Diseases of Aorta

Question 1

What are the layers of the aorta?

Answer 1

Intima, media, adventitia

Question 2

Which layer of the aorta is the layer that provides strength?

Answer 2

Adventitia

Question 3

What are the two major structural proteins of the aorta?

Answer 3

Collagen

Elastin

Question 4

What layer contains most of the collagen?

Answer 4

Adventitia (layer of strength)

Question 5

What layer contains most of the elastin?

Answer 5

Media

Question 6

What happens to the ratio of collagen:elastin as you go down the aorta?

Answer 6

Collagen:elastin increases

Question 7

What will happen with elastin digestion?

Answer 7

Decreased compliance

Question 8

What will happen with collagen digestion?

Answer 8

Decreased tensile strength, increased rupture risk

Question 9

What is the deficiency of Marfan’s syndrome?

Answer 9

Fibrillin

Can lead to dilating disease of aorta

Question 10

What is the deficiency of Ehler-Danlos?

Answer 10

Collagen

Can lead to dilating disease of the aorta

Question 11

What is the function of matrix metalloproteinases (MMPs)?

Answer 11

Cause extracellular matrix breakdown, can lead to aneurysms

Question 12

What is a major source of matrix metalloproteinases (MMPs)?

Answer 12

Inflammatory cells 
Bacterial infection (hence why some bacterial infections can cause aneurysms)
- Maybe could use doxycycline to stop aneurysm growing?

Question 13

What does the term ‘cystic medial necrosis’ refer to?

Answer 13

The connective tissue degeneration seen in Marfan’s syndrome

Question 14

Describe a fusiform dilation

Answer 14

Diffuse weakness, circumferential
Spindle shaped
Less chance of rupture due to uniformity

Usually due to cystic medial necrosis, Marfan’s, primary diseases of arterial components

Question 15

Describe a saccular dilation

Answer 15

Focal weakness, asymmetric
Greater chance of rupture

Usually due to invasion of the arterial wall by inflammatory cells, infective or immune aortitis, mechanical injury

Question 16

Describe an ectasia

Answer 16

Enlarged aorta, but not yet characterized as aneurysmal

Question 17

What is the result of dilating disease?

Answer 17

Rupture, hemorrhaage, death

Question 18

What is the result of constricting disease?

Answer 18

Ischemia

Question 19

What are major causes of dilating disease of the aorta?

Answer 19

Congenital (Marfans, Ehlers-Danlos, etc.)
"Nonspecific" aneurysm - multifactorial
Injury - dissection
Infection
Unusual causes

Question 20

What is the definition of an aortic aneurysm?

Answer 20

Dilation of an artery >1.5 times its normal diameter

Question 21

Where do most aneurysms occur?

Answer 21

Infrarenal segment of aorta

Question 22

What will occur over time to all aneurysms?

Answer 22

Will grow

And risk of rupture is proportional to aneurysm diameter

Question 23

What are complications of aneurysms?

Answer 23

Rupture
Thrombosis
Embolization
Compression of adjacent structure

Question 24

When should surgery be performed on aortic aneurysm?

Answer 24

Repair if AAA > 5.5 cm in diameter

Question 25

What is the definition of a pseudoaneurysm?

Answer 25

Dilation does not involve all layers of the aorta | Essentially a hole in the aorta

Question 26

What are the two types of pseudoaneurysms?

Answer 26

``` Penetrating aortic (atherosclerotic) ulcer Infection - "mycotic aneurysm" - mushroom shape ```

Question 27

How does an aortic atherosclerotic ulcer form?

Answer 27

Intimal tear Calcium deposit Ulcer formation

Question 28

What infectious organisms commonly cause mycotic aneurysms?

Answer 28

Salmonella | Syphillis

Question 29

Describe the initial and secondary events of an aortic dissection

Answer 29

Initial - rupture of intima and media, forming a cleavage plane Secondary even - propagation proximally and distally within the aorta

Question 30

What are the Stanford type A and B aortic dissections and which is more common?

Answer 30

Type A - more common - involves ascending aorta, younger patients, high mortality Type B - descending aorta, older patients, hypertension

Question 31

What is a major complication of the dissection?

Answer 31

Can occlude branch arteries like renal artery

Question 32

What occurs with a traumatic rupture?

Answer 32

Full thickness rupture with tamponade by periaortic tissues

Question 33

What are principal consequences of constricting disease of the aorta?

Answer 33

Restricted arterial flow Reduced organ perfusion Infarction

Question 34

Which layer of the aorta does atherosclerosis affect?

Answer 34

Intima

Question 35

Where is atherosclerosis of the aorta more common?

Answer 35

Abdominal aorta >> thoracic aorta

Question 36

In what patients population will you see aortic atherosclerosis?

Answer 36

Small female smokers

Question 37

What are clues to abdominal aortic aneurysm?

Answer 37

``` Abdominal pain (radiates to back) Hypotension Mass in abdomen ```