Review about carotid artery revascularization

1. Carotid Endarterectomy versus
Carotid Artery Stenting
Krishna Prasad Nevali
16th April 2019

3. • The principal causes of ischaemic, carotid territory stroke are
thromboembolism from the internal carotid artery (ICA) or middle
cerebral artery (MCA) (25%), small vessel intracranial disease (25%),
cardiac embolism (20%)
• Carotid artery stenosis (CS) accounts for up to 20–25% of all ischemic
strokes
• Treatment of this disease consists of the best medical treatment
(BMT) and carotid revascularization (CR), including carotid
endarterectomy (CEA) and carotid artery stenting

4. • There is a drive towards performing carotid interventions as soon as
possible after onset of symptoms
• Because the highest risk for recurrent stroke is within the 7 to 14 days
after onset of symptoms
• Carotid endarterectomy is the accepted procedure for carotid artery
revascularization
• This has been proven in multiple trials notably ECST and NASCET trials
comparing endarterectomy with medical management in
symptomatic patients

5. CEA versus Medical therapy in asymptomatic
• The ACAS and ACST trials were pivotal in developing international
practice guidelines, most of which advise that CEA should be
performed with a 30-day death/stroke rate <3% and that the patient
should have a predicted survival >5 years

6. • CEA is the standard treatment-shown to benefit patients who have
had indications of CS for a long time-limitations because of patients’
comorbidities, unfavorable neck anatomy and surgical complications
• CAS, therefore, has been developed to increase safety and provide a
minimally invasive procedure
• Concerns associated with CAS because of its periprocedural
complications, especially stroke
• We review the important RCTs and meta analyses that compared
carotid artery stenting versus carotid endarterectomy and the latest
guidelines on carotid revascularization

10. • CREST results indicate that carotid-artery stenting and carotid
endarterectomy were associated with similar rates of the primary
composite outcome — periprocedural stroke, myocardial infarction,
or death and subsequent ipsilateral stroke — among men and women
with either symptomatic or asymptomatic carotid stenosis
• However, the incidence of periprocedural stroke was lower in the
endarterectomy group, whereas the incidence of periprocedural
myocardial infarction was lower in the stenting group

11. • Quality-of-life analyses among survivors at 1 year in our trial indicate
that stroke had a greater adverse effect on a broad range of health-
status domains than did myocardial infarction
• Younger patients having a slightly better outcome with carotid artery
stenting and older patients having a better outcome with carotid
endarterectomy (vascular tortuosity and severe vascular calcification)
• Limitation of this study was that there was a lead in training period
for operators of carotid artery stenting so generalization to a day to
day population is ?????

14. • Patients had a history of transient ischemic attacks (6.1% in the
stenting group and 7.4% in the endarterectomy group), amaurosis
fugax (1.7% and 1.4%), or stroke (6.7% and 4.7%) more than 180 days
before enrollment

16. • Primary composite end point of death, stroke, or myocardial
infarction by 30 days after the procedure or ipsilateral stroke by 1
year, stenting was noninferior to endarterectomy (event rates, 3.8%
and 3.4%, respectively)
• The 30-day rate of stroke was numerically higher in the stenting group
than in the endarterectomy group (2.8 vs. 1.4%, P = 0.23), and the 30-
day rate of death or stroke was 2.9% in the stenting group and 1.7% in
the endarterectomy group (statistically not significant)

17. • Limitation of this study is it dint compare medical therapy with
intervention in asymptomatic patients
• Observational studies have shown that the annual risk of a stroke
among asymptomatic patients is probably less than 1% per year with
modern medical therapy

20. Fatal or disabling stroke Anystroke

21. All cause death

22. ipsilateral stroke more than 30 days after treatment

23. • The ICSS primary analysis shows that stenting is as effective as
endarterectomy in preventing fatal or disabling stroke in patients with
symptomatic carotid stenosis up to 10 years after treatment
• Carotid stenting was associated with a higher procedure-related and
long-term risk of non-disabling stroke than endarterectomy, but
functional ability did not differ overall

25. • Meta analysis of 5 RCTs

26. Results
• The aggregated efficacy/safety outcome (composite outcome of
periprocedural death, stroke, MI, or non periprocedural ipsilateral
stroke) was not significantly different between CAS versus CEA (295 of
3,636 [8.1%] vs. 218 of 2,890 [7.5%]; OR: 1.22; 95% CI: 0.94 to 1.59)
• The risk of any periprocedural stroke plus nonperiprocedural
ipsilateral stroke was significantly greater with CAS (275 of 3,636
[7.6%] vs. 161 of 2,890 [5.6%]; OR: 1.50; 95% CI: 1.22 to 1.84; NNH
.50)

27. • Composite of periprocedural death, stroke, MI, cranial nerve palsy
was significantly lower with CAS (224 of 3,636 [6.2%] vs. 263 of 2,890
[9.1%]; OR: 0.75; 95% CI: 0.60 to 0.93; NNT . 34)
• Associated periprocedural stroke was significantly higher with CAS
(169 of 3,636 [4.6%] vs. 73 of 2,890 [2.5%]; OR: 2.07; 95% CI: 1.56 to
2.75, NNH .47, which was mainly attributable to minor strokes (124 of
3,636 [3.4%] vs.44 of 2,890 [1.5%]; OR: 2.43; 95% CI: 1.71 to 3.46,
NNH . 52)
• The risk of associated periprocedural major stroke was not different
between CAS and CEA (39 of 3,636 [1.0%] vs. 27 of 2,890 [0.9%]

28. • This meta-analysis provide evidence that CEA may be a safer
treatment option than CAS for asymptomatic carotid stenosis

29. • Recent meta-analyses , which included the latest large studies, seem
to support the superiority of CEA over CAS in the periprocedural
period whereas long term results are inconclusive
• Another meta-analysis published in 2011 showed that CAS, when
compared with CEA, was associated with an increased risk of
periprocedural outcomes of death, MI or stroke except for cranial
nerve injury and MI
• In the same meta analysis CAS was associated with 19% increase in
the risk for the composite of periprocedural death, MI or stroke plus
ipsilateral stroke in the intermediate to long-term outcomes
Bonati LH Cochrane Database Syst Rev 2012

32. • Plaque morphology and vessel anatomy influence the outcomes of
CAS. Distal embolization can occur during manipulation or crossing of
the carotid plaque
• According to the AHA grading system using MRI, type IV/V plaque
(lipid or necrotic core) was defined as vulnerable whereas type VI
plaque (intraplaque hemorrhage or fibrous cap rupture) was
associated with a high risk of stroke
• Heavily calcified, extensive (>15 mm) and preocclusive lesions
increase the risk of periprocedural stroke after CAS
• Screening plaques with MRI can identify patients at high-risk from
CAS

33. High-risk features of patients with
asymptomatic carotid stenosis
• Progression of stenosis
• History of contralateral transient ischemic attack or stroke
• Unfavorable plaque characteristic on ultrasound (irregularity, ulcerations,
echolucency, gray-scale values and plaque area)
• Intraplaque hemorrhage on MRI
• Microemboli detected by transcranial Doppler ultrasound (TCD)
• Silent infarcts on CT
• Reduced cerebrovascular reserve
• Selection of asymptomatic patients based on their respective ‘high-risk
features for CR would be reasonable and beneficial to prevent stroke

34. Explanation for increased MI after CEA
• The only endpoint that favored stenting was periprocedural
myocardial infarction (in addition to cranial nerve injury)
• Combined antiplatelet therapy, which is the standard therapy used to
prevent cardiovascular disease, is less commonly used in patients
scheduled for endarterectomy (compared to stenting) to decrease the
risk of bleeding
• Cervical incision during the endarterectomy procedure induces local
inflammation and produces proinflammatory cytokines, which could
lead to thrombus formation
• Yang Li et al PLoS ONE 12(7): e0180804

35. High risk Surgery patients
• Clinically significant cardiac disease (congestive heart failure, abnormal
stress test, or need for open-heart surgery)
• Severe pulmonary disease
• Contralateral carotid occlusion
• Contralateral laryngeal nerve palsy
• Previous radical neck surgery
• Cervical radiation therapy
• Recurrent stenosis after CEA and age >80 years
• At these levels of risk, none would gain benefit in terms of late stroke
prevention, suggesting they should be treated medically

43. Take Home message
• Periprocedural minor stroke is a concern while attempting CAS for
carotid revascularizaton
• Long term results inconclusive
• Medical therapy advanced and can be tried in asymptomatic patients
• Periprocedural complications can be decreased by extensive operator
training
• Defining the plaque prior to the procedure by MRI cn help in
identifying high risk cases
• The anatomy of vessels along the access route of CAS can complicate
the procedure

44. Asymptomatic Patients Randomized trials
• In CREST-1, the 4-year rate of ipsilateral stroke (including the
perioperative risk) was 8% following CAS, versus 6.7% after CEA
• In ACT-1, including perioperative stroke/death/MI, the 1-year rate of
ipsilateral stroke was 3.8% after CAS versus 3.4% after CEA. The 5-
year rate of ipsilateral stroke (excluding perioperative events) was
2.2% after CAS and 2.7% after CEA (p . .51)