Ital. J. Neurol. Sci. 13.'469-473, 1992
Prevention of ischemic stroke: the role of carotid endarterectomy in symptomatic patients Del Sette M.*/**, Hachinski V.C.** * Clinica Neurologica, Universit& di Genova ** Department of Clinical Neurological Sciences, University of Western Ontario, University Hospital London, Ontario, Canada
Carotid endarterectomy (CE) has recently been proved to be beneficial in symptomatic patients with severe (70-99%) appropriate carotid stenosis. After discussing the historical evolution of CE as a possible preventive treatment of ischemic stroke, we review the results of North American and European trials in order to give practical information for the management of cerebrovascular patients.
Key Words: Carotid stenosis - - stroke - - TIA - - carotid endarterectomy
Introduction Carotid endarterectomy (CE) enjoyed growing popularity in the USA in the period from 1970 to 1985. The number of patients who underwent CE in the USA rose from 15,000 per year in 1971 to 107,000 per year in 1985 [27], but in 1985 the popularity of CE began to wane. Better knowledge of risk factors and natural history of cerebrovascular disease, improved medical care, along with awareness of the potential risks of surgical procedures fostered uncertainty about CE. Review articles and editorials voiced concerns [4, 10, 34, 35] that have helped to generate a number of doubts about CE: 1. Decline in the number of first and fatal strokes [2, 7, 24]. 2. Relatively low rate of stroke per year in TIA patients [11]; surgery, to be of benefit should not carry a higher level of risk. Moreover, if a stroke occurs after a TIA, there is at least a 30% chance of its being in another vascular territory from that of the TIA [ 11 ]. 3. Recognition and better management of some risk factors, such as hypertension [17, 23] and smoking [29]. Received 14 January 1992 - Accepted 28 February 1992
4. Better detection of cardiac causes of stroke. Recent techniques of cardiac imaging allow the detection of cardiac sources of emboli [3, 19] even in patients with carotid disease. In a 19% of one series of TIA patients, it was possible to find a potential cardiac source of emboli associated with appropriate carotid disease [6]. 5. Identification of subgroups of stroke syndromes more likely caused by small vessel disease rather than by embolic or hemodynamic mechanisms [16, 20]. 6. Demonstration of efficacy of antiplatelet treatment in secondary prevention of stroke [1, 9, 18, 22]. 7. Failure to demonstrate the efficacy of CE. The only randomized trials on CE, mainly because of high perioperative risk for stroke and death, did not show any advantage of surgery over medical treatment [5, 15, 28]. However, the degree of risk has recently been reduced, probably because of better monitoring techniques and experience [32, 33]. 8. Finally, another surgical approach to the prevention of stroke, such as EC/IC bypass, proved to be useless in reducing the risk of ischemic stroke [13], and these results helped to undermine 469
The Italian Journal of Neurological Sciences
confidence in "cerebrovascular surgery" overall. Recent studies Recently two randomized, controlled studies have provided crucial new information on CE in symptomatic patients [14, 25]. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) involves 50 centers in Canada and the United States, and has recently published the resuits of the analysis of the group of patients with severe carotid stenosis. 659 patients with severe carotid stenosis (70-99%) were randomized for medical (ASA, recommended dose 1300 mg daily) or medical plus surgical (CE) treatments. The clinical characteristics of patients were: 1. Age less than 80 years. 2. Symptoms related to carotid vascular territory: TIAs or minor strokes (hemispheric or retinal symptoms); episode occurring up to 120 days before randomization. 3. Exclusion of possible cardiac sources of emboli.
4. Angiographic evidence of 70-99% carotid stenosis and absence of intracranial vascular lesions more severe than the surgically accessible one. The 30-day perioperative stroke and mortality rate was 5.8% and for permanent disabling stroke or death it was 2.1%. The cumulative risks at 2 years are shown in Table I. For the surgical group, there was a relative risk reduction of 65% for any ipsilateral stroke, and 81% for ipsilateral disabling or fatal stroke. Considering the surgical risks, all the survival curves crossed at 3 months, when the benefit of surgery outweighed its risk. The European Carotid Surgery Trial (ECST) involves 80 centers in 14 European countries. The results for patients with mild (0-29%) or severe (70-99%) carotid stenosis were recently published [14]. The selection criteria of patients were almost the same as NASCET; a focal neurological deficit had to have occurred up to 180 days before randomization. The patients were randomized for medical (ASA, dose not specified) or medical plus surgical (CE) treatments. For 374 patients with mild stenosis there was very
TABLE I. Results from NASCET (two-year follow-up). Medical Group (331 pts.)
Surgical Group (328 pts.)
events
events
Any ipsilateral stroke (that lasted more than 1 day) Major* or fatal ipsilateral stroke
61 (26.0%)
26 (9.0%)
29 (13.1%)
8 (2.5%)
Any major* stroke or death
38 (18.1%)
19 (8.0%)
Absolute Difference _+SE
17.0-+3.5% (p
Prevention of ischemic stroke: the role of carotid endarterectomy in symptomatic patients Del Sette M.*/**, Hachinski V.C.** * Clinica Neurologica, Universit& di Genova ** Department of Clinical Neurological Sciences, University of Western Ontario, University Hospital London, Ontario, Canada
Carotid endarterectomy (CE) has recently been proved to be beneficial in symptomatic patients with severe (70-99%) appropriate carotid stenosis. After discussing the historical evolution of CE as a possible preventive treatment of ischemic stroke, we review the results of North American and European trials in order to give practical information for the management of cerebrovascular patients.
Key Words: Carotid stenosis - - stroke - - TIA - - carotid endarterectomy
Introduction Carotid endarterectomy (CE) enjoyed growing popularity in the USA in the period from 1970 to 1985. The number of patients who underwent CE in the USA rose from 15,000 per year in 1971 to 107,000 per year in 1985 [27], but in 1985 the popularity of CE began to wane. Better knowledge of risk factors and natural history of cerebrovascular disease, improved medical care, along with awareness of the potential risks of surgical procedures fostered uncertainty about CE. Review articles and editorials voiced concerns [4, 10, 34, 35] that have helped to generate a number of doubts about CE: 1. Decline in the number of first and fatal strokes [2, 7, 24]. 2. Relatively low rate of stroke per year in TIA patients [11]; surgery, to be of benefit should not carry a higher level of risk. Moreover, if a stroke occurs after a TIA, there is at least a 30% chance of its being in another vascular territory from that of the TIA [ 11 ]. 3. Recognition and better management of some risk factors, such as hypertension [17, 23] and smoking [29]. Received 14 January 1992 - Accepted 28 February 1992
4. Better detection of cardiac causes of stroke. Recent techniques of cardiac imaging allow the detection of cardiac sources of emboli [3, 19] even in patients with carotid disease. In a 19% of one series of TIA patients, it was possible to find a potential cardiac source of emboli associated with appropriate carotid disease [6]. 5. Identification of subgroups of stroke syndromes more likely caused by small vessel disease rather than by embolic or hemodynamic mechanisms [16, 20]. 6. Demonstration of efficacy of antiplatelet treatment in secondary prevention of stroke [1, 9, 18, 22]. 7. Failure to demonstrate the efficacy of CE. The only randomized trials on CE, mainly because of high perioperative risk for stroke and death, did not show any advantage of surgery over medical treatment [5, 15, 28]. However, the degree of risk has recently been reduced, probably because of better monitoring techniques and experience [32, 33]. 8. Finally, another surgical approach to the prevention of stroke, such as EC/IC bypass, proved to be useless in reducing the risk of ischemic stroke [13], and these results helped to undermine 469
The Italian Journal of Neurological Sciences
confidence in "cerebrovascular surgery" overall. Recent studies Recently two randomized, controlled studies have provided crucial new information on CE in symptomatic patients [14, 25]. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) involves 50 centers in Canada and the United States, and has recently published the resuits of the analysis of the group of patients with severe carotid stenosis. 659 patients with severe carotid stenosis (70-99%) were randomized for medical (ASA, recommended dose 1300 mg daily) or medical plus surgical (CE) treatments. The clinical characteristics of patients were: 1. Age less than 80 years. 2. Symptoms related to carotid vascular territory: TIAs or minor strokes (hemispheric or retinal symptoms); episode occurring up to 120 days before randomization. 3. Exclusion of possible cardiac sources of emboli.
4. Angiographic evidence of 70-99% carotid stenosis and absence of intracranial vascular lesions more severe than the surgically accessible one. The 30-day perioperative stroke and mortality rate was 5.8% and for permanent disabling stroke or death it was 2.1%. The cumulative risks at 2 years are shown in Table I. For the surgical group, there was a relative risk reduction of 65% for any ipsilateral stroke, and 81% for ipsilateral disabling or fatal stroke. Considering the surgical risks, all the survival curves crossed at 3 months, when the benefit of surgery outweighed its risk. The European Carotid Surgery Trial (ECST) involves 80 centers in 14 European countries. The results for patients with mild (0-29%) or severe (70-99%) carotid stenosis were recently published [14]. The selection criteria of patients were almost the same as NASCET; a focal neurological deficit had to have occurred up to 180 days before randomization. The patients were randomized for medical (ASA, dose not specified) or medical plus surgical (CE) treatments. For 374 patients with mild stenosis there was very
TABLE I. Results from NASCET (two-year follow-up). Medical Group (331 pts.)
Surgical Group (328 pts.)
events
events
Any ipsilateral stroke (that lasted more than 1 day) Major* or fatal ipsilateral stroke
61 (26.0%)
26 (9.0%)
29 (13.1%)
8 (2.5%)
Any major* stroke or death
38 (18.1%)
19 (8.0%)
Absolute Difference _+SE
17.0-+3.5% (p
