70% Carotid Stenosis: Do You Really Need Surgery?

In short: A severe carotid narrowing is a real finding that deserves medical attention — but “severe” and “needs surgery” are not the same thing. The decision depends heavily on whether you’ve had symptoms, what modern medical treatment can already achieve, and whether the expected benefit of a procedure outweighs its risks. A major trial, CREST-2, has brought new evidence to this decision for people without symptoms, showing why treatment needs to be individualized rather than based on a percentage alone.

A 70% Narrowing Sounds Like It Needs Fixing — Does It?

It’s a natural assumption: a high percentage sounds urgent, and urgent things get fixed.

But carotid disease doesn’t quite work that way.

Some people live for years with severe carotid narrowing without experiencing a stroke. Others develop neurological symptoms with a less severe narrowing.

The percentage matters, but it cannot tell your doctor everything about your future risk — or whether a procedure would protect you better than modern medical treatment.

A 70% narrowing deserves proper evaluation. It does not automatically mean you need an operation.

The Decision Starts With One Question: Have You Had Symptoms?

This is one of the most important distinctions in carotid disease.

If you develop sudden weakness on one side, difficulty speaking, facial drooping, or temporary loss of vision in one eye — even if the symptoms disappear within minutes — seek emergency medical care immediately.

These can be warning signs of a transient ischemic attack (TIA, sometimes called a mini-stroke) or stroke.

When recent symptoms are linked to a significantly narrowed carotid artery, a procedure can substantially reduce the risk of another stroke in appropriately selected patients.

When surgery is indicated after a TIA or nondisabling stroke, doctors often aim to perform it within two weeks because the risk of another event can be highest early on.

But what if you’ve never experienced related symptoms?

Doctors call this asymptomatic carotid stenosis. In this situation, the decision is different because the potential long-term benefit of a procedure must be weighed against the immediate risks of performing it.

What Medication Alone Can Actually Do

Before comparing procedures, it’s worth understanding what modern medical treatment can accomplish.

Carotid plaque is usually part of atherosclerosis — a disease in which fatty and inflammatory material builds up in artery walls throughout the body.

That means treatment must address more than one narrowed artery.

Lowering cholesterol, often with statins, controlling blood pressure and diabetes, stopping smoking, and maintaining healthy lifestyle habits all help reduce cardiovascular risk.

Depending on your medical situation, treatment may also include an antiplatelet medication, such as aspirin, which helps prevent certain blood clots.

These measures can substantially reduce the risk of stroke and other cardiovascular events.

And they remain important even if you eventually undergo surgery or stenting.

Medical treatment isn’t simply what happens when surgery isn’t possible. It’s the foundation of carotid disease management.

Surgery vs. Stenting: Two Ways to Treat the Narrowing

If a procedure is appropriate, there are two established approaches.

Carotid endarterectomy is an operation in which the surgeon opens the artery and removes the plaque directly.

Carotid stenting is a catheter-based procedure in which a small metal mesh tube is placed inside the narrowed artery to help keep it open.

Stenting avoids a surgical incision directly over the carotid artery, but that doesn’t automatically make it safer for every patient.

Studies comparing the two approaches have found broadly similar results for certain long-term outcomes, although their immediate risks differ.

Older patients, for example, have generally had more favorable outcomes with endarterectomy than with traditional stenting performed through an artery in the groin, particularly regarding the risk of stroke around the procedure.

Your age, artery anatomy, plaque characteristics, other medical conditions, and the experience of the treating team all influence which option may be more appropriate.

The important question isn’t which procedure sounds less invasive.

It’s which approach offers the best balance of benefit and risk for you.

The Trial That Changed the Calculus: CREST-2

For years, an important question remained: if someone has severe carotid narrowing but no symptoms, and already receives effective medical treatment, how much additional protection does a procedure actually provide?

CREST-2 investigated this question in nearly 2,500 participants with severe asymptomatic carotid stenosis of at least 70%.

The researchers conducted two separate trials. One compared intensive medical treatment alone with the same treatment plus stenting. The other compared intensive medical treatment alone with the same treatment plus endarterectomy.

The results were important.

In the stenting trial, the main study outcome occurred in 6.0% of patients receiving intensive medical treatment alone, compared with 2.8% of those who also received a stent.

That means approximately 6 versus 3 out of every 100 patients over four years — an absolute difference of 3.2 percentage points.

In the separate surgery trial, the corresponding rates were 5.3% with medical treatment alone and 3.7% with surgery plus medical treatment.

That difference was smaller and was not statistically significant, meaning the study did not establish a clear additional benefit from surgery in that comparison.

There are two important details.

First, these numbers represent the study's combined primary outcome: any stroke or death during the first 44 days, followed by an ischemic stroke on the same side as the narrowed artery during the remaining four-year follow-up. They are not simply the risk of having any stroke over four years.

Second, stenting and surgery were tested in separate trials. CREST-2 did not establish that stenting is superior to endarterectomy.

The findings also do not mean that surgery never helps people without symptoms.

Instead, they show why the decision must account for the relatively low event rates achievable with modern medical treatment and the risks associated with an intervention.

For some patients, adding a procedure offers meaningful additional protection. For others, the expected benefit may not justify the immediate risks.

Why Two Doctors Might Give You Different Advice

You may receive different recommendations from different specialists.

That doesn't automatically mean one of them is wrong.

American vascular surgery guidelines have supported endarterectomy in selected patients with severe asymptomatic narrowing and low procedural risk.

European guidelines have generally taken a more selective approach, emphasizing additional features associated with increased stroke risk, sufficient life expectancy, and a low expected complication rate.

Both sets of guidelines were published before the CREST-2 results became available.

That is one reason carotid treatment remains an evolving area of vascular medicine.

Your symptoms, overall health, expected lifespan, artery anatomy, and the results a treating team can realistically achieve all matter.

A recommendation should reflect those factors — not simply the percentage printed on an ultrasound report.

Vascular Surgeon’s Take

When a patient comes in with a 70% or 80% narrowing and no symptoms, the conversation I want to have isn't simply, “When do we operate?”

It's, “What does your artery and your overall health look like beyond this number, and how much additional protection would a procedure realistically offer?”

In some patients, an intervention provides meaningful protection against future stroke.

In others, modern medical treatment may already provide such a low risk of stroke that the immediate risks of a procedure become harder to justify.

Neither situation can be decided by the percentage alone.

The goal isn't simply to open an artery because it looks severely narrowed.

The goal is to prevent a stroke with the safest and most effective treatment for your individual situation.

Related Reading

Carotid Stenosis: What It Actually Means for Your Stroke Risk — the companion patient guide explaining what a carotid finding means and how doctors assess stroke risk.

How Carotid Plaque Is Actually Evaluated and Treated — the full clinical deep dive, including the major trials, guidelines, and evidence behind carotid treatment decisions.