II. Epidemiology
- Most common cause of significant Gastrointestinal Bleeding in children
- Meckel's Diverticulum occurs equally in both genders
- Complications are more common in males by ratio of 3:2
- Lifetime complication rate: 4%
- More than 50% of complications occur before age 10
III. History
- Initial report by Hildanus in 1598
- Detailed description by Johann Meckel in 1809
IV. Pathophysiology: Meckel's Diverticulum
- Meckel's Diverticulum is the most common congenital malformation of the Gastrointestinal Tract
- Incomplete closure of vitelline duct (omphalomesenteric remnant)
- Omphalomesenteric duct (vitelline duct) connects primitive gut to Yolk Sac in early fetal development
- Duct typically closes and obliterates when the placenta replaces the Yolk Sac at 7 weeks gestation
- Incomplete elimination of the Omphalomesenteric duct (vitelline duct) results in various remnants
- Meckel's Diverticulum
- Enterocyst
- Fibrous Cord
- Fistula
- Characteristics
- Meckel's Diverticulum contains all intestinal wall layers (serosa, Muscle, submucosa, mucosa)
- Meckel's Diverticulum may be lined with gastric mucosa (85%) and other heterotopic tissue
- Ectopic tissue occurs most often at the Diverticulum tip
- Gastric mucosa acid secretion may lead to ulceration, bleeding
- Other heterotopic tissue
- Pancreatic tissue
- Brunner's glands
- Duodenal mucosa
- Colonic mucosa
- Hepatobiliary mucosa
- Endometrial mucosa
- Blood supply is ultimately from superior Mesenteric Artery (derived from omphalomesenteric artery)
- Location
- Proximal to ileocecal valve by 100 cm
- Usually within 45 to 60 cm of ileocecal valve
- Follows the rule of 2's (roughly)
- Affects 2% of the population (range 0.4 to 4%)
- Often presents before age 2 years
- May contain two types of ectopic tissue, such as gastric (85%) and pancreatic tissue
- Symptomatic presentations or complications affect 2-4% of those with Meckel's Diverticulum
- If symptoms are to occur, they occur by age 2 years in 50% of cases (age 10 in some references)
- Occurs 2 feet (up to 100 cm) proximal to the ileocecal valve
- Meckel's Diverticulum is 2 cm wide and 2 cm long
V. Findings
- Episodic Rectal Bleeding
- Painless intermittent bleeding is the most common presentating symptom in children
- Bleeding may occur from ulceration of gastric or pancreatic ectopic tissue, or from intermittent intussception
- Acute Meckel's Diverticulitis and other complications (e.g. obstruction)
- Abdominal Pain
- Intractable Vomiting
- Tachycardia
VI. Differential Diagnosis: Meckel's Diverticulitis
VII. Complications: Meckel's Diverticulum
- Meckel's Diverticulum has an overall complication rate of 4%
-
Lower Gastrointestinal Bleeding (25-50% of complications)
- Often associated with ectopic gastric mucosa
- Profuse Hemorrhage may occur
- Hemorrhage is most common presentation under age 2
- Resolves spontaneously in most cases
- Meckel's Diverticulitis (10 to 20% of complications)
- Similar in presentation to Appendicitis
-
Bowel Obstruction (14 to 53% of cases, esp. adults)
- Volvulus at fibrotic band attached to abdominal wall
- Intussusception
- Incarcerated Inguinal Hernia (Littre's Hernia)
- Bowel Perforation
- Malignancy
- Carcinoid Tumor
- Sarcoma
- Stromal Tumor
- Intraductal Papillary Mucinous Adenoma of Pancreatic Tissue
- Miscellaneous tumors and adenocarcinomas
VIII. Imaging
- Radionuclide Scintigraphy (Meckel's Scan)
- Performed via IV injection of Sodium Tc-pertechnetate (99m)
- May require sedation in young children
- Each image frame is acquired over 1 minute, and total series requires more than an hour
- Preferential uptake by gastric tissue
- Detects ectopic gastric mucosa
- Most accurate test in Meckel's Diverticulum
- Test Sensitivity: 85% to 90% in children
- Test Specificity: 95% in children
- Less accurate in adults
- Cimetidine increases accuracy in adults
-
Small Bowel enema
- Indicated for negative scintigraphy in adults
- Arteriography (indicated for acute Hemorrhage)
- Tests to evaluate differential diagnosis (but not typically useful in diagnosis of Meckel's Diverticulum or Diverticulitis)
- Abdominal XRay
- Abdominal Ultrasound
- May show blind-ended thick-walled loop eminating from Small Bowel
- Evaluates for other diagnosis (e.g. intussception, Appendicitis)
- CT Abdomen and Pelvis with oral and IV contrast
- Excludes other Abdominal Pain causes (e.g. Appendicitis, Small Bowel Obstruction)
- Meckel's Diverticulum or Diverticulits is missed unless perforation or other complications are present
IX. Evaluation
- Maintain a high index of suspicion
- Delayed diagnosis is common
X. Management: Meckel's Diverticulum
- Symptomatic (e.g. Meckel's Diverticulitis)
- Prompt surgical resection of Meckel's Diverticulum
- Segmental bowel resection indications
- Perforation
- Intestinal Ischemia
- Ectopic tissue extends to Diverticulum junction or into intestinal mucosa
- Asymptomatic incidental finding on other surgery
- Resect all symptomatic cases (as above)
- Prophylactic resection of Meckel's Diverticulum indications
- Age <8 years old (some guidelines recommend <40 years old)
- Male gender (higher complication rate)
- Meckel's Diverticulum >2 cm
XI. References
- Broder (2022) Crit Dec Emerg Med 36(12): 20-1
- Thompson and Ruttan (2021) Crit Dec Emerg Med 35(5):12-3
- Townsend (2001) Sabiston Surgery, Saunders, p. 907-9
- Cullen (1994) Ann Surg 220:564-9 [PubMed]
- Kuru (2018) 110(11): 726-32 [PubMed]
- Rossi (1996) AJR 166:567-73 [PubMed]
- Yahchouchy (2001) J Am Coll Surg 192:658-62 [PubMed]