OVERVIEW: What every practitioner needs to know

Are you sure your patient has intussusception? What are the typical findings for this disease?

The classic presenting triad of intussusception is crampy abdominal pain, currant jelly stools and a palpable abdominal mass. However, the diagnosis must be entertained in any child of appropriate age who presents with a bowel obstruction. Typically children will present with intermittent colicky abdominal pain and vomiting that progresses to bilious vomiting. Children may also raise their knees towards their chest in an attempt to alleviate pain. Feeding intolerance or irritability may also be a presenting symptom.

What other disease/condition shares some of these symptoms?

Any cause for bowel obstruction in a child should be included in the differential diagnosis for intussusception. Hernias, adhesive bowel obstruction, ileus, or constipation may mimic intussusception. Notably, malrotation and midgut volvulus, intestinal atresia, and meconium ileus are typically not considered in the differential as volvulus presents as a proximal small bowel obstruction and the others present in the neonatal period.

What caused this disease to develop at this time?

Intussusception is a common cause of bowel obstruction in infants and toddlers. It is defined as the invagination of a proximal piece of bowel (intussusceptum) into a distal piece of bowel (intussuscipiens). It can be primary (idiopathic) or secondary.

Primary intussusception is more common in younger children and usually results from lymphoid hyperplasia, perhaps secondary to a viral infection. Intestinal peristalsis is thought to “grab” an enlarged lymphatic nodule and cause that section of bowel to invaginate into the distal bowel. This commonly occurs in the ileocolic region.

As children become older (>2 years), pathologic lead points become more common. The mechanism is similar to ileocolic, but rather than lymphoid tissue, the lead mass consists of entities such as Meckel’s diverticulum, hamartomas associated with Peutz-Jeghers syndrome, sub-mucosal hemorrhage associated with Henoch-Schonlein purpura, pancreatic rests, hemangioma or tumors (e.g., lymphoma).

Ileocolic intussusception is the most common. Small bowel into small bowel intussusception typically has a pathologic lead point. Either type requires definitive reduction. Ileocolic intussusception commonly responds to reduction in the radiology suite.

What laboratory studies should you request to help confirm the diagnosis? How should you interpret the results?

While basic laboratory data such as a complete blood count, basic metabolic panel, serum inflammatory markers, lactate and blood gases are helpful in assessing the global status of the patient; no laboratory test is diagnostic of intussusception.

Would imaging studies be helpful? If so, which ones?

Plain radiographs consisting of three views of the abdomen are often suggestive of intussusception. Many institutions have adopted ultrasonography as the radiographic test of choice for the diagnosis of intussusception. Whichever is chosen, contrast or air enema is subsequently used to confirm the diagnosis and provide initial attempts at reduction of the intussusception.

Confirming the diagnosis

See Figure 1.

Figure 1

Clinical decision algorithm.

If you are able to confirm that the patient has intussusception, what treatment should be initiated?

The presence of intussusception requires reduction. In the absence of peritonitis or shock, initial attempts should be performed in the radiology suite utilizing fluoroscopy. Both hydrostatic and air contrast reduction are used. It is important when using hydrostatic reduction to assure that the column of fluid is never raised over 3 feet above the child as this increases the risk of perforation. There should be no more than three attempts of 3 minutes each.

It is also important to use water-soluble contrast material rather than barium. Should perforation occur, use of barium would result in permanent barium soiling of the peritoneal cavity. Air contrast reduction may also reduce the intussusception, but no more than 80 mm Hg should be used in young children and no more than 120 mm Hg in older children.

Failure of radiologic reduction mandates operative exploration of ileocolic intussusception. The classic operation utilizes an open approach with manual reduction of the intussusception. The transition zone between the intussuscipiens and distal bowel is determined. The intussuscuptum is then milked in a retrograde fashion, similar to squeezing a tube of toothpaste, until the intussusceptum is reduced. Constant steady pressure is often beneficial. Complete reduction is confirmed when the bloodless fold of Treves is identified.

Advances in laparoscopic surgery over the last 3 decades have been applied to surgery for intussusception. Many pediatric surgeons now initially approach reduction of intussusception laparoscopically. Atraumatic bowel graspers are used and the ileum just proximal to the intussusception is pulled while the cecum is pushed away from the ileum, thereby reducing the intussusception.

What are the adverse effects associated with each treatment option?

Regardless of how the intussusception is finally reduced (radiographically, laparoscopically, or with an open operation) the risk of perforation exists. One drawback to radiographic reduction is the inability to assess bowel viability and reduction. Because of the risk of perforation, bowel necrosis or sepsis, children have been observed in the hospital after radiographic reduction. Recently, though, there has been a trend towards observing these children in the Emergency Department after reduction. If surgical reduction is necessary, bowel viability can be assessed directly and compromised bowel resected. If bowel resection is necessary, primary anastomosis is usually achieved. An appendectomy is performed to avoid future confusion.

What are the possible outcomes of intussusception?

Reduction of intussusception leads to a spectrum of outcomes. Whatever method is used, high fever in the few hours post-reduction is common and does not require further work-up unless associated with signs and symptoms of peritonitis including indirect symptoms such decreased urine output. Many children quickly regain bowel function, tolerate oral intake and remain in the hospital for no more than 24-48 hours. Perforation, peritoneal soiling, bowel necrosis and sepsis may result in prolonged intensive care unit and hospital stays.

What causes this disease and how frequent is it?

Intussusception may occur at any age and is approximately twice as common in males. It is most common between 3 and 36 months of age with the highest incidence at 5-10 months of age. Primary (idiopathic) intussusception is increasingly less likely as children get older, especially beyond 36 months of age.

What complications might you expect from the disease or the treatment of the disease?

Complications of intussusception include bowel necrosis and perforation if intussusception is not recognized early. If intussusception is allowed to progress, the intussusceptum can protrude from the anus and be confused with rectal prolapse. Radiographic or operative reduction may also result in perforation, which often results in bowel resection and primary anastomosis.

Recurrent intussusception occurs from 2% to 20% of the time, though 5% is a widely accepted recurrence rate. Most recurrences will occur within 24 hours, but recurrences up to 6 months have been described. Recurrence should raise the suspicion of a patholigic lead point, though recurrences are as likely to respond to radiographic reduction as initial intussusceptions.

How can intussusception be prevented?

There are no known methods of preventing intussusception.

What is the evidence?

Seifarth, FG., Ryan, ML., Triana, J., Knight, CG.. “Diagnosis and laparoscopic treatment of ileoileal intussusception secondary to heterotopic pancreas in an infant: case report and review of the literature”. J Pediatr Surg.. vol. 46. 2011. pp. e33-6. (Good review of secondary causes of intussusception and management.)

Waseem, M., Rosenberg, HK.. “Intussception”. Pediatric Emergency Care. vol. 24. 2008. pp. 793-800. (This article discusses clinical presentation and state-of-the-art diagnostic and treatment.)

Beres, AL., Baird, R., Fung, E., Hsieh, H., Abou-Khalil, M., Gerstle, TJ.. “Comparative outcome analysis of the management of pediatric intussusception with or without surgical admission”. J Pediatr Surg. vol. 49. 2014. pp. 750-2. (This article compares outcomes in the patients admitted to the hospital after radiographic reduction with those discharged from the ED.)
These three articles describe diagnosis and managment of intussusception with emphasis on radiological aspects:

Navarro, O, Daneman, A.. “Intussusception: Part 1: a review of diagnostic approaches”. Pediatr Radiol. vol. 33. 2003. pp. 79-85.

Navarro, O, Daneman, A.. “Intussusception: Part 2: an update on the evolution of managment”. Pediatr Radiol. vol. 34. 2003. pp. 97-108.

Navarro, O, Daneman, A.. “Intussusception: Part 3: diagnosis and management of those with an identifiable or predisposing cause and those that reduce spontaneously”. Pediatr Radiol. vol. 34. 2004. pp. 305-12.

Ongoing controversies regarding etiology, diagnosis, treatment

There is controversy regarding laparoscopic reduction of intussusceptions. This depends on the preference and capabiliy of the individual surgeon. Some intussusceptions are easily reduced and are amenable to laparoscopic reduction. Long-segment intussusception are not as amenable to laparoscopic reduction. Little is lost by attempting laparoscopic reduction and proceeding to open reduction if the laparoscopic approach fails.