Intussusception

What is intussusception?

Intussusception is a serious problem in the intestine. When intussusception occurs, one part of the intestine slides into another section.

This is a condition in which a proximal portion of the bowel (intussusceptum) telescopes into the adjacent distal bowel (intussuscipiens). When the inner loop and its mesentery become impacted, a small bowel obstruction results.

It folds into itself like a collapsible tube with one part slipping inside another part. This creates a blockage and causes the intestines to not work properly.

What are the symptoms of intussusception?

Symptoms of this condition include:

Intussusception is a medical emergency. If it is left untreated, it may cause severe complications such as infection or even death.

• Severe abdominal pain (that can last for 15 to 20 minutes at a time)
• Swelling in the abdomen
• Vomiting
• Irritability
• Bloody stools
• Fever

What causes intussusception?

In most cases in children, the cause of intussusception is idiopathic. In less than 5% of cases, the intussusception contains a lead point, such as a polyp, a Meckel’s diverticulum, or hypertrophic lymphatic tissue. Most intussusceptions are ileocolic in origin.

There is no known cause for most cases of intussusception. Rarely, intussusception is caused by conditions such as appendicitis, tumors or a polyp (a growth inside the intestine).

Clinical signs

The classic clinical triad of intussusception is intermittent colicky abdominal pain, currant jelly stools, and a palpable abdominal mass. However, less than 50% of patients actually present with these symptoms. Children often cry and are very irritable during bouts of abdominal pain, and then become drowsy and lethargic. Vomiting and fever may also occur. Intussusception is most common in children 3 months to 4 years of age, with a peak incidence occurring at 3 to 9 months of age, and occurs more commonly in boys.

Who is at risk for intussusception?

Intussusception is the most common cause of intestinal blockage in children between 3 months and 3 years of age. Most cases of intussusception occur in babies younger than 1 year of age. For unknown reasons, boys are affected more often than girls. Intussusception also occurs in older children and adults, but there are far fewer cases in these groups.

Diagnosis

How is this condition diagnosed with imaging?

The most accurate imaging technique for the diagnosis of intussusception is ultrasonography (US).

The characteristic US appearance is an easily detectable mass measuring in the range of 3 to 5 cm. In the transverse plane, the mass has a “target” appearance (which contains echogenic fat), while the “pseudokidney” sign is how it will appear in the longitudinal plane.

A contrast enema (utilizing water-soluble contrast material or air) with fluoroscopy can also be used to diagnose intussusception.

Although conventional radiographs have been used in the past to diagnose intussusception via occasional detection of a soft tissue mass in the right upper quadrant with associated lack of a large amount of bowel gas, studies have shown poor interobserver agreement and a predictive value of only approximately 50%.

How will my doctor know my child has intussusceptions?

Your doctor will note your child’s symptoms and perform a physical exam. Your doctor may use an ultrasound (which uses sounds waves to create pictures) to see if intussusception is causing your child’s symptoms.

How is this condition treated?

An intussusception is treated by air or hydrostatic enema using barium or water-soluble contrast material (the latter is favored) under fluoroscopic guidance. Some radiologists will attempt to perform the reduction under US guidance during a water-soluble contrast enema, with final confirmation of reduction with a single overhead frontal radiograph obtained on the fluoroscopy table.

The advantages of the air enema are that it is quicker, less messy, and easier to perform and delivers less radiation to the patient. The only contraindications to enema reduction of intussusception are presence of pneumoperitoneum or peritonitis.

The air enema can generate pressures of up to 120 to 140 mm Hg in order to reduce the intussusceptions, but pressure above this is to be avoided in order to prevent iatrogenic perforation.

In many cases, intussusception is corrected with an air enema. Your doctor will put air into your child’s rectum through a small tube. The air pushes the folded intestine back into place, clearing the blockage. Your doctor may also want to get an X-ray of your child’s abdomen to check whether or not the procedure was effective. Antibiotics are usually not needed. Sometimes surgery is necessary to correct intussusception if the intestine doesn’t stop collapsing into itself or if the cause of intussusception is a tumor or polyp.

Intussusception is a medical emergency. If your child has symptoms of intussusception, seek medical help right away. When left untreated, intussusception may cause severe complications.

How to know that an intussusception has been successfully reduced?

If a successful air reduction has been performed, fluid with air bubbles should be seen passing through the ileocecal valve into the terminal ileum. If a successful reduction with contrast material has been performed, contrast material must reflux into multiple loops of small bowel. If reflux into the small bowel is not seen, the intussusception may not have been completely reduced, and a distal lead point may have been overlooked. A “pseudomass” may remain in the region of the edematous ileocecal valve despite successful reduction, not to be mistaken for a residual intussusception.

Complications

Will my child be okay?

With prompt treatment, most children recover completely from intussusception. Occasionally, complications such as infection can occur if the intussusception is not treated quickly. If this happens, part of the bowel must be surgically removed. It is important to see your doctor quickly if your child has symptoms of intussusception.

Questions

• What can I do to make my child more comfortable before surgery?
• What risks are there for my child who is having surgery?
• What is an air enema?
• Will my child be able to live a normal life after surgery?
• Could the intussusception happen again?
• If one of my children has intussusceptions, could the others develop it, as well?