Thoracic outlet syndrome




Introduction

Thoracic outlet syndrome is a group of disorders that occur when the blood vessels or nerves in the thoracic outlet — the space between your collarbone (clavicle) and your first rib — become compressed. This can cause pain in your shoulders and neck and numbness in your fingers.

There are several subdivisions of thoracic outlet syndrome, depending on the cause. Sometimes, doctors can't determine the cause of thoracic outlet syndrome.

Treatment for thoracic outlet syndrome may involve physical therapy, medications, surgery and other approaches.

Signs and Symptoms

Generally, there are three subdivisions of thoracic outlet syndrome.
  • Neurogenic (neurological) thoracic outlet syndrome. This form of thoracic outlet syndrome is characterized by compression of the brachial plexus. The brachial plexus is a network of nerves that come from the spinal cord and control muscle movements and sensation in the shoulder, arm and hand. In the majority of thoracic outlet syndrome cases, the symptoms are neurogenic.
  • Vascular thoracic outlet syndrome. This type of thoracic outlet syndrome occurs when one or more of your subclavian vessels (the arteries and veins under the clavicle) are compressed.
  • Nonspecific-type thoracic outlet syndrome. Also called disputed thoracic outlet syndrome or common thoracic outlet syndrome, some doctors don't believe it exists, while others say it's a common disorder. People with nonspecific-type thoracic outlet syndrome have chronic pain in the area of the thoracic outlet, but the specific cause of the pain can't be determined.
Thoracic outlet syndrome symptoms can vary, depending on which structures are compressed. When nerves are compressed, signs and symptoms of neurologic thoracic outlet syndrome often include:
  • Numbness, tingling or both in your fingers
  • Pain in your shoulder and neck
  • Ache in your arm or hand
  • Weakening grip
Signs and symptoms of vascular thoracic outlet syndrome — compression of your veins, arteries or both — can include:
  • Discoloration of your hand (bluish color)
  • Subclavian vein thrombosis
  • Arm pain and swelling, possibly due to blood clots
  • Throbbing lump near your collar bone
  • Lack of color (pallor) in one or more of your fingers or your entire hand
  • Tiny black spots (infarcts) on your fingers


Causes

In general, the cause of thoracic outlet syndrome is compression of the nerves and blood vessels in the thoracic outlet, just under your collarbone. The cause of the compression itself, however, can vary and can include:
  • Anatomical defects. Inherited defects that are present at birth (congenital) may include a cervical rib — an extra rib located above the first rib — or an abnormally tight fibrous band connecting your spine to your rib.
  • Poor posture. Drooping your shoulders or holding your head in a forward position can cause compression in the thoracic outlet area.
  • Trauma. A traumatic event, such as a car accident, can cause internal changes that then compress the nerves in the thoracic outlet. The onset of symptoms related to a traumatic accident is often delayed.
  • Repetitive activity. Doing the same thing over and over can, over time, wear on your body's tissue. You may notice symptoms of thoracic outlet syndrome if your job requires you to repeat a movement continuously, such as typing on a computer for extended periods, working on an assembly line, or stocking shelves and repeatedly lifting things above your head. Athletes such as baseball pitchers and swimmers also can develop thoracic outlet syndrome from years of repetitive movements. If you repeatedly carry heavy loads low on your body (rather than against your chest), you may also notice signs and symptoms of thoracic outlet syndrome.
  • Pressure on your joints. Obesity can put an undue amount of stress on your joints, as can carrying around an oversized bag or backpack.
  • Pregnancy. Because joints loosen during pregnancy, signs of thoracic outlet syndrome may first appear while you are pregnant.


Treatment

In most cases, a conservative approach to treatment is effective, especially when the condition is diagnosed early. Conservative thoracic outlet syndrome treatments may include:
  • Physical therapy. You'll learn how to do exercises that strengthen your shoulder muscles to open the thoracic outlet, improve your range of motion and improve your posture. These exercises, done over time, will take the pressure off your blood vessels and nerves in the thoracic outlet.
  • Relaxation. Techniques that help you relax, such as deep breathing, can keep you from tensing your shoulders and remind you to maintain good posture.
  • Medications. Your doctor may prescribe pain medications, muscle relaxants and anti-inflammatory drugs — aspirin or ibuprofen (Advil, Motrin IB, others) — to decrease inflammation and encourage muscle relaxation.
If conservative treatments don't improve your symptoms or if you're experiencing signs of significant nerve damage, worsening muscle weakness or incapacitating pain, your doctor may recommend surgery. Your doctor may also recommend surgery if you've been diagnosed with true neurogenic thoracic outlet syndrome, in which case surgery is often the only treatment option.

Surgical options
Surgical treatment is usually effective in relieving the pain associated with thoracic outlet syndrome, but is often not as successful in treating muscle weakness, especially if the condition has gone untreated for an extended period of time.

A specialist in thoracic surgery or vascular surgery will perform the procedure. All surgical options to treat thoracic outlet syndrome pose a significant risk of injury to the brachial plexus. The most common surgical approaches for thoracic outlet syndrome treatment are:
  • Anterior supraclavicular approach. This approach repairs compressed blood vessels. Your surgeon makes an incision just under your neck to expose your brachial plexus region. He or she then is able to look for signs of trauma or may discover fibrous bands contributing to compression near your first (uppermost) rib and can repair any compressed blood vessels.
  • Transaxillary approach. In this surgery, your surgeon makes an incision in your chest to access the first rib, then removes a portion of the first rib to relieve compression. The advantage of this type of surgery is that it gives the surgeon easy access to the first rib without disturbing the nerves or blood vessels. But it also means the surgeon has limited access to the area's nerves and vessels, and most fibrous bands and cervical ribs that may be contributing to compression are hidden behind these nerves and blood vessels.


Prevention

Thoracic outlet syndrome that goes untreated for years can cause permanent neurological damage, so it's important to deal with the symptoms early or, more important, to prevent the disorder altogether. If you're susceptible to thoracic outlet syndrome, avoid repetitive movements and lifting heavy objects. If you're overweight, you can prevent or relieve symptoms associated with thoracic outlet syndrome by losing weight.

Even if you don't have symptoms of thoracic outlet syndrome, avoid carrying heavy bags over your shoulder, because this can increase pressure on the thoracic outlet. Stretch daily, and perform exercises that keep your shoulder muscles strong.

Informations obtained from National Institute of Health.
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