Chapter 43: Small Intestine- Meckel's Diverticulum

Question 1

What is it?

Answer 1

Remnant of the omphalomesenteric duct/vitelline duct, which connects the yolk sac with the primitive midgut in the embryo

Question 2

What is the usual location?

Answer 2

Within ≈2 feet of the ileocecal valve on the antimesenteric border of the bowel

Question 3

What is the major differential diagnosis?

Answer 3

Appendicitis

Question 4

Is it a true diverticulum?

Answer 4

Yes; all layers of the intestine are found in the wall

Question 5

What is the incidence?

Answer 5

≈2% of the population at autopsy

Question 6

What is the gender ratio?

Answer 6

Twice as common in men

Question 7

What is the average age at onset of symptoms?

Answer 7

Most frequently in the first 2 years of life, but can occur at any age

Question 8

What are the possible complications?

Answer 8

1. Intestinal hemorrhage (painless)

• ​50%; accounts for half of all lower GI bleeding in patients younger than 2 years
• Bleeding results from ectopic gastric mucosa secreting acid → ulcer → bleeding

1. Intestinal obstruction

• 25%
• most common complication in adults; includes

1. volvulus and intussusception
2. Inflammation (± perforations)—20%

Question 9

What are the signs/symptoms?

Answer 9

Lower GI bleeding, abdominal pain, SBO

Question 10

What is the most common complication of Meckel’s diverticulum in
adults?

Answer 10

Intestinal obstruction

Question 11

In what percentage of cases is heterotopic tissue found in the
diverticulum?

Answer 11

>50%

Question 12

What heterotopic tissue type is most often found?

Answer 12

Gastric mucosa (60%)

but duodenal, pancreatic, and colonic mucosa are also found

Question 13

What is the “rule of 2s”?

Answer 13

• 2% of patients are symptomatic
• Found ≈2 feet from the ileocecal valve
• Found in 2% of the population
• Most symptoms occur before age 2 years
• Ectopic tissue found in 1 of 2 patients
• Most diverticula are ≈2 inches long
• 2:1 male-to-female ratio

Question 14

What is the role of incidental Meckel’s diverticulectomy (surgical
removal upon finding asymptomatic diverticulum)?

Answer 14

• Most would remove in all children
• Adults:
  
  • Ectopic tissue (fullness) or
  • Mesodiverticular band

Question 15

What is a Meckel’s scan?

Answer 15

Scan for ectopic gastric mucosa in Meckel’s diverticulum; uses technetium pertechnetate IV, which is preferentially taken up by gastric mucosa

Question 16

What is the treatment of a Meckel’s diverticulum that is causing
bleeding and obstruction?

Answer 16

Surgical resection, with small bowel resection as the actual ulcer is usually on the mesenteric wall opposite the diverticulum!

Question 17

25-year-old female with history of several abdominal surgeries
now with 2-day history of abdominal distention, vomiting, and no
gas or bowel movements

Name the diagnostic modality:

Answer 17

Abd/pelvis CT scan with oral contrast to rule out SBO (small bowel
obstruction)

Question 18

52 year old male alcoholic with history of blood in vomit

Name the diagnostic modality:

Answer 18

EGD

Question 19

What is the treatment?
67-year-old female with history of several abdominal surgeries
presents with several days of crampy abdominal pain and
vomiting, and x-ray reveals air fluid levels; normal WBC afebrile,
nl lactic acid level, pH is normal, mild tenderness on exam

Answer 19

CT scan with oral contrast and NGT decompression, IVF, serial and exams for SBO (oral contrast is thought to be therapeutic!)

Question 20

Jejunal ulcers

What is the correct diagnosis?

Answer 20

Zollinger–Ellison syndrome

Question 21

17-year-old s/p MVC with abdominal pain, seatbelt sign across
abd, free fluid without solid organ injury on abd CT scan

What is the correct diagnosis?

Answer 21

Small bowel injury

Question 22

Name the radiographic test for localizing the following:
Meckel’s diverticulum

Answer 22

Technetium-99m sodium pertechnetate scan