INTRODUCTION

  • The most common cause of intestinal obstruction in children <2 years of age
  • Peak incidence is between 3 months and 1 year
    • 80% of cases occurring <2 years of age
  • Occurs when a segment of bowel “telescopes” into another segment of bowel
  • Ileocecal intussusception is the most common type
  • Lymphoid hyperplasia (Peyer’s patches) is the etiology most commonly proposed
  • In older children and in those with recurrence, a pathologic “lead point” may be present. These include:
    • Intestinal polyps
    • Meckel’s diverticulum
    • Tumors (e.g. lymphoma)
    • Intestinal duplications
  • Henoch-Schonlein Purpura colitis is a distinct risk factor for intussusception (commonly ileoilial intussusception)

CLINICAL MANIFESTATIONS

  • Sign/Symptom profile dependent upon age group (Mandeville 2012, PMID: 22929138)
Signs/Symptoms <12 mo 12-36 mo >36 mo
Abdominal pain 90% 96% 97%
Emesis 94% 79% 64%
Guaiac-positive stool 83% 60% 67%
Grossly bloody stools 83% 41% 37%
Irritability 71% 51% 14%
Bilious emesis 48% 24% 31%
Lethargy 47% 26% 13%
Diarrhea 38% 34% 41%
Constipation 13% 24% 25%
Abdominal mass 33% 23% 22%
Abdominal distention 25% 18% 21%

 

  • Bilious vomiting and lower gastrointestinal bleeding are late findings
  • “Currant jelly” stools occur in less than 50% of cases
  • Mental status changes described as alternating periods of lethargy and irritability
  • Sausage-shaped mass may be palpated in the right upper quadrant
  • Stool exam for blood may or may not be positive

DIAGNOSTIC IMAGING

  • Abdominal XR
    • May be helpful to rule in but not rule out
    • The most common finding is “non-specific bowel gas pattern”
    • May reveal signs of obstruction or a soft tissue mass
    • Specific findings include:
      • Absent liver edge sign (soft tissue mass in the RUQ)
      • Target sign (intussuceptum seen in a transverse plane)
      • Crescent sign (the head of the intussusception)
    • Presence of air in the ascending colon on a three view XR series (prone, supine and lateral decubitus) may effectively rule out intussusception in patients with low suspicion for the diagnosis (Roskind, PMID: 22929143)

  • Ultrasound
    • Diagnostic modality of choice
    • In the transverse cut, one can see a ring of bowel within bowel (donut sign)
    • The longitudinal appearance, one can see the appearance of multiple layers (submarine sandwich or pseudokidney sign)
    • A negative ultrasound by an experienced radiologist may limit the need for a contrast enema
    • Ultrasound performed / interpreted by pediatric and emergency radiologists (Hryhorczuk 2009, PMID: 19657636)
      • Had a sensitivity of 97.9% and specificity of 97.8% (NPV = 99.7%)
    • POCUS performed by relatively novice pediatric emergency medicine faculty and fellows (Riera2012, PMID: 22424652)
      • Had a sensitivity of 85% and specificity of 97%

MANAGEMENT

  • A contrast enema may be both diagnostic and therapeutic
  • Air enemas decrease the risk of contrast material peritonitis in the case of perforation with similar rates of success
    • Success rates for hydrostatic reduction of intussusception via enema have been reported as high as 80-90%
      • Successful reduction is indicated by flow of air into proximal bowel
    • Complications:
      • Perforation
      • Partial reduction
      • Reduction of a necrotic segment of bowel
      • Missing a pathologic lead point
    • A surgeon should be available immediately in case the bowel becomes perforated during the procedure or the reduction is unsuccessful
  • Patients who have had their intussusception reduced are typically admitted to the hospital for a period of observation though a recent study has suggested that admission may not be necessary
    • Rates of both late and early recurrence (approximately 15%) were similar in the group observed in the ED for 4 hours and as an inpatient for 24 hours (Mallicote 2017, PMID: 28969892)
  • Recurrence is rare
    • Over a 10 year interval, 245 episodes of intussusception occurred in 210 patients. Six patients (2.45%) had a recurrent ileocolic intussusception with 7-28 after initial successful reduction. (Simanovsky 2019, PMID: 30143943)

REFERENCES

Hryhorczuk AL, Strouse PJ. Validation of US as a first-line diagnostic test for assessment of pediatric ileocolic intussusception. Pediatr Radiol. 2009;39(10):1075-9. PMID: 19657636

Mallicote MU, Isani MA, Roberts AS, Jones NE, Bowen-Jallow KA, Burke RV, et al. Hospital admission unnecessary for successful uncomplicated radiographic reduction of pediatric intussusception. Am J Surg. 2017;214(6):1203-7. PMID: 28969892

Mandeville K, Chien M, Willyerd FA, Mandell G, Hostetler MA, Bulloch B. Intussusception: clinical presentations and imaging characteristics. Pediatr Emerg Care. 2012;28(9):842-4. PMID: 22929138

Riera A, Hsiao AL, Langhan ML, Goodman TR, Chen L. Diagnosis of intussusception by physician novice sonographers in the emergency department. Ann Emerg Med. 2012;60(3):264-8. PMID: 22424652

Roskind CG, Kamdar G, Ruzal-Shapiro CB, Bennett JE, Dayan PS. Accuracy of plain radiographs to exclude the diagnosis of intussusception. Pediatr Emerg Care. 2012;28(9):855-8. PMID: 22929143

Simanovsky N, Issachar O, Koplewitz B, Lev-Cohain N, Rekhtman D, Hiller N. Early recurrence of ileocolic intussusception after successful air enema reduction: incidence and predisposing factors. Emerg Radiol. 2019;26(1):1-4. PMID: 30143943