Carotid Disease Flashcards
blood supply to brain?
circle of willis
- left and right internal carotid arteries (no branches in neck, arise from common carotids)
- left and right vertebral arteries (arise from subclavian - 1st branch and travel within transverse foramina of C6-C1)
purpose of carotid endartectomy?
remove atherosclerostic plaque which is narrowing the carotid artery
reducing risk of ischaemic event (prophylactic procedure)
describe circle of willis?
..
how many strokes arise from asymptomatic ICA stenosis?
10-15%
…
medical management of carotid artery disease following TIA?
dual antiplatelet
statin
manage hypertension
definitive management of carotid artery disease after TIA?
urgent carotid artery duplex
if stenosis is 70-90% of vessel then urgent referral for carotid endartectomy within 2 weeks
indication for endartectomy?
> 70% stenosis in affected artery
should be done within 2 weeks
should have confirmed on 2 imaging methods (duplex + CT (or sometimes MRI)) but duplex alone can sometimes be enough
benefits and risks of doing carotid endartectomy after TIA?
there is a high risk of further stroke/TIA in the 2-4 weeks following TIA
procedure greatly reduces this risk
there is however a 3% risk of disabling stroke during the procedure (still less than otherwise though)
contraindication for carotid endartectomy?
100% eclusion
is procedure done if 50-70% occlusion in vessel?
grey area can be done depending on guideline, gender, time since event, surgeon and patient preference multiple TIA (crescendo TIAs) in a short time would be an indication for the procedure even if only 50% occluded
what type of anaesthetic is used?
depends on hospital
regional/local = can check for signs of ischaemia during operation
general = still surgical field
studies show no benefit of one over the other
how is procedure done?
incision along anterior margin of sternocleidomastoid
pull back sternocleidomastoid allowing exposure of carotid sheath
dissection and control of common, internal and external carotid arteries (maximal stenosis occurs at ostium/bifurcation)
clamp the artery
insert a shunt into common and internal carotid (if under GA) to bypass hole in artery and restore blood flow to brain
remove plaque, intima and media of vessel
closure with patch of bovine pericardium
complications of operation?
pain infection bleeding and haematoma (haematoma can lead to airway obstruction due to enclosed space in neck) damage to surrounding structures stroke death
how is bleeding/haematoma risk managed?
heparin during procedure as well as dual antiplatelets
what surrounding structures can be damaged?
hypoglassal (most common as it crosses over internal carotid), recurrent laryngeal and facial nerves