No abstract

MES counts of greater than 50/h in the early postoperative phase of carotid endarterectomy are predictive of the development of ipsilateral focal cerebral ischaemia.

C arotid artery stenosis, particularly involving the origin of the internal carotid artery, is a frequent clinical problem. These stenoses, almost invariably atherosclerotic, can present as asymptomatic bruits discovered on physical examination, one or more transient ischemic attacks related to embolization of thrombus from stenotic lesions or to hypoperfusion, or less commonly, as an ischemic stroke. From the results of three high-quality prospective randomized trials, 1-3 it has become apparent that symptomatic stenoses that narrow the diameter of the carotid artery more than 60% to 70% lead to a significant incidence of stroke if treated medically. The risk of stroke associated with such a lesion in symptomatic patients treated with antiplatelet therapy alone is thought to be 26%. 3 With carotid endarterectomy and aspirin, this risk is lowered to 9%, a statistically significant difference. 3 In patients with or without symptoms who have a stenosis Յ60%, the effectiveness of either medical therapy or carotid endarterectomy in preventing significant neurological events is not known. In symptomatic patients with Ͻ30% stenosis, medical therapy is superior to surgical therapy. 2 Studies attempting to define the benefit of therapy in symptomatic patients with Ͻ60% stenosis are currently under way. Accrual of patients has slowed, however, because data show clear efficacy in symptomatic patients with stenoses Ն70%, leading to a bias toward surgery in symptomatic patients with less severe stenoses. In general the role of surgery for asymptomatic stenosis remains controversial, with some recent opinions suggesting that it may not be indicated. 4 In one high-quality trial with selected experienced surgeons, there was a modest reduction in absolute risk in asymptomatic patients with stenosis Ն60%, but the significance of this finding has been debated. 5,6 Although mortality associated with conventional antiplatelet therapy has been minimal, 7 surgery clearly has significant perioperative morbidity and mortality. This risk varies as a function of the skill and experience of the surgeon and ancillary personnel. In one large study of symptomatic patients, 3 surgical complication rates were 0.6% mortality; 5.5% perioperative cerebrovascular events; and 2.1% major stroke. By contrast, over the same 32-day observation period, patients treated medically had a 0.3% fatality rate, a 3.3% risk of a cerebrovascular event, and a 0.9% risk of a major event. In a recent review of the published literature, risk of stroke and/or death following carotid endarterectomy in symptomatic patients was found to be 5.6%, although there was substantial variation in incidence as a function of the type of study and the nature of postoperative evaluation and surveillance. 8 Surgery, then, in this symptomatic group of patients with significant carotid artery stenosis has a low but significant incidence of periprocedural complications. More importantly, however, according to actuarial analysis, by 2 years the risk of an ipsilateral stroke was 9% for su...

Carotid artery stenosis, particularly involving the origin of the internal carotid artery, is a frequent clinical problem. These stenoses, almost invariably atherosclerotic, can present as asymptomatic bruits discovered on physical examination, one or more transient ischemic attacks related to embolization of thrombus from stenotic lesions or to hypoperfusion, or less commonly, as an ischemic stroke. From the results of three high-quality prospective randomized trials, 1-3 it has become apparent that symptomatic stenoses that narrow the diameter of the carotid artery more than 60% to 70% lead to a significant incidence of stroke if treated medically. The risk of stroke associated with such a lesion in symptomatic patients treated with antiplatelet therapy alone is thought to be 26%. 3 With carotid endarterectomy and aspirin, this risk is lowered to 9%, a statistically significant difference. 3 In patients with or without symptoms who have a stenosis Յ60%, the effectiveness of either medical therapy or carotid endarterectomy in preventing significant neurological events is not known. In symptomatic patients with Ͻ30% stenosis, medical therapy is superior to surgical therapy. 2 Studies attempting to define the benefit of therapy in symptomatic patients with Ͻ60% stenosis are currently under way. Accrual of patients has slowed, however, because data show clear efficacy in symptomatic patients with stenoses Ն70%, leading to a bias toward surgery in symptomatic patients with less severe stenoses. In general the role of surgery for asymptomatic stenosis remains controversial, with some recent opinions suggesting that it may not be indicated. 4 In one high-quality trial with selected experienced surgeons, there was a modest reduction in absolute risk in asymptomatic patients with stenosis Ն60%, but the significance of this finding has been debated. 5,6 Although mortality associated with conventional antiplatelet therapy has been minimal, 7 surgery clearly has significant perioperative morbidity and mortality. This risk varies as a function of the skill and experience of the surgeon and ancillary personnel. In one large study of symptomatic patients, 3 surgical complication rates were 0.6% mortality; 5.5% perioperative cerebrovascular events; and 2.1% major stroke. By contrast, over the same 32-day observation period, patients treated medically had a 0.3% fatality rate, a 3.3% risk of a cerebrovascular event, and a 0.9% risk of a major event. In a recent review of the published literature, risk of stroke and/or death following carotid endarterectomy in symptomatic patients was found to be 5.6%, although there was substantial variation in incidence as a function of the type of study and the nature of postoperative evaluation and surveillance. 8 Surgery, then, in this symptomatic group of patients with significant carotid artery stenosis has a low but significant incidence of periprocedural complications. More importantly, however, according to actuarial analysis, by 2 years the risk of an ipsilateral stroke was 9% for su...