Aortic Dissection

Question 1

Definition of aortic dissection

Answer 1

Tear in intima resulting in blood dissecting through media & separating layers - surgical emergency

Question 2

Who is this most likely going to occur in?

Answer 2

Men 50-70

Question 3

AA are due to?

Answer 3

Mechanical wall stress, weakened aortic wall

Question 4

Risk factors for AD?
What’s the main cause?

Answer 4

Hypertension (MC) due to stress = increased blood vol or coarctation (narrowing)

Connective tissue disorders (marfins syndrome, Ehlers Danlos syndrome)

Family history

AAA/AD

Trauma

Smoking

Aneurysms

Question 5

What are the 2 main locations for AD?

Answer 5

1. Sinotubular junction - where aortic root becomes ‘tubular’ aorta, near aortic valve - most common (A)

2 just distal to left subclavian artery (in descending aorta - thoracic) (B)

Question 6

What is the Stanford classification for location of AD?

Answer 6

A - proximal to left subclavian artery (ascending + arch) 2/3 MC

B - distal to left subclavian (descending thoracic) 1/3 LC

Question 7

Pathology of AD

Answer 7

Blood dissects intima + media + pools in false lumen which can propagate forwards (anterograde) -along aorta or backwards (retrograde- towards aortic root)

Low perfusion to end organ = organ failure + shock

Question 8

Signs and symptoms of AD

Answer 8

Sudden onset, ripping, tearing chest pain (radiate to back)
Shock/hypotension
Decreased peripheral pulse (brachial/femoral - left arm)
Difference in BP in L&R arms
Neurology deficit
Cardiac tamponade
New aortic insufficiency murmur (aortic regurgitation)

Question 9

Differential diagnosis

Answer 9

MI
Central crushing with gradually worsening intensity

Question 10

Diagnosis of AD

Answer 10

Chest x ray = widened mediastinum/aorta >8cm = suspicious

Gold standard = TOE (transoesophageal echocardiogram)
More invasive than TTE but more specific & sensitive for AD
Classify AD as A or B

CT angiogram (also v specific + sensitive) - intimal flap, false lumen, rupture/leak
Used more if patient haemodynamically stable

Question 11

Surgical treatment for AD

Answer 11

Type A = open repair (remove dissected aorta & reconstruct it)

Type B = EVAR (stent inserted) - if less severe = treat with BB & nitroprusside

Question 12

If hypotensive, what do we give?

Answer 12

Consider IV fluid, blood transfusion & adrenaline

Question 13

Medical treatment for AD

Answer 13

1. Special BB
   Esmolol or labetolol
2. Vasodilator sodium nitroprusside

Question 14

Complications of AD

Answer 14

Cardiac tamponade
Blood backs up into pericardial space

Hole in all layers = bleed in mediastinum

Aortic insufficiency = regurgitation

Pre renal AKI

Stroke (ischemic)