Do asymptomatic patients with blocked carotid arteries always require surgery?
Medically reviewed by Giuseppe Lanzino, M.D.Treatment options for patients diagnosed with partially blocked carotid arteries but without symptoms such as a mini-stroke, or transient blindness in one eye (amaurosis fugax), should be carefully considered and recommendation made on an individualized basis, according to a review of medical literature published in Mayo Clinic Proceedings.
The carotid arteries connect the heart and the brain in the front of the neck. Stenosis occurs when the arteries become clogged with fatty deposits. Stroke can be a concern. “There can be a knee jerk response when patients are found to have a blockage,” says Giuseppe Lanzino, M.D., a Mayo Clinic neurosurgeon and lead author of the research review. “The response often is, ‘You need surgery.’”
“A blockage doesn’t necessarily mean that a patient is going to have a stroke,” says Dr. Lanzino. A partial blockage (greater than 60 percent) in patients without symptoms carries a risk of stroke of about 2 percent each year. That increased risk needs to be weighed against the risk and benefits of treatment.
Dr. Lanzino says that patients need a careful multispecialty evaluation to determine the best treatment option, and treatment must be individualized. Treatment can include:
Medication (antiplatelet drug therapy) and risk factor management. Risks factors include high blood pressure, obesity, high cholesterol, diabetes, and tobacco use.
Carotid endarterectomy, a surgery where the carotid artery is opened and the fatty deposits are removed.
Carotid angioplasty and stenting, where a long, hollow plastic tube (catheter) is inserted in the groin artery and threaded to the narrowed carotid artery. A tiny balloon at the end of the catheter is inflated to open the narrowed artery. A metal stent is inserted to prevent the artery from narrowing again.
Dr. Lanzino worked with Mayo Clinic neurologists Alejandro Rabinstein, M.D., and Robert D. Brown, M.D., to review the most current studies dealing with the medical, surgical, and endovascular treatment of carotid artery stenosis. Their findings, published in April 2009, included:
Surgery is best for most patients with symptoms: Carotid endarterectomy should be strongly considered for symptomatic patients with 70 to 99 percent blockage in the carotid artery. It also should be considered for those with 50 to 69 percent stenosis. Doctors agree that for most patients with moderate to severe blockage, surgery is the safest and most effective treatment, if it is done by a surgical team that has a very low complication rate.
Symptoms of carotid artery stenosis include transient blindness in one eye, weakness or numbness of an arm, leg or the face, or the temporary inability to speak or to understand conversation.
Angioplasty and stenting is an option for higher risk symptomatic patients: Patients with symptoms of carotid artery stenosis who have other health risks precluding surgery may be good candidates for angioplasty and stenting.
Treatment choices less clear for asymptomatic patients: Most patients with partially blocked carotid arteries don’t have symptoms and the best intervention remains controversial. Surgery has been considered the standard but it’s not clear that surgery offers more benefit than angioplasty and stenting or medical therapy alone (antiplatelet medications and aggressive correction of risk factors). Large studies are under way to determine the most effective treatment option.
Differentiating symptomatic and asymptomatic patients is critical: Patients often are diagnosed with carotid artery stenosis after seeing a doctor for dizziness, blurry vision, floaters in the vision or generalized weakness. These are not considered symptoms of carotid artery stenosis even when imaging shows a blockage is present.
Age matters when determining treatment: For patients 75 and older, especially those with other health conditions, the risk of treating carotid artery stenosis may exceed the benefit. For patients age 80 and older, angioplasty and stenting has a higher risk of stroke than surgery (carotid endarterectomy).
Below is a youtube video with Dr. Lanzino talking about the study.