Approach

Most people with Meckel diverticulum are asymptomatic. The diagnosis of Meckel diverticulum is frequently an incidental finding during an imaging study or operative exploration.[3][13][18]​​​​[22][23] Physical exam and laboratory evaluation are usually normal in asymptomatic patients.

Risk factors for the development of symptoms include male sex and age less than 2 years.

Consider Meckel diverticulum as a possible diagnosis in patients with symptoms of gastrointestinal (GI) bleeding, intestinal obstruction, peritonitis, and/or perforation.[3][13][23][24]

Rule of 2s

A useful mnemonic describing Meckel diverticulum is the "rule of 2s": 2% prevalence; 2:1 male:female ratio for symptomatic presentations; location most commonly 2 feet (60 cm) proximal to ileocecal valve in adults; 2 types of ectopic tissue (gastric and pancreatic); commonly 2 inches (5 cm) long; and half of those who are symptomatic are younger than 2 years of age.[25]

Clinical evaluation of symptomatic patients

Bleeding

  • GI bleeding is a common presenting symptom in both children and adults (30% to 40% of cases).[1][3][14][15]

  • Up to 90% of bleeding diverticula contain heterotopic gastric mucosa that secretes acid, resulting in ileal mucosal ulceration adjacent to the diverticulum.[13]

  • Classically, the bleeding is acute, episodic, and painless.

  • Patients may also be hemodynamically unstable, with tachycardia and hypotension.

Obstruction

  • Small bowel obstruction is one of the commonest presentations in both children and adults, accounting for 40% to 50% of symptomatic cases.[1][3][15]

  • Patients present with intractable constipation (obstipation), crampy abdominal pain, nausea, and vomiting.

  • A palpable abdominal mass may, rarely, be present, if intussusception is the cause of the obstruction.[18]​ Patients with intussusception may also have dark red, maroon, or “currant jelly” stools.

Inflammation and perforation

  • Meckel diverticulitis is usually seen in adults rather than children, and accounts for 20% to 35% of symptomatic cases in adults.[18][19]​​[Figure caption and citation for the preceding image starts]: Inflamed Meckel diverticulumFrom the collection of Dr Ali Tavakkoli; used with permission [Citation ends].com.bmj.content.model.Caption@15cec77a

  • Clinical presentation is typically abdominal pain in the periumbilical area that radiates to the right lower quadrant.[3]

  • It is often clinically indistinguishable from acute appendicitis and may be diagnosed during preoperative imaging or during surgical exploration.[3][13][19]​​[26] In general, a Meckel diverticulum is less prone to inflammation than the appendix, because most diverticula have a wide mouth and are therefore less likely to become obstructed.

  • Diverticular obstruction can lead to distal inflammation, necrosis, and perforation, resulting in an abscess, peritonitis, or, rarely, hemoperitoneum.[6] Meckel diverticulitis or small bowel obstruction may progress to bowel perforation. If perforation is present, patients may present with a diffuse abdominal tenderness.

Investigation of symptomatic patients

Bleeding

  • All patients require a CBC, which may show a significantly decreased hemoglobin and hematocrit. Leukocytosis with a left shift may be present.

  • In hemodynamically stable patients with occult bleeding, capsule endoscopy is often used as part of the work up, and may provide direct observation of Meckel diverticulum in adults and children.[27][28][29][30]

  • Guidelines on imaging for gastrointestinal bleeding recommend cross-sectional imaging with CT enterography if capsule endoscopy is negative or contraindicated.[27]​ However, an uncomplicated Meckel diverticulum may be difficult to visualize with CT enterography.[27]​ For patients with suspected Meckel diverticulum without active bleeding, request a technetium-99m pertechnetate scan ("Meckel scan").[31]​ A Meckel scan is considered the imaging modality of choice for diagnosis of Meckel diverticulum in children, but a negative result does not exclude the possibility. This scan takes advantage of the way the tracer accumulates in certain tissues, including ectopic gastric tissue that is sometimes found in Meckel diverticulum. Studies show a sensitivity of 0.80 (95% CI: 0.73 to 0.86) and specificity of 0.95 (95% CI: 0.86to 0.98), with lower sensitivity in adults.[32][33]​​​

  • ​​​In patients with active bleeding or hemodynamic instability, CT angiography or mesenteric angiography is the preferred initial investigation.[27][33]​ Active bleeding can cause false negatives on Meckel scan.[33]​ CT angiography is typically performed before conventional angiography as it is faster, noninvasive, and widely accessible.[27]​ Mesenteric angiography can detect hemorrhage in the range of 0.5 to 1.0 mL/min and is generally employed only to localize the bleeding; however, it can have a therapeutic role too.

  • If primary diagnosis remains unclear or the patient is hemodynamically unstable, a surgical abdominal exploration may be necessary, during which the diagnosis may be established.​​[18][19]​​

Obstruction

  • The initial test for patients with suspected obstruction is a CT scan of the abdomen, which may show the Meckel diverticulum or related intussusception. Ultrasound may be the preferred option for children.[34][35]

  • If intussusception is suspected, diagnostic contrast enema may be performed; however, air or hydrostatic reduction in the setting of Meckel diverticulum has not been found to be useful. Contrast enema is contraindicated if peritonitis, shock, perforation, or an unstable clinical condition is present.[36]

  • In cases where intestinal ischemia or perforation is suspected and the patient has general peritonitis, an urgent abdominal exploration should be performed without any delays for imaging.

Inflammation

  • Meckel diverticulitis is often clinically indistinguishable from appendicitis. A CT scan of the abdomen may show the inflamed Meckel diverticulum; ultrasound may be preferred in children. However, imaging should not delay surgery if perforation is suspected.[34][35]

Direct observation of Meckel diverticulum can be helpful in making the diagnosis. This can be done surgically, either by laparoscopy or laparotomy, or with endoscopy of the small intestine.[1] Double-balloon endoscopy allows the endoscope to travel further into the ileum until the Meckel diverticulum is found and may be considered if other investigations have failed to reveal the diagnosis.

One study comparing capsule endoscopy and double-balloon endoscopy found that double-balloon endoscopy was able to observe 64 of 74 possible Meckel diverticula.[37] Of the 26 patients who underwent both techniques, 20 of 22 Meckel diverticula detected by double-balloon endoscopy went undetected on capsule endoscopy. The 10 Meckel diverticula that were undetected by double-balloon endoscopy were subsequently found on surgery.[37]

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