Carotid angioplasty and stenting: are they therapeutic alternatives?

Clinical trials have shown that carotid surgery prevents stroke, but also has a significant risk of morbidity. Percutaneous transluminal angioplasty and stenting (endovascular treatment) can also be used to treat carotid stenosis and have the advantage of avoiding general anaesthesia, cranial nerve injury and the discomforts of surgery. However, there are several potential complications of endovascular treatment, including intimal dissection and plaque rupture, and the long-term consequences of restenosis. More embolic signals are detected during and immediately after carotid angioplasty than during carotid surgery, although a randomised comparison showed no difference in neuropsychological outcomes. The large published case series of carotid endovascular treatment suggest a similar major morbidity rate to surgery, but a small single centre randomised trial reported very poor results in stented patients. Trial data from the much larger Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS) has been more encouraging. Results are available from 504 patients with carotid stenosis randomised to surgery or endovascular treatment. Endovascular treatment was carried out by percutaneous transluminal angioplasty using balloon catheters with the adjunct use of stents in 22%. Audited safety analysis by intention to treat showed no difference in the outcome measure of disabling stroke or death within 30 days of treatment, but the rate of treatment related death or stroke lasting more than seven days was relatively high in both groups (endovascular treatment 10%, surgery 9.9%). Minor complications, particularly cranial nerve palsy and haematoma were significantly less frequent in the endovascular group, but restenosis was significantly more common. Both treatments appeared equally effective at preventing stroke recurrence with no difference in the rates of stroke during follow-up for up to 3 years. Techniques of carotid angioplasty and stenting improved over the course of CAVATAS, and new designs of stents, filters and protection devices are being developed. Further large, multicentre randomised trials are therefore being started which will evaluate primary stenting of carotid artery stenosis in patients with cerebrovascular disease. Until the results are available, it will remain uncertain whether angioplasty and stenting are safe and effective therapeutic alternatives to surgery.