Aortic dissection

Question 1

What is an aortic dissection?

Answer 1

• tear in the tunica intima of the wall of the aorta

Question 2

What are the associations of an aortic dissection?

Answer 2

1. hypertension: the most important risk factor
2. trauma
3. bicuspid aortic valve
4. collagens: Marfan’s syndrome, Ehlers-Danlos syndrome
5. Turner’s and Noonan’s syndrome
6. pregnancy
7. syphilis

Question 3

What are the features of an aortic dissection?

Answer 3

1. chest pain: typically severe, radiates through to the back and ‘tearing’ in nature
2. aortic regurgitation
3. hypertension
4. other features may result from the involvement of specific arteries. For example coronary arteries → angina, spinal arteries → paraplegia, distal aorta → limb ischaemia
5. the majority of patients have no or non-specific ECG changes.
6. In a minority of patients, ST-segment elevation may be seen in the inferior leads

Question 4

What is the Stanford classification of an aortic dissection?Stanford classification?

Answer 4

Stanford classification

Type A - ascending aorta, 2/3 of cases

Type B - descending aorta, distal to left subclavian origin, 1/3 of cases

Question 5

What is the DeBakey classification?

Answer 5

type I - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally

type II - originates in and is confined to the ascending aorta

type III - originates in descending aorta, rarely extends proximally but will extend distally

Question 6

How do you manage Type A dissections?

Answer 6

Surgical management

• blood pressure should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention

Question 7

What is the management of Type B dissections?

Answer 7

Conservative management

1. bed rest
2. reduce blood pressure: IV labetalol to prevent progression

Question 8

What are the complications of a backward tear?

Answer 8

1. Aortic incompetence/regurgitation
2. MI: inferior pattern often seen due to right coronary involvement

Question 9

What are the complications of a forward tear?

Answer 9

• unequal arm pulses and BP
• stroke
• renal failure