Aortic Dissection

Aortic Dissection

Stanford Classification

Type A – Involves the ascending aorta, regardless of the origin of the primary tear

Type B – All other dissections that do not fit criteria as Type A

DeBakey’s Classification

Type 1 – Originates in the ascending aorta and propagates to at least the aortic arch

Type 2 – Originating in and confined to the ascending aorta

Type 3 – Originates in the descending aorta and extends distally or proximally (but not further than the left subclavian artery)

Predisposing conditions 

• Hypertension
• Atherosclerosis
• Connective tissues disease (i.e. Marfan’s, Ehlers Danlos)
• Bicuspid aortic valve
• Previous aortic manipulation
• Previous aortic aneurysm
• Vasculitis

Complications of Aortic Dissection

• Aortic regurgitation (involvement of the aortic root)
• Pericardial effusion or tamponade (proximal tears)
• Acute myocardial infarction (obstruction of aortic sinuses)
• Stroke (involvement of the carotids) 
• Acute kidney injury (involvement of renal arteries)
• Visceral ischaemia (i.e. gut, spleen, liver, limbs, spine)
• Aortic rupture or aneurysm

Management of Aortic Dissection

Anti-Impulse therapy – IV esmolol to aim BP <120/80. If HR drops below 60, consider vasodilator (i.e. sodium nitroprusside)

If the dissection involves the ascending aorta – will require immediate surgical referral for operative management

If no involvement of ascending aorta – managed with haemodynamic control (unless complicated – i.e.occlusion of an aortic branch resulting in ischaemia, persisting, uncontrolled pain, persistent hypertension despite medical therapy, aneurysm expansion or aortic rupture

X-Ray Features of Aortic Dissection

Widened mediastinum in context of aortic dissection

References:

Bell, D.J., E., Gaillard, F. (2021). Aortic Dissection. Radiopaedia. Retrieved 14th August 2021 from https://radiopaedia.org/articles/aortic-dissection

Black, J.H., Manning, W.J. (2021) Clinical Features and Diagnosis of Aortic Dissection. UpToDate. Retrieved 14th August 2021 from https://www.uptodate.com.acs.hcn.com.au/contents/clinical-features-and-diagnosis-of-acute-aortic-dissection