Carotids (extra) Flashcards
How do you determine proximal stenosis in CCA
dampened velocities and spectral broadening in ICA
How do you determine distal occlusion and high grade stenosis in ICA
dampened velocities and low EDV in ICA
What are characteristics of post stenotic waveform in ICA
low velocity wave form with delayed upstroke (parvus tardus)
Carotid preocclusive thump
short narrow peak with no flow through diastoly
absent bilateral diastolic flow in carotids
cardiac disfunction
carotid dissection classification
1) minimal injury or irregular intima
2) dissection with raised intimal flap / IMH with luminal narrowing >25% / Intraluminal thrombosis
3) PSA
4) vessel occlusion or complete thrombosis
5) vessel transection
Shamblin classification
1) localized to carotid bifurcation
2) partially surround ECA and ICA
3) completely encases ECA and ICA
common carotid division
upper border of thyrdoi cartillage
external carotid artery branches
1) ascending pharyngeal
2) superior thyroid
3) lingual
4) facial
5) occipital
6) posterior auricular
7) terminal branches: superficial temporal and maxillary
segments of vertebral artery
1) from subclavian to C6 foramina
2) through foramina of C6 - C2
3) from C2 foramen transversarium to dura mater
4) pierces through the dura mater to formed basillary artery
familial carotid body tumor gene
succinyl dehydrogenase
Fontaine’s sign
carotid body tumor will move left to right but not up and down
Hollenhorst plaque
cholesterol crystal embolization to retinal circulation, incidental, not associated with increased risk of stroke
> 30% in stent carotid stenosis
> 150cm/s
> 50% in stent carotid stenosis
> 220cm/s
> 80% in stent carotid stenosis
> 325cm/s
criteria for ICA occlusion
bidirectional flow in ICA stump and externalization or high resistance flow patterns in ipsilateral CCA with absent, decreased or reversed flow in diastole
Indirect carotid stenosis criteria
1) decreased EDV in CCA or ICA in presence of distal lesion
2) internalization of ECA
3) reversal of flow in ophtalmic artery
4) anterior cross filling via anterior communicating artery
5) posterior communicating artery flow
6) increased flow pulsatility in unilateral CCA
7) decreased flow pulsatility in unilateral MCA
8) abnormal flow acceleration and pulsatility transmission index (MCA)
Stent deformity or re-stenosis criteria
1) b-mode >30% narrowing
2) focal velocity increase >150cm/sec and stenotic to pre-stenotic PSV ratio of 1:>=2
3. evidence of plaque or thrombus formation
Bowhunter’s syndrome
positional posterior insufficiency caused by dynamic compromise of dominant left vertebral artery –> transient dizziness when looking upwards with head rotated
Vertebral artery stenosis
PSV >= 2 (ratio of the stenotic to pre or post stenotic area)
Normal carotid values
ICA PSV <125
ICA EDV <40
ICA/CCA <2
50-69% carotid stenosis
ICA PSV 125-230
ICA EDV 40-100
ICA/CCA 2-4
70-79% carotid stenosis
ICA PSV >230
ICA EDV 100-125
ICA/CCA 2-4
80-89% carotid stenosis
ICA PSV >230
ICA EDV >125
ICA/CCA >4
Costocervical trunk branches
deep cervical
superior intercostal
thyrocervical trunk branches
inferior thyroid
suprascapular
ascending cervical
transverse cervical
parts of ICA
- cervical
- petrous
- lacetum
- cavernous
- clinoid
- ophtalmic
- communicating
- terminal branches: anterior cerebral and middle cerebral
what parts of ICA have branches
petrous
cavernous
ophtalmic
communicating
what are the branches of petrous ICA
vidian
caroticotympanic
what are the branches of cavernous ICA
meningohypophyseal
inferolateral trunk
what are the branches of ophtalmic ICA
ophtalmic
superior hypophyseal
what are the branches of communicating ICA
posterior communicating
anterior choroidal
sound of carotid bruit with 50-69% stenosis
low pitched
short
systemic
gruff
sound of high grade stenosis bruit
high pitched, soft
extracranial carotid artery aneurysm
if untreated 50% risk of stroke and death
>2cm absolute indication for operation
NASCAT trial results
- 70-99% any ipsilateral stroke reduction: 9% vs 26% at 2 years
- 50-69% any ipsilateral stroke reduction: 16 vs 22% at 5 years (p=0.045)
- <50%: no benefit
- near occlusion: no benefit
timing of CEA:
- TIA - next elective schedule
- non disabling stroke (minor fixed deficit or TIA with small CTA / MR stroke): 48h - 2 weeks
- major hemispheric stroke: 4 weeks at least
- crescendo TIA or stroke in evolution - urgent CEA (but increased perioperative risk)
ACAS trial
asymptomatic patients with stenosis >60%, 1662 patients randomized
Endpoint: stoke and death
5% in surgery group and 11% with any medical management
risk reduction of 53%
EVA 3s trial
2006, stopped before completion
symptomatic patients with severe disease
EPD was not always used
30 day stroke rate: 3.9 in CEA and 9.6 in CAS
SPACE trial
symptomatic patients
Endpoint was stroke and death. EPD used 27% of time
No difference in end point between groups
recurrent stenosis: 4.6 in CEA and 10.7% in CAS
Failed to prove CAS was not inferior
ICSS trial
symptomatic patients
stroke, MI, or death: 5.2 in CEA and 8.2 in CAS
what’s the difference of new area brain infarctions between CAS and CEA
50% in CAS and 17% in CEA
CREST trial
symptomatic and asymptomatic patients, endpoint: combined stroke, MI and death composit endpoint: 4.5% CEA and 5.2 in CAS (not statistically different), but if you took out MI, CEA is statistically better CEA only higher in MI patients over 70 did better with CEA younger patients did better with stent women did worse with stenting
What’s the pathology of stroke
85% due to cerebral infarction
Technique for stump pressure measurement in the carotid
Clamp CCA and ECA leaving ICA open, and then measure pressure
Results of CREST trial for CEA patch vs no patch
66% patch and 29%primary closure, eversoion excluded
Priprocedural outcomes: statistically significant increase in stroke and death in the no patch group
More restenosis
Mechanism for postoperative stroke in carotid
Embolization
Unsatisfactory technical result —> thromboembolism
Uncontrolled hypertension
Inadequate cerebral perfusion intraoperatively
Proven indications for carotid endarterectomy
Symptomatic: hemispheric or mononuclear TIA or stroke, providing m&m <6%, 70-99% stenosis both genders, for men also 50-69%
Asymptomatic: providing surgical m&m <2.3%, 60-99% stenosis
What lesions have higher risk of stroke with carotid stenting
Long lesions (1.2 cm), dysynchronous or sequential lesions, lesions distal to carotid bulb
SAPPHIRE trial
Randomized prospective controlled for patients at high risk for endarterectomy
Asymptomstic patients >80%, symptomatic >50%
70% if patients were asymptomstic and high risk - critique: should have been managed medically
1 year endpoint (stoke and death) 12.2% in CAS and 20.1% in CEA. More pronounced in asymptomstic patients.
High anatomical risk for CEA
Previous CEA with recurrent stenosis Prior radiation therapy to neck Previous ablative neck surgery Lesion at C2 Lesion below the clavicle Contralatetal vocal cord palsy / laryngectomt Tracheostomy aroma Contralateral occlusion (?) Immobile neck Tandem lesion
How do you anchor exchange wire with carotid stenting
Use external carotid artery
What does fluoro field include for carotid atenting
Arch and guide wire tip
Usually best in LAO
High risk for CAS?
Tortuous arch Calcified arch Diseased great vessels Tortuous carotid artery Pre occlusive lesion Heavy plaque burden Circumferential calcification Echolucent plaque
Which stents have more Neuro events for carotid stenting
Open cell. Plaque protrudes through the stent cells
Where does vertebral artery enter transverse foramen
Variable but most commonly at C6
How many patients have vertebral artery Origin at the Athens
6%
What’s the most common size of vertebral arteries compared to each other
85% asymmetrical with left side dominant in ⅔ cases
Vertebral artery branches
V1 - no branches
V2- radiculo-medullary
V3- posterior spinal artery, lateral recurrent artery
V4- anterior spinal artery and PICA
What does lateral recurrent artery (of V3) anastomoses with
Ascending cervical and deep cervical artery
Vertebral artery compression mechanism
Bone compression by osteophytes, c7 transverse process, posterior laminate C1
Muscular compression by longus Colli or longus capitis
Arterial kinks
Neural by sympathetic chain
Surgical indications for proximal vertebral transposition
Ischemia from fixed stenosis / occlusion
Embolism from proximal plaque
Positional symptoms from compression
Subclsvian steal
What do you have to divide in distal vertebra artery bypass to get to the target
Levantine scapulae
Anterior army’s if C2 nerve
Management of trachea-innominate fistula
Bleeding control with balloon/covered stent
Immediately followed by left to right carotid to carotid bypass,
Median sternotomy
Ligation of the innominate artery
Muscle flap to close the tracheal defect
In patients with carotid bulb lesion, intracranial ICA lesion and symptoms, what’s the tx algorithm
Just treat the bulb first.
Intracranial only if symptoms persist
Maneuvers to get distal exposure of ICA
Medial mobilization of the hypoglossal nerve NT intubation Division of posterior belly of digastric Resection of styloid process Anterior subluxation of the mandible
What’s stump syndrome and how do you treat it
Chronically occluded ICA with “stump” of ICA being an origin of emboli. Best results are in mononuclear amaurosis fugax
Treatment - endarterectomy of CCA and ECA with transaction and ligation of ICA stump.
Resolution of symptoms 83%, 7% additional improvement
Overall neuro events 5%
Mortality periop 3% due to stroke mainly
Radiation induced carotid disease
Unusual location
Extensive rather than focal
Maneuver most likely to injury glossopharyngeal nerve
Transaction of posterior belly of digastric muscle
How to manage traumatic carotid dissection
OR / endovascular if patient has worsening or fluctuating neuro symptoms
Anticosgulation if no contraidication
Antiplatelets if contraindication to anticoagulation
Intracranial aneurysm algorithm
If coexists with carotid disease each part should be treated separately
Significant symptomatic carotid disease should be treated before aneurysm
Asymptomstic aneurysm found incidentally maybe treated before asymptomstic carotid disease if the aneurysm is 8mm or larger
Complications associated with vertebral artery open repair
Horners 8-28% Chylothorax 5% Immediate thrombosis 4% Lymphocele 4% Vague and recurrent laryngeal nerve palsy 2%
Two independent predictors of poor outcome for asymptomstic carotid stenosis in dialysis patients
Age >70
Dialysis >2 years
History of renal transplant is protective
When should you do a CEA after a TIA
3-14 days
Pre op studies for carotid body tumor
24 hour urin collection for metanephrines and catecholamines
123 I-metaiodobenzylbuanidine scintigraphy or CT/MRI of chest and abdomen
What’s carotid sinus
Innervated by the nerve of Hering (of glossopharyngeal)
Barorrceptors that produce bradycardia and hypotension when stimulated by increased pressure
