Carotid Disease Flashcards
Definition of stroke
Focal neurological deficit lasting >24 hours as result of disease process of vascular origin
Definition of TIA
Focal neurological deficit lasting <24 hours
Percentage of stroke that are
1) Ischemic
2) Hemorrhagic
1) 80%
2) 20%
Percentage of ischemic stroke due to
1) thromboembolic of ICA/Middle cerebral artery
2) Small vessel disease
3) Cardiogenic brain embolism
4) Hematological
5) Other causes
1) 50%
2) 25%
3) 15%
4) 5%
5) 5%
Causes of ischemic stroke
Thromboembolism of ICA/MCA
Small vessels disease
Cardioembolic brain embolism (post MI, AF, vegetation)
Hematological
Others: FMH, arteritis, carotid dissection, carotid tumor, vasculitis
Non-atheromatous carotid diseases
Fibromuscular hyperplasia
Takayasu arteritis
Giant cell arteritis
Carotid aneurysm
Carotid dissection
Carotid body tumor
Carotid body
1) Location
2) Function
1) located within the adventitia of posterior aspect of carotid bifurcation
2) monitor blood gas and pH
Carotid body tumour
1) Pathological origin
2) Percentage malignant
3) Percentage bilateral
1) neural crest ectoderm
2) 5%
3) 5%
Clinical presentation of carotid body tumour
Pulsatile neck mass
Local compression:
-Hoarseness of voice (RLN)
-Horner’s syndrome
-CN palsies
Hormonal mediated:
-Flushing
-Dizziness
-Hypertension
-Arrhythmias
Lyre’s sign
Carotid splaying
Widening of the carotid bifurcation
DDX for carotid body tumor
Glomus vagale
Glomus jugular tumors
Cranial nerves at risk in management of carotid body tumour
Glossopharyngeal
Vagus
Accessory
Hypoglossal
Classic carotid territory symptoms
1) Hemimotor/ sensory signs
2) Transient monocular blindeness
3) Higher cortical dysfunction (dysphasia, visuospatial neglect)
Classic vertebrobasilar territory symptoms
Bilateral blindness
Problems with gait and stance
Hemi- or bilateral motor/sensory signs Dysarthria
Homonymous hemianopia
Diplopia, vertigo and nystagmus (provided it is not the only symptom)
ABCD2 score
Predicts 7-day risk of stroke after TIA
Age >60
SBP >140, DBP >90
Clinical features (unilateral weakness, speech disturbance)
Duration of symptoms
Diabetes
0-3 low risk
4-7 high risk
Total anterior circulation infarct (TACI)
Hemisensory/motor deficit
Higher cortical dysfunction
Homonymous hemianopia
Posterior circulation infarct
Vertebrobasilar infarct
Bilateral blindenss
Gait and stance
Nystagmus
Diplopia
Vertigo
Dysarthria
Management of symptomatic carotid stenosis
Medical treatment
Screen for reversible factors:
-Transcranial color DopplerL: intracerebral arteries
-Duplex USG of neck: carotid arteries
-DSA (gold standard)
Carotid endarterectomy vs endovascular stenting
Evidence in carotid endarterectomy vs medical treatment
ECST (European Carotid Surgery Trial)
NASCET (North American Symptomatic Carotid Endarterectomy Trial)
Conclusion: surgery decreases risk fo stroke significantly in pt with history of TIA/non-disabling stroke in recent 6 months
Evidence for surgical intervention in asymptomatic carotid stenosis
ACAS, ACST: small but significant decrease in stroke risk
Cochrane meta analysis: does not recommend routine surgery
Evidence of CEA vs stenting
Controversial
2005 Cochrane meta-analysis
EVA 2006
SPACE
3 other RCTs ended prematurely
Timing for CEA
1) Immediate
2) Urgent (< 24 hours)
3) Early (within 2 weeks)
- Immediate CEA: Thrombosis secondary to CEA, angiography or angioplasty
- Urgent CEA: Evolving stroke, Crescendo TIA, stuttering hemiplegia particular if an unstable plaque demonstrated
- Early CEA recommended: within 2-4/52 to reduce 20% risk of recurrent stroke within 6 weeks
Criteria for CEA
Symptomatic moderate to severe carotid stenosis should meet the following conditions:
● An ipsilateral TIA or nondisabling ischemic stroke as the symptomatic event
● A surgically accessible carotid artery lesion
● A life expectancy of at least five years
● No prior ipsilateral endarterectomy
● No contraindications to revascularization
Subgroups that would benefit from CEA
Men >50% stenosis
Men and women 70-99% stenosis
Criteria for carotid artery stenting (CAS)
select patients with recently symptomatic carotid stenosis of 50 to 99 percent who have any of the following conditions:
●A carotid lesion that is not suitable for surgical access
●Radiation-induced stenosis
●Restenosis after endarterectomy
●Clinically significant cardiac, pulmonary, or other disease that greatly increases the risk of anesthesia and surgery
●Unfavorable neck anatomy including contralateral vocal cord paralysis, open tracheostomy, or prior radical surgery
Carotid Endarterectomy procedure
Procedure
- Supine, head resting on donut
- Neck extended and head turned to opposite side
- Oblique incision anterior to sternocleidomastoid muscle (mastoid to mid-clavicle)
- Deepened to exposed CCA, ICA & ECA
- Protect hypoglossal and vagus nerves
- Arteries slinged and after heparinisation (systemic 5000 units), clamp with soft clamp
- Longitudinal arteriotomy from CCA across stenosis to ICA
- Plaques raised with dissector from CCA to ICA and proximal end cut with microscissors.
- Proximal end tacked with prolene sutures
- Arteriotomy closed with patch angioplasty
Patch angioplasty vs primary closure in CEA
Patch closure (vein / PTFE / Dacron)
Evidence (systemic review):
- decrease frequency of stenosis
- lower rate of ipsilateral stroke
CAS technique
- LA with sedation
- unfractionated heparin 5000-7500units
- percutaneous femoral arterial access
- Atropine delivered either via the sheath or intrave- nously to block the carotid sinus baroreceptors
- Cross stenosis with distal embolic protection device
- Stent delivered across stenosis
- Dilation of stent for adequate apposition against arterial wall
- Angiography performed in at least two planes
Shamblin Staging
1) Type 1
2) Type 2
3) Type 3
1) tumors localized and easily resectable
2) tumor adherent or partially surrounding vessel
3) tumor intimately surrounding or encasing vessels
Management of carotid body tumor
Surgery (main stay treatment for young good fit patient) +/- preop embolization +/- preop ECA stenting
RT
Embolization
