Description

The invagination or telescoping of a proximal portion of bowel (the intussusceptum) into a distal segment of bowel (the intussuscipiens) which can result in ischemia and obstruction

Epidemiology

• Worldwide prevalence of 74 per 100,000 children <1 year of age
• Male-to-female ratio: 2:1
• Generally occurs in patients 3 months to 3 years of age
• Peak age: from 5 to 9 months
• The most frequent cause of bowel obstruction in infancy and second most common cause of abdominal pain (next to constipation)

Risk Factors

• Children <3 years:
  • Usually idiopathic (95%) or due to an enlarged Peyer patch (from infection), which is circumferential in distal ileum (common location of condition)
• Children ≥3 years:
  • Higher incidence of a pathologic lead point (4%): Meckel diverticulum, polyps, and lymphomas are most common.
  • Other common etiologies include Henoch-Schönlein purpura (HSP), Peutz-Jeghers syndrome, intestinal duplications, inflammatory bowel disease, appendix, and tumors.
• Postoperative (<1%):
  • Can occur in children who have had large retroperitoneal tumors removed (usually within 1 week of surgery)
• Recent vaccination
  • Increased incidence after administration of the RotaShield^® rotavirus vaccine (no longer available)
  • Current vaccines (RotaTeq^® or Rotarix^®) present a small but significant increase in risk 1 to 7 days after first dose of the vaccine.

Pathophysiology

• The invagination or telescoping of a proximal portion of bowel (the intussusceptum) into a distal segment of bowel (the intussuscipiens)
  • Can be unremitting (80%) or transient (20%)
  • 85% are ileocolic; ileoileal and colocolic types also occur.
  • Telescoping of the bowel occurs over a “lead point”—a lesion or defect in the bowel wall.
• Telescoping of the bowel causes diminished venous blood flow and bowel wall edema, which can result in ischemia and obstruction.
  • Over time, arterial blood flow is inhibited and infarction of the bowel wall occurs, which results in hemorrhage or perforation.
  • If untreated, can lead to death
• Bowel necrosis can occur within 48 to 72 hours after onset.
• Clinical presentation can vary but usually includes the following:
  • “Paroxysms of pain”: episodes of calmness interspersed with fussiness
  • Persistent vomiting
  • “Currant jelly stools” which represent mucosal sloughing