An international research team who compared the long-term effects of carotid artery surgery and stenting found the risk of stroke “remarkably low” even 10 years later, regardless of the type of procedure.

Short-term stroke prevention was found to be better among surgery patients, but stenting technology has improved since these patients were implanted, said the study’s lead author, who predicted that short-term outcomes of stenting could soon match those of surgery.

As many as 100,000 people in the United States undergo either carotid endarterectomy to remove built-up plaque or stent placement to improve blood flow and prevent stroke, according to the Mayo Clinic. The typical patient with a narrowed carotid artery is 70 years old. Life expectancy is another 16 years for women and another 14 years for men.

Published in Lancet Neurology, the study followed 4,754 patients in 19 countries. Those patients, who were participants of previous studies comparing the two procedures, had been assigned randomly to undergo endarterectomy or stenting. One of those studies was the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST), led by Mayo Clinic. Another was the International Carotid Stenting Study, led by University College London.

“This was the largest study to date comparing the efficacy and durability of carotid surgery and carotid stenting,” said first author Thomas Brott, M.D., a neurologist on Mayo Clinic’s Florida campus, in a prepared statement. “We found the likelihood of having a stroke on the same side where treatment was performed — even years later — to be remarkably low.”

The research team followed patients’ outcomes for up to 10 years after the procedures and found the long-term rate of stroke following either procedure was as low as 0.6% per year regardless of the patients’ gender, age or history of smoking.

The team also compared the incidence of stroke in the immediate days and months after treatment, when patients are at risk of a poor result due to the risks of surgery or stenting. The researchers found endarterectomy to have better post-procedure results. However, Brott said that several factors, including newer stenting technology and proper patient selection, have continued to improve over the years since patients in the current study had their procedures. Brott said he expects that short-term outcomes of stenting could soon match those of surgery.

While patients over 70 and those with very hardened or very tortuous arteries tend to do better with surgery than with stenting, clinicians now have better information to help match the right treatment to each patient, according to study co-author Martin Brown, M.D., a neurologist from University College London in England.

“These trials had similar designs, which allowed us to combine the data with two other trials from France and Germany, to answer important questions concerning stroke treatment,” Brown said.