I - Surgery for Carotid Artery Stenosis
Carotid endarterectomy has established benefits when compared to medical treatment in the management of symptomatic and asymptomatic internal carotid artery stenosis.
a) Symptomatic carotid artery stenosis
Surgery provides a significant reduction of the long term risk of stroke or death in symptomatic patients with =70% stenosis of the internal carotid artery when compared to medical treatment.
In NASCET (North American Symptomatic Carotid Endarterectomy Trial), symptomatic patients with severe carotid stenosis were randomised to medical treatment or carotid endarterectomy (1).
In the surgical group,
- The overall rate of perioperative stroke or death was 6.5% (2).
- The absolute risk reduction of any ipsilateral stroke at 2 years was 17% for patients after carotid endarterectomy (p < 0.001).
- Major perioperative medical complications were mostly cardiovascular and occurred in <10% of patients (3).
- These benefits have been confirmed by other randomised controlled trials in patients with severe symptomatic carotid internal artery stenosis (4,5).
In symptomatic patients with moderate (58%–69%) stenosis, surgery has also demonstrated a superior risk reduction when compared to medical treatment (6).
b) Asymptomatic carotid artery stenosis
Surgery provided superior results when compared to medical treatment in the Asymptomatic Carotid Atherosclerosis Study which included 1662 patients with asymptomatic carotid artery stenosis in patients with carotid artery stenosis >60%.
- The risk of ipsilateral stroke over 5 year period was reduced (5% vs. 11%) in the surgery group assuming an average mortality or stroke rate <3% (7).
- Similar results were reported in the Asymptomatic Carotid Surgery Trial which demonstrated a reduction of 50% in the risk of stroke with endarterectomy at five years, even though such a benefit is not realised untill two years after the endarterectomy (8).
The long term benefits of carotid endarterectomy for both symptomatic and asymptomatic patients need to be weighed against the immediate risk of complications of the procedure, thus benefit is tangible only in the presence of a low perioperative complication rate. The surgical procedure should be performed by an experienced surgeon with good patient selection and as such continues to be the gold standard.
II- Carotid Angioplasty
Carotid angioplasty has evolved with procedural technologic advancements supplemented by the introduction of intravascular stents and new antiplatelet drugs.
The SAPPHIRE trial (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy) had concluded that carotid-artery stenting was not inferior to endarterectomy with a lower risk of myocardial infarction within 30 days after carotid stenting.
- There was no significant difference in the rates of stroke or death at either 30 days (3.6% vs. 3.1%) or at 1 year.
- The authors advocated this procedure as a viable option in the treatment of carotid artery stenosis particularly in high-risk patients such as restenosis after previous carotid surgery, radiation-induced disease and the presence of significant co-morbidities (e.g. severe coronary artery or chronic pulmonary disease) (9).
Subsequent studies such as SPACE (Stent-Supported Percutaneous Angioplasty of the Carotid Artery versus Endarterectomy) gave contradictory results.
- It failed to prove non-inferiority of carotid-artery stenting compared with carotid endarterectomy expressed as the rate of ipsilateral stroke or death within 30 days after treatment in symptomatic patients with moderate to severe symptomatic stenosis of the carotid artery.
- The conclusions of this trial were that there was a tendency towards better results in the carotid endarterectomy group, apart from death within 30 days and hemorrhagic stroke.
- However the authors advised against a short-term widespread use of carotid-artery stenting for treatment of carotid-artery stenosis (10).
In the EVA-3S study (Endarterectomy versus Stenting in Patients with Symptomatic Severe Carotid Stenosis)
- Patients with symptomatic carotid stenosis =60% had inferior 1 and 6 months mortality and stroke rates with endarterectomy compared with stenting.
- The 30-day risk of any stroke or death was significantly higher after stenting (9.6%) than after endarterectomy (3.9%), resulting in a relative risk of 2.5 (95% CI, 1.2 to 5.1) (11).
A meta-analysis of 5 randomised clinical trials revealed a periprocedural complication rate (stroke and death within 30 days) of 8.1% in the carotid stenting group and 6.3% in the endarterectomy group (12).
The use of embolic protection devices has been shown to reduce thromboembolic complications and increase the safety of carotid-artery stenting. However, this remains a continuing debate (13).
Patients should be informed that there are insufficient data for long-term comparison between carotid angioplasty and surgery. Stenting does not seem to be safer than surgery despite a small difference between the two treatments in the order of 4 events in 600 patients per group. The US Food and Drug Administration advocates stenting only in symptomatic patients with stenosis of the internal carotid artery >70% who are at high risk for complications after surgery.
The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.