				Using the search form

If you prefer to view this article in PDF form, click here.

Thoracic outlet syndrome

Thoracic outlet syndrome (TOS) is a condition that can cause pain and discomfort in your shoulder, arm, and hand.

What is the thoracic outlet? It is a space in your upper body between your neck and armpit. Think of the outlet as a box. Two sides of the box are formed by muscles in the side of your neck. These are muscles that help you move your head.

The bottom of the box, in most people, is formed by the top rib. But some people have an extra bone above the top rib, which is known as a cervical rib. This makes the space in the “box” smaller.

Some patients have an extra band of tissue that connects the top rib to the spine. This also makes the box smaller.

Some of the nerves that pass through the outlet provide muscle control and sensation to your arm. They also affect the blood supply to your shoulder and arm.

If these nerves are squeezed when they pass through the outlet, you will feel pain and discomfort. That’s TOS.

What are the symptoms of TOS? You may feel weakness in your hand or numbness in your ring and pinkie fingers. Or you may feel that one arm is more sensitive to cold temperatures than the other is. The blood pressure in the more sensitive arm may be lower than in your other arm. You could have a combination of these symptoms.

In most cases, TOS affects only one arm. Women are more likely than men to have TOS.

What causes TOS? Anything that restricts the space in the thoracic outlet box can cause TOS. It could be

•   An extra rib
•   Extra tissue between the top rib and spine
•   Swelling after an injury
•   A tumor or tumors in the upper lung
•   Changes in bone structure after a broken collarbone, or
•   Poor posture, especially in patients with large amounts of breast tissue.

How will you know what’s causing my symptoms? We will perform a careful physical examination to find out what’s causing your pain.

We may order a chest x-ray to see if an extra rib is present, or to find out if a tumor is causing your symptoms. We may order a nerve conduction study to find out where the pain in your arm is coming from.

Depending on what these tests show, we may need to get an MRI or CT scan, an ultrasound exam, or a more invasive procedure called an arteriogram.

Will TOS get better on its own? It may. But there’s a risk that the damage to your nerves and blood vessels will get worse. This could lead to permanent loss of feeling throughout your arm or to paralysis. It could also lead to blood clots that can cause serious damage to other vital organs.

What can be done to treat TOS? Our goal is to keep your symptoms under control and prevent further damage to the tissue. Treatment may include physical therapy, surgery, or a combination of the two.

We usually start by sending our patients to physical therapy and prescribing anti-inflammatory medication.

What does physical therapy involve? Physical therapy teaches you to avoid the positions that cause pain and discomfort. You’ll probably be given some combination of stretching and strengthening exercises, massage, ultrasound, electrical stimulation, or changes in posture.

The therapist will design a program just for you. In many cases, though, physical therapy and medication will not solve the problem.

You may need surgery. If that possibility arises, we will discuss it with you in detail.

Can surgery fix TOS? Studies show that surgery successfully relieves the symptoms of TOS in 45% to 80% of cases. However, some patients who get relief from their pain after surgery may or may not regain full strength of the affected muscles.

The most common surgery for TOS is known as transaxillary. The surgeon makes a small incision under your arm. If you have an extra rib, the surgeon will remove it. If you have an extra band of thick tissue between your top rib and spine, the surgeon will divide it to reduce the irritation it causes.

It’s important to remember that no surgery is without risk. This surgery will require general anesthesia. The anesthesiologist will discuss this with you ahead of time.

Other risks of surgery include possible nerve damage to the shoulder, bleeding with the possible need for transfusion, and poor relief or worsening of symptoms. These complications are not very common.

We still can’t predict for certain which patients will benefit the most from surgery for TOS. We hope to find a better way to identify the people who have the best chance of getting relief from their symptoms.

Until then, the best thing to do is develop a good, open relationship with your health providers so they can help you make the best decisions about your care.