Please select from the following frequently asked questions for the answers:
Definitions
- What is bladder exstrophy?
The word Exstrophy is derived from the Greek word ekstriphein, which literally means to "turn inside out." Bladder exstrophy is a malformation of the bladder, in which the bladder and related structures are turned inside out. The skin of the lower abdominal wall that normally covers the bladder also does not form properly and is separated, thus exposing the inside of the bladder to the external world. If you imagine a balloon that has been split and opened up so that the inside of the balloon is visible, you will have a picture of what has happened.
- What other abnormalities are associated with bladder exstrophy?
A baby with this condition will usually also have all, or some, of these other associated abnormalities:
- Epispadias: In boys, the urethra (the tube through which urine is funneled out of the body from the bladder) has not formed completely, and it may be extremely short and split. Because of this, it opens on the upper surface rather than on the end of the penis. The split may be small or involve the entire length of the penis. In the later case, the penis will be flat and short looking like a small shovel. In girls, the urethral opening is located between a split clitoris and labia minora.
- Dorsal chordee: This means that the penis is pulled up against the abdomen with a slight downward curve. This is caused by a shorter than normal tendon in the upper part of the penis.
- Absence of a bladder neck and sphincter: The bladder neck is the funnel shaped lower portion of the bladder which contains the ring of muscles that open and close the bladder outlet. It is this muscle ring (sphincter) which makes it possible to achieve bladder control or continence. When it is absent there is no ability for bladder control.
- Small bladder capacity: This means that the bladder is unable to hold a normal quantity of urine.
- Abnormally positioned ureters: Ureters (the tubes which channel urine from the kidneys to the bladder) enter the bladder abnormally resulting in urine backing up toward the kidneys (reflux).
- Separation (diastasis) of the pubic bones: The large bones which make up the pelvic cavity normally develop as a ring. The pelvis supports the bladder, the reproductive and the lower intestinal organs. The pubic bones normally join to form the front portion of the pelvis and to protect the bladder, the urethra, and the muscles of the abdominal wall. In bladder exstrophy the pubic bones have failed to join, leaving a wide opening. This open pelvic ring also results in the hips being turned outward (rotated). This causes the child with exstrophy to "toe-out", or to have their feet point away from one another when they stand or walk. However, children with exstrophy should be able to run, jump, and play normally despite the pelvic deformity, and there is no evidence that exstrophy results in arthritis of the hips in later years.
- An anus positioned further forward than usual: The opening of the rectum is positioned more anterior (closer to the scrotum /vagina). This positioning is typically not accompanied by problems with bowel function.
- A low positioned belly button (umbilicus): The umbilicus is not usually visible and is removed when the bladder is surgically closed.
Causes and Disease Development
- At what stage of prenatal development does bladder exstrophy occur?
The condition of exstrophy occurs during the development of the embryo (the name given to the baby during this stage) very early in the pregnancy, about 4 to 5 weeks after conception. The cause and nature of the faulty development is not exactly certain. It is 4 to 5 weeks after conception that the various organs and different types of muscles and tissues of the body begin to form from layers of cells that separate, divide and fold. One theory suggests that something goes wrong during this early folding and separation, causing the cloacal membrane to fail to close, leaving the bladder outside of the abdominal wall. A second theory proposes that the layer of skin which forms over the bladder at this stage is thin and unable to hold in the bladder. It pulls apart, again leaving the bladder inside out.
- What determines the extent of the exstrophy?
The extent of the exstrophy depends on how small or how large the opening is. One can think of exstrophy as a spectrum of conditions that ranges from the milder form, epispadias (only a urethral defect or opening), to the most severe form, cloacal exstrophy (defect of the urethra, bladder and bowel), with classic bladder exstrophy (defect of urethra and bladder) being in the middle.
- What causes bladder exstrophy?
Medical science has no explanation for why an embryo may develop bladder exstrophy. It is not because of anything the mother or father did or did not do during the pregnancy. On the other hand, it is not simply an inherited condition.
- What is the likelihood that a child will be born with bladder exstrophy?
Although bladder exstrophy occurs in only 1:30,000 births in the general population, it may be more likely to recur in a family. Based on some studies, there may be a 1:100 chance of it among siblings and a 1:70 chance of it among offspring of a person with bladder exstrophy. Exstrophy of the bladder also occurs 2-3 times more frequently in males than in females.
- Cloacal exstrophy: The incidence of cloacal exstrophy is 1:200,000 and is much less common in females. This disorder is much more complex than exstrophy and requires an extensive evaluation for associated abnormalities of the nervous system, upper urinary tract, and gastrointestinal tract. The treatment of storage abnormalities of the bladder usually involves bladder augmentation with intestinal segments. Clean intermittent catheterization also may be required to maintain urinary continence.
- Female epispadias: Female epispadias may result in a variable presentation depending on the severity of the urethral defect. In complete epispadias, incontinence results secondary to (1) a foreshortened and widened urethra, (2) a partially absent external urethral sphincter, and (3) a poorly developed bladder neck. Treatment is directed at reconstruction of these deficient structures and at ureteral reimplantation proximal to the reconstructed bladder neck region. Persistent incontinence may be treated with collagen injection at the bladder neck.
- FAQ's
- I have one child with exstrophy. What is the chance of our having another?
Once you have a child with exstrophy, the chance of having another drops from 1/40,000 to 1/250 or so. But you must first have a proband (the child with the actual birth defect) before the risk goes up. This statistic is from Campbell's Urology (2008).
- Why does the risk go up after having a child with exstrophy?
As soon as the gene is found for exstrophy we will know more definitively. Generally speaking, once a gene is expressed (a birth defect happens) it is more likely to be expressed again.
Treatment
- How are bladder exstrophy and its related conditions treated?
Exstrophy of the bladder requires surgical repair. The treatment plan devised for your child will depend on the type and the extent of the abnormality. Just as no two exstrophy children are exactly the same, no two treatment plans will be the same. The surgical care of the child with exstrophy has evolved significantly, and research continues with the goal of correcting the defect and achieving continence with one single procedure.
- How long does treatment last?
At this time the current treatment involves a series of surgeries over a number of years. This plan is called staged reconstruction. The exact timing, nature, and outcome of these surgeries will depend on your child's particular situation. Your surgeon will discuss with you the plan for your child and how successful you can expect it to be.
- What are the goals of treatment?
The goals of the staged reconstruction include (a) closure of the bladder and urethra, (b) closure of the abdominal wall, (c) preservation of kidney and sexual function, (d) satisfactory cosmetic appearance of the penis in the male and external genitalia in the female, and (e) a psychologically stable child and family.
- How is treatment usually approached?
The following is an overview of the staged reconstruction and the way in which surgical treatment is usually approached:
- Primary closure of the bladder is usually performed within 24-48 hours of birth. During this surgery, the separated pelvic bones are brought together, the bladder is closed and remodeled to allow it to hold urine, the bladder is placed inside the pelvis, and the abdominal wall is closed over the repaired bladder.
- Genital repair is often accomplished at different times for the boy and girl with exstrophy. In females, the genitalia and urethral repair can often be accomplished at the time of the initial bladder closure. In males, reconstruction of the penis and urethra (epispadias repair) is usually accomplished between 1 and 2 years of age. This surgery is also important in that it usually causes some urethral resistance, which in turn results in pooling of urine in the bladder which can stimulate bladder growth and capacity.
- Bladder neck reconstruction is accomplished to allow the child to achieve control of urine. It is typically performed at approximately 5 years of age, to allow for continence before starting school. During this surgery, the ureters are repositioned to prevent reflux of urine back up to the kidneys and a bladder sphincter is created that can open and close. This procedure is usually accomplished only after the bladder has grown to a reasonable size.
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