Bladder exstrophy is a congenital anomality in which part of the urinary bladder

Urinary bladder

The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...

 is present outside the body. It is rare, occurring once every 10,000 to 50,000 live births with a 2:1 male:female ratio. The diagnosis involves a spectrum of anomalies of the lower abdominal wall, bladder, anterior bony pelvis, and external genitalia. It occurs due to failure of the abdominal wall to close during fetal development and results in protrusion of the anterior bladder wall through the lower abdominal wall.

Treatment is with surgical correction of the defect, but patients can still have long term issues with urinary tract infections and urinary incontinence.

Pathogenesis

The cause of bladder exstrophy is maldevelopment of the lower abdominal wall, leading to a rupture which causes the bladder to communicate with the amniotic fluid.

Spectrum of anomalies

The typical manifestation of exstrophy-epispadias complex is

• bladder everted through a midline lower abdominal wall defect
• widening of the pubic symphysis
  Pubic symphysis
  The pubic symphysis or symphysis pubis is the midline cartilaginous joint uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis...
  
  
• epispadias
  Epispadias
  An epispadias is a rare type of malformation of the penis in which the urethra ends in an opening on the upper aspect of the penis. It can also develop in females when the urethra develops too far anteriorly...
  
   in males (dorsal cleft in the penis, exposing the urethral mucosa)
• the anus and vagina appear anteriorly displaced
• the testicles may be undescended
  Cryptorchidism
  Cryptorchidism is the absence of one or both testes from the scrotum. It is the most common birth defect regarding male genitalia. In unique cases, cryptorchidism can develop later in life, often as late as young adulthood. About 3% of full-term and 30% of premature infant boys are born with at...
  
  .
• bifid clitoris
  Clitoris
  The clitoris is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not...
  
   in females, with a short "urethral strip" indistinguishable from bladder mucosa.

The spectrum of disease extends from spade penis and epispadias

Epispadias

An epispadias is a rare type of malformation of the penis in which the urethra ends in an opening on the upper aspect of the penis. It can also develop in females when the urethra develops too far anteriorly...

 on one hand, to exstrophy with cloaca (also known as cloacal exstrophy

Cloacal exstrophy

Cloacal exstrophy is a severe birth defect wherein much of the abdominal organs are exposed. It often causes the splitting of both male and female genitalia , and the anus is occasionally sealed.Cloacal exstrophy is an extremely rare birth defect, present in only one in 200,000 pregnancies - one...

).

Diagnosis

Prenatal diagnosis of bladder exstrophy is difficult and sometimes impossible. Feature on prenatal ultrasound can include the absence of bladder filling, a low-set umbilicus, widening of the pubic ramus, small external genitalia and a lower abdominal mass. It can be found if the Sonographer cannot identify a normal bladder filling and emptying, despite adequate time spent looking. Most often the diagnosis is made after birth with the finding of an exposed bladder.

Evaluation and Management at Birth

At birth, the bladder mucosa is exposed and is quite sensitive. The umbilical cord should be tied with a 2-0 silk suture rather than a clamp to prevent trauma to the delicate mucosa. In addition, the bladder should be covered with a non-adherent film (Plastic Wrap) to prevent sticking of the bladder to diapers or clothing. With each diaper change the plastic wrap should be removed and the bladder irrigated with sterile saline and a clean wrap should be placed. The child should then be transferred to a tertiary care pediatric hospital for management of their bladder exstrophy.

Treatment

Modern therapy is aimed at surgical reconstruction of the bladder and genitalia, most often through a staged approach. The initial surgical management consists of bladder, posterior urethral and abdominal wall closure (with or without osteotomies). Bladder closure may be delayed if the bladder is deemed too small to close. The surgical management epispadius usually occurs at approximately 6–12 months of age. Reconstruction of the bladder neck is typically done at toilet training age (approximately age 4-5), once the child is able to and interested in participating in a bladder retraining program. In very carefully selected patients surgical management may be carried out in a single stage or in combined procedures.

Prognosis

Even with successful surgery, patients may have long-term problems with

• incontinence
• urinary reflux (see Vesicoureteral reflux
  Vesicoureteral reflux
  Vesicoureteral reflux is an abnormal movement of urine from the bladder into ureters or kidneys. Urine normally travels from the kidneys via the ureters to the bladder...
  
  )
• repeated urinary tract infections
• bladder adenocarcinoma
• colonic adenocarcinoma
• self-image
• uterine prolapse

Bladder exstrophy carries an increased risk for development of renal cell carcinoma.

Sexual function and libido are normal in exstrophy patients. Successful pregnancies and delivery in exstrophy patients have been reported.

External links

• Bladder exstrophy page at Children's Hospital Boston