Intussusception In Children

Intussusception is a term derived from the Latin intus (within) and suscipere (to receive). One segment of the bowel (intussusceptum) invaginates into another (intussuscipiens) just distal to it leading to obstruction. The bowel may simply telescope on itself (non-pathological lead point), or some pathology may be the focus of the invagination (pathological lead point).

Pathogenesis¹

The mesentery of the intussuscepted bowel becomes compressed. The bowel wall distends and obstructs the lumen. Peristalsis is disrupted leading to colic and vomiting. Lymphatic and venous obstruction occurs, causing ischaemia. In most children the intussusception is ileo-caecal, though ileo-ileocolic and ileo-ileal or colocolic cases can occur.

• The male to female ratio is approximately 3:2.
• Two-thirds of patients are under one year, the peak age being between 5-10 months.
• Intussusception is the commonest cause of intestinal obstruction in patients aged 5 months - 3 years, and accounts for up to 25% of abdominal emergencies in children up to 5.
• It is rare pre-term.
• One large Swiss study found an overall incidence of 38, 31, and 26 cases per 100,000 live births in the first, second, and third year of life respectively.³

• Usually of sudden onset, maybe more insidious in the older child
• Paroxysms (about every 10-20 minutes) of colicky abdominal pain (>80%) ± crying
• May appear well between paroxysms initially
• Early vomiting – rapidly becoming bile stained
• Lethargy common, especially in infants
• Palpable “sausage-shaped” mass (often in right upper quadrant)
• Absence of bowel in right lower quadrant (Dance sign)
• Dehydration, pallor, shock
• Irritability, sweating
• Later mucoid and bloody “red currant stools”
• Late pyrexia

Non-pathological lead point (>90%)

• Viral 50% - rotavirus, adenovirus & human herpes virus 6 (HHV6)
• Amoebomata, Shigella, Yersinia^6,7
• Peyer's patch hypertrophy

Pathological lead point (<10%)

• Older patients (may have longer history)
• Meckel's diverticulum(75%)
• Polyps & Peutz-Jeghers' syndrome (16%)⁸
• Henoch-Schönlein purpura (3%)
• Lymphoma & other tumours (3%)
• Reduplication (a process by which the bowel wall is duplicated)(2%)
• Cystic fibrosis
• Ascariasis⁹
• Nephrotic syndrome¹⁰
• Foreign body¹¹
• Post-operative¹²
• Hyperperistalsis¹³
• Exclusive breastfeeding¹⁴
• Weight above average
• Rotavirus vaccine¹⁵

• Full Blood Count - may show neutrophilia
• Urea and Electrolytes - may reflect dehydration
• Abdominal X-Ray - may show dilated gas-filled proximal bowel, paucity of gas distally, multiple fluid levels (but may be normal in the early stages)
• Ultrasound - may show doughnut or target sign , pseudokidney / sandwich appearance¹⁶
• Bowel enema - barium has been gold standard (crescent sign, filling defect) but air and water-soluble double-contrast now available, each has pros and cons, choice left to individual radiologist^1,17
• CT / MRI - more often used in adults than children¹⁸

• Resuscitation - “drip & suck” - nasogastric tube and iv fluids
• Radiological - reduction (3 tries for 3 min each) if no sign of peritonitis, perforation or shock
• Air enema <120mmHg of pressure or barium enema - the choice of enema usually left to radiologist (many now favour air enema)¹⁵
• Laparotomy (reduction/resection) - indications:
  • Peritonitis
  • Perforation
  • Prolonged history (>24hr)
  • High likelihood of pathological lead point
  • Failed enema
• Admit to hospital, even if reduction appears successful, as significant recurrence rate

• Missed diagnosis
• Ischaemia of the intussusceptum / intussuscipiens¹⁹
• Necrosis
• Haemorrhage
• Perforation
• Infection & peritonitis
• Failure of enema reduction
• Chronic intussusception – rare cause of failure to thrive²⁰

• Prognosis - excellent with treatment
  • Post-reduction recurrence :
    • Radiological: 5%
    • Surgical: 1-4%
• Mortality: 1% with treatment, fatal if untreated