II. Definitions

  1. Intussusception
    1. Bowel 'telescopes' onto itself in early childhood

III. Epidemiology

  1. Most common cause Intestinal Obstruction age <6 years
  2. Incidence: 1 to 4 in 1000 newborns
  3. Gender predominence: Males > Females by 3:1 ratio
  4. Ages affected
    1. Rare before age 3 months
    2. Most common ages 3 to 12 months (66%)
    3. Peak Incidence at 10 months of age
    4. Less common after age 36 months
    5. Adult cases account for <0.08% of Intussusception cases (malignancy related in 15 to 65% of cases)
      1. See Adult Intussusception

IV. Pathophysiology

  1. Bowel telescopes on itself, causing venous and lymphatic congestion, then ischemia, perforation and peritonitis
  2. Intussusception is the most common cause of Small Bowel Obstruction in young children
  3. Ileocolic Intussusception (90% of cases)
    1. Occurs most commonly at ileocecal junction
    2. However, Intussusception may occur anywhere along ileum, jejunum or colon)

V. Causes: Intussusception Lead Points

  1. Idiopathic (75-90%)
  2. Transient Lead Points typically form at regions of inflammation (most common identified cause)
    1. Associated with recent viral gastrointestinal illness (e.g. Gastroenteritis)
    2. Infection results in lymphatic inflammation with enlarged Peyer's Patch
    3. Inflammation and lead point typically subsides after infection (making recurrence less likely)
  3. Pathologic Lead Point of Intussusception (risk of recurrence)
    1. Intestinal polyp
      1. Peutz-Jeghers Syndrome
      2. Juvenile Polyposis
      3. Familial Polyposis Coli
    2. Henoch-Schonlein Purpura
    3. Hemolytic Uremic Syndrome
    4. Hemangioma
    5. Meckel's Diverticulum
    6. Lymphosarcoma
    7. Lymphoma
    8. Neurofibroma
    9. Intestinal duplication
    10. Abdominal Trauma, prior surgical scar or foreign body
    11. Appendix (rare)

VI. Risk Factors

  1. Cystic Fibrosis
  2. Henoch Schonlein Purpura
  3. Peutz-Jeghers Syndrome
  4. Nephrotic Syndrome
  5. Bowel abnormalities
    1. Meckel Diverticulum
    2. Polyps
    3. Hemangiomas
  6. Indwelling gastrointestinal tubes
  7. Recent infection
    1. Upper Respiratory Infection (Adenovirus, Human Herpes Virus 6)
    2. Acute Gastroenteritis
  8. Vaccinations
    1. Rotavirus Vaccination previously associated with Intussusception (Vaccine removed from marked 1999)
    2. Newer oral Rotavirus Vaccine may have a small increased Intussusception risk

VII. Symptoms

  1. Presentations by Age
    1. Children <12 months: Irritability, Vomiting and bloody stool (late finding)
    2. Children >12 months: Abdominal Pain
  2. Child often appears well between episodes of pain
    1. Appear agitated, inconsolable during painful episodes
    2. May be listless and pale between episodes
    3. Episodic hypotonia may occur
  3. Vomiting (delayed onset by 6-12 hours)
    1. Initially yellow Emesis progressing to Bilious Emesis
  4. Abdominal Pain
    1. Sudden onset
    2. Cramping, colicky with paroxysms of pain in 15-20 minute intervals (may flex knees to Abdomen in pain)
    3. Progressively more severe episodes over time
  5. Stool change
    1. Watery, Diarrheal stools in first 12 to 24 hours
    2. Red Currant Jelly Stools (bloody mucus) are a late finding (occurs in 50% of cases, only 15% at presentation)
      1. Indicates infarcted or necrotic bowel

VIII. Signs

  1. Children may be pain free in up to 20% of cases
  2. Lethargy may be only presenting finding (10% of cases)
    1. May be associated with Altered Mental Status
  3. Evolution of abdominal examination
    1. Initial: Benign Abdomen
    2. Later: Abdominal Distention with peritoneal signs
  4. Right upper quadrant or epigastric, sausage-shaped abdominal mass

X. Differential Diagnosis: Gastrointestinal Symptoms and Associated Altered Mental State (Late Presentation)

XI. Evaluation: Predictive Findings of Intussusception

  1. Four clinical signs and symptoms are most associated with Intussusception
    1. Crying
    2. Abdominal mass
    3. Pallor
    4. Vomiting
  2. Interpretation
    1. All four clinical signs and symptoms: 95% Intussusception probability
    2. Intussusception is unlikely if all 4 criteria absent
  3. References
    1. (2014) Pediatr Emer Care 30:718-22 [PubMed]

XII. Evaluation: Findings that make Intussusception Less Likely

  1. Fever
    1. Consider other etiology (e.g. Urinary Tract Infection, Appendicitis, Gastroenteritis)
    2. Fever is uncommon in Intussusception (<1% in at least one study)
      1. Levinson (2019) Pediatr Emerg Care 35(2): 121-4 [PubMed]

XIII. Precautions

  1. Consider in any child with irritability and Vomiting without Diarrhea (esp. with lethargy between episodes)
    1. Classic triad (Abdominal Pain, bloody stools, palpable abdominal mass) is only present in 40% of cases
  2. Have a low threshold for evaluation (Ultrasound)
    1. Ultrasound is definitive (in experienced hands), non-invasive and inexpensive
    2. Missed Intussusception is lethal
  3. Listen to parents with concern regarding Abdominal Pain out of proportion to exam
  4. References
    1. Cantor (2016) Literature Review, ACEP PEM Conference, Orlando, attended 3/8/2016

XIV. Imaging

  1. Ultrasound
    1. Preferred first screening for Intussusception
    2. Technique: General
      1. Linear Probe follows course of Large Bowel
      2. Child supine
      3. Normal colon with haustra and minimal peristalsis compared with Small Bowel
    3. Technique: Option 1
      1. Linear probe transverse with probe marker at lateral right lower quadrant
      2. Identify the psoas Muscle and set the depth to 6 cm
      3. Follow ascending colon from RLQ, then transverse colon from RUQ, then descending colon from LUQ
        1. Keep the transducer transverse to bowel (e.g. cranial-caudal for transverse colon)
      4. Stomach may be used as acoustic window if there is Bowel Obstruction with fluid in Stomach
    4. Technique: Option 2 (Adam Sivitz, MD)
      1. Follow ascending colon from RUQ to RLQ (identifies most cases of Intussusception)
    5. Findings: Abnormal
      1. Transverse axis (Short Axis)
        1. Target sign (concentric rings) measuring >3 cm
      2. Longitudinal axis
        1. Sandwich, hayfork or pseudo-Kidney (bowel layers invaginate into one another)
    6. Efficacy
      1. Emergency Bedside Ultrasound is accurate (but operator dependent)
      2. Efficacy for pediatric emergency physicians after a 1 hour course
        1. Test Sensitivity 85%, Test Specificity: 97%
        2. Riera (2012) Ann Emerg Med 60(3): 264-8 +PMID:22424652 [PubMed]
      3. Efficacy for experienced clinicians and ultrasonographers
        1. Test Sensitivity: 95-98%
        2. Test Specificity: 98-99%
        3. Lin-Martore (2020) West J Emerg Med 21(4): 1008-16 [PubMed]
        4. Tsou (2019) Am J Emerg Med 37(9): 1760-9 [PubMed]
    7. References
      1. Claudius and Seif in Herbert (2013) EM:Rap 13(11): 1-3
  2. Contrast Enema
    1. Sensitivity: 95% of Intussusception
    2. Curative in most early cases of Intussusception
    3. Contraindications
      1. Patient unstable
      2. Surgical Abdomen
  3. Abdominal XRay
    1. Primarily indicated in suspected bowel perforation (free air)
    2. Signs of Intussusception (variably present, Ultrasound in preferred)
      1. Right lower quadrant abdominal mass
      2. Absent bowel gas in right upper quadrant
      3. Target sign or Cresent sign
        1. Air trapped between the bowel lumens

XV. Management: General

  1. Fluid Resuscitation
    1. Perform prior to air contrast reduction
  2. Immediate air or contrast enema if no contraindication (see below)
  3. Emergent Surgical Consultation
  4. Prophylactic Antibiotic Indications
    1. Emergency Surgical Intervention
    2. Previously prophylactic antibiotics were considered prior to attempted air contrast reduction
      1. Prophylactic antibiotics are no longer recommended before air contrast enema
      2. Prophylactic antibiotics do not reduce the risk of bacteremia or enteritis with enema

XVI. Management: Air Contrast Enema Reduction

  1. Air Contrast Enema is performed by Radiology (typically under Fluoroscopy guidance)
    1. Effective in 76 to 81% Ileocolic Intussusception cases
    2. Recommended to be performed at centers capable of complication management
      1. Radiology able to perform percutaneous bowel needle decompression
      2. Emergency surgical backup
    3. Ultrasound guidance of saline enema has also been used
      1. Flaum (2016) J Pediatr Surg 51(1): 179-82 [PubMed]
  2. Risk Factors for Failed Reduction
    1. Intussusception symptoms >24 hours
    2. Diarrhea
    3. Lethargy
    4. Distal Intussusception
    5. Fike (2012) J Pediatr 47(5): 925-57 [PubMed]
  3. Failed first attempt at enema reduction
    1. May repeat Air Contrast Enema at 0.5 to 4 hour intervals if prior attempt without complications
    2. Efficacy of delayed, repeat attempts: 50% (if predictors below are present)
    3. Predictors of safe repeated enema (0.8% perforation risk)
      1. Intussusception movement or partial reduction with prior attempt
      2. Cardiopulmonary stability
      3. No peritoneal signs
  4. Complications
    1. Bowel perforation
    2. Hemodynamic Instability
      1. Treat with percutaneous bowel needle decompression, ABC Management and surgical intervention
  5. References
    1. Kelley-Quon (2021) J Pediatr Surg 56(3): 587-96 [PubMed]

XVII. Management: Surgical Intervention

  1. Typically performed under laparoscopy, with transition to open surgery as needed
  2. Preparation
    1. Fluid Resuscitation
      1. Prophylactic Antibiotics
  3. Indications
    1. Hemodynamic instability
    2. Peritoneal Signs
    3. Bowel perforation
    4. Multiple failed Air Contrast Enema reduction attempts
    5. Air Contrast Enema Reduction not available in timely manner

XVIII. Managament: Small Bowel to Small Bowel Intussusception

  1. Small Bowel to Small Bowel Intussusception is typically transient
    1. Does not require intervention in most cases (contrast with Small Bowel to colon, or colon to colon)
  2. Small Bowel to Small Bowel cases in which surgical intervention may be needed
    1. Focal Abdominal Pain
    2. Long intussception
    3. Prior abdominal surgery

XIX. Management: Disposition

  1. Most patients are admitted and observed for recurrence for at least 24 hours
    1. Due to risk of recurrence in 5-10% of cases
  2. Indications for discharge after 6-8 hours of observation (studies support 3 hour observation)
    1. Asymptomatic for at least 3 hours after reduction AND
    2. Tolerating oral liquids AND
    3. Reliable family and able to return urgently to Emergency Department if needed AND
    4. Reduction successful within 3 attempts AND
    5. No serious findings before reduction (e.g. bloody stool, fever, long prodrome)
    6. Ravel (2015) Pediatrics 136(5):e1345-52 +PMID: 26459654 [PubMed]

XX. Complications

  1. Ischemic Bowel
  2. Bowel Perforation
  3. Sepsis
  4. Intussusception Recurrence
    1. Recurrence in 3 to 11% of cases (most in first day to first week)
    2. Recurrence risk factors
      1. Age over 2 years
      2. Pathologic lesions (see above)
  5. Death
    1. Mortality 1 to 3% with early treatment
    2. Fatal if not treated within 2-5 days

XXI. References

  1. Ayub and Smith (2021) Crit Dec Emerg Med 35(10): 3-8
  2. Guess and Ojo (2022) Crit Dec Emerg Med 36(3): 10-11
  3. Bisset (1988) Radiology 168(1): 141-5 [PubMed]
  4. West (1987) Surgery 102(4): 704-10 [PubMed]
  5. Yamamoto (1997) Am J Emerg Med 15(3):293-8 [PubMed]

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