Asymptomatic severe carotid stenosis

Abstract

The management of asymptomatic carotid stenosis remains controversial. From December 1983 to December 1987, 188 symptom-free patients were found to have severe (>75%) stenosis by duplex imaging (performed as screening examination). Patients with nonhemispheric symptoms or contralateral symptomatic lesions (within 7 years) were excluded from the study. Follow-up data were available for 141 patients (range 3 to 36 months; mean 21 months). Sixty-two patients received nonoperative therapy. The remaining 79 patients underwent 100 carotid endarterectomies (CAE) (21 staged bilateral repairs and 58 unilateral repairs). There were no statistically significant differences in sex, age, or risk factors (i.e., hypertension, diabetes, or smoking) or in the incidence of bilateral disease. Significant differences were found in the incidence ofischemic attacks (0 vs 21%; p < 0.001) and stroke (2.5% vs 18%; p < 0.01) in the operative vs nonoperative group. None of the 11 strokes in the nonoperative group were preceded by neurologic events. The operative group had an overall stroke rate of 2.5% (2/79), a perioperative mortality rate of 1.3% (1/79), and a restenosis (>50%) rate of 3.8% (3/79). Thus favorable results can be achieved with prophylactic CAE. These data support the use of prophylactic CAE in any patient with greater than 75% stenosis identified by duplex image, regardless of sex, age, risk factors, or bilateral disease. (J VAsc SURG 1989;9:361-6.) Controversy exists over prophylactic carotid endarterectomy (CAE) in symptom-free patients. The Framingham study 1 and others 2 suggest a stroke risk of 0.1% to 0.4% per year in symptom-free patients. The marker of disease in these studies was the presence of a bruit and not necessarily documented stenosis. When a stenosis is found, however, the risk of stroke increases to 0.7% to 6%Y Recent reports by Hertzer et al. 6 and Moneta et al. 7 have demonstrated a beneficial result ofendarterectomy in reducing transient ischemic attacks (TEAs) and stroke in symptomfree patients with >75% diameter stenosis. However, Hertzer et al. could demonstratc a reduction of _~roke risk only in symptom-free male patients. Still others report no benefit of prophylactic endarterectomy in any patients. 3-5,s-~° Because the presence of a bruit does not correlate well with significant internal carotid stenosis, s'9 other screening maneuvers have been developed. Noninvasive tests, in particular duplex scanning, has been well documented to be a reliable screening tool for the detection of carotid stenosis, n The results of du-From the

Temporal Trends and Determinants of Stroke Risk in Patients With Medically Treated Asymptomatic Carotid Stenosis

“…After screening of 5915 unique reports and assessing the full texts of 231 for eligibility, we included 73 studies reporting 28 625 patients with ≥50% ACAS (Figure 1; Table S2). 8–10,16–85…”

Carotid Artery Disease: Selecting the Appropriate Asymptomatic Patient for Intervention

“…Prior to the published report of ACAS in 1995, a number of smaller uncontrolled studies had suggested that patients with asymptomatic severe stenosis were at risk for future ischemic cerebrovascular events and might benefit from prophylactic CEA. 12,[14][15][16][17][18][19] Norris et al 20 found that with a stenosis greater than 75%, the combined TIA and stroke rate was 10.5% per year, with 75% of the events ipsilateral to the stenotic artery. Additionally, the North American Symptomatic Carotid Endarterectomy Trial (NASCET) 21 demonstrated a higher risk of stroke in the medically treated patients as the degree of stenosis increased.…”

Rational approach to combined carotid and ischaemic heart disease

“…Schwartz et al 21 also found that the risk of postoperative stroke increased with increasing severity of disease ; 3·8 per cent of patients with a unilateral stenosis greater than 50 per cent suffered a hemispheric stroke, compared with 8·3 per cent of those with bilateral internal carotid artery stenosis of 80-99 per cent. The presence of an asymptomatic internal carotid artery stenosis of 50 per cent or greater is associated with a mean annual ipsilateral stroke rate of only 2·8 (range 0·9-4·7) per cent [22][23][24][25][26][27] . For patients with an asymptomatic stenosis of 75 per cent or more, the mean annual risk of stroke is 3·6 (range 1·8-10·1) per cent [28][29][30][31][32][33][34] , with only 75 per cent of strokes being ipsilateral to the stenotic artery. Three prospective randomized trials [35][36][37] designed to show the efficacy of prophylactic carotid endarterectomy in the treatment of patients with asymptomatic stenosis have failed to demonstrate that stroke or stroke-free survival is influenced by endarterectomy for asymptomatic carotid stenosis.…”