220 likes | 326 Views
Learn neurology “stroke by stroke.” C.M.Fisher. History. Wepfer was the first in 1658, to recognize the significance of carotid obstruction and its relationship to underlying "fibrous masses" and thrombus.
E N D
History • Wepfer 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 stroke • The 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-focal • The focal neurological symptoms are negative in quality • The onset of the focal neurological symptoms was sudden • The 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 minutes • Among TIA pts who go to ED: • 5% have stroke in next 2 days • 25% have recurrent event in next 3 months • Stroke risk decreased with proper therapy
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 factors • The 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
Prevention • Absolute risk reduction • Relative risk reduction • Number need to treat • Life expectency • Procedure risk • Subgroup analysis
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 CEA • The 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 disease • The Asymptomatic Carotid Surgery Trial (ACST) • The ACST showed that the net benefit of CEA is delayed • Seventeen 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 disease • If 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 stenting • CAVATAS: 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)
Carotid artery stenting • SAPPHIRE 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 Risk • Clinically significant cardiac disease • Contralateral carotid occlusion • Severe pulmonary disease • Contralateral laryngeal-nerve palsy • Previous radical neck surgery or radiation therapy to the neck • Recurrent stenosis after endarterectomy • High cervical lesion or low common carotid lesion poorly accessible by surgery • Severe tandem lesions and intracranial lesions
Conclusion • CEA 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