Lec 27 Diseases of the Aorta Flashcards
What is a true aneurysm vs false aneurysm?
true = dilatation of all 3 layers of aorta [>50% increase in diameter]
false = rupture through intimal and medial layers contained by adventitia or perivascular thrombus/clot
What is fusiform vs saccular aneurysm? which is more common?
fusiform = more comm, symmetrical on both side saccular = localized just one side
What is primary pathogenesis of ascending thoracic aortic aneurysm?
cystic medial necrosis/degeneration = degeneration and fragmention of elastic fibers
normal media components replaced with acellular stuff [collagen/mucoid material]
What are some etiologies of cystic medial necrosis causing ascending aortic aneurysm?
- occurs with aging due to hypertension
- or w/ disorders that affect connective tissue
- – Marfan
- – Loeys-Dietz syndrome
- – Ehlers-Danlos syndrome
- or bicuspid aortic valve
What causes marfan?
missense mutation in fibrillin gene –> impaired formation of elastin
What causes loeys dietz?
autosomal dom. mutation in TFG-B receptors
What causes ehler-danlos syndrome?
mutation in collagen
What is pathogenesis of anuerysms of descending thoracic and abdominal aorta?
usually due to atherosclerosis
What are some risk factors for descending aorta aneurysm?
- smoking
- dyslipidemia
- men
- HTN
- age [older]
== atherosclerotic risk factors
What is most common location of aortic aneurysm?
abdominal aorta
Besides the most common cystic medial necrosis and atherosclerosis, what are some other possible etiologies of aortic aneurysm?
- post-stenotic
- infection of arterial wall
- vasculitis [giant cell arteritis/takayasu arteritis]
What is natural history of aortic aneurysms?
expand by avg 1-4 mm/year
What are predictors of rate of abdominal aortic expansion?
- initial size [bigger size = faster expansion]
- active smoking
- hypertension
At what diameter abdominal aortic aneurysm should you call surgery? what about in marfans pt?
at 5.5 cm for normal pt; 5 cm for marfans
What are most common complications of abdominal aortic aneurysm?
- death
- rupture
- dissection
What is normal clinical presentation of aortic anuerysm?
- usually asymptomatic
- if thoracic –> may have cough/ dyspnea/ dysphagia from compression neighboring struct
- if ascending –> may have aortic regrug and symptoms of CHF
- if abdominal –> may have ab or back pain or nonspecific GI symptoms
How is aortic aneurysm normally discovered?
pt has chest or ab radiograph for some other reason and see dilation of vessel
How do you diagnose aortic aneurysm?
- chest or abdominal radiograph –> widened mediastinum