynamic disease that can have lifelong effects on the bladder. These patients need long-term follow-up care to monitor and treat the effects of altered bladder compliance.

	PICTURES	Section 10 of 11
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Caption: Picture 1. Posterior urethral valves (PUV). Note hypertrophied bladder neck and dilated posterior urethra proximal to valve narrowing.
	View Full Size Image
Picture Type: X-RAY

Caption: Picture 2. Posterior urethral valves. Note irregular trabeculated bladder and high-grade vesicoureteral reflux (VUR).
	View Full Size Image
Picture Type: X-RAY

	BIBLIOGRAPHY	Section 11 of 11
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

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Posterior Urethral Valves excerpt