Carotid surgery for silent stenosis cuts long-term stroke risk

For patients younger than age 75 with asymptomatic carotid stenosis, successful carotid endarterectomy (CEA) reduces the risk of stroke over the next 10 years by about 46%, with about half of this reduction in disabling or fatal strokes, suggest the Asymptomatic Carotid Surgery Trial-1(ACST-1) results published September 25, 2010 in the Lancet.

However, the perioperative risk of stroke or death is about 3%, note Dr Allison Halliday (John Radcliffe Hospital, Oxford, UK) and colleagues. They conclude that "for otherwise-healthy men and women younger than 75 years . . . the results from this trial suggest net benefit from CEA, as long as perioperative risks remain low."

In a statement on the study, Halliday notes that this trial took more than a decade to complete, "because we wanted to know about the long-term effects of surgery. The finding that successful carotid artery surgery can substantially reduce the stroke risk for many years is remarkable, because it means that most of the risk of stroke over the next five years in patients with a narrowed carotid artery is caused by that single carotid lesion."

Reached for outside comment, Dr Martin M Brown (National Hospital for Neurology and Neurosurgery, London, UK) said: "The problem with the conclusions of the trial is that over the long time it has taken to complete the study, medical treatment to prevent stroke in patients with carotid stenosis has improved considerably.

"There is considerable evidence," he said, "that modern medical treatment approximately halves the risk of stroke associated with carotid stenosis."

Halliday and colleagues do point out in their article that the "net benefit [of CEA] in future patients will depend on their risks from unoperated carotid lesions (which will be reduced by medication), on future surgical risks (which might differ from those in trials), and on whether life expectancy exceeds 10 years."