Children's Hospital Boston's Center for Exstrophy
By: Joseph Borer, MD, Alan Retik, MD, chief of Urology and
Rosemary Grant, RN, Urology
What is bladder exstrophy?
Bladder exstrophy is a complex congenital anomaly involving the urinary, reproductive and intestinal tracts, as well as the musculoskeletal system. The abdominal wall and underlying structures don't properly fuse in utero, and the infant is born with the bladder exposed inside-out on the outside of the body. Associated conditions can include a widened pubic bone, abnormally-shaped and weakened abdominal muscles, and a shorter than average urethra and vagina or penis.
Who does it affect?
There are approximately 400 new cases of bladder exstrophy per year in the United States, and males are affected 1.5 to 2.3 times more often than females. Children's Hospital Boston's Center for Exstrophy is known internationally for its preeminent care of these children, caring for 23 newborns with the diagnosis since 1996.
What causes it?
While it isn't known exactly what causes bladder exstrophy, the most popular theory suggests overdevelopment of the cloacal membrane, a temporary membrane that gives way during normal fetal development. Overdevelopment of the cloacal membrane prevents appropriate tissue development and growth of the lower abdominal wall structures, which results in "herniation" of the open bladder and urethra on the front lower abdomen.
How is it diagnosed?
Bladder exstrophy is diagnosed either immediately at birth or during a fetal ultrasound. A prenatal diagnosis is optimal because it provides time for education and preparation for the expectant parents, a scheduled induction of labor, a scheduled pre-operative evaluation and surgery, and continuity of care with familiar and experienced clinicians.
How is it treated?
The complex surgical repair of bladder exstrophy is performed with either the staged approach or the recently re-
popularized complete primary repair technique.
The staged approach consists of three surgical components:
The bladder, posterior urethra and abdominal wall are closed during the newborn period.
The urethral closure (epispadias repair) is done at 6 months to 1 year of age.
- The bladder neck reconstruction for urinary continence and bilateral ureteral re-implantation (for vesicoureteral reflux-the abnormal flow of urine from the bladder back into the ureters), are performed at 4 to 5 years of age, when the child has adequate bladder capacity, and is willing and able to participate in a voiding program after the surgery.
Although there are numerous successful outcomes with a staged approach, there has been a renewed interest in complete primary repair of exstrophy (CPRE). This technique combines the goals of staged reconstruction into a single operation. Taking this approach means the complete surgical repair is done sooner, and normal bladder function (filling and emptying) can begin earlier. This allows for optimal bladder growth and development, making CPRE the preferred method of treatment for bladder exstrophy at Children's.
After surgical repair, the Urology team and the child's caregivers share the responsibility of lifelong follow-up care, paying careful attention to the child's development, growth, and overall health, particularly bladder and kidney function. Vesicoureteral reflux, upper urinary tract deterioration, and urinary tract infections are some complications that can arise and require further medical care.
What is the typical outcome?
The most important goals in the treatment of bladder exstrophy are to preserve normal kidney function, to develop adequate bladder function, including urinary continence, and to provide acceptable appearance and function of the external genitalia. Although further surgery beyond the initial repair is sometimes required to meet these goals, the majority of patients with bladder exstrophy do achieve urinary continence and adequate bladder function, as well as normal sexual function and fertility potential.
Are there support groups?
Children's has pioneered efforts in the support and psychosocial development of patients with bladder exstrophy. The Exstrophy Support Group is a combined effort of Children's Department of Urology, Center for Families, and other staff and volunteers. They provide education and interaction among patients and families with teen chats, guest speakers, parent-to-parent networking, and medical play for younger children.
Innovative Treatments and Research at Children's
Antenatal intervention, such as covering the exstrophy tissue or repairing the exstrophy itself in utero, is being considered. Investigational efforts in an animal model have proven the capability of taking a biopsy of the fetal bladder tissue, expanding this tissue in the laboratory and having it available for postnatal return to the newborn if deemed necessary.
Detailed analysis of the soft tissue and bony anatomy of the pelvis through an MRI is a staple in the pre- and post-operative CPRE evaluation of children with bladder exstrophy. This analysis will help assess attempts to recreate normal pelvic anatomy, and correlate findings with clinical aspects of outcome, such as urinary continence.
Innovative surgical techniques
Based on the critical review of anatomical detail, new and more effective surgical techniques and approaches are being developed to improve outcomes.