Diseases of thoracic Aorta

Question 1

Describe the tunica intima

Answer 1

• Layer of endothelial cells
• Subendothelial layer - collagen and elastic fibres
• Separated from tunica media
  via interanal elastic membrane

Question 2

Describe the tunica media

Answer 2

• Smooth muscle cells

- Secrete elastin in the form of sheets or lamellae

Question 3

Describe the tunica adventitia

Answer 3

• Thin connective tissue layer
• Collagen fibres and elastic fibres
• The collagen in the adventitia prevents elastic arteries from stretching beyond their physiological limits during systole

Question 4

Define an aneurism

Answer 4

A localised enlargement of an artery caused by a weakening of the vessel wall

Question 5

Describe the two types of classifying aortic aneurisms

Answer 5

True/False

By location

Question 6

Describe a ‘true’ aneurism

Answer 6

• Weakness and dilatation of wall involving all 3 layers

Question 7

Describe a ‘false’ aneurism

Answer 7

• Rupture of wall of aorta with the haematoma either contained by the thin adventitial layer or by the surrounding soft tissue

Question 8

State the 4 locations used to classify aortic aneurisms

Answer 8

• Ascending
• Arch
• Descending
• Abdominal

Question 9

Describe the signs/symptoms of an aneurism

Answer 9

• Could be asymptomatic
• Based on location of aneurysm
• SOB
• Dysphagia and hoarseness
• Back pain
• Pulsatile mass

Question 10

Describe the investigations for a suspected aneurism

Answer 10

CXR
Echo
CT angiogram aorta
MRI aorta

Question 11

What are the 2 diagnostic tests for an aneurism

Answer 11

CT angiogram aorta

MRI aorta

Question 12

What would a CXR show for an aneurism

Answer 12

Widened aneurism

Question 13

What does an echo do in terms of assessing for an aneurism?

Answer 13

Assess aortic root size and aortic valve (limited views of distal ascending aorta and arch)

Question 14

What is an aortic dissection?

Answer 14

Tear in the inner wall of aorta

Question 15

Describe the aeitology of an aortic dissection

Answer 15

• Hypertension
• Atherosclerosis
• Marfa’s syndrome
• Bicuspid aortic valve
• Trauma

Question 16

What is a false lumen?

Answer 16

It occurs when blood enters the medial layer of the aortic wall through a tear or penetrating ulcer in the intima and tracks longitudinally along with the media, forming a second blood-filled channel (false lumen) within the vessel wall

Question 17

What may the dilation of ascending arota cause?

Answer 17

Aortic regurgitation

Question 18

What are some complications of aortic dissections?

Answer 18

• False lumens
• May occlude branches (coronary, mesenteric, carotid, renal, spinal)
• Rupture - back into the lumen or externally into the pericardium (tamponade) or mediastinum

Question 19

Describe what is meant by a Type A aortic dissection - defined by the stanford classification system

Answer 19

All dissections involving the ascending aorta, regardless of origin

Question 20

Describe what is meant by a Type B aortic dissection - defined by the stanford classification system

Answer 20

All dissections not involving the ascending aorta

Question 21

Describe what is meant by a type I aortic dissection as classified by the DeBakey classification system

Answer 21

Originates in the ascending aorta, propagates at least to the aortic arch and often beyond it daily

Question 22

Describe what is meant by a type II aortic dissection as classified by the DeBakey classification system

Answer 22

Originates in and is confined to the ascending aorta

Question 23

Describe what is meant by a type III aortic dissection as classified by the DeBakey classification system

Answer 23

Originates in the descending aorta and extends distally down the aorta or rarely retrograde into the aortic arch and ascending aorta

Question 24

Describe the presentation of someone with an aortic tear

Answer 24

Chest pain - severe, sharp, radiating to back
Collapse - tamponade, acute AR, external rupture
Stroke - Involvement of carotid arteries

Question 25

Describe the signs of an aortic tear

Answer 25

- Reduced or absent peripheral pulses - Hyper/hypotension - BP mismatch between sides - Soft early diastoic murmur (aortic regurg) - Pulmonary oedema - Signs of CVA

Question 26

Describe the investigations used for an aortic dissection and what they may show?

Answer 26

ECG - might show ST elevation indicating coronary involvement CXR - widened mediastinum CT angiogram aorta - confirms diagnosis Transthoracic echocardiogram (TEE) - assess aortic root, aortic regurg, pericardial effusion

Question 27

Describe both treatment options for an aortic dissection

Answer 27

``` Blood pressure control: - B blocker - IVI nitrate - CCB - IVI Na Nitroprusside AND EITHER - emergency surgery OR percutaneous (endovascular) intervention ```

Question 28

Describe what is meant by a bicuspid aortic valve

Answer 28

- 2 leaflets in aortic vlaves fuse - Most common congenital abnormality 1-2% prevalence - Prone to aortic valve stenosis and or regirg - Associated with regurgitation - Abdominal aorta has reduced tensile strength - Prone to aneurism/Dissection - Monitor with echo/MRI