Thoracic Outlet Syndrome

Thoracic Outlet Syndrome is a broad term for a collection of symptoms caused by compressed blood vessels or nerves between the lower neck and upper chest, an area known as the thoracic outlet.

When identified early, before progressive nerve damage, Thoracic Outlet Syndrome symptoms are treated with physical therapy and anti-inflammatory medications or muscle relaxants. The rare cases affecting blood vessels (arteries or veins), however, usually require surgery.


Your pain and discomfort will depend on which blood vessels or nerves are compressed.

Here are three types of Thoracic Outlet Syndrome, with associated symptoms:

Venous TOS: When at least one vein under the collarbone is compressed. (Five percent of cases.) A compressed vein can cause blood clots, or Paget-Schroetter syndrome (also known as effort thrombosis).

  • Tingling in hand and arm, often painful.
  • Increased prominence of veins in neck, shoulder and hand.
  • Bluish hands and arms.

"These patients commonly have symptoms of intermittent arm swelling associated with prominent superficial veins, especially at the upper arm(near shoulder) and anterior chest wall area," says Dr. Parth Shah, a vascular and endovascular surgeon at the Heart & Vascular Institute.

Arterial TOS: When at least one artery under the collarbone is compressed. (One percent of cases.)

  • Blockage (embolism) of an artery in the hand or arm.
  • Tingling, numbness in fingers.
  • Cold, pale fingers or hands.
  • Wounds or ulcerations in the fingers that don’t heal properly.
  • Arm fatigue when in use.
  • Hand pain or weakness, often sudden.

Neurogenic (neurological) TOS: In 90 percent of all cases, the syndrome affects the brachial plexus, a network of nerves extending from the backside of the base of the neck through the armpit.

  • Numbness, tingling in arms or fingers.
  • Pain, weakness in shoulders or arms.
  • Pain, aches in neck, shoulder or hand.
  • Arms tire easily.
  • Tingling in fingers or arms.

Symptoms overlap with common orthopedic and neurological diagnoses, such as carpal tunnel syndrome, ulnar nerve compression/injury, shoulder problems and cervical spine problems. At the Heart & Vascular Institute, we have a multidisciplinary approach to managing patients with nTOS: our rehabilitation network and physicians from Thoracic, Vascular and Neurosurgery and Neurology departments will work together for you.

"These patients have often been suffering from these symptoms for long duration (months to years) before the diagnosis of the nTOS is made," says Dr. Shah.


Compressed nerves or blood vessels in the area below the collarbone produce symptoms associated with Thoracic Outlet Syndrome, but what causes that compression is less certain.

It has been attributed to everything from a congenital abnormality to poor posture.  More often, an injury, repetitive motion and even neck muscles thickened by bodybuilding compresses nerves or blood vessels.

"Thoracic outlet syndrome can be very difficult to diagnose and treat," says Dr. Mario Katigbak, chief of thoracic surgery at Hartford Hospital. "The pathology lies at the intersection of muscle, bone, blood vessels and nerves. The symptoms can overlap these varied structures."

Other possible causes:

  • A cervical rib (an extra rib growing form the cervical spine, the neck area that connects the pine to the skull).
  • Sleep disorders.
  • Stress.
  • Depression.
  • Repetitive-stress shoulder injury.
  • Whiplash (lingering arm, hand symptoms).
  • Weight gain.
  • Tumor or large lymph nodes in upper chest or underarm area.


With some uncertainty about its origins, Thoracic Outlet Syndrome becomes more challenging to diagnose. Your doctor also must be able to recognize the difference between the different types of Thoracic Outlet Syndrome.

Your doctor will review your medical history, paying particular attention for any condition related to nerves (such as carpal tunnel syndrome or cervical spine disease). To reproduce symptoms, your doctor might ask you to move your arms, neck or shoulders.

Confirming a diagnosis might require at least one of these tests:

  • X-ray.
  • Ultrasound.
  • MRI (Magnetic Resonance Imaging).
  • CT scan (Computerized Tomography).
  • Angiography.
  • EMG (electromyography).
  • Nerve conduction study.
  • Arteriography/Venography.

If your doctor suspects Neurogenic Thoracic Outlet Syndrome:

Scalene block: If a local anesthetic that numbs your neck muscles relieves your symptoms, it’s more likely you have Neurogenic TOS.


Veins or arteries affected by Thoracic Outlet Syndrome typically require surgery combined with blood thinners for clotting and medications called thrombolytics if clots form in a vein.

If you require surgery, expect to spend one or two nights (nTOS) or up to five nights (for either vTOS or aTOS) in the hospital. A small drain placed during surgery is typically removed in the next day or two.

"The primary focus," says Dr. Shah, "is on pain control, usually by patient-controlled analgesia, and deep-breathing exercises (incentive spirometry). A chest X-ray is usually performed in the recovery room."

Patients are encouraged to resume full range of motion as soon as they are able. Physical therapy is a critical element of postoperative recovery, usually starting three to five weeks after surgery, depending on the recovery and pain control.

Venous Thoracic Outlet Syndrome: In what is called a paraclavicular (above and below collarbone) approach, surgeons remove the first rib and both the scalene (anterior and middle scalene) and subclavius (a triangular muscle between the clavicle and first rib) muscles. It requires a 1.5- to 2-inch incision above the collarbone and 1-inch incision below the collarbone.

"Patients with acute presentation in VTOS, usually require two-staged therapy," says Dr. Shah. "The first step is anticoagulation and catheter-directed thrombolysis therapy to dissolve the blood clot in the arm veins."

Arterial Thoracic Outlet Syndrome: When this rare condition requires surgery, it typically includes removal of scalene muscles, the first rib and the cervical (extra) rib if you have one.

"Patients with arterial TOS have the greatest potential for disability and poor outcomes," says Dr. Shah, "which are usually dictated by the extent of distal thromboembolism and ischemia before surgical treatment."

Neurogenic Thoracic Outlet Syndrome: Physical therapy is the standard first option. Anti-inflammatories and muscle relaxants can also relieve symptoms. When these treatments fail, your doctor might recommend surgery that includes removal of the cervical (extra) or first rib using a supraclavicular (above the clavicle) approach.

"Neurogenic thoracic outlet syndrome is an often-disputed diagnosis that has resulted in variable successful outcome rates in the literature,” says Dr. Joel Bauman, a Heart & Vascular Institute neurosurgeon. “Our thorough multidisciplinary approach affords three valuable surgical opinions about the candidacy of a patient for successful surgery. Through careful pre-operative evaluation, we believe that the best possible outcomes are assured BEFORE surgery is actually performed."