Meckel's Diverticulitis

Aka: Meckel's Diverticulitis, Meckel's Diverticulum, Meckel Diverticulum

advertisement

II. Epidemiology

  1. Most common cause of significant Lower Gastrointestinal Bleeding in children (esp. age <2 years)
  2. Prevalence: 0.3 to 3% (roughly 2%) of U.S. population
  3. Meckel's Diverticulum occurs equally in both genders
    1. Complications are more common in males (ratio of 2:1 to 3:2)
  4. Lifetime complication rate: 4%
    1. More than 50% of complications occur before age 10 (and esp. before age 2 years)
    2. Complications decrease with age

III. Background

  1. Initial report by Hildanus in 1598
  2. Detailed description by Johann Meckel in 1809

IV. Pathophysiology: Meckel's Diverticulum

  1. Meckel's Diverticulum is the most common congenital malformation of the Gastrointestinal Tract
  2. Incomplete closure of vitelline duct (omphalomesenteric remnant)
    1. Omphalomesenteric duct (vitelline duct) connects primitive gut to Yolk Sac in early fetal development
    2. Duct typically closes and obliterates when the placenta replaces the Yolk Sac at 7 weeks gestation
    3. Incomplete elimination of the Omphalomesenteric duct (vitelline duct) results in various remnants
      1. Meckel's Diverticulum
      2. Enterocyst
      3. Fibrous Cord
      4. Fistula
  3. Characteristics
    1. Meckel's Diverticulum contains all intestinal wall layers (serosa, Muscle, submucosa, mucosa) and mesentery
    2. Blood supply is via vitelline artery
      1. Branch of the superior Mesenteric Artery (derived from omphalomesenteric artery)
    3. Meckel's Diverticulum may be lined with gastric mucosa (85%) and other heterotopic tissue
      1. Ectopic tissue occurs most often at the Diverticulum tip
      2. Gastric mucosa acid secretion may lead to ulceration and painless Rectal Bleeding
      3. Other heterotopic tissue
        1. Pancreatic tissue
        2. Brunner's glands
        3. Duodenal mucosa
        4. Colonic mucosa
        5. Hepatobiliary mucosa
        6. Endometrial mucosa
  4. Location
    1. Proximal to ileocecal valve (within 100 cm)
    2. Typically at 45 to 60 cm proximal to the ileocecal valve
  5. Follows the rule of 2's (roughly)
    1. Affects 2% of the population (range 0.4 to 3%)
    2. Often presents before age 2 years
    3. More common in males by 2:1 ratio
    4. May contain two types of ectopic tissue, such as gastric (85%) and pancreatic tissue
    5. Symptomatic presentations or complications affect 2-4% of those with Meckel's Diverticulum
    6. If symptoms are to occur, they occur by age 2 years in 50% of cases (age 10 in some references)
    7. Occurs 2 feet (up to 100 cm) proximal to the ileocecal valve
    8. Meckel's Diverticulum is 2 cm wide and 2 cm long

V. Findings

  1. Precautions
    1. Maintain a high index of suspicion (delayed diagnosis is common)
    2. Many meckel Diverticula are discovered incidentally during laparoscopy
  2. Episodic Rectal Bleeding (20 to 25% of those who are symptomatic of a Meckel's Diverticulum)
    1. Painless intermittent bleeding is the most common presentating symptom in children
    2. Bleeding may occur from ulceration of gastric or pancreatic ectopic tissue, or from intermittent intussception
    3. Hematochezia with brick red or currant jelly red
  3. Acute Meckel's Diverticulitis and other complications (e.g. Small Bowel Obstruction)
    1. Abdominal Pain (may mimic Appendicitis with RLQ Abdominal Pain)
    2. Intractable Vomiting
    3. Tachycardia

VI. Differential Diagnosis: Meckel's Diverticulitis

  1. See Appendicitis
  2. See Lower Gastrointestinal Bleeding
  3. Viral Gastroenteritis
  4. Constipation
  5. Intussusception
  6. Inflammatory Bowel Disease
  7. Infectious Colitis
  8. Hemolytic Uremic Syndrome
  9. Peptic Ulcer Disease

VII. Complications: Meckel's Diverticulum

  1. Meckel's Diverticulum has an overall complication rate of 4%
  2. Lower Gastrointestinal Bleeding (25-50% of complications)
    1. Often associated with ectopic gastric mucosa
    2. Profuse Hemorrhage may occur
    3. Hemorrhage is most common presentation under age 2
    4. Resolves spontaneously in most cases
  3. Meckel's Diverticulitis (10 to 20% of complications)
    1. Similar in presentation to Acute Appendicitis
    2. Pouch obstruction occurs from enteroliths, foreign bodies or less commonly Parasitic Infections
    3. Obstruction leads to local inflammation, perforation and peritonitis
  4. Bowel Obstruction (14 to 53% of cases, esp. adults)
    1. Volvulus at fibrotic band attached to abdominal wall near Umbilicus
    2. Intussusception
    3. Incarcerated Inguinal Hernia (Littre's Hernia)
  5. Bowel Perforation
  6. Malignancy
    1. Carcinoid Tumor
    2. Sarcoma
    3. Stromal Tumor
    4. Intraductal Papillary Mucinous Adenoma of Pancreatic Tissue
    5. Miscellaneous tumors and adenocarcinomas

VIII. Imaging

  1. Radionuclide Scintigraphy (Meckel's Scan)
    1. Performed via IV injection of Sodium Tc-pertechnetate (99m)
      1. Gastric mucosa cells that produce mucin, uptake Tc-pertechnetate
      2. Pentagastrin enhances study by stimulating gastric cell uptake of pertechnetate
    2. May require sedation in young children
      1. Each image frame is acquired over 1 minute, and total series requires more than an hour
    3. Preferential uptake by gastric tissue
      1. Detects ectopic gastric mucosa (more likely to be found in Lower Gastrointestinal Bleeding)
      2. Other ectopic tissues (e.g. pancreatic or duodenal tissue) is not identified on this scan
    4. Efficacy
      1. Decreased Test Sensitivity with slow bleeding or reduced vascular supply, Anemia
      2. Most accurate test in Meckel's Diverticulum
        1. Test Sensitivity: 81% to 90% in children
        2. Test Specificity: 95% to 97% in children
      3. Less accurate in adults (Test Sensitivity 60%)
        1. Histamine blockers (e.g. Cimetidine), Glucagon, pentagastrin increase Test Sensitivity in adults
  2. Small Bowel enema
    1. Indicated for negative scintigraphy in adults
  3. Mesenteric Angiography or Arteriography
    1. Indicated for acute brisk Hemorrhage (>0.5 ml/min) requiring bloodtransfusion
  4. Tests to evaluate differential diagnosis (but not typically useful in diagnosis of Meckel's Diverticulum or Diverticulitis)
    1. Abdominal XRay
    2. Abdominal Ultrasound
      1. May show blind-ended thick-walled loop eminating from Small Bowel
      2. Evaluates for other diagnosis (e.g. intussception, Appendicitis)
    3. CT Abdomen and Pelvis with oral and IV contrast
      1. Excludes other Abdominal Pain causes (e.g. Appendicitis, Small Bowel Obstruction)
      2. Meckel's Diverticulum is missed unless inflammation or perforation are present

IX. Management: Meckel's Diverticulum

  1. Symptomatic (e.g. Meckel's Diverticulitis, Lower Gastrointestinal Bleeding)
    1. Supportive care
      1. Acute Resuscitation (e.g. pRBC transfusion for acute Hemorrhagic Shock)
    2. Prompt surgical resection of Meckel's Diverticulum
      1. Simple diverticulectomy (with careful removal of all ectopic tissue) OR
      2. Segmental Small Bowel resection
        1. Indicated in perforation or Intestinal Ischemia
        2. Also indicated when ectopic tissue extends to Diverticulum junction or into intestinal mucosa
  2. Asymptomatic incidental finding (on other surgery or imaging)
    1. Resect all symptomatic cases (as above)
    2. Non-surgical observation is typically preferred in asymptomatic cases
    3. Prophylactic resection of Meckel's Diverticulum indications
      1. Age <8 years old (some guidelines recommend <40 to 50 years old)
      2. Male gender (higher complication rate)
      3. Meckel's Diverticulum >2 cm
      4. Palpable abnormality
      5. Fibrous cords

X. References

  1. Broder (2022) Crit Dec Emerg Med 36(12): 20-1
  2. McLure (2023) Crit Dec Emerg Med 37(6): 14-5
  3. Stannard, Rogers and Kernen (2023) Crit Dec Emerg Med 37(7): 24-9
  4. Thompson and Ruttan (2021) Crit Dec Emerg Med 35(5):12-3
  5. Townsend (2001) Sabiston Surgery, Saunders, p. 907-9
  6. Cullen (1994) Ann Surg 220:564-9 [PubMed]
  7. Kuru (2018) Rev Esp Enferm Dig 110(11): 726-32 +PMID: 30032625 [PubMed]
  8. Malik (2010) Saudi J Gastroenterol 16(1):3-7+PMID: 20065566 [PubMed]
  9. Rossi (1996) AJR 166:567-73 [PubMed]
  10. Uppal (2011) Clin Anat 24(4):416-22 +PMID: 21322060. [PubMed]
  11. Yahchouchy (2001) J Am Coll Surg 192:658-62 [PubMed]

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Meckels Diverticulitis." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Studies

Related Topics in Gastroenterology

advertisement