Intussusception
Intussusception occurs when an intestinal segment invaginates or “telescopes” into an adjacent segment, causing bowel obstruction +/- ischaemia.
>80% of cases are ileocolic – where the terminal ileum invaginates into the colon.
Causes and Risk Factors
~90% of cases are idiopathic (esp. in younger children) [Ref1][BSPR]
- More common in males
- May be associated with mucosal lymphoid hyperplasia (e.g. from recent gastroenteritis)
Intussusception in older children is more likely to have an underlying structural cause, such as: [Ref1][BSPR]
- Meckel’s diverticulum (esp. if inverted) – most common structural cause
- Intestinal polyp
- Lymphoma
Clinical Features
Peak age of incidence: 6-18 months [BSPR]
The initial manifestation results from bowel obstruction (as one segment of bowel “telescopes” into another) [BSPR]
- Colicky abdominal pain
- Vomiting (bilious)
- Abdominal distension
When bowel ischaemia occurs, it may cause: [BSPR]
- Rectal bleeding / bloody stools (“red currant jelly stools“)
- Pallor
- Lethargy
The classic triad of intussusception: abdominal pain + vomiting + bloody stools is only seen in ~20% of cases. Most children present with vague or non-specific symptoms. [Ref]
Presentation may also vary depending on the age group: [Ref]
- Younger children / infants: more frequently present with vomiting, lethargy, bloody stools
- Older children: more frequently present with predominantly abdominal pain
Complications
Primary clinical manifestation: mechanical bowel obstruction [BSPR]
Bowel obstruction may progress into bowel ischaemia → bowel infarction → bowel perforation → peritonitis → sepsis → death [BSPR]
Investigation and Diagnosis
Diagnostic test of choice: ultrasound [BSPR]
- 100% sensitivity and 80-100% specificity
- Classic findings
- Target sign / Doughnut sign on transverse view
- Pseudo-kidney sign on longitudinal view
If ultrasound is equivocal, consider: [BSPR]
- Fluoroscopic contrast enema, or
- Surgical review +/- operative exploration
The following investigations are NOT recommended routinely for suspected intussusception: [BSPR]
- Abdominal X-ray (exception: if bowel perforation is suspected or to exclude alternative abdominal pathologies e.g. volvulus, NEC)
- CT
- MRI
Management
Initial assessment and resuscitation should be performed before definitive treatment, including correction of dehydration, management of shock and treatment of sepsis where present
Definitive management:
| 1st line (non-operative): image-guided pneumatic (air) enema reduction [BSPR] | Involves introducing air into the colon under fluoroscopic guidance to generate pressure that pushes the intussuscepted bowel back into its normal position
Contraindications to pneumatic reduction (ANY of the following would require immediate surgical exploration):
|
| 2nd line: surgical management (if non-operative management failed, or is contraindicated) [BSPR] | Involves manual reduction of the intussusception +/- resection of non-viable bowel
Any underlying structural cause (e.g. Meckel’s diverticulum) may also require resection |