Thoracic Outlet Syndrome (TOS)

What Is Thoracic Outlet Syndrome?

The thoracic outlet is an area in the upper chest, between the ribcage and clavicle (collarbone). In this area, a group of blood vessels and nerves called the brachial plexus sends messages between your brain and your hand and arm.

Thoracic outlet syndrome (TOS) describes several uncommon conditions that compress the brachial plexus. There are three types of thoracic outlet syndrome:

• Arterial TOS: People with arterial TOS have an extra rib above the highest rib, closest to the neck. This extra rib compresses the subclavian artery, the blood vessel that carries blood behind the collarbone to your arm and hand. It can cause pain and numbness in the hand due to blood clots. Some people form a dangerous aneurysm, a balloon-like bulge in the artery.
• Neurogenic TOS:The most common type of TOS, neurogenic refers to nerves. Tears in the scalene muscles on the sides of the neck cause muscle spasms that can irritate the nerves in the brachial plexus.
• Venous TOS: This type of TOS affects the subclavian vein, which runs between the collarbone and first rib. Athletes who frequently lift or throw a ball overhead can develop injuries in the vein. Clots and blockages can result.

What Causes Thoracic Outlet Syndrome?

Most often, thoracic outlet syndrome develops from a combination of the way your body is built and frequent motions of the area. The thoracic outlet is a narrow space, where compression can easily occur. Sometimes, the space is too narrow for nerves and blood vessels to travel smoothly through this space between the upper ribs and collarbone.

Other causes of pressure that leads to thoracic outlet syndrome may include having:

• An extra rib above the first rib
• A change in the first rib
• An unusually tight band of fibrous muscle connecting your ribs and spine
• Past injuries to the brachial plexus
• Shoulder overuse, especially in overhead activities like lifting or throwing
• Long necks and sloped shoulders, which can put extra pressure on the area

Thoracic Outlet Syndrome Symptoms

Thoracic outlet syndrome usually affects young, active people. Neurogenic TOS more often affects women, while arterial TOS and venous TOS affect people of all genders.

Symptoms of thoracic outlet syndrome include:

• Cold feeling or other signs of poor circulation in the forearm or hand
• Neck and shoulder pain or tingling
• Sores on the fingers that don’t heal well
• Swelling in the affected arm
• Tingling or numbness in the fingers (especially the pinky and ring fingers) or inner forearm
• Weak grip in the hand muscles

Diagnosing Thoracic Outlet Syndrome

Diagnosing thoracic outlet syndrome requires specialized skill. Penn Medicine vascular surgeons have special interest in thoracic outlet syndrome and have successfully diagnosed and treated many patients with all forms of TOS.

We begin thoracic outlet syndrome tests by performing a physical exam and thoroughly discussing your symptoms, lifestyle and activities. We will ask about your family history and how long you have experienced the condition.

You may also have imaging tests to study the relationship between your blood vessels, ribs, nerves and muscles in the area of the brachial plexus. These tests help your doctor rule out other causes of your symptoms and determine the type of thoracic outlet syndrome. Your testing in our vascular testing and diagnosis labs may include:

• CT scan: A series of X-rays shows details of bones and tissue in cross-section.
• MRI scan: Powerful magnets produce images of your bones, nerves and blood vessels without radiation.
• Catheter-based arteriography or venogram: Working from inside blood vessels, this test shows detailed images of blood vessels through X-rays and contrast dye.
• Stress maneuver testing: Your health care provider places your head or arm in specific positions to see how results change during other testing.
• Electromyography (EMG) and nerve conduction velocity study: Your provider attaches electrodes to your arm or hand and stimulates the nerves with mild electric shocks to test your nerve response and speed.

Thoracic Outlet Syndrome Treatment at Penn Medicine

Thoracic outlet syndrome treatment involves a careful assessment of the cause of your symptoms and the best treatment for you. Penn’s Vascular Surgery and Endovascular Therapy Program provides comprehensive care for thoracic outlet syndrome.

Depending on the type of TOS, treatment may involve a combination of physical therapy, medication and thoracic outlet decompression surgery. You may also have nerve block injections to relieve pain and discomfort while undergoing therapy or awaiting surgery.

Thoracic Outlet Decompression Surgery

For all types of thoracic outlet syndrome, Penn surgeons frequently perform thoracic outlet decompression. In this procedure, surgeons remove parts of the scalene muscles and carefully clear scar tissue away from nerves. Your surgeon may also need to modify tendons or remove an extra rib, if you have one.

After surgery, you begin working with a physical therapist right away to regain your range of motion. You will continue physical therapy when you leave the hospital.

Surgery for Arterial Thoracic Outlet Syndrome

Before thoracic outlet decompression surgery, surgery for arterial TOS often involves removing a clot blocking blood flow to your hand and arm. Our team first performs any procedures necessary to remove the clot. In a separate surgery, surgeons remove the extra rib and repair the subclavian artery, if there is an aneurysm.

Procedures and Surgery for Venous Thoracic Outlet Syndrome

Many people with venous thoracic outlet syndrome seek care because a clot in the vein needs urgent treatment. Your care may begin with thrombolysis to remove the clot.

In addition to thoracic decompression surgery, your surgical team may recommend one or more procedures to reconstruct the vein, including:

• Angioplasty and stenting: Using a catheter (a fine tube) inside the vein to place a stent (metal mesh tube) that holds the vein open and may emit medicine to prevent clots
• Patch angioplasty: Placing a patch made of synthetic (human-made) material or tissue over thinned or weakened areas of the vein to strengthen it
• Venous bypass: Redirecting blood flow by attaching a synthetic tube or part of another blood vessel above and below the damaged part of a vein

Schedule Your Appointment

Call 800-789-7366 or request a callback.

Penn Programs & Services for Thoracic Outlet Syndrome