Chapter 91 - Carotid endarterectomy Flashcards
CEA first done in
1950’s
CEA should be done in asymptomatic stenosis 60-99 if
1) periop stroke/death < 3% 2) 3-5 years life expectancy
POISE trial key point
Vascular disease patients benefit from perioperative beta blockers goal HR 60-80
Heparin use in perioperative CEA
1) no level I evidence 2) OHSU suggest use in crescendo TIA 3) perioperative prevent thrombosis (use with ASA)
General anesthesia vsersus local anesthesia for carotid surgery GALA
1) protamine does not increase perioperative stroke risk
Dextra use in platelet
1) Polysaccharide inhibits platelet aggregation 2) control embolic episodes both preop and postop 3) can be used post-CEA to control platelet aggregation for 24 hours
Asymptomatic carotid artery progression study (ASAPS) on statin use in carotid
1) lovastatin reduces carotid artery intima-media thickness 2) lower rate of combined CV events 3) no change to stroke rate
Statin benefits
1) reduce stroke 2) reduce restenosis 3) reduce MI and CV events
Injury to greater auricular nerve
numbness of earlobe
Measuring stump pressure
1) clamp CCA and ECA 2) needle connected to pressure line placed into distal CCA below bifurcation
Eversion carotid endarterectomy Debakey etheredge kieney
DeBakey but only partial transection Etheredge revised it with complete transection below bifurcation Kieney modified 1985 oblique ICA excision and everted alone then reattach after standard endarterectomy done on the CCA and ECA
Pro and con of eversion endarterectomy
1) faster 2) less prone to restenosis 3) no patch needed 4) more extensive dissection harder 5) endpoint inspection suboptimal complete study should be done
EVEREST (eversion CEA vs standard trial study)
1) 1400 patients 2) no difference in outcome 3) higher incidence of perioperative complication with eversion 4) higher incidence of restenosis with standard (confirmed by metaanalysis)
Strategies for higher exposure of a carotid
1) nasotrachial intubation (displaces mandible anteriorly 1-2 cm) 2) divide digastric 3) resect styloid process (gains 4-5 mm) 4) anterior subluxation of mandible
Nerve injury with digastric division
1) spinal accessory - tendinous portion of SCM in upper third 2) glossopharyngeal - deep to digastric
Steps to resect styloid process
1) divide posterior belly of digastric 2) divide styloid apparatus muscle insertions 3) divide styloid process with raunger 4) ligate occipital artery behind inferior border of digastric
Muscles that insert to the styloid process
1) Styloglossus 2) stylopharyngeus 3) stylohyoid muscle
Nerve injury in styloidectomy
Facial nerve
Anterior subluxation of mandible
1) described in 1984 2)place circumdental wires around mandibular cuspid and bicuspid teeth 3) corresponding wires placed on contralateral maxillary teeth 4) sublux mandible anterioly and twist wire together to hold fixation 5) osteotomy through vertical ramus of mandible if needed
ligaments holding the mandible in socket
1) capsular ligament 2) lateral ligament
Methods to determine when to shunt
1) stump pressure 2) EEG 3) somatosensory evoked potential 4) TCD to measure MCA flow 5) cerebral oximetry 6) awake surgery
Shunt types
1) pruitt-inahara 2) javid 3) argyle pruitt less likely to maintain physiological flow javid higher risk of embolism
AbuRahma meta analysis on stroke rate for CEA with shunting
1) 1990-2010 routine shunt: 1.4% never shunt 2% awake 1.1% EEG or stump pressure 1.6% TCD 4.8%
Stump pressure
did not correlate well with EEG or TCD use
Rate of stroke in abnormal EEG without shunt
9% EEG is overly sensitive
SSEP for monitoring
not reliable
TCD first introduced
Schneider 1988
TCD abnormality correlation with EEG criteria
60% only not very reliable to predict cerebral ischemia