Carotid Disease Flashcards
What percentage of ischemic strokes are due to carotid disease?
20%
In patients with carotid disease - what conditions increase their stroke rate?
HTN, DM, DLD, Smoking, excessive alcohol
How should blood pressure be controlled to reduce risk of stroke?
Decrease Sbp by 10 and dbp by 5 or to 140, or 130 for pt with recent lacunae Treat all patients regardless of baseline BP. In patients with acute stroke, wait 24h to optimize cerebral perfusion.
Which class of antihypertensives is better for stroke reduction?
No benefit of one agent over another
What is target Hgb a1c for stroke reduction?
< 7. Tighter control not more effective in stroke risk reduction and could increase risk of death (ACCORD, ADVANCE)
What did the SPARCL trial conclude?
At 5 years, ARR of subsequent stroke in TIA/stroke pts is reduced with atorvastatin 80 (13-11%).
Define metabolic syndrome
3/5: - large waist circumference - elevated TG - low HDL - high BG - high BP
Which antiplatelet should you put patients on for stroke risk reduction?
ASA - No significant diff with plavix (5.32% plavix, 5.83% asa CAPRIE) - CHARISMA - no difference with asa/plavix vs. ASA alone, but increased bleeding risk
What is the most important predictor of future stroke?
Recent (within 6 months) ipsilateral neurologic symptoms
What is the stroke rate for symptomatic patients >70% stenosis?
26% w BMT vs. 9% w CEA in 2 years
What is the stroke rate for symptomatic patients with 50-60% stenosis?
22% in 5 year (vs 16% with CEA) - NASCET
What is the stroke risk of asymptomatic patients with >60% stenosis?
11% in 5 year (vs 5% in 5 year) - ACAS
How was degree of stenosis measured in NASCET, ECST and ACAS?
Angio - NASCET ECST Duplex us - ACAS
Patients with what life expectancy will benefit from asymptomatic CEA? Symptomatic patients?
3-5 years asymptomatic ACAS/ACST 2 years symptomatic NASCET
Which women benefit from CEA?
Symptomatic >70% (NASCET) ACAS did not find benefit for women but enrollment was small, ACST found benefit in both men and women
What are the indications for carotid stenting over CEA?
Cardiac ischemia/heart failure Lesion above C2 or below clavicle Scarring from radiation or previous surgery Recurrent carotid stenosis (higher risk of CN injury with repeat CEA) Stoma in neck
Is there a benefit of CEA compared with CAS in symptomatic patients?
Yes - 9.4% stroke rate CAS, 2.8% CEA in a metanalysis of 3 European trials
How often does carotid stenosis recur after intervention?
10% (8 for CAS and 12 for CEA)
What are indications for a CEA
Symptomatic >50%, most benefit >70% Asymptomatic > 60% if periop stroke/death < 3% and at least 5 yr life expectancy
Which landmark trial shows peri op CEA w beta blockage with HR 60-80 is recommended
POISE
When should you use IV heparin for carotid disease?
Crescendo TIA. International stroke trial showed no benefit of routine heparin administration. UFH is used intraop but no level 1 evidence.
Does protamine increase stroke risk after CEA?
No (GALA - general anesthesia vs local anesthesia for carotid surgery trial)
What is dextran?
A polysaccharaide that inhibits platelet aggregation to control embolic episode. Rutherford authors use dextran infusion for 24h after CEA.
What are advantages and disadvantages of eversion endarterectomy?
Pro: fast, no patch/foreign material Con: difficult to shunt, difficult to visualize endpoint on ICA and often need completion studies No significant difference with CEA (EVEREST trial)
* Name 11 maneuvers to expose distal internal carotid artery for high lesions?
- Nasotracheal intubation
- Divide ansa, retract hypoglossal
- Division of digastric (risk to hypoglossal, spinal accessory and glossopharyngeal)
- Divide ascending pharyngeal artery
- Divide occipital artery and venous branches
- Divide SCM from mastoid and resect parotid (protect facial nerve)
- Styloid process resection (risk to occipital artery, facial nerve)
- Anterior subluxation of mandible
- Vertical osteotomy through vertical ramus of mandible
- Drill/remove portions of the inferior portin of the petrous temporal bone
- Use shunts or balloons to control ICA back bleeding.
How high should stump pressure be?
>50 mm Hg
What are ways to monitor intra-op cerebral perfusion
Stump pressure EEG Evoked potential TCD Awake
What patch materials are available for CEA?
GSV - prone to aneurysmal expansion in up to 17%, harvest site complications PTFE, Dacron, Bovine pericardium - no difference in outcomes
What is the risk of cranial nerve injury during CEA? Which nerves most likely?
5% in CREST Hypoglossal > recurrent laryngeal > superior laryngeal > marginal mandibular > glossopharyngeal > accessory
Which nerve is responsible for numbness at angle of mandible?
Greater auricular nerve
What post-op BP parameters after CEA?
Within 20 mm Hg of pre-op. Treat hypotension with fluids and phenylephrine if necessary
What are risk factors for recurrent carotid stenosis?
Women, current smokers, DLD, HTN, DM
What branchial arch do carotid body tumours derive from?
3rd
What is the “lyre” sign?
Splayed carotid bifurcation associated with carotid body tumour
What are 3 classes of carotid body tumours?
Sporadic, familial, hyperplastic
What causes hyperplastic carotid body tumours?
Prolonged hypoxia - living at high altitudes or COPD
How does the carotid body work to regulate breathing/BP?
Stimulated by partial pressure of O2 and pH. type 1 glomus cells release neurotransmitters, signals carried through the glossopharyngeal nerve to medulla oblongata.
How does the carotid body respond to hypoxia, hypercapnia or acidosis?
Increase resp rate, increase tidal volume, increase BP with vasoconstriction
Where do malignant carotid body tumours metastasize?
Regional lymph node, cerebellum, thyroid, brachial plexus, lung, kidney, pancreas bones and breast
What symptoms do carotid body tumour patients present with?
Tenderness, fullness, numbness, dysphagia, hoarseness, cough, tinnitus, horners, dizziness. Lateralizing neurologic findings are uncommon
Why is percutaneous needle biopsy or incisional biopsies contraindicated in carotid body tumour?
Too vascular
What is the Shamblin classification?
Type 1 - Small, easily dissected from walls Type 2 - Larger, more adherent to adventitia Type 3 - Encase internal and external carotid arteries Type 2 and 3 may have to resect ECA and uncommonly ICA en bloc
When should you resect carotid body tumours?
As soon as diagnosed. Later it becomes larger, more nerve injury, malignant potential
What treatment options are there for unresectable or recurrent carotid body tumours?
Radiation
What does pre-op carotid body embolization involve?
Selective catheterization of ECA - emboilization of branch vessels feeding the tumour. Usually for shamblin 2 or 3. Controversial.
What are 6 differential diagnoses for carotid body tumours?
- Congenital lesion (AV malformation) - Benign mass (lipoma, cyst) - Infectious lymphadenopathy - Malignancy (h&n cancer, lymphoma) - Carotid kinks/aneurysms - Other cervical paragangliomas
What are the components for stroke TIA/risk - ABCD2?
Age > 60 = 1
BP > 140 or > 90 = 1
Clinical features of TIA (unilateral weakness = 2, speech = 1), Duration of TIA (> 1hr = 2, 10 min-hr = 1)
Type 2 diabetes = 1
What is the carotid duplex criteria for > 70% stenosis?
PSV > 230, EDV > 100.
ICA/CCA > 4
Diameter reduction B mode > 50%
What percent of ischemic strokes are due to carotid dissection?
2% (but 10-20% of stroke in young/middle age people)
What are risk factors for spontaneous carotid dissection?
Connective tissue disease, remote mild trauma/chiropractory, winter - likely because of infections with coughing, HTN
Which vascular conditions are associated with spontaneous carotid dissection?
Ehlers Danlos, fibromuscular dysplasia, cystic medial necrosis, marfans, polycystic kidney disease, osteogenesis imperfeca type 1
What vascular anatomic findings are associated with carotid dissection?
Intracranial aneurysm, arterial redundance, aortic root dilation, increased arterial distensibility
What symptoms are associated with carotid dissection?
Ipsilateral headache most common. Also - Horners, neck pain, amarosis fugax, unequal pupils, pulsatile tinnitus, CN 9-12 affected esp 12.
Why would a patient with carotid dissection have ptsois, miosis but no anhydrosis?
Ptosis/miosis (oculosympathetic palsy) is associated with the sympathetic fibers accompanying internal carotid artery. Anhydrosis is from sympathetic fibers running with external carotid artery
What is the classic triad of carotid dissection?
ipsilateral head or neck pain, ipsilateral partial horners, ipsilateral cerebral or retinal ischemia.
What percentage of carotid dissection patients present with the classic triad?
less than 1/3
What is the most common cause of traumatic carotid dissection?
MVC - severe cervical hyperextension or lateral hyperflection
What signs/symptoms of head and neck trauma mandate imaging?
Active bleeding, neck hematoma, expanding hematoma, cervical bruit in patients > 50, central or lateralizing neuro deficits, horners, c-spine fracture, petrous bone fracture, GCS < 6, diffuse axonal injury, basal skull fracture, Le Forte 2 or 3
What percent of blunt carotid injuries have severe permanent neurologic deficits?
Up to 20%
What percent of spontaneous carotid dissections bave persistent neurologic deficits
Up to 60%
What did the CADISS trial show with respect to medical management of carotid dissection?
Trial assessed if anticoag vs antiplatelet modifies the persistence or development of carotid aneurysms after dissection. No difference
How do you medically treat carotid dissection?
Antiplatelet or anticoagulation. CADISS and other trials show no significant difference in stroke/mortality in symptomatic carotid dissection
What are indications for acute surgical intervention for carotid artery dissection?
Fluctuating/deterioration in neurologic status despite medical treatment, contraindication to anticoagulation, symptomatic/expanding aneurysm
What are indications for surgical intervention 6 months after carotid dissection?
Aneurysm 2x diameter of normal, persistent high grade stenosis
When surgically intervening on carotid dissection, what would make it safe to ligate the internal?
Stump pressure > 70 mm Hg
What is the rate of post-op stroke when surgically intervening on carotid dissection?
Up to 10%
What trial demonstrated that periop betablockers are of benefit for vascular patients?
POISE
What percentage of strokes are hemorraghic vs ischemic?
80% ischemic, 20% hemorraghic
When should you use heparin for carotid disease?
- Crescendo TIAs
- Intraop (no evidence)
Why dont you put all symptomatic carotid disease patients on heparin?
International Stroke Trial showed no benefit and higher rate of hemorrhagic stroke and fatal bleeding
Is it safe to use protamine during carotid endarterectomies? What trial supports your answer?
Yes - GALA (general vs local anesthesia trial)
What has better outcomes - eversion endarterectomy or CEA with patch? What is your source?
Both are the same - EVEREST trial
What are the potential complications of a GSV patch for carotid, how frequent?
Aneurysmal degeneration (up to 17%) and rupture (up to 4%). Some evidence this may be avoided if only GSV > 3.5 mm used
Why should you patch/evert instead of primary closure?
Primary closure associated with higher periop stroke (5% vs 2%) & higher periop stroke and death (6% vs 2.5%) and higher restenosis/re-operation
What were the results for NASCET symptomatic carotid stenosis 70-99% and 50-69%
70-99% 2 year benefit of CEA vs medical management - 9% stroke vs 26%, benefit persisted at 8 year follow up
50-69% - 5 year benefit - 22% vs 17%, benefit persisted at 8 year follow up
What is the 30 day stroke risk of patients with significant symptomatic ICA stenosis?
CREST - 3%
Interantional Carotid Surgery Trial - 5%
What is the benefit of CEA for asymptomatic carotid stenosis?
ACAS - > 60%, 5 year benefit 5% vs. 11%
ACST > 60%, 5 year enefit 6% vs 12%
In decreasing order, what are the 6 most common nerves injured during carotid endarterectomy?
- Hypoglossal 4–17%
- Recurrent laryngeal 1.5-15%
- Superior laryngeal 1.8-4.5%
- Marginal mandibular 1 -3%
- Glossopharyngeal 0.2-1.5%
- Spinal accessory <1%
Which 2 cutaneous nerves are often damaged during CEA, and what are their resulting symptoms?
- Greater auricular nerve - numbness of ear and angle of mandible
- Transverse cervical nerves - numbness of anterior neck
Name 3 risk factors for hyperperfusion syndrome
- Hypertension
- Contralateral high grade stenosis or occlusion
- Contralaeral CEA within 3 months.
What is the most important risk factor for stroke?
Hypertension
What percentage of strokes are preceeded by a warning TIA?
15%
What are 10 differential diagnoses for vertebrobasilar ischemia?
- Cardiac arrythmia
- Pacemaker malfunction
- Cardioemboli
- Labryinthine dysfunction
- Tumours of the cerebellopontine angle
- Antihypertensive meds
- Cerebellar degeneration
- Myxedema
- Electrolyte imbalance
- Hypoglycemia
What is the Duplex US criteria for a totally occluded carotid artery?
PSV undetectable
Plaque visible
ICA/CCA N/A
EDV N/A
What is the Duplex US criteria for a nearly occluded carotid artery?
PSV high low or undetectable
Plaque visible
ICA/CCA variable
EDV variable
What is the Duplex US criteria for a 70-99 % stenosed carotid artery?
PSV >230 cm/s
Plaque > or = 50 %
ICA/CCA > 4
EDV > 100 cm/s
What is the Duplex US criteria for a <50 -69% stenosed carotid artery?
PSV 125 - 230 cm/s
Plaque > or = 50 %
ICA/CCA 2-4
EDV 40-100 cm/s
What is the Duplex US criteria for a <50% stenosed carotid artery?
PSV < 125 cm/s
Plaque < 50 %
ICA/CCA < 2
EDV < 40 cm/s
What is the Duplex US criteria for a normal carotid artery?
PSV < 125 cm/s
Plaque %
ICA/CCA < 2
EDV < 40 cm/s
Who should be screened with DUS for carotid artery disease?
According to SVS - patients > 55 year old w CV risk factors
US Preventative Task Force recommends against screening
What is ICA stump syndrome?
An occluded ICA stump acts as a vault/reservoir of fresh thrombus that embolizes up the ECA into the brain via retrograde flow through supra & infraorbital vessels
What is the most common etiology of post-operative stroke within 24 h of carotid endartrectomy?
Postoperative carotid thrombosis (POCT)
Name 8 factors that would make someone better suited for carotid stenting (patient, anatomic, etc)
- Prior neck irradiation
- Prior radical neck disection or laryngectomy
- Patent tracheostomy
- History of CN injury
- Proximal CCA stenosis below clavicle
- Distal ICA stenosis above C2
- Symptomatic + one of: 1) EF < 30% 2) Uncorrectable severe CAD 3) Oxygen dependent COPD
Name 4 factors that would make someone better suited for carotid medical management (patient, anatomic, etc)
- Life expectancy < 3 years
- Asymptomatic patients with one of the following:
i) EF < 30
ii) Severe uncorrectable CAD
iii) Oxygen dependent COPD
Name 8 factors that would make someone better suited for carotid endarterectomy (patient, anatomic, etc)
- Age > 70
- Severe aortic arch calcification
- Type 3 arch
- Carotid artery tortuosity
- Circumferential heavy plaque calcification
- Ulcerated/soft plaque on duplex
- Near occlusive lesion
- Extensive > 15 mm plaque
Name 4 carotid artery morphology or plaque features that make it more difficult to stent
- Tortuosity - ICA-CCA angulation > 60 degrees increases risk of death/stroke by 5 x
- Highly stenotic string sign makes stent delivery difficult
- Length of leasion - > 10mm associated with 2.36x risk of death/stroke after CAS
- Echolucent plaques
Name 4 access options, in decreasing frequency used, for carotid artery stenting
- Right femoral if right handed
- Left femoral if right femoral very diseased
- Transcarotid (via CCA cutdown or US guided access)
- Transbrachial/transradial (shaggy aorta, egg shell aorta, severe aortoiliac disease)
Name 3 ways of providing embolic protection during carotid artery stenting
- Filter wires: pro = uninteruppted cerebral blood flow, con = must pass the filter through the lesion prior to deployment
- Distal occlusion balloon: used before filter wires
- Flow stasis: CCA and ECA occlusion balloons using single delivery catheter, causes flow stasis during deployment
- Flow reversal: transcarotid access + external shunt containing filter between carotid artery and shorter introducer in femoral vein
What are 4 things you can do if your patient becomes hypotensive/bradycardic during carotid stenting (baroreceptors stretching)
- Aggressive volume expansion
- IV atropine
- Less commonly - IV phenylephrine
- Less commonly - IV dopamine
What are 5 anatomic risk factors for persistent hypotension after carotid stenting?
- Distance from carotid bifurcation to max stenotic lesion < 10 mm
- Plaque morphology (echogenic)
- Eccentric stenosis
- Calcification at carotid bifurcation.
Name 9 complications of carotid artery stenting and how you might manage each complication
Technical:
- Acute stent thrombosis - convert to CEA
- Kinking - many can be observed
- Dissection - many can be observed, add stent if flow limiting
- Access complications - US guidance helps
- Stent fracture - restent
- Restenosis - similar rates CEA/CAS according to CREST, nothing listed about how to manage
Neurological:
- Embolism - catheter directed thrombolysis, uka/tpa, thrombus maceration, aspiration thrombectomy, snare, glycoprotein 2b3a inhibitor admin
- ICH - (nothing listed - consult neurosurgery)
- Hyperperfusion - supportive treatment, BP control
- Subclinical neurocognitive complications (microembolic) - nothing listed
Cardiac:
- MI (lower than in CEA)
- Renal dysfunction - same as other endo procedure, hydrate/minimize contrast use
Name 1 post-operative measure that could reduce periprocedural adverse events during carotid artery stenting
Name 7 intraoperative measures that could reduce periprocedural adverse events during carotid artery stenting
Name 3 pre-operative measures that could reduce periprocedural adverse events during carotid artery stenting
What is the definition of an extracranial carotid artery aneurysm?
Debated because the bulb is naturally dilated. Some proposed thresholds include 150% dilation compared with CCA or 200% compared with ICA
Name 6 causes of extracranial carotid artery aneurysms
- Atherosclerosis
- FMD
- Mycotic
- Trauma
- Pseudoaneurysm
- Dissection
Name 8 differential diagnoses for extracranial carotid artery aneurysm
- Carotid artery kinks/tortuous
- Prominent bulb in thin neck
- Cervical lymph nodes
- Carotid body tumours
- Glomus jugulare tumours
- Cervical metastatic disease
- Branchial cleft cysts
- Cystic hygromas
What are 5 indications to intervene on extracranial carotid artery aneurysms?
- Size > 2 cm
- Any mycotic aneurysm
- Symptomatic aneurysm
- Enlargement on serial imaging
- Thrombus present
What are 10 ways of improving distal exposure for carotid disease (in addition to nasotracheal intubation)?
- Curve incision behind ear
- Divide ansa
- Divide posterior belly of digastric
- Divide occipital artery + venous branches
- Divide ascending pharyngeal artery
- Divide SCM from mastoid + elevate/resect parotid (careful dissection of facial nerve)
- Remove styloid process
- Subluxate the mandible
- Remove part of petrous portion of temporal bone.
- Intraluminal balloons to control distal internal carotid back bleeding
Name 2 endovascular treatment options for extracranial carotid artery aneurysms
- Stent graft coverage (requires sufficient landing zone and larger sheaths)
- Self expanding stent with trans-stent coil embolization
Name 8 nonatherosclerotic causes of cerebrovascular symptoms
- Carotid kink/coil
- Carotid aneurysms
- Spontaneous dissection
- Post-traumatic dissection
- FMD
- Radiation induced arteritis
- GCA
- Takayasu - cardioarterial embolization
What are 3 types of carotid sinus hypersensitivity and their definitions?
- Cardioinhibitory carotid sinus hyperactivity - ventricular pauses greater than 3 seconds
- Vasodepressor carotid sinus hyperactivity - BP drops of > 50 mm Hg without concominant bradycardia
- Mixed - ventricular pauses > 3s + BP drop > 50
In normal physiology how does the carotid sinus respond to abrupt increases in BP to lower it?
- Sudden increase in pressure > 2. expansion of carotid arterial wall > 3. trigger carotid sinus > 4. afferent signal sent via glosspopharyngeal and vagus nerves to brainstem > 5. efferent signal via vagus nerve to heart and blood vessels.
Increase vagal activity = decreased sympathetic activity (vasodilation, bradycardia, hypotension)
Name 2 conservative measures to manage carotid sinus hypersensitivity
- Adequate fluid and salt intake
- Avoid triggers (physical maneuvers that place pressure on carotid sinus)
Name 3 drugs that may be effective in managing carotid sinus hypersensitivity.
- Midodrine
- SSRI
- Fludrocortisone.
What is the 1st line treatment for patients with bradycardia due to cardioinhibitory carotid sinus hyperactivity? Other treatment option?
1st line - dual chamber pacemaker
2nd line - carotid sinus denervation with adventitial stripping
How would you treat intracranial arterial stenosis medically?
1) Risk factor modification: HTN, smoking, DM, dyslipidemia
2) ASA + Plavix
- no benefit of warfarin vs. ASA in WASID trial 2005
- benefit of ASA + plavix over just ASA in CLAIR 2010 study
Which study shows that medical management (ASA + plavix) was better than medical management + angioplasty/stent for intracranial arterial stenosis?
SAMMPRIS (stenting versus aggressive medical tx for intracranial arterial stenosis).
In addition to DSA, CTA, MRA - which investigations can aid in the diagnosis of cerebral vasculitis?
- EEG
- CSF analysis: look for pleocytosis and intrathecal immunoglobulin synthesis
- Gold standard: histology
What treatment options are there for cerebral vasculitis?
- Steroids
- If systemic vasculitis with CNS invovement, can consider revascularization procedures when extracranial arteries or proximal intracranial arteries are diseased
What is the definition of a lacunar stroke?
Non-cortical infarcts resulting from single penetrating branch occlusion of larger cerebral arteries.
Name 7 methods of characterizing carotid plaque morphology
- B-mode ultrasound - juxtaluminal black area > 10 mm^2 associated with higher risk of neuro sx
- U/S virtual histology: IPH and LRNC associated with higher risk of neuro sx
- 3D U/S: evaluate luminal surface irregularities, thinning of fibrous cap/ulcerated cap
- Contrast enhanced U/S: late phase enhancement may be a marker of unstable plaque
- U/S Elastography - plaque strain imaging
- IVUS
- MRI: increased IPH, LRNC, thin fibrous cap associated with increased neuro events.
*Name 9 cranial nerves that can be injured during carotid endarterectomy and their associated deficit
- Hypoglossal - ipsilateral tongue deviation, difficulty with mastication
- Vagus/recurrent laryngeal - hoarseness, weak cough (if bilateral - airway obstruction)
- Superior laryngeal nerve - fatiguability of voice, difficulty with high registers
- Marginal mandibular branch of the facial nerve - ipsilateral mouth droop - cosmetically bothersome but functionally insignificant
- Glossopharyngeal - symptoms range from mild dysphagia to recurrent aspiration
- Spinal accessory nerve - shoulder droop/winged scapula
- Greater auricular nerve - earlobe numbness
- Transverse cervical nerves - numbness of anterior neck skin
- Sympathetic chain - Horner’s
Which classification is this?
Shamblin 1
Which classification is this?
Shamblin 2
Which classification is this?
Shamblin 3
