Two European trials have failed to show stenting to be equivalent or better than carotid endarterectomy in symptomatic patients - the current standard of care for stroke prevention in patients needing treatment for carotid artery stenosis.
At the 33rd annual Veith Symposium for vascular surgeons in New York last month, experts discussed the results of the most recent randomised trials - the German SPACE and the French EVA-3S, both of which looked at how stenting compares with surgery. At this year’s meeting, a lot of the heat surrounding the debate dissipated compared with the previous year, given the latest data emerging from these two trials that concluded that carotid stenting comes with a greater procedural risk than surgery.
Every year in Germany, 200,000 people suffer from a stroke. Around 30,000 are caused by carotid stenosis, a narrowing of the carotid artery because of plaque. Removal of this plaque is one of the most successful means of preventing strokes in these patients, and the benefits outweigh the risks of further strokes or death after operations. Past clinical trials reveal that in professional hands, the perioperative risk of stroke in symptomatic patients is 6% and in asymptomatic patients as low as 3%.
Some physicians questioned the conclusions reached by these trials because both were halted before they were finished, resulting in fewer numbers of patients and leaving them unable to prove statistically significant results from which to draw definitive conclusions.
D. Peter Bell is a vascular surgeon at the Leicester Royal Infirmary in the United Kingdom and an outspoken critic of carotid stenting. He says: ‘As far as symptomatic patients are concerned, the EVA-3S and SPACE trials have shown no benefit for CAS in patients with symptoms who need treatment.’
The only trial that has shown a benefit for CAS is the SAPPHIRE trial, which Bell describes as ‘deeply flawed’. It has now been discredited, since the principal investigator was also involved in the trial design. The results showed higher risks for stroke for CAS and CEA groups in a largely asymptomatic patient population, for which the necessity for intervention remains questionable anyway.
For these patients, a risk of having a stroke without any treatment would be as low as 2% a year, rendering unacceptable the results of the SAPPHIRE trial that showed a perioperative stroke risk rate of 5.8% at 30 days.
With no trials demonstrating clear evidence in favour of stenting, this procedure should not be used more widely. Dr Bell warns: ‘These [EVA-3S and SPACE] trial results show that the CAS procedure is dangerous even in the hands of experts and should not be used more widely. Otherwise, disaster will occur.’