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Thoracic Outlet Syndrome (TOS)

The thoracic outlet is a small area between your collarbone, first rib and vertebra. Thoracic outlet syndrome (TOS) is a group of conditions characterized by compression of the nerves, arteries or veins in this space. Thoracic outlet syndrome can cause neck and shoulder pain, numbness and tingling of the fingers and a weak grip. If left untreated, TOS can lead to increased pain and decreased function. Certain forms of the disease can cause serious blood clots.

Thoracic outlet syndrome can be difficult to diagnose as its symptoms can mimic other disorders. Expert vascular specialists in the Division of Vascular and Endovascular Surgery at the Brigham and Women’s Hospital (BWH) Heart & Vascular Center provide specialized diagnostic services to identify TOS as well as proven medical and surgical techniques to relieve symptoms.

Thoracic Outlet Syndrome Topics

Types of Thoracic Outlet Syndrome (TOS)

There are three types of thoracic outlet syndrome (TOS):

  • Nerve-related (neurogenic) involves compression of one or more brachial plexus nerves from the neck to the hands
  • Artery-related (arterial) involves compression of the subclavian artery as it exits the chest and travels to the arm
  • Vein-related (venous) involves occlusion of the subclavian vein as it enters the chest cavity from the shoulder
Causes of Thoracic Outlet Syndrome (TOS)
  • Anatomical defects such as an extra rib
  • Injury to the back or neck
  • Obesity
  • Poor posture
  • Pregnancy
  • Repetitive injuries from lifting heavy loads
  • Sports that require repetitive arm motion or heavy lifting
  • Tumors that press on nerves
Symptoms of Thoracic Outlet Syndrome (TOS)

Symptoms of TOS vary depending upon whether the compression is nerve, artery or vein-related.

Nerve-related thoracic outlet syndrome

  • Gilliatt-Sumner hand (severe wasting in the fleshy base of the thumb)
  • Numbness or tingling in your arm or fingers
  • Pain in your neck, shoulders, or hands
  • Weak grip

Vein or artery-related thoracic outlet syndrome

  • Bluish color to your hand
  • Swelling and pain in your arm
  • Blood clots in veins or arteries in the upper body
  • Lack of color in one or more fingers, or in hand
  • Weak or no pulse in affected arm
  • Cold fingers, hands or arms
  • Fatigue in arm after activity
  • Numbness or tingling in fingers
  • Weakness of arm or neck
  • Throbbing lump near your collarbone
  • Padgett-Schroeder Syndrome – effort thrombosis of axillary vein
Diagnosis of Thoracic Outlet Syndrome (TOS)

Your vascular surgeon will often work in conjunction with a neurologist to evaluate your symptoms. A physical examination will be conducted to determine outward signs of TOS such as discoloration or swelling. Diagnostic tests may include:

  • Arteriography and venography, tests which can see if a vein or artery is compressed or has a clot
  • Electromyography (EMG) measures electrical activity in muscles
  • Elevated arm stress test
  • Imaging tests, including X-ray, CT-scan, ultrasound
  • Nerve conduction study (NCS) can determine nerve damage and destruction
  • Thoracic outlet specific MRI of the chest
Treatment for Thoracic Outlet Syndrome (TOS)

Specialists from the BWH Heart and Vascular Center develop individualized treatment plans for patients based on:

  • Age
  • Overall health
  • Medical history
  • Severity and form of the disease
  • Tolerance for specific medications or procedures
  • Expectations for course of the disease
  • Presence of other conditions

Specific treatment varies depending on the type of TOS and may include:

  • Physical therapy
  • Pain medications, such as ibuprofen, stronger pain medications or muscle relaxants
  • Lifestyle changes
    • Maintain good posture
    • Avoid strenuous activities
    • Avoid repetitious activities, such as sitting at a computer for too long
    • Weight loss, if you are overweight
  • Thrombolytic therapy to dissolve clots if you have vascular thoracic outlet syndrome
  • Surgery
    • An extra rib may be removed and certain muscles are cut
    • A section of the first rib is removed to release pressure in the area
    • Vascular TOS may require repair of veins and arteries
    • Bypass surgery to reroute blood around the compression or remove the area that is causing the symptoms
    • Angioplasty, if the artery is narrowed.
What You Should Expect

The Heart & Vascular Center is located in the Shapiro Cardiovascular Center, across the street from BWH’s main 75 Francis Street entrance. The Heart & Vascular Center brings together the full range of services in one location, fostering seamless and coordinated care for all cardiovascular patients.

If you are having surgery or a procedure, you will likely be scheduled for a visit to the Watkins Clinic for pre-operative information and tests.

The day of surgery, you care will be provided by surgeons, anesthesiologists and nurses who specialize in surgery for patients with thoracic outlet syndrome. After surgery, you will go to the post-surgical care unit where you will receive comprehensive care by an experienced surgical and nursing staff.

During your surgery, family and friends can wait in the Shapiro Family Center. Staff members will provide surgery updates and caregivers who leave the hospital will be contacted by cell phone.

Multidisciplinary Care

Patients benefit from the teamwork of vascular and endovascular surgeons who collaborate with colleagues in other medical specialties. They work alongside nurses, physician assistants, physical therapists, dietitians and social workers to achieve outstanding outcomes for our patients.


Learn more about vascular conditions in our health library.

Visit the Kessler Health Education Library in the Bretholtz Center where patients and families can access computers and knowledgeable staff.

Access a complete directory of patient and family services.


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