Ch 12 Uncommon Carotid Pathology Flashcards
What is an aneurysm?
Localized dilatation of the wall of an artery that involves ALL layers of the arterial wall
What is a carotid body tumor?
-Benign mass (aka paraganglioma or chemodectoma) of the carotid body that is a small round mass at the carotid bif
-Forms from chemoreceptor cells
What is a dissection?
-Tear along in intima layer, resulting in splitting/separation of the walls of the vessel
-Due to trauma or rupture of vasa vasorum
What is fibromuscular dysplasia?
-Abnormal growth + development of the muscular layer of an artery wall with fibrosis + collagen deposition causing a localized series of stenoses
-A non atherosclerotic inflammatory disease in artery wall
What is an intimal flap?
-Small tear in vessel wall resulting in part of the intima + media protruding into the lumen of the vessel
-May move with pulsations of flow
What is a pseudoaneurysm?
-Disruption of an arterial wall or anastomosis that results in a pulsating/expanding hematoma outside the artery
-Dilatation NOT covered by all layers of wall
-Aka a false aneurysm
Which vessel is m/c affected by tortuosity?
ICA
What angle makes a kink sharp?
<30 degrees
(m/c kinks are less acute from 30-90 degrees)
Symptoms of tortuosity?
-M/c asymptomatic
-If kinked there can be symptoms of stroke or TIA
What is the benefit of using power doppler over CD when evaluating tortuous vessels?
It can demonstrate the course of the vessel w/o distracting angle changes seen with CD
Where should we place our SVB when using PW in a normal vessel?
Place in middle of vessel b/c it avoids accelerated velocity along the edges
Where should we place our SVB when using PW in a tortuous vessel?
-Place it through the tortuous segment/kink
-Do PW before, in + after the curves/kinks
How to know if a tortuous vessel may be turning into a stenosis?
-Turbulence
-Drop in distal velocity
-Distal tardus parvus waveform
-Doubling velocity in kink
Dissections are seen in what 3 clinical situations?
-Extension into CCA from Ao dissection
-Trauma/microtrauma of ICA
-From underlying diseases in vessel
If a rupture re-enters the lumen, what will the 2 flow channels be?
-True lumen above intima
-False lumen below intima
Most Ao dissections will propagate into the ___?
CCA
What is the hallmark of an ICA dissection?
An intramural hematoma with luminal narrowing or occlusion of the true lumen
When there is a true + false lumen, what are the 3 ways blood can exit out the false lumen?
-Through the same tear in false lumen
-Through secondary tear distal to original tear (antegrade flow)
-Through secondary tear prox to original tear (retrograde flow)
(blood in false lumen can also thrombose + cause true lumen to narrow)
___ is the m/c cause of a stroke in young/middle aged people?
Dissections - due to blood clots that embolize
___ is suspected when a young pt has major trauma or symptoms of stroke, with no risk for atherosclerosis?
ICA dissection
Symptoms of ICA + CCA dissection?
ICA:
-unilateral pain in head/face/neck
-partial horner syndrome
-cerebral or retinal ischemia
CCA:
-headaches
-neck pain
How to identify an Ao dissection in the CCA?
Must identify true + false lumen, with dissection flap
2D:
-intraluminal line that flutters in 2 planes
CD:
-may show different directions of flow in 2 lumens
Spectral:
-true lumen has normal waveform, mild spectral broadening + elevated PSV
-false lumen has irregular waveform, very pulsatile + high resistance
How to identify an ICA dissection?
-M/c can not identify on carotid scan
-If it is seen, there will be a hematoma in false lumen with the true lumen appearing narrowed
-Waveform will appear high resistance (opposite of normal) with no/small plaque
How would FMD appear?
-Multiple areas of narrowing + dilatations
-String of beads pattern (fibromuscular ridges with arterial dilations)
-M/c in mid to distal ICA + renal arteries
