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Thoracic Outlet Syndrome (TOS)

Thoracic outlet syndrome (TOS) is a disorder that may compress the blood vessels or nerves in the upper chest region. This area — called the thoracic outlet — is behind and below the collarbone opposite the first rib.

At the UPMC Heart and Vascular Institute, we take a team approach to quickly and correctly diagnose your TOS. Then we'll create a treatment plan that's right for you.

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What Is Thoracic Outlet Syndrome (TOS)?

Thoracic outlet syndrome (TOS) is a group of disorders that puts pressure on the arteries, veins, or nerves in the upper chest.

TOS may cause symptoms in the:

  • Upper back.
  • Neck.
  • Arm.
  • Hand.

Types of thoracic outlet syndrome

There are three types of TOS. Symptoms help doctors determine the type of TOS you have.

Arterial thoracic outlet syndrome (ATOS)

In ATOS, an artery in the thoracic outlet compresses, narrows, or dilates.

An extra rib at the top of the rib cage or an abnormal first rib may cause this type of TOS.

Complications of ATOS can include:

Venous thoracic outlet syndrome (VTOS)

In VTOS, a vein in the thoracic outlet becomes compressed and damaged. The most common cause is repetitive, strenuous shoulder and arm use.

Complications of VTOS can include:

Neurogenic thoracic outlet syndrome (NTOS)

In NTOS, the brachial plexus — the bundle of nerves in the thoracic outlet — compresses, often from:

  • A prior injury.
  • Trauma.
  • Repetitive forces from exertional movements.

NTOS complications can include:

  • Neck, arm, shoulder, or back pain that disrupts sleep, work, and daily activities.
  • Neck, arm, or shoulder weakness.
  • Nerve damage.

Thoracic outlet syndrome causes

Compressed blood vessels or nerves in the tight corridor of the thoracic outlet get irritated and can cause TOS.

Causes of compression may be:

  • Bony and soft tissue abnormalities, such as an extra rib or an old collarbone injury.
  • Tumors or enlarged lymph nodes in the upper chest or armpit.
  • Playing sports that involve repetitive arm or shoulder movement, such as golf, baseball, swimming, volleyball, tennis, etc.
  • Repetition injuries from carrying heavy shoulder loads.
  • Injury to the neck or back, such as whiplash.
  • Poor posture.
  • Heavy weightlifting.

Complications of thoracic outlet syndrome

TOS can occur on either side of the body but most often affects your dominant hand's side because of constant use.

Complications vary depending on the type of TOS you have.

A blood clot may break apart, and smaller pieces — called emboli — can move down the arm.

A blood clot can block blood flow to the hand, causing:

  • Pain.
  • Coolness.
  • Numbness.
  • Discoloration.

It's vital to restore blood flow to the hand quickly.

Thoracic outlet syndrome risks

TOS happens to people of all ages and genders, but it is more common in young women.

Factors that can increase your risk of TOS include:

  • Stress from repetitive tasks.
  • Playing a sport with repetitive arm motion — like baseball, volleyball, swimming, or tennis.
  • Having poor thoracic posture.
  • Prior cervical spine or neck trauma.

Our TOS experts

Thoracic Outlet Syndrome (TOS) Symptoms and Diagnosis

TOS most often causes symptoms in the upper body, such as the:

  • Arm.
  • Hand.
  • Back.
  • Neck.

Symptoms vary based on the type of TOS.

Arterial TOS (ATOS) symptoms

Symptoms of ATOS include:

  • Pain, coldness, and paleness or change of color in the hand.
  • Cramping when using the arm.

Venous TOS (VTOS) symptoms

Symptoms of VTOS include:

  • Swelling and dark color in the arm.
  • Arm pain.
  • Heaviness or fullness.
  • Dilated chest wall veins.

Neurogenic TOS (NTOS) symptoms

Symptoms of NTOS include:

  • Pain, numbness, tingling, or weakness in the arm and hand.
  • Pain that starts in the shoulder and moves down the arm into the fingertips.
  • A tired feeling in the arm.
  • Neck pain.
  • Headaches at the back of the head.

When to see a doctor about TOS symptoms

Make an appointment with your doctor if you have any signs or symptoms of TOS, and they don't go away.

Thoracic outlet syndrome diagnosis

To confirm a diagnosis of TOS, your team at the UPMC Heart and Vascular Institute will start by:

  • Asking about your TOS symptoms.
  • Reviewing your medical history.
  • Performing a thorough exam.
  • Asking you to perform exertional movements that may reproduce the symptoms.

They also may order heart imaging and other tests, including:

  • X-rays of your neck and chest.
  • Ultrasound to create pictures of the blood flow through your blood vessels.
  • Nerve conduction velocity test to measure how fast an electrical impulse moves through a nerve.
  • CT scan to create detailed 3D images.
  • MRI to produce clear images of the blood vessels.
  • Arteriography or venography to view your arteries or veins.

Our TOS experts

Thoracic Outlet Syndrome (TOS) Treatment

Vascular surgeons at the UPMC Heart and Vascular Institute offer a range of treatments for arterial, venous, and neurogenic TOS.

Based on the type of TOS you have, we'll provide a course of treatment that meets your needs.

Arterial thoracic outlet syndrome (ATOS) treatment

Surgery for ATOS

Your surgeon may operate to:

  • Repair your artery if needed.
  • Expand the thoracic outlet.
  • Remove the first rib or extra rib above it, if present.

Venous thoracic outlet syndrome (VTOS) treatment

Minimally invasive catheter-based treatments

  • Thrombolysis — a catheter sends clot-busting drugs directly into the vein to break up a blood clot.
  • Venoplasty — doctors thread a balloon-tipped catheter into the vein and expand the balloon to open up the vein.

Medicine to treat VTOS

  • Blood thinners help prevent new clots from forming.

Surgery for VTOS

Your vascular surgeon may operate to:

  • Remove the blood clot.
  • Repair or replace the damaged vein.
  • Remove the abnormal rib.
  • Expand the thoracic outlet.

Neurogenic thoracic outlet syndrome (NTOS) treatment

Physical therapy to treat NTOS

  • Stretching the affected area can help improve your range of motion and strength.
  • Improves body posture and conditioning.
  • Helps you avoid motions that cause symptoms.
  • Can assess your work site and suggest changes.

Medicine to treat NTOS

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin or ibuprofen.
  • Pain relievers.

Surgery for NTOS

Doctors may suggest surgery for those who fail to respond to physical therapy or medicine.

Your surgeon may:

  • Expand the thoracic outlet.
  • Remove the first rib.
  • Clean the scar tissue around the nerves.

Our TOS experts

Learn More at UPMC Health Beat

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