Intusussception

Question 1

Intussusception - background

Answer 1

1. Definition = invagination of proximal segment of bowel into distal bowel lumen
2. Commonest occurrence = segment of ileum moving into colon through the ileocaecal valve
3. May occur at any age. Most commonly in 2mo-2y age group, peak incidence at 5-9mo. Incidence 1 in 500
4. Majority of intussusceptions are in association with viral gastroenteritis. Enlarged Peyer’s patch in ileum acts as the lead point, which then invaginates into the distal bowel
5. In older children and adults - more likely to be due to a pathological lead point (e.g. polyp, Meckel’s diverticulum)

Question 2

Intussusception - pathology

Answer 2

1. Causes SBO
2. Intussuscepted bowel becomes engorged, which causes rectal bleeding -> eventually becomes gangrenous
3. Following this, perforation and peritonitis will occur
4. Most common site = ileocolic, followed by ileoileal
5. Small bowel intusussception may occur as a post-operative complication in infants, typically following nephrectomy

Question 3

Intussusception - presentation

Answer 3

1. Spasms of colic associated with pallor, screaming and drawing up legs
2. Child falls asleep between episodes
3. Later, as the intestinal obstruction progresses, bile-stained vomiting and rectal bleeding (‘red currant jelly stools’) develop
4. The child will appear ill, listless and dehydrated
5. In late cases, circulatory shock or peritonitis will be present

Question 4

Intussusception - ex (3)

Answer 4

1. In 30% of cases, the intussusception will be palpable as a sausage-shaped abdominal mass
2. May have blood on rectal examination
3. Late signs = distended abdomen, hypovolaemic shock

Question 5

Intussusception - ix

Answer 5

1. AXR = may show SBO; occasionally, a soft tissue mass will be visible
2. U/S = confirms dx by showing a characteristic ‘target sign’
3. Air enema = diagnostic and therapeutic. Contraindication = peritonitis and septicaemia

Other ix

4. FBE, UEC, BGL - if child looks unwell
5. Blood group and hold prior to theatre

Question 6

Intussusception - mx

Answer 6

1. IV access and NBM. If shocked, IV fluid resuscitation with 20mL/kg NS boluses
2. Analgesia (e.g. morphine), notify ED consultant and surgical registrar. Admit pt
3. If AXR shows perforation, perform laparotomy with NGT on free drainage, IV fluids and IV cefazolin + metronidazole
4. If no perforation but SBO/infant vomiting, use NGT on free drainage + IV fluids. Perform U/S, give IV cefazolin/metronidazole then air enema. Risk of incomplete reduction and perforation
5. Laparotomy if air enema fails or contraindicated. Supportive after-care