Carotid Endarterectomy

In March 1951, Fisher’s report on occlusion of the internal carotid artery characterized basic clinical and pathological features of an important disease syndrome.1 Fisher described fleeting neurological symptoms attributable to atherosclerotic narrowing, thrombosis, and cerebral embolism that might arise from thrombotic material lying in the carotid sinus. He suggested that vascular surgical bypass of the occluded portion of the artery by anastomosis of the external carotid artery or one of its branches with the internal carotid artery above the area of narrowing might be feasible. In October 1951, Carrea et al2,3 of Buenos Aires, Argentina, who were aware of Fisher’s work,1 performed the first successful carotid reconstruction. This included partial ablation of the atherosclerotic plaque and end-to-end anastomosis of the proximal portion of the external carotid to the distal portion of the internal carotid. In May 1954, Eascott et al4 performed resection and reconstruction of the common and internal carotid arteries by direct end-to-end anastomosis, an operation that gave impetus to the development of extracranial carotid surgery.3 However, in 1953, DeBakey5 was credited with performing the first successful carotid endarterectomy (CEA), the procedure that has dominated surgery for extracranial carotid occlusive disease for the past 4 to 5 decades.3 These pioneers1–5 helped to usher in the modern era of CEA. Early attempts at surgical correction of extracranial carotid artery occlusive disease led to the Joint Study of Extracranial Arterial Occlusion in 1959.6 The Joint Study was designed to assess the efficacy of carotid surgery and included 6535 patients (69% men). In 1961, 5 and later 13 of the centers agreed to a controlled trial whereby patients would be randomly assigned to surgical or nonsurgical therapy. The main finding of the trial was that there was no statistically significant difference in stroke or death between the 2 treatment groups. The study had shortcomings and was criticized for being inconclusive. The trial, however, was the only major randomized and controlled study until the 1980s. The 1980s were punctuated by cautionary notes concerning CEA.7–9 Concern was fueled by startling reports of high complication rates,10,11 yet there was exponential growth in the performance of the procedure based largely on anecdotal evidence. It was estimated that only 35% of CEAs were being performed for appropriate indications.12 By the mid-1980s, dissemination of such sobering news may have led to a decline in the number of CEAs.13 CEA had become a topic of emotional debate and uncertainty since rigorous scientific investigation was wanting.14,15 Finally, in the 1990s the main results of large-scale clinical trials were published.16–25 At last, the debate would end—or would it? The National Institute of Neurological Disorders and Stroke supported 3 of these major trials.17,18,22,23 What have we learned from these clinical trials? The main results for symptomatic and asymptomatic patients are summarized in Table 1. CEA is beneficial in symptomatic patients with high-grade carotid stenosis (70% to 99%). This was a main conclusion of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Medical Research Council European Carotid Surgery Trial (ECST).17,19 Furthermore, within the range of 70% to 99% carotid diameter stenosis as defined by cerebral arteriography, NASCET showed a stenosisdependent effect for degree of carotid stenosis (70% to 79%, 80% to 89%, and 90% to 99%) and degree of risk reduction after CEA in a secondary analysis.17 The final results of ECST20 suggested that the cutoff point for major benefit with CEA in arteriography-determined stenosis was approximately 80%, which correlated with approximately 60% stenosis in NASCET (ECST and NASCET used different methods for measuring carotid stenosis26; an arteriographic stenosis equivalence scale is shown below Table 1). ECST showed a downward trend in the benefit of surgery for carotid stenosis from a range of 90% to 100% to a range of 80% to 89%.20 Overall, men had more benefit than women, and younger patients had more benefit over a narrow range of severe stenosis than older patients.20 The Veterans Affairs Cooperative Study21 was halted when results of NASCET and ECST became available. The results of this study of 193 participants supported a stenosis-dependent effect that favored CEA and showed the benefit of CEA when there was high-grade stenosis (.70%). Less severe carotid stenosis (0% to 29%) was studied in ECST.19 In this group the risk of ipsilateral ischemic stroke was low, even in the absence of surgery, and any benefits of CEA were outweighed by early operative risks. What are the results when there is moderate stenosis (eg, 30% to 69%)? In NASCET, when there was ,50% stenosis, the failure rate did not differ significantly in the surgically treated and medically treated groups.18 Among those with 50% to 69% stenosis, however, there was a “moderate” The opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association. From the Department of Neurologic Sciences, Rush Medical College, Chicago, Ill. Correspondence to Philip B. Gorelick, MD, MPH, Center for Stroke Research, 1645 West Jackson, Suite 400, Chicago, IL 60612. (Stroke. 1999;30:1745-1750.) © 1999 American Heart Association, Inc.