Vascular GI Diseases (Tombazzi and Nichols)

Question 1

The main arteries involved in GI vascular support include

Answer 1

celiac trunk, superior mesenteric artery and inferior mesenteric artery

Question 2

What is the most sensitive artery to ischemic events

Answer 2

SMA

Question 3

Superior mesenteric is responsible of giving the vascular support to

Answer 3

pancreatico-duodenal area
small intestine
right colon

Question 4

the SMA terminates as the

Answer 4

ileo-colic artery

Question 5

provides protection from ischemia in setting of segmental vascular occlusion

Answer 5

collateral circualtion

Question 6

accounts for a wide fluctuation in splanchnic blood flow

Answer 6

Changes in the resistance of mesenteric arterioles

Question 7

hormones that cause vasoconstriction of GI arterioles

Answer 7

catecholamines
Ang II
vasopressin
**secreted during shock and heart failure

Question 8

hormones that cause vasodialtion of GI arterioles

Answer 8

gastrin
CCK
secretin
**secreted after mealtime

Question 9

describe the intracellular signal responsible for vasodilation

Answer 9

production of NO

Question 10

describe the intracellular signal responsible for vasoconstriction

Answer 10

activation of PLC –> IP3 –> release of Ca from SR

Question 11

most sensitive part of the GI tract/will die first

Answer 11

top of the villi

**as ischemia persists, necrosis will progress down towards/thru the wall

Question 12

How much of the bowel wall must be infarcted for you to clinically see rebound tenderness

Answer 12

to the serosa = transmural

Question 13

clinically how does a mucosal infarct present?

Answer 13

bleeding

Question 14

How much of the wall must be infarted to clinicallt see ileus?

Answer 14

villi/mucosa must be gone = mural or transmural

Question 15

Causes of acute ishemia involving small bowel

Answer 15

1. embolism from L side of heart to SMA
2. thrombosis of SMA
3. non-occusive ischemia (HF or shock)
4. Mesentreric venous thrombosis (hypercoag state–think autoimmune dz)
5. neoplasm or vasculitis
   * *Goljian

Question 16

radiographic findings seen with small bowel infarction

Answer 16

thumbprinting = due to edema in lamina propria
bowel distension with air fluid level
**Goljian

Question 17

Common pathogenesis and presentation of ischemic colitis

Answer 17

Pathogen: artherlosclerosis of SMA
Presents: pain and tenderness (at splenic flexure commonly) ,hematochezia

**Diffuse disease of small vessels (diabetes mellitus, vasculitis) can also lead to this

Question 18

Outcome of ischemic colitis

Answer 18

generally benign, but fibrosis can lead to strictures and obstruction

Question 19

What part of the GI tract does ischemic colitis typically invovle

Answer 19

watershed/splenic flexure and rectosigmoid area

rarely rectum

Question 20

Presentation of acute mesenteric ischemia

Answer 20

early: abdominal pain, NO ileum
later: rebound tenderness and ileus
* *there is NOT always blood

Question 21

What does portal vein gas indicate?

Answer 21

air from lumen of GI is getting into venous system (??? i think thats what he said??) or bacteria colonizing venous system is producing gas

Question 22

term used to describe dead bowel

Answer 22

dusky

Question 23

pseudomembrane and mucin depletion is assc with acute or chonic bowel ischemia

Answer 23

acute

Question 24

hyalinization and withering of crypts is assc with acute or chonic bowel ischemia

Answer 24

chronic

Question 25

gangrenous necrosis, pneumatosis intestinalis and segmental absence of muscularis propria

Answer 25

Neonatal necrotizing enterocolitis (NEC)

Question 26

How is ischemic colitis distinguished from acute mesenteric ischemia

Answer 26

IC: > 60 yo, not an acute cuase, mild pain and tenderness, bleeding AMI: any age, usually acute, severe pain, tenderness appears late, uncommonly assc with bleeding

Question 27

Hallmark presentation of chronic bowel ishemia

Answer 27

abdominal pain after eating --> weight loss | ** 2 of the 3 splanchnic arteries usually have significant occlusive disease

Question 28

most common cause of chronic ischemia

Answer 28

artherlosclerosis

Question 29

time course to presentation of venous mesenteric ischemia relative to arterial

Answer 29

venous takes longer--several days

Question 30

upper vs. lower GI bleed is distinguished as being above or below ...

Answer 30

the ligament of Treitz | **attaches jejunum/duodenum to diaphragm

Question 31

upper or lower acute GI bleed is more common

Answer 31

upper

Question 32

epidemiology of acute upper GI bleed

Answer 32

men and the elderly

Question 33

T or F: most acute upper GI bleeding requires intervention

Answer 33

F: 80% are self limiting

Question 34

causes of acute upper GI bleed

Answer 34

``` Peptic ulcers Gastritis and duodenitis Tumors Vascular malformation Esophagitis Varices Other ```

Question 35

Endoscopy can predict the risk of re-bleeding in duodenal ulcers. what finding on endoscopy is assc with the greatest risk of re-bleeding? lowest?

Answer 35

active bleeding white ulcers

Question 36

duodenal ulcers located ___ are most likely to bleed and rebleed

Answer 36

high on lesser curvature of stomach (how is this a duodenal ulcer, but whatevs?) and inferior wall of the duodenal bulb

Question 37

are gastric or duodenal ulcers more likely to bleed

Answer 37

duodenal

Question 38

esophageal varcies are often secondary to

Answer 38

portal HTN and cirrhosis | **Predictive factors fro bleeding include size and grade of liver dysfunction

Question 39

treatment for esophageal varices

Answer 39

endoscopic banding

Question 40

Gastric varices may occur as a result of ...

Answer 40

plenic vein thrombosis resulting from pancreatitis or pancreatic malignancy

Question 41

caused by forceful gastric mucosa prolapse with retching

Answer 41

Mallory-Weiss Tear

Question 42

Treatment of Mallory Weiss Tear

Answer 42

80-90% spontaneously resolve so only need to stabilize patient

Question 43

What infections can cause upper GI bleed

Answer 43

CMV and Herpes

Question 44

What is the most common cases of acute lower GI bleeding

Answer 44

diverticulosis and angiodysplasia

Question 45

What is the most common cases of chronic lower GI bleeding

Answer 45

hemorrhoids and neoplasia

Question 46

What causes the bleeding in diverticulosis

Answer 46

results from penetration of a colonic artery into the dome of a diverticula

Question 47

What is angiodysplasia?

Answer 47

degenerative change in blood vessels (become tortuous and dilated) then then bleed

Question 48

Where in the GI tract does angiodysplasia typically occur?

Answer 48

cecum and right colon | **usually multiple of them at once

Question 49

angiodysplasia can be secondary to...

Answer 49

advanced age, chronic renal failure, prior radiation (if in rectum), watermelon stomach, osler-weber-rendu

Question 50

what are hemorrhoids

Answer 50

a real pain in the ass!! badadum... Variceal dilations of anal and perianal venous plexus

Question 51

hemorrhoids develop secondary to

Answer 51

persistent elevated venous pressure | constipation, pregnancy

Question 52

What is the difference between external and internal hemorroids?

Answer 52

External hemorrhoids: from inferior rectal vein, below pectinate line, PAINFUL Internal hemorrhoids: superior rectal vein, above pectinate line, PAINLESS