Bladder Exstrophy (BE) is a rare, serious congenital birth defect characterized by the bladder being open and exposed outside the body, affecting the lower urinary tract, pelvic bones, and abdominal wall. Occurring in approximately 1 in 10,000 to 50,000 live births, it requires immediate and specialized surgical intervention. The condition is more common in males than in females, with a male-to-female ratio ranging from approximately 2:1 to 6:1. Despite its complexity, modern medical and surgical advances allow affected individuals to achieve a functional and healthy life.
Defining Bladder Exstrophy and the Exstrophy-Epispadias Complex
Bladder Exstrophy represents the middle and most common presentation within the Exstrophy-Epispadias Complex (EEC). The classic presentation involves the bladder’s inner lining, or bladder plate, being visible on the lower abdominal wall. This visible defect is accompanied by a failure of the abdominal wall to fully close below the umbilicus.
A defining feature is the separation of the pubic bones (pubic diastasis), which widens the pelvic ring and alters the attachment points for the pelvic floor muscles. This anatomical difference contributes to challenges in achieving urinary continence later in life. The condition is always associated with epispadias, an abnormality where the urethra is malformed and opens on the upper surface of the penis in boys or is split and positioned abnormally in girls.
The Exstrophy-Epispadias Complex includes a spectrum of severity. Epispadias is the mildest form, where only the urethra is malformed and the bladder remains inside the body. Classic Bladder Exstrophy (CBE) is the next level, involving the exposed bladder. The most severe form is Cloacal Exstrophy, where the defect extends to include the bowel, with the bladder and a portion of the large intestine being exposed.
Embryological Origins and Detection
The precise cause of Bladder Exstrophy remains unknown, but it results from a failure of normal development between the fourth and eighth weeks of gestation. The prevailing theory suggests that the cloacal membrane, a temporary structure covering the lower abdomen, ruptures or fails to be properly reinforced by the inward migration of mesoderm tissue. This failure prevents the development of the lower abdominal muscle wall and the midline closure of the pelvic bones.
The cause is considered multifactorial, involving a mix of environmental and genetic influences, but most cases are sporadic, meaning they are not inherited. Although there is a slightly increased risk if a parent or sibling has the condition, it is not typically a straightforward genetic inheritance pattern.
Bladder Exstrophy is often detected during routine prenatal ultrasound examinations, allowing families and medical teams to prepare for specialized care. Key signs on prenatal imaging include:
- Inability to visualize a properly filling bladder.
- A bulge noted in the lower abdomen.
- A low-set umbilical cord insertion.
- Abnormal widening of the pelvic bones.
If not identified prenatally, the diagnosis is made immediately after birth due to the unmistakable sight of the exposed bladder tissue.
Surgical Treatment and Reconstruction
Surgical intervention is required immediately after birth and is the only treatment method for Bladder Exstrophy. The primary goals are to close the bladder and abdominal wall, preserve upper urinary tract function, and reconstruct the external genitalia for acceptable appearance and function. The most common approach is the Modern Staged Repair of Exstrophy (MSRE), a series of operations performed over several years.
The first stage, the initial bladder closure, is typically performed within the first few days of life. This procedure aims to place the bladder back inside the pelvis and close the abdominal defect. In infants older than 72 hours or those with wide pubic bone separation, a pelvic osteotomy (cutting and repositioning the pelvic bones) may be performed to allow for a tension-free closure and better support.
The second stage, usually performed between six and twelve months of age, involves the repair of the epispadias to reconstruct the urethra and genitalia. This procedure uses techniques like penile disassembly to create a functional urethra and improve the appearance of the external genitalia. The final stage is the bladder neck reconstruction, typically performed around four to five years of age when the bladder has grown sufficiently.
This third operation aims to tighten the muscles around the bladder outlet to achieve urinary continence. An alternative is the Complete Primary Repair of Exstrophy (CPRE), which combines the initial bladder closure, epispadias repair, and bladder neck reconstruction into a single, complex surgery, often performed within the first few weeks of life. While CPRE can reduce the number of procedures, many patients still require multiple additional surgeries to achieve full functional goals.
Life After Repair: Long-Term Health and Function
Long-term outcomes for individuals with repaired Bladder Exstrophy have improved significantly, but ongoing follow-up care is necessary. Achieving urinary continence remains the most significant long-term challenge. Continence rates vary widely, but specialized centers report that up to 80% of children can achieve social continence (defined as a dry interval of three hours or more) following a full staged repair.
A large portion of continent patients achieve this through bladder neck reconstruction; however, only a select group (estimated around 25%) can void normally through the urethra without further intervention. Many individuals require Clean Intermittent Catheterization (CIC) to fully empty their bladder, even after successful reconstruction. For those who do not achieve adequate bladder capacity or continence, further procedures such as bladder augmentation may be necessary.
Preservation of renal health is a primary concern, requiring long-term monitoring of the upper urinary tract. Patients are at risk for conditions such as vesicoureteral reflux (VUR), where urine flows backward from the bladder toward the kidneys. If not managed, VUR can lead to recurrent urinary tract infections and potential renal scarring.
Reconstruction aims to provide cosmetically acceptable and functional genitalia. While male patients may experience a shorter penile length, sexual function is generally possible. Fertility is preserved in females, although the vaginal opening may be anteriorly displaced or narrowed. In males, fertility may be affected due to anatomical factors, but conception is still possible for many.