Aortic dissection

Question 1

What is an aortic dissection?

Answer 1

When the tunica intima of the aortic wall tears and blood fills between the tunica intima and tunica media. This leads to vessel dilation

Question 2

What is the false lumen?

Answer 2

Blood pooling between the tunica intima and tunica media

Question 3

What are the 2 types of aortic dissection?

Answer 3

Type A- occurs in the first 10cm of the ascending aorta (most common) Type B- occurs in the descending aorta (distal to the left subclavian artery)

Question 4

What is the main risk factor for aortic dissection?

Answer 4

Chronic hypertension- due to increased stress, greater blood volume and/ or coarctation (narrowing) of the aorta

Question 5

Name some other risk factors for aortic dissection?

Answer 5

• Weakened aortic wall (connective tissue impairment) - aneurysms - aortic atherosclerosis -crack cocaine

Question 6

Name some causes of weakened aortic walls?

Answer 6

Marfan’s syndrome, Ehlers-Danlos syndrome and reduced blood flow in the vasa vasorum

Question 7

Name some complications of aortic dissection

Answer 7

1. Pericardial tamponade- blood flows back from the aorta into the pericardial space 2. Bleed into the mediastinum- when blood wears out the aortic wall 3. Hypoperfusion to other structures- false lumen can extend to other vessels and compress them

Question 8

What is the hallmark symptom for aortic dissection

Answer 8

sudden-onset tearing chest pain radiating to the back- pain is intense from the onset

Question 9

if aortic dissection affects other arteries, what other symptoms could patient present with?

Answer 9

2. Carotid artery – blackout, dysphasia 3. Coronary artery- chest pain/ angina 4. Subclavian artery- ataxia, LOC 5. Anterior spinal artery- paraplegia (paralysis of lower body) 6. Renal artery- renal failure, anuria 7. Coeliac axis- severe abdominal pain

Question 10

State some signs on examination

Answer 10

• Weak pulse in downstream arteries • Absent pulse in one arm due to occlusion of the root of the brachiocephalic or left subclavian artery by the dissection. • Difference in BP between left and right arm (>20mmHg)

Question 11

What sort of murmur can manifest?

Answer 11

aortic regurgitation- early diastolic murmur

Question 12

Name the investigations you would do for aortic dissection

Answer 12

• CXR- widened aorta/ mediastinum - Transoesophageal echocardiogram - CT/ MRI angiography - Bloods- FBC; U&E, clotting screen - ECG- usually normal

Question 13

What is the treatment of a Type A aortic dissection?

Answer 13

Surgical- this is an emergency Removal of dissected aorta and reconstruct with synthetic graft (sometimes held open by stent).

Question 14

What is the treatment of Type B aortic dissection?

Answer 14

Give beta blockers/ nitroprusside