Ischemic and Vascular GI Disorders

Question 1

What is the most important artery for ischemia of the mesentery and bowel?

Answer 1

Superior Mesenteric Artery

Question 2

List the connections between branches of the aorta in the abdomen?

Answer 2

• SMA-Celic
• IMA-SMA
• Iliac-IMA

Question 3

Where do the colonic veins lie?

Answer 3

parallel to the arteries

Question 4

What are the main regulators of vasodilation/constriction in the GI

Answer 4

NO-vasodilation

Phospholipase C - constrictoin

Question 5

ON TEST: Massive hemorrhage leading to reduced blood volume has an affect on splanchnic blow flow. Describe the pathway and result.

Answer 5

Reduced blood volum leads to diminished venous return to heart, which results in fall in CO and arterial hypotension. These lead to increased TPR, leading to redistribution of blood flow to heart, brain lung and kidney. This end result is decreased splanchnic blood flow.

Question 6

What are of the villi are most sensitive to die within first hour of ischemia?

Answer 6

The top of the villi, which have the longest pathway from the main arteriole in each villi.

Question 7

Why is ileus a late manifestation of acute mesenteric ischemia?

Answer 7

It requires the complete death of the area to cause a complete stop of movement.

Question 8

What are the four major ischemic dz of gi tract?

Answer 8

ischemic colitis
acute mesenteric ischemia
chronic mesenteric ischemia
venous mesenteric ischemia

Question 9

What is the presentation of ischemic colitis?

Answer 9

hematochezia, diarrhea, abdom pain with abdom tenderness on exam

Question 10

Ischemic colitis typical patient?

Answer 10

older person with chf or some form of low vascular support

Question 11

What is the presentation of acute mesenteric ischemia?

Answer 11

early abd pain without ileus, peritoneal signs only in advanced dz, not always blood.

Question 12

What is an example of something that may cause acute mesenteric ischemia?

Answer 12

emoboli from the heart

Question 13

On CT, what is a bad sign prognosticator for acute mesenteric ischemia?

Answer 13

portal vein gas

Question 14

How do you distinguish between ischemic colitis and acute mesenteric ischemia?

Answer 14

IC - over 60, acute cause is rare, mild pain, tenderness, bleeding, colonoscopy

AMI - age varies, acute cause is typical, severe pain, tenderness is not prominent early, bleeding uncommon, angiography

Question 15

When do you see abdominal pain in chronic mesenteric ischemia? Why do you see it?

Answer 15

See it after eating

At least two of three splanchnic arteries usually have significant occlusive dz

Question 16

Who classical presents with venous mesenteric ischemia?

Answer 16

middle aged women

Question 17

What are general clinical presentations of GI bleeding?

Answer 17

melena - black tarry loose sticky malodorous stool caused by degraded blood in intestine

hematochezia - bright red blood from rectum, may be mixed with stools.

Question 18

What do melena indicate?

Answer 18

an upper GI source, although may originate in right colon

Question 19

What does hematochezia indicate?

Answer 19

lower GI lesion, or massive upper GI hemorrhage

Question 20

What is the epidemiology of upper GI bleeding?

Answer 20

most frequent GI bleed, common in elderly and men

80% are self-limited

Question 21

What are various causes of upper GI bleed?

Answer 21

peptic ulcers, gastritis and duodenitis
tumors
vascular malformation
esophagitis
varices

Question 22

What is a mallory-weiss tear?

Answer 22

A tear due to violent wretching

Question 23

Where in the GI does herpes like to infect?

Answer 23

GEJ

Question 24

Acute lower Gi bleeding arises where?

Answer 24

Below the ligament of Treitz

Question 25

What are the most common causes of acute lower GI bleed?

Answer 25

diverticulosis and angiodysplasia

Question 26

What is the most common cause of chronic lower Gi bleed?

Answer 26

hemorrhoids and neoplasia

Question 27

with what things to do you see angiodysplasia?

Answer 27

advanced age, chronic renal failure, osler-weber-rendu, prior radiation therapy, watermelon stomach

Question 28

what is angiodysplasia?

Answer 28

slow intermittent blood loss, primary cecum and right side colon