Cloacal Anomalies

A cloacal anomaly is a rare type of anorectal malformation that occurs while a female fetus is still developing in its mother's womb. The rectum, vagina, and urinary tract are supposed to separate, creating three openings at the surface of the skin. In a cloacal anomaly, the rectum, vagina, and urologic structures join into one common channel. Cloacal malformations are rare and occur in about 1 in 20,000 to 1 in 25,000 newborn females.

The most complicated cloacal anomaly is cloacal exstrophy, a severe birth defect in which a child is born with many intra-abdominal structures, such as the large intestine and bladder, exposed. An omphalocele (a birth defect in which abdominal organs stick out of the navel) is often present as well.

There are many variations of cloacal anomalies, but all of them involve a single opening in the skin where the urethra would normally open. This usually leads to a common channel where the urethra and bladder, genital tract and the rectum join. Normally, each of these channels has a separate opening at the skin’s surface, but in a cloacal anomaly, the three tracts merge into one common channel and one opening.

Cloacal anomalies can vary depending on where these three tracts merge. If they join at a low point, the baby lacks a visible anus but has a short common channel, which allows waste to leave the body freely.

If the three tracts come together at a high point, the common channel is long, which makes it more difficult for waste to leave the body.

Specific defects may include:

• Variation in the degree of development of the bladder, reproductive organs, abdominal wall, and rectum
• Vaginal duplication or atresia (absence or abnormal closure of the vagina)
• Lack of or failure in the development of other female reproductive structures such as the uterus and fallopian tubes
• Imperforate anus, a condition where the anus has not been formed or is perforated and the colon connects to the bladder

Cloacal anomalies are often associated with the following conditions:

• Anomalies of the upper urinary system, sometimes including anomalies in one or both kidneys
• Anomalies of the bones in the pelvis or lower spine
• Anomalies of the spinal cord and, sometimes, the affected nerves

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

In some instances, cloacal anomalies can be diagnosed before birth with a prenatal ultrasound, which may be confirmed by magnetic resonance imaging (MRI). After birth, your baby’s doctor can make or confirm this diagnosis with a physical examination.

Your baby’s physician will likely conduct a careful analysis of structures of the upper urinary system and sacrum, as well as perineal and pelvic anatomy, using some combination of the following diagnostic imaging studies:

• Magnetic resonance imaging (MRI).
• Examination under anesthesia and endoscopy. This involves the insertion of a small instrument called an endoscope to view the interior of a hollow organ, such as the rectum, urethra, or vagina.
• Special types of X-ray tests called fluoroscopy studies. These include a 3D cloacagram, voiding cystourethrogram, and contrast enema.
• Abdominal ultrasound (sonography). This imaging method is used to view the anatomy of the internal organs as they function, and to assess blood flow.
• X-rays.

We may also recommend that your child undergo evaluation for esophageal, vertebral, tracheal, radial, or cardiac anomalies that are sometimes associated with cloacal anomalies.

Cloacal anomalies require surgical repair. The treatment plan devised for your child will depend on the type and extent of the abnormality.

Stabilizing your newborn

Before forming a treatment plan to correct a cloacal anomaly, your doctor’s immediate concern will be to stabilize your baby’s condition. This may involve the creation of a diverting colostomy to allow the passage of stool. In a colostomy, the large intestine is divided into two sections and the ends of the intestine are brought through surgically created openings (stomas) in the abdomen. The upper section allows stool to pass into a collection bag, while the lower section allows for drainage of mucus produced by the intestine.

The urinary bladder may also need to be decompressed to relieve obstruction of urine flow from the bladder and, at times, the kidney. Some children will be able to void urine on their own, but for others, intermittent catheterization may be needed to help eliminate urine. The vagina, if it develops an accumulation of fluid called hydrocolpos, sometimes also needs to be decompressed with a drain.

Surgical correction

After stabilization, and when your baby has had a chance to grow, our doctors will confirm the anatomic features of the anomaly and make a plan to correct it. Treatment typically involves the surgical creation of a urethra and vagina. In some children with less severe anomaly, the urethra and vagina are intact and do not need to be created, but simply have their openings brought to the skin surface. Finally, a reconstruction of the bowel, through a procedure called a "pull-through" of the colon, must be completed. For this procedure, the surgeon may have to open the abdomen to complete the connection of the colon to the rectum. This procedure is sometimes called a posterior sagittal anorectovaginourethroplasty (PSARVUP).

Follow-up and further surgery

Once your child has healed, a third operation will be performed to close the colostomy and reestablish normal bowel movements through the rectum. Further urinary or genital tract surgery may also be needed. At the time of colostomy closure, the team will also examine the urethra, vagina, and rectum for adequate healing.

Sometimes, depending on the malformation, more urologic reconstruction will be needed in the future. Your child’s urologist will decide if this is necessary.

The outlook for a child with a cloacal anomaly depends on a number of factors, including the extent of the problem, associated anomalies, whether the sacrum is affected, and the procedure used to correct the problem. The clinicians at Boston Children's have a great deal of experience treating children with all kinds of cloacal anomalies.

Our team will discuss your child’s potential for potty training for urine and stool. If your child is unable to potty train for stool, she can do our bowel management program. If your child has difficulty with potty training for urine, the urologist will help with different medical therapies to keep her dry and in normal underwear. Children with cloacal anomalies will require routine follow-up as they approach puberty. Our gynecologist is experienced in treating girls with cloacal anomalies.

Cloacal anomalies require surgical repair. The clinicians in the Colorectal and Pelvic Malformation Center at Boston Children’s Hospital have extensive experience in repairing a wide range of cloacal anomalies. We work together as a team to provide you and your child with a coordinated plan for reconstruction and future follow-up care — and can start planning interventions even before your child is even born.