Comparison of SVS and ESVS carotid disease management guidelines
Article Outline
Both the Society for Vascular Surgery (SVS) and the European Society for Vascular Surgery (ESVS) have now published clinical practice guidelines for the management of carotid artery atherosclerosis.1, 2 Although the documents differ slightly in the methods used and in the level of detail, they reveal trans-Atlantic consensus in most key areas.
The SVS document uses the grade system, which rates strength of recommendations (I = strong and II = weak) separately from the quality of the data on which these recommendations are based (high, moderate, low, and very low). In this system, recommendations are based not just on data but also on prevailing values and preferences.3
The ESVS document uses a simpler system in which only the quality of the supporting data are graded (A = supported by at least one high-quality randomized controlled trial [RCT]; B = supported by good clinical trials but no RCTs; and C = supported only by expert opinion or experience).
Despite this fundamental methodologic difference, the guidelines that emerge are quite similar (Table). First, in symptomatic patients there is consensus that carotid endarterectomy (CEA) is most appropriate for patients with carotid territory transient ischemic attack or minor stroke with good recovery and ≥50% (North American Symptomatic Carotid Endarterectomy Trial [NASCET] criteria) ipsilateral stenosis (SVS: grade I/high; ESVS: grade A). The ESVS document adds a guideline that CEA in symptomatic patients should take place within 2 weeks of the symptom (ESVS: grade A), based on an analysis of pooled data from European Carotid Surgery Trial (ECST) and NASCET.4
Table. Comparison between SVS and ESVS guidelines for the management of carotid artery atherosclerosis
| Guideline | SVS | ESVS |
|---|---|---|
| Indication for surgery in symptomatic stenoses | >50% | >50% |
| Timing | . . . | Within 2 weeks |
| Indication for stenting in symptomatic stenoses | High-risk patients | High-risk patients |
| Comments | . . . | Equivalent midterm stroke prevention with CEA and CAS |
| Indication for surgery in asymptomatic stenoses | >60% | >70% |
| Caveats | As long as peri-op risk is low | Males <75 years if risk <3%; younger, fit women |
| Indication for stenting in asymptomatic stenoses | Not indicated | Only as part of RCT or in high-volume centers with documented excellent results |
| Caveats | . . . | Stenosis thresholds for stenting have not been validated |
| Technical recommendations for CEA | . . . | Patch closure recommended over primary closure |
| . . . | Routine shunting not supported | |
| . . . | Surgeon preference for other technical aspects | |
| Technical recommendations for CAS | . . . | Dual antiplatelet therapy for the periprocedural period |
There is equally strong consensus that CEA is inappropriate for symptomatic patients with <50% stenosis (SVS: grade I/high; ESVS: grade A). There is general consensus as well on the role of carotid artery stenting (CAS) in symptomatic carotid stenosis. The SVS and the ESVS documents both support consideration of CAS in high-risk symptomatic patients, although the recommendation and supporting data (SVS: grade II/low; ESVS: grade C) are much weaker than those supporting CEA. The ESVS document adds a recommendation that CEA is the preferred treatment in symptomatic patients (ESVS: grade A) and that midterm stroke prevention with CEA and CAS are equivalent (ESVS: grade A), based on midterm results of the Stent-Supported Percutaneous Angioplasty of the Carotid Artery versus Endarterectomy (SPACE) and Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis (EVA-3S) trials.5, 6
In the recommendations for the management of asymptomatic patients, there are some subtle differences between the SVS and ESVS documents. The threshold degree of stenosis for intervention in asymptomatic patients in the SVS document is 60%, based on the Asymptomatic Carotid Atherosclerosis Study (ACAS), whereas in the ESVS document, it is 70%, based on the Asymptomatic Carotid Surgery Trial (ACST). The SVS and ESVS documents recommend CEA for asymptomatic patients with stenoses exceeding these threshold values (SVS: grade I/high; ESVS: grade A).
Recommendations in both documents, however, include caveats: in SVS, “as long as perioperative risk is low”; and in ESVS, “males <75 if risk <3% and younger, fit women.” Results from the available RCTs indicate that the ESVS gender-related caveat seems appropriate, although data of lower quality suggest no gender-related differences in risk or stroke prevention benefit. The ESVS age-related caveat is more problematic because few data are available to support an absolute age threshold over which benefit is lost.
The SVS and ESVS guidelines on the role of CAS in asymptomatic patients reflect the considerable uncertainty and controversy shrouding this area. The SVS document does not support CAS for asymptomatic patients (grade I/low). The ESVS supports CAS in asymptomatic patients only as part of an RCT or in high-volume centers with documented excellent results (grade C). In reality, as stated in their discussion, the SVS authors could not reach consensus on this recommendation, which might more properly be grade II/low. The caveat added by the ESVS writing group is most appropriate: “The assumption that a patient can be treated with CAS when he has an (evidence-based) indication for CEA (carotid stenosis >50% in symptomatic or >70% in asymptomatics) has not been validated.”
The differences between the two documents are primarily in their scope. The ESVS authors chose to include much more detail on the techniques of CEA and CAS. In general, their technical recommendations for CEA are vague and support surgeon preference, including eversion vs longitudinal technique, general vs regional anesthetic, cerebral monitoring and protection, and completion quality control studies. It should be noted, however, that these vague recommendations are based on meta-analyses from the Cochrane Library, reflecting the best currently available data. A more definitive recommendation is made for carotid closure, where patch closure is recommended over primary closure (grade A). Also, routine shunting is not supported (grade A), but the origin of this recommendation is unclear because the authors present no data suggesting that routine shunting is inferior to selective shunting or nonshunting.
The SVS writing group felt that the quality of the data and the likely strength of recommendations with respect to the technical aspects of CEA and CAS were such that inclusion of only brief technical notes was appropriate. The SVS writing group espoused a broad range of technical options, especially for CEA, and consensus was elusive.
The ESVS writing group also included a detailed analysis of technique for carotid stenting. The only grade A recommendation to come from this analysis was for the use of dual antiplatelet therapy (aspirin plus clopidogrel) for the periprocedural period. Other technical recommendations, including the development of validated training programs, the use of cerebral protection devices, and the duration of dual antiplatelet therapy, were given grade B or C.
The SVS writing group did not attempt a systematic review of the evidence supporting technical aspects of CAS, although the brief technical notes and recommendations from the SVS group are nearly identical to those of the ESVS group.
Finally, the ESVS group evaluated evidence on the management of concurrent carotid disease and peripheral arterial disease (PAD) and on the management of concurrent carotid disease and coronary disease. Only grade C recommendations for not deferring PAD treatment in the setting of asymptomatic carotid disease and for individualizing the management of concurrent carotid and coronary disease resulted.
Comparison of the SVS and ESVS carotid disease management guidelines reveals trans-Atlantic consensus regarding the role of CEA in the management of symptomatic and asymptomatic patients. This should not be surprising, because the relevant data are both high quality and explicit in their clinical application. Less clear and much less explicit are the data supporting CAS, especially in asymptomatic patients. It is not surprising, therefore, that the emerging role of CAS is, as of now, much less clearly defined in both North America and Europe.
References
- Management of atherosclerotic carotid artery disease: clinical practice guidelines of the Society for Vascular Surgery. J Vasc Surg. 2008;48:480–486
- ESVS Guidelines (Invasive treatment for carotid stenosis: indications, techniques). Eur J Vasc Endovasc Surg. 2009;37(4 suppl):1–19
- Grading quality evidence and strength of recommendations. BMJ. 2004;328:1490
- . Carotid Endarterectomy Trialists Collaboration (Endarterectomy for symptomatic carotid stenosis in relation to clinical subgroups and timing of surgery). Lancet. 2004;363:915–924
- Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial: results up to 4 years from a randomised, multicentre trial. Lancet Neurol. 2008;7:885–892
- Results of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study to treat symptomatic stenoses at 2 years: a multinational, prospective, randomised trial. Lancet Neurol. 2008;7:893–902
This paper is published simultaneously in the Journal of Vascular Surgery and European Journal of Endovascular Surgery (DOI:10.1016/j.ejvs.2009.05.017).
PII: S0741-5214(09)01035-0
doi:10.1016/j.jvs.2009.05.023
© 2009 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
