doi: 10.1161/01.STR.0000170649.49688.5e
(Stroke. 2005;36:1357.)
© 2005 American Heart Association, Inc.
Letters to the Editor |
The Risk and Benefit of Endarterectomy In Women With Symptomatic Internal Carotid Artery Disease
Long Island Vascular Center, Roslyn, NY
To the Editor:
We read with interest the recent article by Alamowitch et al1 on the risk and benefit of endarterectomy in women with symptomatic internal carotid artery disease. Whereas women and men with 
70% symptomatic stenosis had a similar benefit from a carotid endarterectomy, women with 50% to 69% stenosis did not benefit from the procedure. The 30-day perioperative risk of death was 2.3% in women and 0.8% in men, and the combined risk of stroke and death was 7.6% in women and 5.9% in men. Because the data for this study were taken from the North American Symptomatic Carotid Endarterectomy Trial (NASCET),2 the conclusions must be understood with the design of the NASCET study that involved 50 clinical centers in North America. Patients with high-grade stenosis were enrolled and randomized from January 1988 to February 1991. The parallel study of patients with medium-grade stenosis (30% to 69%) was continued until December 1996.3 Though patients older than age 80 years were excluded before February 1991 for both the moderate and severe parallel studies, older patients were included in the second phase of the NASCET study.
One concern in interpreting the current study is that the moderate stenosis group included older patients than the severe stenosis group, and that the benefit of carotid endarterectomy may be less, in part, from the older age of some patients with moderate carotid stenosis. Because the surgical technique was left to the discretion of the surgeon, it is unclear how different operative techniques affected the results. How many patients had shunts? How experienced were the surgeons who performed the carotid endarterectomies? We know that high volume carotid endarterectomy surgeons and high volume hospitals obtain better outcomes.4,5 We believe that the type of closure also affects the outcome, and that women should be closed with a greater saphenous vein patch.6 Our 30-day perioperative mortality rates with the vein patch closure were 0.5% and 0.4%, the nonfatal stroke rates were 0% and 0.8%, and the combined death and stroke rates were 0.5% and 1.2%, respectively, for male and female patients.7 We now have performed vein patch angioplasty and carotid endarterectomy for in 300 females with 350 procedures and in 435 males with 491 procedures. Approximately 70% of our patients had the operation for symptomatic moderate and severe internal carotid artery stenosis, and no significant difference in the perioperative risks has been found between asymptomatic and symptomatic patients. A recent study also reports a significant reduction in perioperative complications with a patch closure with a mortality rate of 0.9%, fatal stroke rate of 0.2%, and any stroke or death rate of 2.5%.8 Because the annual stroke rate for patients with symptomatic moderate internal carotid stenosis has been reported to be 6%, we believe that patients who are symptomatic should be considered for surgical intervention.9 Low and acceptable perioperative mortality and morbidity rates can be achieved in the symptomatic female with moderate or severe carotid stenosis if vein patch angioplasty and carotid endarterectomy are performed by high-volume vascular surgeons at high-volume institutions.
References
1. Alamowitch S, Eliasziw M, Barnett HJM. The risk and benefit of endarterectomy in women with symptomatic internal carotid artery disease. Stroke. 2005; 36: 27–31.
2. Barnett HJM, Taylor DW, Elisaziw M, Fox AJ, Ferguson GG, Haynes RB, Rankin RN, Clagett GP, Hachinski VC, Sackett DL, Thorpe KE, Math M, Meldrum HE. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. N Engl J Med. 1998; 339: 1415–1425.
3. North Am Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991; 325: 445–453.[Abstract]
4. Cowan JA Jr, Dimick JB, Thompson BG, Stanley JC, Upchurch GR Jr. Surgeon volume as an indicator of outcomes after endarterectomy: an effect independent of specialty practice and hospital volume. J Am Coll Surg. 2002; 195: 814–821.[CrossRef][Medline] [Order article via Infotrieve]
5. Menzoían JO. Presidential address: carotid endarterectomy, under attack again! J Vasc Surg. 2003; 37: 1137–1141.[Medline] [Order article via Infotrieve]
6. Chang JB, Stein TA. Long-term success of vein-patch and carotid endarterectomy. Int J Angiol. 1998; 7: 177–180.[CrossRef]
7. Chang JB, Stein TA. Ten-year outcome after saphenous vein patch angioplasty in males and females after carotid endarterectomy. Vasc Endovasc Surg. 2002; 36: 21–27.
8. Bond R, Rwekasem K, Naylor AR, AbuRahma AF, Rothwell PM. Systematic review of randomized controlled trials of patch angioplasty versus primary closure and different types of patch materials during carotid endarterectomy. J Vasc Surg. 2004; 40: 1126–1135.[CrossRef][Medline] [Order article via Infotrieve]
9. Mansour MA, Mattos MA, Fraught WE, Hodgson KJ, Barkmeier LD, Ramsey DE, Sumner DS. The natural history of moderate (60% to 79%) internal carotid artery stenosis in symptomatic, nonhemispheric, and asymptomatic patients. J Vasc Surg. 1995; 21: 346–357.[CrossRef][Medline] [Order article via Infotrieve]
Response:
Department of Community Health Sciences, and Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
Stroke Unit, Department of Neurology, Tenon Hospital, AP-HP, Paris, France
The John P. Robarts Research Institute, London, Ontario, Canada.
We thank Drs Chang and Stein for their comments regarding our comparisons of benefit from carotid endarterectomy (CE) in women and men with symptomatic severe (70%) and moderate (50% to 69%) internal carotid artery stenosis.1 In their letter, Drs Chang and Stein mistakenly stated that we reported no benefit in women with moderate stenosis. This was only true if women had none or few of the prespecified risk factors for stroke. In the presence of a high risk factor profile, women did receive benefit from CE. We thus concluded that women with a symptomatic moderate carotid stenosis should not automatically undergo CE but should be carefully assessed for additional risk factors that would lead to greater benefit with CE than from best medical care alone.
Drs Chang and Stein suggested that the modest increase in the average age of the group with moderate stenosis (66.4 years old) compared with the severe group (64.3 years old) may have diminished the benefit of CE among the moderates. On the contrary, previous analyses from NASCET showed that the benefit from CE in elderly patients exceeded that found in younger patients. This increase in benefit resulted from having a combination of a higher risk of stroke on medical therapy alone and a lower perioperative surgical risk than the younger patients.2 It must be recalled that at no age were patients enrolled into NASCET who had recent evidence of life-threatening heart disease or evidence of failure of other vital organs.
In regards to the operative procedure itself, NASCET did not include surgeons as participants into the trial unless they demonstrated, by audit, that they had a perioperative rate of stroke and death of <6% in a minimum of 50 consecutive cases accumulated over 2 years. Over the course of the trial, the Surgical Committee of NASCET monitored the surgeons’ performance in each center. Stroke neurologists were responsible for patient assessment and reporting of all outcome events, followed by external adjudication. Although NASCET surgeons were not constrained to follow any standardized surgical technique, other than their normal practice, we are confident that they were experts in the performance of CE. The low perioperative mortality rate of 1.1% and disabling stroke rate of 0.9% attest to this.3
NASCET was not a trial designed to test the relative value of a variety of technical differences in the performance of CE. Nonetheless, details of anesthetic techniques and surgical variations, including the use of intraoperative shunts and patch grafts, were recorded in the Surgical Case Report Form. Among the 1415 patients who were randomized into the surgical arm and received CE, 41.0% had an intraluminal shunt.3 The perioperative stroke and death rate among those who had a shunt was 6.2% compared with 6.7% among those without a shunt (P=0.71). Patch closure was used in 19.8% of the patients. Among those with patching, the perioperative stroke and death rate was 5.0% compared with 6.8% among those who had simple closure (P=0.36). The trend favoring patching is congruent with Drs Chang and Stein’s beliefs of its value to CE. Nevertheless, without trials in which patients are randomly assigned to receive or not receive these technical variations, subgroup analyses and beliefs remain as hypothesis-generating rather than practice-altering certitudes. A recent systematic review of arteriotomy closure is a step in the right direction.4 Even so, it was based on 13 trials of small size and of variable quality. The obvious next step would be to conduct a randomized trial of sufficient size to compare different types of closures and materials, bearing in mind that operative risks are different between women and men, and between symptomatic and asymptomatic patients. Until such a time when this type of trial can be completed, the decision of whether to use a patch routinely will be left to the discretion of the operating surgeon.
References
1. Alamowitch S, Eliasziw M, Barnett HJM. The risk and benefit of endarterectomy in women with symptomatic internal carotid artery disease. Stroke. 2005; 36: 27–31.
2. Alamowitch S, Eliasziw M, Algra A, Meldrum H, Barnett HJM. Risk, causes, and prevention of ischaemic stroke in elderly patients with symptomatic internal-carotid-artery stenosis. Lancet. 2001; 357: 1154–1160.[CrossRef][Medline] [Order article via Infotrieve]
3. Ferguson GG, Eliasziw M, Barr HWK, Clagett GP, Barnes RW, Wallace MC, Taylor DW, Haynes RB, Finan JW, Hachinski VC, Barnett HJM. The North Am Symptomatic Carotid Endarterectomy Trial: Surgical results in 1415 patients. Stroke. 1999; 30: 1751–1758.
4. Bond R, Rerkasem K, Naylor AR, AbuRahma AF, Rothwell PM. Systematic review of randomized controlled trials of patch angioplasty versus primary closure and different types of patch materials during carotid endarterectomy. J Vasc Surg. 2004; 40: 1126–1135.[CrossRef][Medline] [Order article via Infotrieve]
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