Introduction
Aortic dissection is a rare but serious cause of chest pain.
Classification
Stanford classification
DeBakey classification
- type A - ascending aorta, 2/3 of cases
- type B - descending aorta, distal to left subclavian origin, 1/3 of cases
DeBakey classification
- 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
Epidemiology
- Incidence: 3.00 cases per 100,000 person-years
- Peak incidence: 70+ years
- Sex ratio: more common in males 2:1
| Condition | Relative incidence |
|---|---|
| Acute coronary syndrome | 66.67 |
| Pulmonary embolism | 23.33 |
| Myocarditis | 6.67 |
| Pneumothorax | 5.00 |
| Aortic dissection | 1 |
| <1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Aetiology
Associations
- hypertension: the most important risk factor
- trauma
- bicuspid aortic valve
- collagens: Marfan's syndrome, Ehlers-Danlos syndrome
- Turner's and Noonan's syndrome
- pregnancy
- syphilis
Pathophysiology
Tear in the tunica intima of the wall of the aorta
Clinical features
Features:
- chest pain: typically severe, radiates through to the back and 'tearing' in nature
- aortic regurgitation
- hypertension
- other features may result from the involvement of specific arteries. For example coronary arteries → angina, spinal arteries → paraplegia, distal aorta → limb ischaemia
Management
Type A
Type B*
- surgical management, but blood pressure should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention
Type B*
- conservative management
- bed rest
- reduce blood pressure IV labetalol to prevent progression
Complications
Complications of backward tear
Complications of forward tear
- aortic incompetence/regurgitation
- MI: inferior pattern often seen due to right coronary involvement
Complications of forward tear
- unequal arm pulses and BP
- stroke
- renal failure