Aortic Dissection

Tear in the tunica intima, which creates a false lumen where blood can flow between the layers. The true lumen will often become smaller due to compression by the blood flowing into the false lumen. Risk factors for it include HTN, Valvular HD, and Cocaine/amphetamine use.

It's classified by the Stanford criteria:

• Type A - Involves the ascending and aortic arch

• Type B - Involves the descending aorta

Presentation

Patient's typically present with a sudden onset ‘tearing’ chest pain that radiates to the back.

Signs that will be found O/E - BP difference between arms, Radio-radio delay (Type A), or Radio-femoral delay (Type B).

Investigations and Management

The important investigations to do include:

• BP in both arms

• CT Aorta w/contrast - will show a double lumen

Initial management - Cardiac monitoring, Strict BP control

Definitive management - Depends on the type of dissection:

• Type A - Surgical intervention (e.g. aortic graft)

• Type B - Conservative intervention with:

  • BP control of systolic < 120mmHg (B-blockers are 1st line e.g. IV Labetalol)

    • This is important to minimise the amount of stress on the dissection and to limit further propagation

  • Opioid analgesia

Complications

• Rupture and internal haemorrhage

• Cardiac tamponade

• Embolism - Stroke, Limb and mesenteric ischaemia

• Propagation (extend), in which the dissection can extend:

  • Anterograde (down towards the iliac arteries) – This can cause branch occlusion → ischaemia of affected area e.g. renal ischaemia

  • Retrograde (back towards the aortic valve) – This can cause cardiac tamponade, myocardial infarction, acute aortic regurgitation