Congenital urinary bladder anomalies often occur without other genitourinary abnormalities. They may cause infection, retention, incontinence, and reflux. Symptomatic anomalies may require surgery.
Bladder diverticulum
A bladder diverticulum is a herniation of the bladder mucosa through a defect in bladder muscle. It predisposes to urinary tract infections (UTIs) and may coexist with vesicoureteral reflux. It is usually discovered during evaluation for fetal hydronephrosis or recurrent UTIs in young children.
Diagnosis of bladder diverticulum is by voiding cystourethrography.
Surgical removal of the diverticulum and reconstruction of the bladder wall may be necessary.
Bladder exstrophy
In exstrophy, there is a failure of midline closure from the umbilicus to the perineum, resulting in bladder mucosa continuity with the abdominal skin, separation of the pubic symphysis, and epispadias or bifid genitalia. The bladder is open suprapubically, and urine drips from the open bladder rather than through the urethra. Despite the seriousness of the deformity, normal renal function usually is maintained.
The bladder can usually be reconstructed and returned to the pelvis, although vesicoureteral reflux invariably occurs and is managed as needed. Additional surgical intervention may be necessary to treat a bladder reservoir that fails to expand sufficiently or has sphincter insufficiency. Reconstruction of the genitals is required and may be done in the immediate postnatal period or may be delayed.
Megacystis syndrome
In this syndrome, a large, thin-walled, smooth bladder without evident outlet obstruction develops, usually in girls. Vesicoureteral reflux is common.
Megacystis syndrome is poorly understood. The syndrome may be a manifestation of a primary myoneural defect, especially when intestinal obstruction (eg, megacystis-microcolon, intestinal hypoperistalsis syndrome) is also present.
Symptoms are related to urinary tract infections (UTIs).
Ultrasonography with the bladder empty may disclose normal-appearing upper tracts, but voiding cystourethrography may show reflux with massive upper tract dilation.
Ureteral reimplantation may be effective, although some patients benefit from antibacterial prophylaxis, timed voiding with behavioral modification, intermittent catheterization, or a combination.
Neurogenic bladder
Neurogenic bladder is bladder dysfunction caused by neurologic disorders, including spinal cord or central nervous system abnormalities, trauma, or the sequelae of pelvic surgery (eg, for sacrococcygeal teratoma or imperforate anus).
The bladder may be flaccid, spastic, or a combination. A flaccid bladder has high-volume, low-pressure, and minimal contractions. A spastic bladder has normal or low-volume, high-pressure, and involuntary contractions. When present, chronically elevated bladder pressure (> 40 cm H2O) often causes progressive kidney damage, even without infection or reflux.
Manifestations include recurrent UTIs, urinary retention and/or incontinence, and potentially renal insufficiency.
The underlying neurologic abnormality is usually readily apparent. Usually, postvoiding residual volume is measured, renal ultrasonography is done to detect hydronephrosis, and serum creatinine is measured to assess renal function. Urodynamic testing is often done to confirm diagnosis and to monitor bladder pressures and function. These studies are often repeated at scheduled intervals as the child grows to assess for deterioration of bladder and renal function.
Management goals include lowering risk of infection, maintaining adequate bladder storage pressure and volume, effective bladder emptying, and achieving social continence. Treatment of neurogenic bladder includes drugs (eg, anticholinergics, prophylactic antibiotics), intermittent catheterization, and/or surgical intervention (eg, augmentation cystoplasty, appendicovesicostomy, botulinum toxin injections, neurostimulation). Children with neurogenic bladder often also have a neurogenic bowel with constipation and stool incontinence that also require proper management.
