Chapter 43: Small Intestine- Meckel's Diverticulum Flashcards
What is it?
Remnant of the omphalomesenteric duct/vitelline duct, which connects the yolk sac with the primitive midgut in the embryo
What is the usual location?
Within ≈2 feet of the ileocecal valve on the antimesenteric border of the bowel
What is the major differential diagnosis?
Appendicitis
Is it a true diverticulum?
Yes; all layers of the intestine are found in the wall
What is the incidence?
≈2% of the population at autopsy
What is the gender ratio?
Twice as common in men
What is the average age at onset of symptoms?
Most frequently in the first 2 years of life, but can occur at any age
What are the possible complications?
- 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
- Intestinal obstruction
- 25%
- most common complication in adults; includes
- volvulus and intussusception
- Inflammation (± perforations)—20%
What are the signs/symptoms?
Lower GI bleeding, abdominal pain, SBO
What is the most common complication of Meckel’s diverticulum in
adults?
Intestinal obstruction
In what percentage of cases is heterotopic tissue found in the
diverticulum?
>50%
What heterotopic tissue type is most often found?
Gastric mucosa (60%)
but duodenal, pancreatic, and colonic mucosa are also found
What is the “rule of 2s”?
- 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
What is the role of incidental Meckel’s diverticulectomy (surgical
removal upon finding asymptomatic diverticulum)?
- Most would remove in all children
- Adults:
- Ectopic tissue (fullness) or
- Mesodiverticular band
What is a Meckel’s scan?
Scan for ectopic gastric mucosa in Meckel’s diverticulum; uses technetium pertechnetate IV, which is preferentially taken up by gastric mucosa
What is the treatment of a Meckel’s diverticulum that is causing
bleeding and obstruction?
Surgical resection, with small bowel resection as the actual ulcer is usually on the mesenteric wall opposite the diverticulum!
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:
Abd/pelvis CT scan with oral contrast to rule out SBO (small bowel
obstruction)
52 year old male alcoholic with history of blood in vomit
Name the diagnostic modality:
EGD
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
CT scan with oral contrast and NGT decompression, IVF, serial and exams for SBO (oral contrast is thought to be therapeutic!)
Jejunal ulcers
What is the correct diagnosis?
Zollinger–Ellison syndrome
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?
Small bowel injury
Name the radiographic test for localizing the following:
Meckel’s diverticulum
Technetium-99m sodium pertechnetate scan
