Percutaneous transluminal angioplasty and stenting for carotid artery stenosis.

BACKGROUND: Carotid artery stenosis may be treated endovascularly by percutaneous transluminal balloon angioplasty with or without stent insertion or by primary stenting. Endovascular treatment may be a useful alternative to carotid endarterectomy (CEA), particularly for lesions not suitable for surgery.

OBJECTIVES: The objective of this review was to assess the benefits and risks of endovascular treatments compared with carotid endarterectomy (in patients suitable for surgery) or medical therapy (in patients not suitable for surgery).

SEARCH STRATEGY: We searched the Cochrane Stroke Group trials register (last searched 1 September 2003). In addition we searched the following bibliographic databases: Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2002), MEDLINE (1966 to June 2003), EMBASE (1980 to June 2003) and Science Citation Index (1981 to June 2003). We also contacted researchers in the field and balloon catheter and stent manufacturers.

SELECTION CRITERIA: We selected randomised trials of carotid endovascular treatment compared with carotid endarterectomy, or endovascular treatment plus best medical therapy compared with best medical therapy alone, in patients with symptomatic or asymptomatic carotid artery stenosis.

DATA COLLECTION AND ANALYSIS: Two reviewers independently applied the inclusion criteria, extracted data and assessed trial quality.

MAIN RESULTS: Two completed trials comparing endovascular treatment with carotid endarterectomy involving 608 patients were found. In addition there were two trials which fulfilled the inclusion criteria and which were stopped early (242 patients), and a third trial which has completed randomisation and 30 day follow up of 307 patients. Four trials are ongoing. Meta analysis of the data from the included studies found no significant difference between the odds of death or any stroke at 30 days post procedure (Odds Ratio [OR] endovascular:surgery 1.26, 95% Confidence Interval [CI] 0.82 to 1.94). The odds of death or disabling stroke at 30 days were similar in the endovascular and surgical group (OR 1.22, CI 0.61 to 2.41). At one year following procedure, there was no significant difference between the two groups in preventing any stroke or death (OR 1.36,CI 0.87 to 2.13). Endovascular treatment significantly reduced the risk of cranial neuropathy (OR 0.12, CI 0.06 to 0.25). There was no significant difference between the two groups when the risk of death, any stroke or myocardial infarction was considered (OR 0.99, CI 0.66 to 1.48). There was substantial heterogeneity between the trials for four of the five outcomes.

REVIEWERS' CONCLUSIONS: Data from randomised trials comparing endovascular treatment for carotid artery stenosis with carotid endarterectomy suggest that the two treatments have similar early risks of death or stroke and similar long term benefits. However, the substantial heterogeneity renders the overall estimates of effect somewhat unreliable. Furthermore, two trials were stopped early because of safety concerns, so perhaps leading to an over-estimate of the risks of endovascular treatment. On the other hand, endovascular treatment appears to avoid completely the risk of cranial neuropathy. There is also uncertainty about the potential for restenosis to develop and cause recurrent stroke after endovascular treatment. The current evidence does not support a widespread change in clinical practice away from recommending carotid endarterectomy as the treatment of choice for suitable carotid artery stenosis. There is a strong case to continue recruitment in the current randomised trials comparing carotid stenting with endarterectomy.