Lecture 20: Pathology of Aorta and Blood Vessel Aneurysm

Question 1

How is aortic plaque progression different from coronary?

Answer 1

More variegated and vascularized; complicated by penetrating ulcer (as opposed to plaque erosion)

Question 2

Complications of atherosclerotic aorta (3)

Answer 2

1. Thromboemboli; 2. Aortic aneurysm; 3. Acute aortic syndrome: dissection, penetrating ulcer, intramural hematoma

Question 3

Two types of aneurysm

Answer 3

1. True: intact/thinned wall (includes atherosclerotic); 2. False: defect in wall –> extra vascular hematoma

Question 4

Atherosclerosis tends to cause aneurysms where? Pathogenesis?

Answer 4

Abdominal aorta; thickened intima –> medial ischemia –> weakening

Question 5

Hypertensive damage tends to cause aneurysms where?

Answer 5

Ascending aorta

Question 6

Marfan’s syndrome tends to cause what kind of aneurysms?

Answer 6

Ascending aorta

Question 7

What infection is commonly associated with a thoracic aneurysm? Histological finding?

Answer 7

Tertiary syphilis due to endarteritis of vasa vasorum; “tree bark” appearance

Question 8

Vit __ deficiency is associated with aortic aneurysms

Answer 8

C

Question 9

Most common site of abdominal aortic aneurysm

Answer 9

Below renals, above bifurcation of iliac arteries

Question 10

What is Fibrillin?

Answer 10

Glycoprotein in ECM that acts like scaffold for elastic fibers

Question 11

Define acute aortic syndrome and what it includes (3)

Answer 11

Spectrum of life threatening, acute, non-traumatic medical emergencies due to complications from aortic intimal and medial pathology: dissection, aortic ulcer, intramural hematoma

Question 12

What is the mechanism of acute aortic syndrome?

Answer 12

Weakened tunica media or ruptured vasa vasorum

Question 13

Define aortic dissection

Answer 13

Intimal tear in vessel wall with separation of layers and extravasation of blood

Question 14

Most common cause of aortic dissection. Why?

Answer 14

Hypertension (older adults); hyaline arterioscerlosis of vaso vasorum decreasing their lumen size –> decreased blood flow –> atrophy of media

Question 15

Who else can get an aortic dissection?

Answer 15

People with connective tissue disorder (Marfan’s)

Question 16

What does an aortic dissection require?

Answer 16

PRESSURE + PRE-EXISTING WEAKNESS OF THE MEDIA

Question 17

Where do aortic dissection usually occur

Answer 17

First 10 cm of aorta

Question 18

Complications of aortic dissection (3)

Answer 18

1. Pericardial tamponade (most common cause of death), 2. Rupture with hemorrhage, 3. Obstruction of branching arteries (malperfusion syndrome)

Question 19

Define a penetrating atherosclerotic ulcer (PAU)

Answer 19

Atheroma ulcerates into aortic media and erodes inner elastic layer of medial wall –> crater-like defect in aortic media

Question 20

PAU creates _______ lesions often in the _______ aorta

Answer 20

Focal; descending

Question 21

Define an intramural hematoma (IMH)

Answer 21

Hemorrhage within the media in the absence of an intiomomedial tear

Question 22

IMH and PAU can both lead to…

Answer 22

Aortic dissection

Question 23

Where is IMH particularly dangerous?

Answer 23

If it’s close to aortic valve