Bladder Exstrophy

Sometimes factors can occasionally interfere with bladder development, as is the case for children with bladder exstrophy. If your newborn has been diagnosed with this condition, what can you expect? The following information should help you talk to your child's doctor.

What is bladder exstrophy?

Bladder exstrophy is an abnormality present at birth in which the bladder and associated structures are improperly formed. Rather than being its normal round shape, the bladder is flattened. The skin, muscle and pelvic bones joining the lower part of the abdomen do not form properly so the inside of the bladder is exposed outside the abdomen. There are associated deficiencies of the abdominal muscles and pelvic bones also.

How often does it occur?

It is a rare occurrence. The incidence of bladder exstrophy varies in different parts of the world, but it occurs in approximately 2.07 per 100,000 live births and is slightly more common in males than females. The risk of a family having more than one child with this condition is approximately one in 100, and children born to a parent with exstrophy have a risk of approximately one in 70 of having the condition. Recent published evidence suggests that the risk of bladder exstrophy in children born as a result of assisted fertility techniques is seven times greater than in children conceived naturally without assistance.

Why does it happen?

There is no known cause for this condition but there are many theories. Some experts believe during the 11th week of pregnancy the embryo undergoes structural changes including ingrowths of tissue in the lower abdominal wall, which stimulates development of muscles and pelvic bones. Up to this point the primitive bladder and rectum are contained within tissue called the cloacal membrane. The rectum then separates from the bladder, and if migration of tissue towards the midline over the primitive bladder fails the cloacal membrane may rupture, creating an exstrophied bladder. The exact timing of premature rupture of the membrane determines whether the child is born with isolated epispadias, classic bladder exstrophy or cloacal exstrophy. Generally classic bladder exstrophy is an isolated birth defect but spinal cord abnormalities occur in about 13 percent of cases.

It is known, however, that it is not a result of anything that a parent did or did not do during pregnancy.

How is it diagnosed?

Frequently it can be detected before birth during a routine sonogram. Nonetheless, this condition will be obvious at birth.

What will happen when the child is born?

If this condition has been detected before birth, arrangements will usually be made for birth at a specialist unit where a pediatrician and surgeon can assess the baby immediately. Alternatively, if the condition is not detected until the time of birth, transfer to such a unit for assessment will need to be arranged for the first day of life. In either case, the bladder will be visible on the outside of the baby's abdomen and assessment of bladder size and quality, the shape of the pelvis and also the condition of the genitals will be made.

What treatments are available?

Bladder exstrophy is treated surgically. Several surgical treatment options are available but they depend upon the severity of the condition.

The primary treatment objectives are:

  1. securely closing the bladder, posterior urethra and pelvis
  2. reconstruction of a cosmetically pleasing and functioning penis in the male and external genitalia in the female
  3. achieving urinary continence while ensuring preservation of kidney function

One form of treatment is modern staged reconstruction that involves closure of the bladder and pelvis in the newborn period, early reconstruction of the epispadiac urethra at approximately six months of age, and bladder neck surgery to achieve continence when the bladder has reached sufficient capacity and the child is psychologically ready to be dry (often around four to five years of age). Often further operations are needed to improve continence. Additional surgical procedures to improve the external genitalia are almost always required. In select cases where the bladder is of good quality and the penis is of good size, closure of the bladder and reconstruction of the penis and urethra can be combined in one operation. This is very technically demanding surgery and should only be performed by an experienced exstrophy surgeon.

The results of staged reconstruction have been well documented, and given the development of a bladder with sufficient capacity, continence can be achieved in up to 73-78 percent of cases. The most important factors in achieving continence are the quality of the bladder template and a successful initial bladder closure in the newborn. Of course, there are instances when the bladder at birth is of poor quality and unsuitable for closure in the way described, and a different management is adopted. Using techniques of modern reconstructive surgery, it is exceptionally rare for a patient to reach late adolescence without achieving continence and cosmetically acceptable external genitalia.

Other methods of treatment involve urinary diversion where the normal flow of urine is re-routed.

Frequently Asked Questions

What is the outlook for a baby born with this condition?

There is no doubt that in modern times, children with exstrophy can and do grow up to be robust individuals with a normal life expectancy and no real restriction on their lifestyle.

Are there other disorders associated with bladder exstrophy?

Yes, some of these may include: epispadias, vesicoureteral reflux, pubic diastasis, small bladder capacity or missing bladder neck and sphincter.