Thoracic Outlet Syndrome

Thoracic Outlet Syndrome Definition

Thoracic Outlet Syndrome (TOS) refers to a rare condition, which is actually a group of disorders collectively termed together, characterized by tingling and numbness of the fingers, a weak grip and pain in the shoulder and neck.

Thoracic Outlet Syndrome ICD9 Code

The ICD9 Code for this condition is 353.0.

Thoracic Outlet Syndrome Incidence

There is no exact statistics regarding the incidence of this condition due to a difficulty in diagnosing TOS, variety of factors contributing to the disease as well as similarity of its symptoms with those of other disorders. As per medical reports, 3-80 out of per thousand in a population are affected by this disease on an annual basis. Some medical researchers, however, are of the opinion that Vascular TOS is rare enough to affect only one out of every million individuals.

Thoracic Outlet Syndrome Types

TOS encompasses three uncommon but interrelated syndromes. These are:

Neurogenic TOS

It occurs due to compression of the nerves located in the base of the neck.

Vascular TOS

It develops due to compression of the veins and the arteries under the arm or collarbone.

Nonspecific type TOS

It occurs due to nerve compression of less specific origin and accounts for most surgical cure for TOS in the United States. It is also referred to as Common TOS or Disputed Neurogenic TOS. The cause for the latter name is the fact that some doctors do not believe in its existence while others suspect it to be a common condition.

Thoracic Outlet Syndrome Symptoms

The typical signs and symptoms of this disorder include:

  • Weakness of the hand muscles
  • Tingling and pain in the shoulders and neck (which is worsened by carrying some heavy object)
  • Numbness, tingling and pain in the ring and pinky fingers as well as in the inner forearm
  • Symptoms of poor circulation in the forearm or hand (characterized by swollen arm, cold hands or bluish color)

Thoracic Outlet Syndrome Causes

Trauma (injury) is the common causative factor for this syndrome. The condition may arise from an irritating incomplete additional rib (known as cervical rib) above the normal first rib. It may also arise as a result of a direct injury to the neck. A rudimentary rib leads to a narrowing of the space below the clavicle (collar bone) and can compress the brachial plexus or lead to an intermittent compression of the subclavian vein corresponding with the movement of the arm.

However, some ribs are normally asymptomatic. Due to this reason, the symptoms of TOS are not automatically explained by the presence of a cervical rib.

The majority of cases of TOS arise in childhood. This indicates that the compression occurs over a period of time as the ligaments and muscles in the region go through changes with use or age. Many TOS sufferers are women in early or mid-adult stages of their life. In such women, the following problems may act as contributory factors:

  • Large breasts
  • Sagging of the shoulders
  • Poor muscle tone (Hypotonia)

TOS may also occur as a consequence of an injury occurring from an auto accident. 1% of the population, who are supposed to be born with anomalous and cervical first ribs, suffer from neck trauma due to repetitive stress or injury. They are supposed to be pre-disposed to Thoracic Outlet Syndrome.

Thoracic Outlet Syndrome Risk Factors

The varied factors that increase the risk of development of TOS include:

Being female

The disorder affects women three times more than men. However, TOS resulting from the compression of the subclavian vein is more common in males.

Being within 20-50 years

The symptoms of TOS generally manifest in sufferers between 20 and 50 years of age.

Lifting heavy objects

The condition mostly affects individuals in certain professions, such as carpentry, construction, repairing and other jobs that require lifting heavy objects all through the day.

Being an athlete

Athletes who suffer injuries to the shoulder or neck during contact sports like football or rugby may also develop this disease.

Thoracic Outlet Syndrome Diagnosis

Health care providers are likely to ask patients questions about their symptoms and their medical history. Sufferers may also be asked to lift some heavy object and doctors look for a possible paleness of hand. In some cases, the following tests may be recommended to confirm the presence of the disease:

  • MRI of the supraclavicular/brachial region and the cervical spine
  • X-ray
  • CT angiogram
  • Electromyography (EMG)
  • Vascular tests like brachial artery angiography
  • Venography or non-invasive vascular exams like Doppler ultrasonography
  • Nerve conduction velocity study

Medical tests may also be conducted to rule out the presence of other problems, such as a damaged nerve or carpal tunnel syndrome as a consequence of problems in the cervical spine or the spinal section in the neck.

Thoracic Outlet Syndrome Differential Diagnosis

The differential diagnosis of TOS involves isolating its symptoms from those of other disorders characterized by similar signs. These include:

  • Tendonitis
  • Epicondylitis
  • Fibromyalgia
  • Multiple sclerosis
  • Myofascial pain
  • Superior sulcus tumor of the lung
  • Acute coronary syndrome
  • Superficial Thrombophlebitis
  • Ulnar neuropathy
  • Rheumatoid arthritis
  • Rotator cuff injuries
  • Spinal cord injuries
  • Carpal tunnel syndrome
  • Cervical disc herniation
  • Repetitive motion syndrome
  • Aneurysm of the subclavian artery

Doctors and nurses must make sure that patients are not actually complaining about symptoms produced by any of the above disorders and are indeed suffering from TOS itself.

Thoracic Outlet Syndrome Treatment

The treatment for TOS can be of two types:

Conservative treatment

A conservative curative approach is effectual in the majority of cases, particularly in those individuals in whom the disorder is detected in the early stages. This type of treatment may involve:

Physical therapy

Patients are taught exercises to strengthen their shoulder muscles, improve their posture and also make their range of motion better. When performed over time, these workouts can ease the pressure on the nerves and the blood vessels in the thoracic duct.


Sufferers are taught various techniques, such as deep breathing, that can help them to relax, maintain a proper posture and prevent them from tensing their shoulders.


If patients complain of painful sensations, which are true in most cases of TOS, physicians may prescribe analgesics (pain-relieving drugs), anti-inflammatory drugs (like Ibuprofen or Aspirin) or muscle-relaxants to reduce inflammation and encourage relaxation of muscles.

Surgical treatment

If conservative methods of cure fail to improve the symptoms or if patients are complaining of signs of acute nerve damage (such as excruciating pain or worsening muscular fatigue), physicians may recommend surgical treatment. This type of treatment is also recommended to individuals diagnosed with true neurogenic TOS or other problems for which operative methods are the only treatment option. These operative procedures are carried out by specialists in vascular or thoracic surgery.

The most common operative approaches for the treatment of TOS include:

Transaxllary approach

In this process, an incision is made in the chest to access the first rib. A part of the first rib is then removed to provide relief from compression. This surgery is advantageous in the sense that surgeons can gain easy access to the first rib without disturbing the blood vessels or the nerves in any way. However, surgeons have a restricted access to the nerves and vessels in the region. The blood vessels and nerves hide from view the cervical ribs and the most fibrous bands that may be contributing to compression.

Anterior supraclavicular approach

This method helps in repairing the compressed blood vessels. An incision is made just under the neck to expose the brachial plexus area. Surgeons then look for signs of trauma or any fibrous bands that may contribute to the compression close to the first rib. They may also be able repair any blood vessels that have been compressed.

If the artery is narrowed, physicians may suggest other alternatives like Angioplasty.

Thoracic Outlet Syndrome Home Remedies and Management

Following diagnostic confirmation, doctors or physiotherapists instruct patients certain lifestyle modification measures and exercises that can be performed at home. These can support and strengthen the muscles around the thoracic outlet.

Some general measures to avoid undue stress on the muscles and shoulders around the thoracic outlet include:

  • Taking frequent breaks at work
  • Maintaining proper posture
  • Practicing relaxation techniques

Local application of hot or cold packs can also help reduce the symptoms of the disease. Correction of the muscular imbalance of the shoulder girdle or abnormal posture may help restore functioning in sufferers. The problems are best addressed by a particular strengthening and stretching program of the shoulder and neck girdle.

Thoracic Outlet Syndrome Prognosis

The symptoms may be eased in certain patients by conducting surgeries to break up tight fibrous bands and removing the extra rib. In more than half of all sufferers, surgery can be successful. A few patients complain about recurrence of symptoms even after surgery.

Patients may be asked to change or avoid activities such as bearing weights directly over the shoulder or lifting heavy objects. They can gain improvement in their condition by working with hands and arms above shoulder level. Ergonomically correct computer stations, workstations and chairs can help reduce repetitive work activities as well as awkward postures that may have acted as contributory factors for the occurrence of the early-stage symptoms.

Thoracic Outlet Syndrome Complications

The complications may arise due to any of the surgical methods conducted for the treatment of TOS. The nature of complications depends on the type of operation and the use of anesthesia.

The risks associated to surgical cure may include:

  • Lung collapse
  • Infection
  • Hemorrhage
  • Leaks from the lymphatic system
  • Damage to the blood vessels or nerves, resulting in weakness of muscles

All operative approaches for the treatment of TOS pose an acute risk of trauma to the brachial plexus. In rare cases, long-term pressure on the brachial plexus nerves can result in atrophy of the muscles innervated by it.

Thoracic Outlet Syndrome Prevention

If left untreated for years, TOS can cause permanent neurological damage. Due to this reason, it is important to deal with the symptoms on an early basis or prevent the development of the condition altogether. Those susceptible to TOS due to involvement in risk-prone professions or athletic activities should avoid lifting heavy objects or performing repetitive movements.

If you, or anyone, in your family is constantly experiencing the symptoms of Thoracic Outlet Syndrome, it is important to see a doctor for early diagnosis and treatment and ensuring a faster recovery.


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