Exstrophy of the bladder (bladder exstrophy)

What is bladder exstrophy?

Bladder exstrophy is a complex combination of disorders that occur during fetal development (while the baby is still in utero). If the abdominal wall and underlying structures don't properly join together, a baby can be born with the bladder and other structures exposed on the outer surface of the body. The condition:

• affects about one in every 40,000 babies
• is more common in boys
• varies in its severity
• may be associated with urinary incontinence and backup of urine from the bladder to the kidneys, called vesicoureteral reflux, either of which may require additional medication or surgery

Are there associated defects?

Bladder exstrophy usually involves several systems within the body, including the urinary tract, reproductive tract (external genitalia) and pelvic skeletal muscles and bones. It’s quite uncommon, but some children’s intestinal tracts are also be involved. The most commonly associated defect is epispadias, a malformation in which the inner lining of the urethra is exposed and visible on the top surface of the penis (in boys) or between the labia (in girls).

Other associated defects include:

• abnormally shaped and weakened lower abdominal wall muscles
• displacement of the belly button, usually immediately above the defect and lower than normal on the abdominal wall
• shortened penis in boys
• narrow vaginal opening, wide-spread labia and short urethra in girls
• widened pubic bones
• outwardly rotated legs and feet

Causes

What causes exstrophy of the bladder?

Unfortunately, we don’t know the cause of bladder exstrophy. We do know that it occurs early in fetal development. Some studies show a clustering of the condition in families, suggesting that there’s an inherited factor. However, the chance for parents to have another child with exstrophy of the bladder is less than 1 percent. The absolute cause of bladder exstrophy is the subject of ongoing investigation. Here at Boston Children's Hospital Urological Laboratories and Manton Center (initative in genetic studies causes dissociations). 

Diagrams: click to enlarge

fig1. Normal urinary tract anatomy

fig2. Exposed inner bladder and urethra of a boy with bladder exstrophy

fig3. Exposed inner bladder and urethraUrinary tract of a girl with bladder exstrophy

FAQ

Q: How many surgeries will my child need for bladder exstrophy?
A: It depends on where your child is treated; please see our Treatment and Care tab for details. Here at Children’s Hospital Boston, we use a method called Complete Primary Repair of Exstrophy (CPRE) to treat the condition with a single surgery within the first few months after the baby is born.

CPRE allows the bladder to be closed and the epispadias to be repaired at the same time. The CPRE operation includes closure and internalization of the bladder (moving it inside the body), closure of the urethra (epispadias repair), repair of the penis in boys or the external genitalia in girls and repair/closure of the lower abdominal wall muscles and soft tissues.

Q: Will my child need bladder neck reconstruction if she undergoes CPRE?
A: The answer to this question is based on your child’s individual need for help achieving urinary continence (the ability to have normal dry periods between voiding/bladder emptying). Your child’s bladder capacity and his/her ability to stay dry—referred to as a dry interval—help to determine the need for a bladder neck reconstruction (BNR).

In the Modern Staged Repair of Exstrophy (MSRE) approach, which is a three-step surgery, BNR is the third stage and is performed on all patients. In the single-surgery Complete Primary Repair of Exstrophy (CPRE) approach, however, BNR is performed only on patients who have not achieved satisfactory urinary continence. So the determination as to whether or not your child will need BNR after CPRE depends on many factors, but perhaps, most importantly, on how her ability to be dry has developed following the initial surgery (CPRE). Based on our experience and that of other institutions, it appears that about three-quarters of boys and one-half of girls may eventually need bladder neck reconstruction following CPRE.

Q: Will my child be continent of urine (have the ability to be appropriately dry)?
A: One of our major goals when treating children with bladder exstrophy is to help your child attain total control of her bladder. Many children do well with the practice of good health habits, such as adequate fluid intake and a regular voiding program. If your child undergoes the CPRE approach to initial surgical management of bladder exstrophy—which entails a single surgery to close the bladder and repair the epispadias wothon the first few hours after a baby is born—she may need bladder neck reconstruction to help attain continence (as described above).

Some children may need help emptying their bladder. We help these children with a technique called Clean Intermittent Catheterization (CIC). This involves the passage of a soft pliable catheter either via the urethra or a well-hidden lower abdominal wall stoma (a surgically constructed tube/opening connecting the bladder to the skin surface). This allows for safe and painless emptying of urine from the bladder.

Although it’s quite uncommon, some children with bladder exstrophy may need bladder augmentation in order to increase the bladder’s capacity for holding urine. Although achieving continence may be challenging, it’s generally achievable in all cases.

Q: Will my child’s genitals look “normal”?
A: In addition to working to provide your child with total control over her bladder, we also aim to ensure that your child’s genital area has a satisfactory cosmetic appearance. Genital repair is performed at different points in care or at different ages for boys and girls, and may depend on whether your child’s doctor opts for single surgery (CPRE) or the three-part surgery (MSRE).

Q: If I have another child, will he or she also have bladder exstrophy?
A: Although there’s a chance that parents can have another child with exstrophy of the bladder, the risk of a sibling being born with bladder exstrophy is very low—less than 1 percent.

Q: Will my child be able to play sports?
A: Definitely. The expectation is that your child should be able to enjoy a normal, active childhood. The one difference is that she will potentially have to take special care regarding urinary continence. Even children with bladder exstrophy who are normally continent during the day may have “stress incontinence” or incontinence while running, jumping, coughing or any other activity that puts stress on the bladder. This may cause your child to have small to moderate urinary leakage and she may need to wear a pad while she’s active. However, this doesn’t mean she can’t play and enjoy sports.

Q: Will my child be able to have children when he or she grows up?
A: Almost all boys with exstrophy produce healthy sperm. However, some may have difficulty fathering children through traditional sexual intercourse. The potential difficulty is in the delivery of the sperm to the egg. Difficulties may be a result of backward flow of semen during ejaculation (also known as retrograde ejaculation), the inability to ejaculate at all or low semen volume. The good news is that, if necessary, men may be able to use Assisted Reproductive Techniques (ART) such as intrauterine insemination and in vitro fertilization.

If girls with bladder exstrophy have a problem with sexual function and infertility, it’s most often a result of an anatomical concern. In some, the vaginal opening may be too narrow and may require surgical enlargement. When necessary, this procedure should allow for normal sexual intercourse and achieving pregnancy. 

Some women with bladder exstrophy may develop uterine prolapse, in which anatomical support for the uterus is lacking and the uterus may protrude into the vagina during the later stages of pregnancy. If this happens, a woman may need surgery, but she can still have babies by vaginal delivery or Caesarean section(C-section), although the latter is often recommended so that her urinary continence isn’t affected during vaginal delivery.

Q: What are the expectations regarding my child’s quality of life?
A: This is a question unique to each family. Our interdisciplinary team welcomes the opportunity to discuss any of your concerns. It’s important to note that we expect that your child will be open to and a capable participant (should she desire) in any and all of life’s joyful moments and childhood activities. Your child’s experience should be much the same as any other child her age, with the understanding and appreciation for the fact that every individual’s life is special and unique.

Glossary of terms

A guide to key terms that you may encounter when coping with your child’s bladder exstrophy.

Anesthesia: General anesthesia refers to a medically controlled, fully relaxed and unconscious state during which one is unaware of any discomfort or feeling. This is typically used during surgery and usually involves the use of a breathing tube.

Antibiotic prophylaxis: A once-daily administration of an oral antibiotic in order to decrease the risk of urinary tract infection.

Bladder (urinary): An organ that is normally the shape of a closed round sphere located deep in the lower abdomen or pelvis. Normal functions of the urinary bladder include storage of urine it receives from the ureters and emptying or urine through the urethra.

Bladder augmentation: This procedure is rarely necessary in a child with bladder exstrophy. Augmentation involves enlarging the bladder and increasing bladder capacity with the use of an intestinal segment or, more rarely, a portion of the stomach.

Bladder capacity: the total amount or volume of urine that the bladder can hold.

Bladder exstrophy: A malformation in which the bladder is open and the inner surface of the bladder is exposed on the lower abdominal wall. Urine leaks freely from the exposed surface of the bladder.

Bladder infection: A urinary tract infection involving the bladder. Typical symptoms may include pain in the lower abdomen, burning or pain with urination, frequent voiding or urgent need to void and/or new urinary incontinence.

Bladder neck: Anatomical site that marks the transition from the bladder to the urethra. This is the site of a urinary sphincter. The bladder neck plays a major role in urinary continence or one’s ability to be dry.

Bladder outlet obstruction: Abnormal narrowing or blockage to the normal flow of urine from the bladder and urethra out of the body. May occur as a result of initial repair of bladder exstrophy or after bladder neck reconstruction.

Catheter: A soft tube made of plastic that allows emptying of urine from the bladder when passed from the surface via the urethra such as during clean intermittent catheterization. A catheter is used to instill fluid in the bladder when performing a bladder x-ray or urodynamic study.

Clean intermittent catheterization: Passage of a catheter into the bladder at regular time intervals in order to empty the bladder of urine in individuals that otherwise can’t empty the bladder. Often needed if a child has a bladder outlet obstruction.

Continence (urinary): The ability of a person to stay dry and hold urine for a normal period of time between voiding or bladder emptying.

Epispadias: A malformation in which the inner lining of the urethra is exposed and lies flat and visible on the top surface of the penis (in boys) or between the labia (in girls).

Incontinence (urinary): Abnormal leakage of urine from the bladder out of the body. The inability to stay continent of urine, or dry for a normal amount of time between voiding or emptying of the bladder. May also be called daytime wetting ordaytime urinary incontinence.

Kidney: An organ in the body that is responsible for production of urine. This helps balance the body’s fluid level and blood pressure. There are typically two kidneys in the body.

Nocturnal enuresis: Term applied to leaking or loss of urine from the bladder during sleep. This is common in children whether or not they have bladder exstrophy or epispadias. May also be called nighttime wetting.

Osteotomy: Surgical incision of one or more of the pelvic or pubic bones. It’ typically performed during an initial bladder exstrophy repair after a baby’s first two or three days of life.

Pyelonephritis: A more severe infection in the urine that involves both the bladder and one or both kidneys. This type of infection is typically associated with a fever. It’s also called an upper urinary tract infection orkidney infection.

Reflux nephropathy: Damage or scarring that may occur in one or both of the kidneys as a result of pyelonephritis. Typically associated with vesicoureteral reflux, infected urine and kidney infection. This damage is not reversible.

Retrograde ejaculation: Backward flow of semen into the bladder during ejaculation in the male.

Sphincter (urinary): A group of muscular structures present at the bladder neck and around the urethra. These muscles have the ability to contract or relax in order to either hold or release urine within the bladder. The urinary sphincter plays a major role in continence and urinating.

Symphysis pubis: Refers to the normal near joining of the pubic bones in the front midline of the body just above the genitals.

Ureter: This is a hollow tubular structure that transports urine from where it is made in the kidney down to the bladder. A ureter has muscle cells within its wall in order to help propel urine toward the bladder.

Ureteral reimplantation: Surgical repositioning of the ureters within the urinary bladder in order to treat and eliminate vesicoureteral reflux.

Urethra: The urethra is a tubular structure that transports urine from the bladder to the outer surface of the body.

Urgency: A strong desire to urinate or void.

Urinary tract infection (UTI): An infection of the urine typically confined to the bladder. It’s also called a bladder infection, a lower urinary tract infection or cystitis.

Urination: Emptying the bladder of urine through the urethra. May also be called voiding or micturition.

Urodynamic study: A bladder function test that determines pressures within the bladder during storage and emptying functions of the bladder.

Uterine/vaginal prolapse: Loss of normal supporting forces or structures that keep the uterus and/or vagina within the body. At times, this may allow one or both of these structures to be visible on the surface.

Vesicoureteral reflux: Backflow of urine from bladder into one or both ureters and, at times one or both kidneys.

Voiding cystourethrogram: A bladder x-ray that assesses anatomy of the bladder and urethra. This study also allows determination of whether or not vesicoureteral reflux is present.

List of abbreviations

ART      Assisted reproductive techniques

BE        Bladder exstrophy

BNR     Bladder neck reconstruction

BUR     Bilateral ureteral reimplantation

CIC      Clean intermittent catheterization

CPRE   Complete primary repair of (bladder) exstrophy

MRI      Magnetic resonance imaging

MSRE   Modern staged repair of (bladder) exstrophy

UDS     Urodynamic study

US       Ultrasound

VUR     Vesicoureteral reflux