Aortic Dissection

Question 1

What is an aortic dissection?

Answer 1

Tear in tunica intima allows blood to flow between the tunica intima and media to form a false, intramural lumen.
The blood in the false lumen can thrombose leading to chronic narrowing of lumen of artery.
Leads to decreased blood flow distal to the dissection due to obstruction to flow

Question 2

Where does an aortic dissection most commonly occur and why?

Answer 2

Right lateral area of ascending aorta
-under increased pressure due to high pressure of blood exit heart

I.e. most common in thoracic aorta

Question 3

What are the risk factors for aortic dissection? What is the classical scenario in exams?

Answer 3

Increased age
Male
Smoking
Hypertension
Poor diet- high in trans fats which can induce hyerlipidaemia
Reduced physical activity
Raised cholesterol
Heavy weight lifting= acute dramatic increase in BP
CVS procedure i.e. bicuspid or aortic valve replacement or CABG
Connective tissue disorders= EDS + Marfans

60 male with background of hypertension

Question 4

What is the typical presentation of aortic dissection?

Answer 4

Ripping or tearing central chest pain which can radiate to the back and between scapula (due to the aorta being a posterior thoracic structure)
Pain location can migrate over time
Differences in blood pressure between arms= >20mmHg
Radial pulse deficit
Collapse
Focal limb weakness and paraesthesia

Question 5

How is a possible aortic dissection investigated?

Answer 5

ECG= exclude MI 
CXR= exclude PE or pneumothorax 

CT angiogram= diagnostic

MRI angiogram= used to get greater detail so can plan management

Question 6

How is someone with aortic dissection managed?

Answer 6

Surgical emergency= surgery dependent on type
Analgesia= morphine
Beta-blockers= control HR and BP to reduce stress on aortic wall

Question 7

What are the 2 types of aortic dissection and what is the difference?

Answer 7

Based on Stanford system
Type A:
-More serious
-Effects the ascending aorta before brachiocephalic artery

Type B:

• Less serious
• affects the descending aorta, after the subclavian artery

Question 8

What type of intervention is recommended for the different types of aortic dissection?

Answer 8

Type A:
-midline sternotomy to remove section of aorta with defect and replace with synthetic graft

Type B:

• can be managed medically unless there is evidence of ischaemic damage
• surgical option= thoracic endovascular aortic repair i.e stent graft inserted along catheter which is put into femoral artery

Question 9

What are the complications associated with aortic dissection?

Answer 9

MI

Stroke

Paraplegia in legs

Cardiac tamponade

AR

Death