Venous Thoracic Outlet Syndrome

Venous thoracic outlet syndrome (TOS) is a condition that happens when the subclavian vein is squeezed or compressed. The subclavian vein is the vein that returns blood from the arm and hand to the heart. To reach the arm, this vein must pass through the thoracic outlet. This is a tight space under the collarbone (clavicle) and above the top rib.

Depending on which structures are affected, you may have symptoms on one or both sides of your body.

What are the causes?

This condition may be caused by doing hard work with your arms, especially if you have to lift your arms above your head. A blood clot may form in the vein.

What increases the risk?

• Doing work with your arms that is repetitive and takes a lot of effort.
• Being male.
• Being overweight.
• Having poor posture.

What are the signs or symptoms?

• Pain and swelling of your whole arm.
• A feeling of heaviness or tightness in your arm.
• Weak or absent pulse in the affected arm.
• Pale or gray skin on the affected arm.
• Muscle loss in your hands. This is rare.

These signs and symptoms may be worse when you hold your arms over your head.

How is this diagnosed?

• Your symptoms and a physical exam. Your health care provider may ask you to hold your arms over your head and in other positions to check whether your symptoms get worse.
• Tests and imaging studies to confirm the diagnosis and to find out the cause of your TOS. These tests may include:
  • X-rays to look for an abnormality of the ribs, such as a cervical rib, which is an extra rib at the base of your neck.
  • An ultrasound. This test uses sound waves to create an image.
  • A CT scan.
  • An MRI scan.
  • An angiogram or venogram. In these tests, X-rays are done after a dye is injected into an artery or vein.
  • A pulse volume recording. This test measures the pulses in your wrists.

How is this treated?

• Medicine, including blood thinners or blood clot dissolvers.
• A procedure to open up the clotted vein and restore blood flow (angioplasty).
• Surgery to remove a blood clot (thrombus).
• Surgery to remove the uppermost rib to make more space in the thoracic outlet.

Follow these instructions at home:

Medicines

• If you are taking blood thinners:
  • Talk with your health care provider before you take any medicines that contain aspirin or NSAIDs, such as ibuprofen. These medicines increase your risk for dangerous bleeding.
  • Take your medicine exactly as told, at the same time every day.
  • Avoid activities that could cause injury or bruising, and follow instructions about how to prevent falls.
  • Wear a medical alert bracelet or carry a card that lists what medicines you take.
• Take over-the-counter and prescription medicines only as told by your health care provider.

Activity

• Do exercises as told by your health care provider or physical therapist.
• Do not lift anything that is heavier than 10 lb (4.5 kg), or the limit that you are told, until your health care provider says that it is safe.
• Do not carry heavy bags over your shoulder or repetitively lift heavy objects over your head.
• Take breaks often to stretch and rest your arms if you work at a keyboard or do other repetitive work with your hands and arms.

General instructions

• Maintain a healthy weight. Lose weight as told by your health care provider.
• Maintain good posture.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• You have pain, cramps, numbness, or tingling in your arm or hand.
• Your arm or hand often feels tired.
• Your arm turns a darker and different skin color than usual.
• Your hand feels cold.
• You have frequent headaches or neck pain.
• You have muscle loss in your hand.

Get help right away if:

• You lose feeling in your arm or hand.
• You cannot move your fingers.
• Your fingers turn a dark color.

Summary

• Venous thoracic outlet syndrome (TOS) is a condition that happens when the subclavian vein, which returns blood from the arm and hand to the heart, is squeezed or compressed.
• This condition may be caused by doing hard work with your arms, especially if you have to lift them above your head.
• Symptoms include pain and swelling of your whole arm, weak or absent pulse in the affected arm, and pale or gray skin on the affected arm.
• Treatment may include medicines, a procedure to restore blood flow (angioplasty), surgery to remove a blood clot, or surgery to remove the uppermost rib to make more space in the thoracic outlet.