Learn neurology “stroke by stroke.” C.M.Fisher

HistoryWepfer was the first in 1658, to recognize the

significance of carotid obstruction and its relationship to underlying "fibrous masses" and thrombus.

It was Fisher who, in 1951, recognized that the two basic mechanisms causing focal cerebral ischemia from carotid artery disease were embolization, decreased flow through the carotid arteries, or both.

In 1954, Eastcott et al reported a successful operation on a 66-year-old woman with recurrent transient ischemic attacks (TIAs) and an angiographically defined carotid stenosis.

Diagnosis of strokeThe diagnosis of stroke is clinical and depends crucially on an

accurate history, taken from the patient,carer or witness.The neurological symptoms and signs are focal (i.e.

neuroanatomically localizing) rather than non-focalThe focal neurological symptoms are negative in qualityThe onset of the focal neurological symptoms was suddenThe focal neurological symptoms were maximal at onset (i.e.

evolving over minutes in all of the affected body parts) rather than progressive

Transient Ischemic Attack (TIA)Reversible focal dysfunction, usually lasts minutesAmong TIA pts who go to ED:

5% have stroke in next 2 days25% have recurrent event in next 3 months

Stroke risk decreased with proper therapy

StrokeStroke

++StrokeStroke

--

Risk Factor Risk Factor ++

aa b a+ba+b

Risk Factor -Risk Factor - cc dd c+dc+d

a+ca+c b+db+d

Reletive Risk (RR)= a/a+b/c/c+d=a(c+d)/c(a+b)

Odds ratio (OR)=a/b/c/d=ad/bc

Risk factorsThe proportion of ischemic stroke in the

population that can be attributed to a particular risk factor is called the attributable risk (AR) .

This equation shows the influence of both relative risk and prevalence of the risk factor on the value of AR.

Carotid Artery Stenosias Patients were classified as symptomatic if they had a

carotid distribution TIA or nondisabling stroke in the preceding 6 months

In asymptomatic patients with stenosis < 80% and Aspirin treatment only, there is 1% per year risk of stroke .

The risk of stroke in symptomatic patients treated with antiplatelet therapy alone is thought to be 26% in 2 years.

Population-based studies indicate that the prevalence of carotid stenosis is 0.5% by the sixth decade of life, but increases to 10% by age 80 years

Extracranial internal carotid artery stenosis accounts for 15 to 20% of ischemic strokes

PreventionAbsolute risk reductionRelative risk reductionNumber need to treatLife expectencyProcedure riskSubgroup analysis

Shall I ……………or shall I not?

symptomatic carotid stenosis North American Symptomatic Carotid

Endarterectomy Trial (NASCET) The European Carotid Surgery Trial (ECST)The 2-year ipsilateral stroke risk in 70 to 99%

stenosis was 26% in the medically treated patients and 9% in the BMT +CE group (p <0 .001).

The absolute risk reduction (ARR) was 17.0% and the number needed to treat (NNT) was six at 2 years.

The greatest benefit found in men, patients above age 75 years, and those randomized within 2 weeks of their last symptomatic event

symptomatic carotid stenosis Benefit for CE was shown for: 50 to 69%

stenosis,ARR of 4.6% (over 5 years), NNT=22.No benefit in stenosis < 50%

symptomatic carotid stenosis A symptomatic carotid stenosis of 70 to 99 percent is a

proven indication for CEAThe surgical risk should not exceed 6 %The greatest benefit from CEA is likely to be achieved if

surgery takes place within two weeks of a nondisabling stroke or TIA.

It is recommended that the patient have at least a 5-year life expectancy.

CEA is acceptable, but with a marginal to moderate degree of benefit, for patients with symptomatic carotid stenosis of 50 to 69 percent (men who have surgery within two weeks of a nondisabling stroke or TIA)

CE should not be considered for symptomatic patients with less than 50% stenosis

Asymptomatic carotid diseaseThe Asymptomatic Carotid Surgery Trial

(ACST) The ACST showed that the net benefit of

CEA is delayedSeventeen patients need to be treated with

CEA to prevent 1 stroke over 5 years.Largest benefit is seen among men aged <65

years.

Asymptomatic carotid diseaseIf CEA is considered for asymptomatic patients,

the potential benefit is most likely to be realized in:

medically stable men with stenoses of 60 to 99 (especially 80 to 99)percent

have a life expectancy of at least five years and treated by surgeons with a demonstrated

perioperative complication rate that is less than 3 percent

The evidence supporting CEA in asymptomatic women is less compelling.

Carotid artery stentingCAVATAS: The Carotid Artery Vertebral Artery

Transluminal Angioplasty Study (CAVATAS)SAPPHIRE: The Stenting and Angioplasty with

Protection in Patients at High Risk for Endarterectomy (SAPPHIRE)

EVA-3S: Endarterectomy versus Angioplasty in Patients with Symptomatic Severe carotid Stenosis

SPACE: Stent Protected Angioplasty versus Carotid Endarterectomy (SPACE)

Risk of any stroke or death (%) within 30 days of treatment

acronym Publication date

Patients

Endovascular

Surgical

Notable features

CAVATAS 2001 504 10% 9.9% 22% stented. No protection

SAPPHIRE

2004 307 4.8% 5.6% Protectiondevices in 100%

EVA-3S 2006 520 9.6% 3.9% Protection devices in 92%

SPACE 2006 1183 7.7% 6.5% Protection devices in 27%

Carotid artery stentingSAPPHIRE trial concluded that, among patients with

severe carotid-artery stenosis and coexisting conditions, carotid stenting with the use of an emboli-protection device is not inferior to carotid endarterectomy.

SPACE failed to prove non-inferiority of carotid stenting compared with endarterectomy.

Ongoing trials include the North American CREST trial that is randomizing patients with >50% symptomatic or >70% asymptomatic carotid stenoses and the International Carotid Stenting Study(ICSS or CAVATAS 2), which is randomizing patients with symptomatic >70% carotid stenoses.

While the durability of CEA is known, the long-term risk of restenosis among stented patients is unclear

High Surgical RiskClinically significant cardiac diseaseContralateral carotid occlusionSevere pulmonary diseaseContralateral laryngeal-nerve palsyPrevious radical neck surgery or radiation

therapy to the neckRecurrent stenosis after endarterectomyHigh cervical lesion or low common carotid

lesion poorly accessible by surgerySevere tandem lesions and intracranial lesions

ConclusionCEA remains the standard of care for patients

with severe carotid disease in the absence of concomitant medical or anatomical conditions known to increase the risk of surgery.

High-risk patients may be potential candidates for stenting, as suggested with the SAPPHIRE trial.

CAS is a reasonable option when performed by operators with established peri-procedural morbidity and mortality rates of 4% to 6%

There is no role for stenting in asymptomatic patients at this time