Anorectal malformations

What are anorectal malformations?

Anorectal malformations occur when a baby’s anal opening, rectum and the associated sphincter muscles and nerves that help the body determine that it is time to go to the bathroom do not develop properly. As a result, the patient is unable to have normal bowel movements, which can lead to a host of other health problems.

Anorectal malformations are congenital defects that occur in developing babies early on in pregnancy. They can range from mild to complex and can develop differently in males and females. Treatment and prognosis will vary depending on the type and severity of the malformation.

What are the different types of anorectal malformations in children?

There are several types of anorectal malformation, each of which has its unique characteristics. Doctors typically classify malformations based on where the rectum ends in the abdomen and if there is a fistula – an abnormal connection that develops between organs which can cause stool to pass into other parts of the abdomen. Types of anorectal malformations include:

• Cloacal malformation: the vagina, rectum and urinary tract are combined into a single channel
• Imperforate anus: the anal opening is missing or blocked
• Rectal atresia: the rectum does not connect to the anus
• Rectal stenosis: the anus or rectum is too small to allow stool to pass
• Rectobladder neck fistula: the rectum connects to the bottom of the bladder, where the urethra begins
• Rectourethral fistula: the rectum connects directly into the urethra
• Rectoperineal fistula: the rectum connects to the perineum, an area of skin between the anus and genitals
• Rectovaginal fistula: the rectum connects to the vagina
• Rectovestibular fistula: the rectum connects to an area just outside of the vagina

What are the symptoms of an anorectal malformation?

Anorectal malformations cause problems with how a child has a bowel movement. These problems will vary depending on the type of malformation. Symptoms may include:

• Stomach swelling
• Not having bowel movements
• Difficulty having bowel movements
• Stool coming from the vagina
• Stool coming from the urine
• Urine coming from the anus

How are anorectal malformations diagnosed in children?

The key to receiving the best possible outcome is an accurate diagnosis. We offer, advanced tests and tools to diagnose anorectal malformations. If your child is being evaluated for an anorectal malformation, the following diagnostic tests may be performed:

• Abdominal ultrasound: to examine the urinary tract, kidneys and to look for fluid build up
• Echocardiogram: to detect possible heart defects
• Spinal ultrasound or MRI: to evaluate for spine abnormalities (such as a tethered cord) which may cause certain neurological problems
• X-rays: to examine the pelvic and stomach area
• A 3D cloacagram: this exam may be used for children born with cloaca to help define the anatomy and plan for surgery.

How are anorectal malformations treated?

Most babies with an anorectal malformation will need one or more specialized surgeries to correct the problem. Our experienced surgeons are trained in the surgical approaches for all types of anorectal malformations including implementingminimally invasive techniques. Surgical repair for anorectal malformation includes:

Colostomy

A colostomy is a surgical procedure that creates an opening for the colon, or large intestine to excrete waste in a small bag located outside of the body. Most babies born with an anorectal malformation will need a temporary colostomy within the first few days of life. The colostomy will ensure the baby can properly pass stool, helps to normalize digestion and greatly reduces the risk of infection.

Posterior Sagittal Anorectoplasty (PSARP)

Anorectal reconstructive surgery, also known as posterior sagittal anorectoplasty (PSARP), is performed to connect the rectum to the anal opening as well as close any abnormal openings that may interfere with the ability to have a normal bowel movement.  In cases where there is an absence of an anal opening, your surgeon will create a new one.

The majority of PSARP procedures are performed when a baby is between one and six months old. The type of PSARP performed will depend on the position of the rectum and anus (whether it is low or high), how well the sphincter muscles work, and if there are any abnormal openings (called fistulas) that need to be repaired. For appropriate cases, pediatric surgeons at the Montreal Children’s Hospital use minimally invasive, laparoscopic techniques to help reduce the damage to surrounding structures and minimize pain post-surgery.

Colostomy Closure

Your child’s colostomy will remain in place for approximately eight weeks following the reconstructive surgery to allow the rectum and anal opening to heal before coming in contact with any waste. When your child is ready and completely healed, the colostomy will be surgically closed. Within a few days, they will begin passing stools on their own through the anus. At first, stools will be loose and occur frequently. To protect your child’s skin from diaper rash and irritation, safe topical treatments should be applied. As your child continues to heal, their stools will normalize, becoming firmer and less frequent.

How will my child recover from surgery for anorectal malformation?

Recovery from anorectal reconstructive surgery will typically require two to four days in the hospital. For several months after surgery, anal dilations may need to be performed to help stretch the anus to the appropriate size for your child’s anatomy and age. Although surgery restores some function, the nerves and sphincter muscles your child relies on to let them know they need to go to the bathroom may be weak.

After surgery, some children continue to experience difficulty with constipation, soiling themselves and have problems potty training, but these can be successfully managed using a bowel management program. If necessary, this program will help restore your child to maximum function and strengthen their muscle after surgery. To combat constipation, a combination of a healthy diet, plenty of fiber and laxatives (if needed) should be maintained. You should speak with your surgeon about what recovery will mean for your child.