Intussusception

• Intussusception is the telescoping of intestine into a neighbouring segment, most frequently seen in infants and young children.
• Epidemiology:

  • 80-90% of cases present before the age of 2
  • Slightly more common in males
• The mesentery of the telescoped segment of intestine is impaired leading to reduced venous and lymphatic outflow:

  • Intestinal oedema
  • Obstruction
  • Ischaemia
• Pathogenesis:

  • Proximal segment of intestine invaginates into a distal segment
  • Intussusceptum = the segment of bowel that telescopes into another
  • Intussuscipiens = the neigbouring portion of bowel that receives the intussusceptum
  • Can occur anywhere but mostly ileocolic - terminal ileum invaginates into the colon
  • Mesentery of affected segment becomes involved and pressure prevents normal venous and lymphatic drainage
  • Invaginated segment becomes oedematous and obstructed
• Causes:

  • Majority are idiopathic - some viral infections may predispose
  • In some cases a 'lead point' is identified:
  • Meckel diverticulum
  • Vascular malformation
  • Lymphoma
  • Parasites
  • Thick stool e.g. cystic fibrosis
  • Polyps
• Symptoms:

  • Worsening abdominal pain
  • Vomiting that becomes bilious
  • Distress
  • Dehydration
  • Bloody stool
  • Red currant jelly stool (blood and mucus, late sign)
• Signs:

  • Sausage shaped mass (often in RUQ)
  • Abdominal tenderness
  • Lethargy
  • Dry mucous membranes
  • Peritonism (late sign)
• Investigations:

  • Ultrasound - first line - classic target sign
  • Abdominal XR - signs of perforation (should not be used alone to exclude)
• Management:

  • Supportive: IV fluid replacement, NG tube, analgesia, antibiotics if perforation suspected
  • Non-operative reduction in stable patients: hydrostatic or pneumatic
  • Operative: evidence of perforation or unstable, or where non-operative reduction failed. Can normally be performed laparoscopically.