7 - Aortic dissection

Summary

Key points

• Aortic dissection may be defined as acute (<2 weeks since symptoms) or chronic (>2 weeks since symptoms)

• Acute aortic dissection is associated with hypertension and pre-existing disease of the aortic wall

• Patients usually present with severe, tearing chest and back pain

• Diagnosis is with transoesophageal echocardiogram and computed tomography (CT) angiogram

• The Stanford or DeBakey classifications are used to describe the pattern of dissection

• Type A dissections require early surgical treatment. The in-hospital mortality is high but the prognosis is very good in patients surviving to discharge from hospital

• Type B dissections are treated medically in the first instance. The in-hospital mortality is much lower but complications may occur following discharge

• Chronic type B dissection may result in aortic dilatation and rupture so surveillance is required

• Endovascular strategies have a role in some situations for acute type A dissection and acute type B dissection, but the role in chronic type B dissection is unclear

Epidemiology

Aortic dissection occurs with an incidence of approximately 3 per 100,000 per year. Accurate estimates are difficult due to the high out-of-hospital mortality for this condition and the low post-mortem rate in most countries. It affects males twice as commonly as females and the risk increases with age. Interestingly, as with a number of other cardiovascular conditions, it demonstrates circadian variation with a peak incidence early in the morning and during the winter. This pattern correlates with times of peak blood pressure.