Aortic Dissection

Question 1

What is aortic dissection?

Answer 1

A condition where a tear in the aortic intima allows blood to surge into the aortic wall, causing a split between the inner and outer tunica media, and creating a false lumen
intima tear -> blood flows in aortic wall -> creates false lumen by splitting the inner and outer tunica media

Question 2

Risk factors for aortic dissection?

Answer 2

Hypertension
Aortic atherosclerosis
Connective tissue disease (e.g. SLE)
Congenital cardiac abnormalities (e.g. aortic coarctation)
Aortitis
Iatrogenic (e.g. angiography/angioplasty)
Trauma 
Crack cocaine

Question 3

Types of aortic dissection and defining features?

Answer 3

Type A = Ascending aorta tear (most common)

Type B = descending aorta tear distal to the left suBclavian artery (past end of the aortic arch)

Question 4

Which arteries may be obstructed by aortic dissection (false aneurysm)?

Answer 4

Subclavian
Carotid
Coronary
Coeliac
Renal

Question 5

Age group/sex most common for aortic dissection incidence?

Answer 5

40-60 years

Males

Question 6

Presentation of aortic dissection?

Answer 6

Sudden, central ‘tearing’ pain
- this may radiate to the back
Aortic dissection can lead to occlusion of the aorta and its branches so SYMPTOMS MAY RELATE to the affected artery(s)

Question 7

Carotid obstruction, secondary to aortic dissection, symptoms?

Answer 7

Hemiparesis
Dysphasia
Blackout

Question 8

Coronary artery obstruction, secondary to aortic dissection, symptoms?

Answer 8

Chest pain (angina or MI)

Question 9

Subclavian artery obstruction, secondary to aortic dissection, symptoms?

Answer 9

Ataxia

Loss of consciousness

Question 10

Anterior spinal artery obstruction, secondary to aortic dissection, symptoms?

Answer 10

Paraplegia

Question 11

Coeliac trunk obstruction, secondary to aortic dissection, symptoms?

Answer 11

Severe abdominal pain - ischaemic bowel

Question 12

Renal artery obstruction, secondary to aortic dissection, symptoms?

Answer 12

Anuria

Renal failure

Question 13

Specific examination finding for aortic dissection?

Answer 13

Murmur on the back below left scapula, descending to abdomen

Question 14

What non-specific examination findings might you find in aortic dissection?

Answer 14

Blood pressure

• hypertension/hypotension
• wide pulse pressure

Aortic insufficiency

• collapsing pulse
• unequal arm pulses

Question 15

Which investigations are indicated in aortic dissection?

Answer 15

Bloods
CXR
CT-chest
Echocardiography

Question 16

Which bloods are useful in investigation/management of aortic dissection?

Answer 16

• FBC
• Cross-match 10 units of blood
• U&Es (renal function)
• Clotting

Question 17

Signs of aortic dissection on CXR?

Answer 17

• widened mediastinum

- localised bulge in the aortic arch

Question 18

Signs of aortic dissection on CT chest?

Answer 18

false lumen of dissection can be visualised

Question 19

Specificity of transoesophageal echocardiography in aortic dissection?

Answer 19

Highly specific

Question 20

Acute management of aortic dissection?

Answer 20

• Fluid resuscitation with blood products
• CT-thorax urgently
• Monitor pulse/BP in both arms, central venous pressure, insert urinary catheter

Question 21

Treatment of Type A aortic dissection?

Answer 21

Emergency surgery because of risk of cardiac tamponade

- affected aorta is replaced by a tube graft

Question 22

Treatment of Type B aortic dissection?

Answer 22

Medical control of BP/reduction of further dissection - IV nitroprusside and/or IV labetalol (use CCB if beta-blocker contraindicated e.g. asthma)

Surgical repair - may be appropriate in more severe cases

Endovascular repair/stent

Question 23

Complications of aortic dissection?

Answer 23

Aortic rupture, cardiac tamponade, pulmonary oedema, MI, syncope, and cerebrovascular/renal/mesenteric/spinal ischaemia (remember the arteries that can potentially become occluded)

Question 24

Prognosis summary for aortic dissection?

Answer 24

Untreated mortality - 30% at 24h, 75% at 2 weeks

Operative mortality - 5-10%

Further 10% have neurological sequelae

Prognosis is better for type B than type A