Bladder Exstrophy
A congenital genitourinary malformation belonging to the spectrum of the exstrophy-epispadias complex (EEC) and is characterized by an evaginated bladder plate, epispadias and an anterior defect of the pelvis, pelvic floor and abdominal wall.
Epidemiology
The prevalence at birth for the EEC is reported at 1/10,000. As epispadias (E), classic bladder exstrophy (CEB) and cloacal exstrophy (EC) are now recognized clinical variants of the same spectrum, accurate epidemiological data on E/EC/CEB are no longer available. However, CEB appears to be more frequent in the white population. Most studies report a male-to-female ratio of around 2.4:1, but ratios as high as 6:1 have also been reported.
Clinical description
CEB is evident from birth, with the reddish bladder mucosa being visible in the lower abdomen and mucosal polyps sometimes present on the surface. Urine drips from the ureteric orifices on the bladder surface. Other findings include pubic diastasis of various degrees with divergent rectus muscles and inguinal hernias. In males, the penis is short and broad with dorsal chordee. The urethral plate covers the whole dorsum of the penis from the open bladder to the glandular grove. Both corpora cavernosa are located beneath the urethral plate and the colliculus seminalis and the ductus ejaculatorii are visible as tiny openings in the area where the prostate is presumably dorsally located. Females present with a bifid clitoris next to the open urethral plate. The vaginal opening appears narrow and the perineum is shortened due to the anterior displacement of the vagina and anus. Women with CEB have a predisposition for vaginal or uterine prolapse. Spinal anomalies occur in about 7% of cases but gastrointestinal anomalies are rare in CEB.
Etiology
CEB results from early abnormal development of the intra-abdominal wall and bladder during rupture of the cloacal membrane. Though the underlying cause remains still unknown, a developmental field defect with both genetic and environmental factors is likely to play a role.
Diagnostic methods
Diagnosis is clinical. However, during follow-up, laboratory and imagining studies (such as ultrasound of the urogenital system, pelvic MRI or X-ray, voiding cystography and urodynamics) are useful to determine renal function and assess bladder capacity and detrusor function.
Management and treatment
Management is primarily surgical, with the main aims of obtaining secure abdominal wall closure, achieving urinary continence with preservation of renal function, and, finally, adequate cosmetic and functional genital reconstruction. Currently, several methods for bladder reconstruction with creation of an outlet resistance and epispadias repair (either as a staged or a one-stage approach) during the newborn period are favored worldwide. Removal of the bladder template with complete urinary diversion to a rectal reservoir can be an alternative.
Prognosis
After reconstructive surgery of the bladder, continence rates of about 80% are expected during childhood. Though spontaneous voiding is the main issue, additional surgery might be needed to optimize bladder storage and emptying function. In cases of definite reconstruction failure, urinary diversion should be undertaken. In puberty, genital and reproductive function constitute increasingly important issues for both sexes. Psychosocial and psychosexual outcome reflect the importance of long-term care (from birth into adulthood) from a multidisciplinary team of experts for parents and children with EEC to facilitate an adequate quality of life.