weekly_question 9/5/2021

[Admin]

A previously healthy eight-year old boy presents to the emergency department following a syncopal event at school. He reportedly passed a large bloody stool with clots. He denies any discomfort. He is tachycardic with orthostatic hypotension with a soft, scaphoid abdomen. The nasogastric aspirate is bile stained and heme negative. The hematocrit is 21% with a normal coagulation profile. After adequate resuscitation and apparent cessation of bleeding, a Meckel scan is obtained without any evidence of technetium uptake outside of the stomach. A colonoscopy is normal. The next day he passes a large bloody stool and becomes hypotensive. After fluid resuscitation, the next most appropriate management of this patient with rectal bleeding is

A upper gastrointestinal endoscopy

B computerized tomography scan

C repeat Meckel scan

D angiography

E laparoscopy

[Admin]

Correct answer
E laparoscopy

While juvenile polyps are the most common cause of lower gastrointestinal bleeding in this age group, a Meckel diverticulum is the more likely source of serious lower gastrointestinal bleeding. It is typically the ectopic gastric mucosa that produces ulceration in the adjacent ileal mucosa. The bleeding is often substantial but episodic. Although the Meckel scan is a very useful diagnostic test its overall sensitivity remains approximately 85%. The predominant heterotopic tissue in a Meckel diverticulum is gastric although tissue of pancreatic origin is present in up to 15% of cases. This is therefore not visible on the Meckel scan which detects the radionuclide technetium 99m pertechnetate excreted by the acid secreting parietal cells of gastric mucosa.

Given the very suggestive history and magnitude of the recurrent bleeding, prompt definitive therapy is indicated. Laparoscopy would be the most expeditious way to diagnose and treat this problem.

If the initial Meckel scan was of a reasonable quality a repeat scan would offer little benefit. The source of the lower gastrointestinal bleeding is unlikely to be seen on computerized tomography. While endoscopy is useful to exclude peptic ulcer disease, the most common cause of significant upper gastrointestinal bleeding, the presentation is much more suggestive of massive lower GI bleeding. Arteriography would not be expected to demonstrate a site unless there is active bleeding at a rate of at least one mL/minute at the time of the study and would furthermore not be the appropriate treatment for a bleeding Meckel diverticulum.

[IbrahimYousef]

A

[Ahmednabilps]

E

[Abdullah]

E

[Mudasir]

B

[Admin]

Correct answer
E laparoscopy

While juvenile polyps are the most common cause of lower gastrointestinal bleeding in this age group, a Meckel diverticulum is the more likely source of serious lower gastrointestinal bleeding. It is typically the ectopic gastric mucosa that produces ulceration in the adjacent ileal mucosa. The bleeding is often substantial but episodic. Although the Meckel scan is a very useful diagnostic test its overall sensitivity remains approximately 85%. The predominant heterotopic tissue in a Meckel diverticulum is gastric although tissue of pancreatic origin is present in up to 15% of cases. This is therefore not visible on the Meckel scan which detects the radionuclide technetium 99m pertechnetate excreted by the acid secreting parietal cells of gastric mucosa.

Given the very suggestive history and magnitude of the recurrent bleeding, prompt definitive therapy is indicated. Laparoscopy would be the most expeditious way to diagnose and treat this problem.

If the initial Meckel scan was of a reasonable quality a repeat scan would offer little benefit. The source of the lower gastrointestinal bleeding is unlikely to be seen on computerized tomography. While endoscopy is useful to exclude peptic ulcer disease, the most common cause of significant upper gastrointestinal bleeding, the presentation is much more suggestive of massive lower GI bleeding. Arteriography would not be expected to demonstrate a site unless there is active bleeding at a rate of at least one mL/minute at the time of the study and would furthermore not be the appropriate treatment for a bleeding Meckel diverticulum.