Arterial Thoracic Outlet Syndrome

Arterial thoracic outlet syndrome (aTOS) is a squeezed, or compressed, subclavian artery between your first rib and collarbone (clavicle). This space between your first rib and collarbone is the thoracic outlet.

Your subclavian arteries carry blood from your heart to each arm. When a nearby bone or muscle squeezes this artery, it limits how much blood it can send to your arm and hand. If you have any symptoms of aTOS, like pain, numbness or blue fingertips, it’s important to see a healthcare provider. They can run tests to diagnose or rule out this syndrome.

If you don’t get treatment (usually surgery), aTOS can cause serious health problems, like blood clots. These may break off and travel through your arm, getting in the way of proper blood flow.

Arterial TOS is the least common type of thoracic outlet syndrome. About 1 in 100 cases of thoracic outlet syndrome is the arterial type. It’s also the most dangerous kind.

Symptoms of arterial thoracic outlet syndrome

Arterial thoracic outlet syndrome symptoms affect your fingers, hand or entire arm. The most common sign is a dull ache or numbness in one arm. Symptoms are worse when you use your arm and are better when you rest. With aTOS, you may feel a lump in your neck that throbs with your heartbeat.

This syndrome can make it harder for your blood to reach your arm. As a result, your fingers, hand or arm may have:

• Coldness
• Numbness or tingling
• Pain
• Weakness
• Pale discoloration or blueness of the fingertips
• Slow-healing wounds

Arterial thoracic outlet syndrome causes

Many people with aTOS were born with an extra rib above their collarbone. This rib, called a cervical rib, sits above what’s usually your first rib.

The extra rib can compress your subclavian artery. Combined with repetitive injury, this weakens your artery. It can lead to a blood clot that blocks blood flow to your arm, hands, neck and head. Being born with an abnormal first rib or other differences in your anatomy can also cause compression.

Other causes of arterial thoracic outlet syndrome can include:

• Physical trauma, like an injury from a car accident
• Repetitive movements, like swinging a tennis racket, throwing a baseball or lifting boxes overhead

Risk factors

Usually, compression of your subclavian artery in your thoracic outlet happens because you were born with an extra rib (cervical rib) or a rib in the wrong place. The syndrome tends to happen between the ages of 20 and 30.

How to lower your risk

There’s no guaranteed way to prevent aTOS. But you can lower your risk by watching for symptoms and understanding your risk if you have an extra rib. It may also help to limit repetitive overhead movements.

Complications of this condition

Severe aTOS can make your arm hurt even if you’re resting and not using your arm. In extreme cases, a lack of oxygen from poor blood flow leads to a loss of the use of your fingers. A provider may need to remove your fingers and wrist if they have dead tissue (gangrene).

Without treatment, arterial thoracic outlet syndrome complications may include severe blood clots in your arteries. The clots can affect blood flow to your arm and hand.

In some people, compression makes the wall of their subclavian artery expand and weaken (aneurysm).

How doctors diagnose this condition

To make an arterial thoracic outlet syndrome diagnosis, your healthcare provider will look at your neck and shoulder area. They may ask you to perform certain movements or tests so they can check your range of motion.

Your provider will also take your blood pressure in both arms and ask you about your symptoms. If they suspect aTOS, you may have imaging tests to evaluate your thoracic outlet.

To view your arteries, blood flow and internal structures, you may have:

• Ultrasound
• Angiogram
• CT angiogram
• MRA
• X-ray

How is it treated?

Arterial thoracic outlet syndrome treatment almost always involves surgery.

Before the operation, your healthcare provider may give you blood-thinning medications, like warfarin or heparin, to break up blood clots. Other options include direct oral anticoagulants (Xarelto® or Eliquis®). Your provider may also remove clots by injecting medication or performing a procedure.

During arterial thoracic outlet syndrome surgery, your healthcare provider may:

• Remove part of your first rib and extra rib (if present) to relieve pressure
• Remove scalene muscles
• Replace a damaged artery with part of a healthy vein from another part of your body (vein graft)
• Replace a damaged artery with an artificial tube (prosthetic graft) to redirect blood flow

When should I see my healthcare provider?

You’ll likely have follow-up visits with your provider two to four weeks, three to six months and 12 months after surgery. Then, you may see them once a year after that, especially if you have a prosthetic graft. Follow-up visits may include ultrasounds to check blood flow in your subclavian artery.

Contact your provider if your symptoms come back or if you have bleeding or an infection after surgery.

Questions to ask your provider may include:

• What’s the most likely cause of aTOS symptoms?
• What tests do I need for diagnosis?
• What are the treatment options?
• What lifestyle changes can I make to improve symptoms?

What can I expect if I have this condition?

Without treatment, arterial thoracic outlet syndrome can cause severe complications. If you have signs or symptoms of this condition, it’s important to get treatment early. This increases your chances of a successful outcome.

Most people have excellent results, including improved symptoms, after treatment. You’ll likely need to take antiplatelet drugs after surgery. Your surgeon can tell you how long you’ll need to take them.

You can expect to play sports again about four to five months after surgery for arterial thoracic outlet syndrome.