Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) describes a group of disorders due to compression of the nerves (brachial plexus) or blood vessels (subclavian vein/artery) as they pass through the thoracic outlet. TOS often afflicts otherwise healthy, young active individuals and symptoms are specific to nerve compression (neurogenic or NTOS), arterial compression (ATOS) or venous compression (VTOS).

Neurogenic TOS (NTOS)

This is the most common form of TOS and is due to compression of the brachial plexus between the first rib, clavicle and scalene muscles. NTOS can result from a combination of a congenitally narrow thoracic outlet with trauma (e.g., falls, motor vehicle accidents, occult first rib fractures) or repetitive trauma from work-related activity (for example, typing or administrative work or manual labor) or recreational activities (baseball, football, swimming, volleyball). Some patients are born with an extra cervical rib or bands of muscle which can further narrow the thoracic outlet and result in significant symptoms due to nerve compression.

Signs and Symptoms of NTOS

  • Pain, numbness and tingling, weakness, discoloration, temperature changes in the arm, hand and fingers, and the forearm
  • Pain and tingling in the surrounding areas such as the base of the neck, chest wall, axilla, breast, upper back and head
  • Worsening of the above symptoms with the arm over head (for example, brushing your hair) or with the arm dangling (for example, carrying heavy objects)

Treatment Options

There is no definitive test to diagnosis NTOS. However there are tests that are useful to rule out other conditions that may cause similar symptoms such as:

  • Electromyography (EMG) to evaluate for peripheral nerve entrapment (ulnar nerve entrapment, carpal tunnel syndrome)
  • MRI to Evaluate for Cervical Spine Disease (e.g., cervical radiculopathy) or Instrinsic Shoulder Disease (e.g., torn rotator cuff)
  • X-ray of the Cervical Spine to evaluate for a Cervical Rib

The initial treatment will include a course of physical and occupational therapy focused on improving flexibility and to relieve tension and discomfort related to compensatory postural changes. If patients do not improve with therapy, surgical decompression with removal of the first rib, the anterior scalene muscle, the middle scalene muscle and resection of scar tissue around the brachial plexus (neurolysis) is recommended.

Recovery

Following surgery, patients have a short inpatient hospital stay and then are discharged home active and able to perform daily activities. During the next few months we have a comprehensive physical and occupational therapy program to allow patients to resume unrestricted activity with resolution of their pre-operative symptoms. During this time we also follow a pre-set medication taper regimen sothat patients are off all post-operative medications by six months.

Venous TOS (VTOS)

This is the second common form of TOS and is due to compression of the subclavian vein between the clavicle, first rib, subclavius muscle and the costoclavicular ligament. VTOS can result from a combination of a congenitally costoclavicular space with frequent, repetitive overhead activity that results in repetitive compression of the subclavian vein with progressive injury and thrombosis.

Signs and Symptoms of VTOS

  • Patients may have the some symptoms that are similar to NTOS
  • If the vein clots off (thromboses) patients will have a blue, swollen arm with significant discomfort
  • Patients with VTOS with a vein that has not thrombosed typically have arm swelling, fullness, heaviness, aching and a change in color with overhead activity

Treatment Options

The diagnosis of VTOS is supported by the following studies:

  • Dynamic CT Venogram/MR Venogram: These are non-invasive studies, with the patient's arm in a neutral position and elevated, that look at compression and patency of the subclavian vein. If the vein is thrombosed or becomes occluded with overhead activity this supports the diagnosis.
  • Venogram with Possible Lysis: In patients with a thrombosed subclavian vein this study allows for the removal of a clot and confirmation of the diagnosis.

If the vein is thrombsed, patients will undergo lysis to restore patency of the vein and a workup to confirm the diagnosis. Occasionally blood tests are required to rule out other causes of thrombosis. Following restoration of blood flow, surgery is performed in 2-6 weeks depending on the venogram. Surgery includes a complete anterior and middle scalenectomy, resection of the entire first rib, removal of the subclavius muscle, intraoperative venography with reconstruction of the subclavian vein as needed.

Recovery

Following surgery, patients have an inpatient hospital stay and then are discharged home active and able to perform daily activities on systemic anticoagulation. During the next few months we have a comprehensive physical and occupational therapy program to allow patients to resume unrestricted activity with resolution of their pre-operative symptoms. Also during this time we follow a pre-set medication taper regimen so that patients are off all post-operative medications by six months. Systemic anticoagulation is usually stopped at 3 months post-surgery.

Arterial TOS (ATOS)

This is the least common form of TOS and is due to compression of the subclavian artery between the first rib, clavicle and scalene muscles. Patients with ATOS can have aberrant bands of muscle or a cervical rib that cause significant compression and injury to the subclavian artery. ATOS results from repetitive injury to the subclavian artery from anatomic compression that can result in narrowing (stenosis) of the artery, enlargement (aneurysm), or formation of clot that can embolize distally to the arm, forearm, hand or brain.

Signs and Symptoms of ATOS

  • Patients may have the some symptoms that are similar to NTOS
  • Pulsating mass: You may notice a pulsating mass above the clavicle
  • Upper Extremity Claudication: Exercise-induced arm discomfort resulting from insufficient blood flow to the arm
  • Upper Extremity Acute/Subacute Ischemia: Pain, numbness, tingling, cold sensation, pale/mottled hand or fingers with black spots, fingertip ulceration or gangrene

Treatment Options

The diagnosis of ATOS is supported by:

  • Dynamic CT/MR Ateriogram: These are non-invasive studies, with the arm in aneutral position and elevated, that look at compression and patency of the subclavian artery.
  • Arteriogram with Possible Lysis: In patients with a thrombosed subclavian artery this study allows for removal of clot and confirmation of the diagnosis.

Patients who present with acute/subacute upper extremity ischemia will need restoration of blood flow through lysis or through open surgery followed by a thoracic outlet decompression with a complete anterior and middle scalenectomy, resection of the entire first rib and possible arterial reconstruction. Patients with an incidentally found pulsating mass, a subclavian aneurysm or arm claudication will need a thoracic outlet decompression and possible arterial reconstruction.

Recovery

Following surgery patients have an inpatient hospital stay and then are discharged home active and able to perform daily activities. During the next few months we have a comprehensive physical and occupational therapy program to allow patients to resume unrestricted activity with resolution of their pre-operative symptoms. Also during this time we follow a pre-set medication taper regimen such that patients are off all post-operative medications by six months. Patients may need to be on aspirin and/or oral anticoagulation for a period of time.

Patient Resources

Thoracic Outlet Syndrome Patient Information Guide PDF

Make an Appointment

To make an appointment to discuss your need for treatment for thoracic outlet syndrome, contact us toll-free at 888-287-1082 or email us at CVCCallCtr@med.umich.edu. To find out more about what to expect when you call us, visit our Make an Appointment page.