What is the first branch of the external carotid? why is this important?
Superior thyroid artery
Imp because: if you see a branch, it’s external: internal doesn’t have branches for a while
Which other structures run with the carotid?
Jugular
Vagus nerve
What is an aneurysm?
local dilatation of artery. Diameter at least 1.5x normal
What is a true aneurysm?
Involves all vessel wall layers (intima, media, adventitia)
What is a false aneurysm?
disruption of aortic wall (or anastomotic site
between vessel and graft). Fibrous capsule made of surrounding tissue contains blood from vessel.
How can aneurysms become problematic?
- rupture
- thrombose
- embolize
- erode
- fistulize
Where can aortic aneurysms be?
Throracic
Thoracoabdominal
suprarenal
pararenal (renal arteries arise from aneurysmal aorta, but not SMA)
juxtarenal (begins just below renal arteries)
infrarenal (there is non-aneurysmal aorta distal to origins of renal arteries)
What are the risk factors for aortic aneurysm?
smoking (current or prior) Advanced age ( esp >70) male Caucasian FMHx other large vessel aneurysms HTN
What is the most common location of AAA?
infrarenal (90-98%)
What is the cause of acute presentation of aortic aneurysm?
Acute expansion or rupture
What are the kinds of true aneurysm?
Saccular (eccentric, only a portion of wall)
Fusiform (concentric, full circumference of wall)
What kind of aneurysm is higher risk for rupture?
Saccular: bc it only involves a portion of the wall, pressure distribution is uneven, making it more vulnerable to rupture
What is the clinical presentation of aortic aneurysm?
- syncope
- pain (chest, abdo, back, flank)
- hypotension
- palpable pulsatile mass above umbilicus
- airway or esophageal: Hoarseness (recurrent laryngeal paralysis), Hemoptysis, Hematemesis
What proportion of aortic aneurysms are asymptomatic?
75% are asymptomatic
What is the classic triad of ruptured AAA?
Hypotension/Collapse
Back/Abdominal pain
Palpable, pulsatile abdominal mass
What are the screening guidelines for AAA?
- one-time u/s in M&F >65 with Hx of tobacco use
- U/s screening in 1st degree relatives of pt who present with AAA
What are the initial investigations in suspected aortic aneurysm?
abdominal u/s!
CBC, lytes, urea, Cr, PTT, INR, type and crossmatch
CT with contrast
peripheral arterial doppler/duplex (to r/o aneurysm elsewhere)
How is aortic aneurysm treated non-surgically?
if asymptomatic & smallish (don’t require surgery):
- risk factor reduction. Smoking, HTN, DM, hyperlipidemia
- exercise, watchful waiting
- surveillance with ultrasound
