Cloacal Exstrophy (OEIS Syndrome)

What is cloacal exstrophy (OEIS Syndrome)?

Cloacal exstrophy, also known as OEIS Syndrome, occurs when a portion of the large intestine lies outside of the body, and on either side of it —and connected to it — are the two halves of the bladder. In boys, the penis is usually flat and short, with the exposed inner surface of the urethra on top. The penis is sometimes split into a right and left half. In girls, the clitoris is split and there may be one or two vaginal openings. Cloacal exstrophy (OEIS syndrome) is a very rare birth defect, affecting 1 in every 250,000 births. Although cloacal exstrophy is a serious condition and requires a series of operations, the long-term outcome is good for many children.

What are the signs of cloacal exstrophy?

In cloacal exstrophy, a baby’s bladder is open in the front and the inner surface is exposed on the lower surface of the abdominal wall. The exposed bladder appears as a right and left half, with the large intestine exposed and connected in the middle. This abnormal connection of the intestine and the bladder allows mixing of stool and urine. Cloacal exstrophy can occur as part of OEIS syndrome, which includes an omphalocele, extrophy, imperforate anus and spinal defects. In an omphalocele, some of the abdominal organs protrude through an opening in the lower abdominal wall muscles in the area of the umbilical cord. A translucent membrane covers the protruding organs. The omphalocele may be small, with only a portion of the intestine protruding, or large, with most of the abdominal organs (including intestine, liver and spleen) protruding outside of the body. In an imperforate anus, the anus has not been formed, and the colon connects to the bladder. Sometimes intestine is also present behind the bladder that is not in continuity. Spinal defects may either be major or minor. Many times, children born with cloacal exstrophy are also born with varying degrees of spina bifida.

What causes cloacal exstrophy?

The cause of cloacal exstrophy is unknown. It does not appear that any medications or activities of the expectant parents have any impact on the development of cloacal exstrophy. Based on our current knowledge, it is very unlikely that this condition can be prevented.

How we care for cloacal exstrophy

Cloacal exstrophy is corrected through a series of operations. The clinicians at the Colorectal and Pelvic Malformation Center at Boston Children’s Hospital have extensive experience in cloacal exstrophy repair and supporting you and your baby throughout the process. Our multidisciplinary team of physicians works together in coordinating initial surgical repair as well as long term follow-up and reconstructive needs.