Intussusception

Key Features

Essentials of Diagnosis

• Most common cause of bowel obstruction in the first 2 years of life

• Most common location is ileocolic and 85% of cases are idiopathic

• Ultrasound is the most sensitive and specific diagnostic modality

• Air enema is the best therapeutic approach in the stable patient, with successful reduction in 75% of cases

General Considerations

• Defined as the invagination of one segment of intestine into another segment

• Most commonly starts just proximal to the ileocecal valve and extends for varying distances into the colon, but can occur anywhere along the small and large bowel

• Swelling, hemorrhage, incarceration, vascular compromise, and necrosis of the intussuscepted ileum may occur, potentially resulting in intestinal perforation and peritonitis

• Implicated primary causes

  • Small bowel polyp

  • Meckel diverticulum

  • Omphalomesenteric remnant

  • Duplication

  • Lymphoma

  • Lipoma

  • Parasites

  • Foreign bodies

  • Viral enteritis with hypertrophy of Peyer patches

• Intussusception of the small bowel can also be seen in celiac disease, cystic fibrosis, and Henoch-Schönlein purpura

• In 85% of cases, the cause is idiopathic but the likelihood of identifying a cause increases with the age of the patient

• In children older than 6 years, lymphoma is the most common cause

• It is three times more common in males than in females

Clinical Findings

• Characteristically, recurring paroxysms of abdominal pain with screaming and drawing up of the knees develops in a previously healthy infant 3–12 months of age

• Vomiting and diarrhea occur soon afterward (90% of cases)

• Bloody bowel movements with mucus appear within the next 12 hours (50%)

• Child is characteristically lethargic between paroxysms and may be febrile

• Abdomen is tender and often distended

• A sausage-shaped mass may be palpated, usually in the upper mid abdomen

• The likelihood of bowel compromise increases with the duration of symptoms

• In older children, sudden attacks of abdominal pain may be related to chronic recurrent intussusception with spontaneous reduction

Diagnosis

• The constellation of abdominal pain, lethargy, vomiting, and a suspicious abdominal radiograph was found to have a sensitivity of 95% in identifying intussusceptions in children

• Abdominal radiographs alone, however, are poorly sensitive for the diagnosis of intussusception

• Abdominal ultrasound carries sensitivity for diagnosis of intussusception of 98–100%

• Barium enema and air enema are both diagnostic and therapeutic

• Reduction of the intussusception by barium enema should not be attempted if signs of strangulated bowel, perforation, or toxicity are present

• Air insufflation of the colon under fluoroscopic guidance is a safe alternative to barium enema that has excellent diagnostic sensitivity and specificity without the risk of contaminating the abdominal cavity with barium

• Rates of successful reduction by air enema approach 75%

Treatment

• Surgery is required for extremely ill patients, in patients with evidence of bowel perforation, or in those in whom hydrostatic or pneumatic reduction has been unsuccessful (25%)

• Surgery ...