Histology of the Aorta
Has a very large elastin layer which contributes elasticity to it. This allows it to expand and contract with the flow of blood and the beat of the heart.
The aorta would crumple if there was no blood within it.
Occurs when a tear in the tunica intima of the aorta causes blood to flow betweenthe layers of the wall of the aorta, forcing the layers apart.
Components To Look for in Aortic Disection
- Intimal tear
- Intimal flap
- True lumen
- False lumen
Type A Dissection
A tear in the arch of the aorta.
Type B Dissection
A tear anywhere but the arch.
Aortic Dissection - Presentation
Usually sudden onset chest pain that is characterised as severe, midline, and a "sharp" or "tearing" sensation.
Can often present with syncope, coma, shock, or sudden death.
Mortality of Aortic Dissection
With medical therapy, the mortality rate is 58% with Type A and 11% with Type B.
With surgical therapy, the mortality rate is 26% with Type A and 31% with Type B.
Medication is indicated with Type B and surgery for Type A.
Treatment of Aortic Dissection
Surgery for Type A
Medication for Type B - IV beta-blockers to reduce BP and reduce heartrate as well as vasodilators to further reduce blood pressure.
Diagnosis of Aortic Dissection
CT angiography is the best as it is quick and accurate.
Echocardiography can also be used.
Giant Cell Aortitis - often presents in patients who are >55 years of age, and often is associated with temporal arteritis.
Takayasu's Aortitis - often affects young females, is an occlusive disorder of aortic branch vessels, hence 'pulseless disease'. Often has associated eye problems.
Is a form of large vessel granulomatous vasculitis with massive intimal fibrosis and vascular narrowing.
Often affects young women of Asian descent around 15-30 years of age. Much more common to affect women than men.
Typically blocks the main branches of the aorta, including the left common carotid artery, the brachiocephalic artery, and the left subclavian artery.
Can present with pulseless upper extremities.