Re: Systematic Comparison of the Early Outcome of Angioplasty and Endarterectomy for Symptomatic Carotid Artery Disease
To the Editor:
In the recent article by Golledge et al,1 the authors attempted to compare the early outcome of angioplasty and endarterectomy, or more specifically, the early complication rates of these 2 procedures.
Notwithstanding the methods, which were well detailed, I wish to draw attention to the authors’ inclusion of 2 specific series (the fourth and fifth series of their Table 2). These 2 series comprised 7 and 9 patients, respectively, in which the disabling stroke or death rates were 43% and 11%. Even though the 2 series account for only 2% of the total 714 patients treated, these complications represent 4 of 28, or 14%, of the disabling strokes or deaths in the overall numbers. Clearly, there is a significantly disproportionate representation of morbidity from these 2 small series, and by comparison the smallest series among the carotid endarterectomy studies numbered 62 patients. Indeed, exclusion of the 2 small angioplasty series leaves 24 disabling strokes/deaths out of 698 carotid arteries, or a 3% incidence, rather than the 4% given. While this is still a significant difference (χ2=3.939, 2-sided P=0.0472), and does not refute the authors’ conclusions, it is not “twice as common” but rather 1% greater than the serious complications of carotid endarterectomy.
Golledge J, Mitchell A, Greenhalgh RM, Davies AH. Systematic comparison of the early outcome of angioplasty and endarterectomy for symptomatic carotid artery disease. Stroke. 2000; 31: 1439–1443.
I would like to thank Dr Lownie for his careful comments regarding our recent article. He correctly points out the very high disabling stroke rate in 2 small series of endovascular treatment of carotid stenoses. Because this therapy is an evolving technique, it would be hoped that these poor outcomes reflect part of the learning curve of a new technique. However, with the availability of an established treatment for symptomatic carotid artery disease, referring clinicians and patients alike need to be aware of the potential complications of this new technique, even in the hands of those taking up this procedure for the first time. As Dr Lownie points out, excluding these 2 more unfavorable series does not distract from the conclusion that the present publications suggest a significantly higher complication rate of carotid stenting: The disabling stroke or death rate (with exclusion of the 2 series mentioned) is 24/698 (3.4%) compared with 107/4973 (2.1%) for the carotid endarterectomy series. Equally, if the 2 most unfavorable series are also removed from the carotid endarterectomy list (numbers 8 and 17 in our Table 3), the serious complication rate of surgery is reduced to 74/4428 (1.7%), ie, half that of carotid stenting (3.4%), as originally stated.