Arterial Thoracic Outlet Syndrome

Arterial thoracic outlet syndrome (TOS) is a condition that happens when the subclavian artery is squeezed or compressed. The subclavian artery is the artery that carries blood from the heart to the arm and hand. To reach the arm, this artery must pass through the thoracic outlet, which is a tight space under the collarbone (clavicle) and above the top rib. There are different types of TOS. The arterial type is the rarest.

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

What are the causes?

This condition is often caused by having a cervical rib. This is an extra rib at the base of your neck that presses on your subclavian artery. Over time, this pressure may cause a clot to form inside the artery, or the artery may weaken and balloon outward (aneurysm).

What increases the risk?

• Being female.
• Being overweight.
• Poor posture.
• A job or hobby that involves repeated movements with your arms over your head.
• A history of Ehlers–Danlos syndrome.

What are the signs or symptoms?

• Pain and cramps in your arm or hand.
• Pale skin or a change in color of the skin on your hand and arm.
• Very cold hand or hands.
• Weak pulses at your wrist.
• Rarely, muscle loss in your hands.

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

How is this diagnosed?

• Your symptoms and a physical exam. You may be asked to hold your arms over your head and in other positions to see if your symptoms get worse.
• Tests to confirm the diagnosis and to find out the cause of your TOS. These may include:
  • X-rays to look for a cervical rib or another problem in the ribs.
  • 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?

• Remove the cervical rib.
• Remove a blood clot (thrombus).
• Repair an aneurysm.

• A procedure to open up the clotted artery and restore blood flow (angioplasty).
• Medicine, including blood thinners or blood clot dissolvers.

Follow these instructions at home:

Medicines

• If you are taking blood thinners:
  • Talk with your health care provider before taking aspirin or NSAIDs. These medicines can raise your risk of bleeding.
  • Take your medicines as told. Take them at the same time each day.
  • Do not do things that could hurt or bruise you. Be careful to avoid falls.
  • Wear an alert bracelet or carry a card that says you take blood thinners.
• Take over-the-counter and prescription medicines only as told by your provider.

Activity

• Do exercises as told by your provider or physical therapist.
• Do not lift anything that is heavier than 10 lb (4.5 kg) until your provider says that it is safe.
• Do not carry heavy bags over your shoulder or do repeated lifting of heavy objects over your head.
• Take breaks often if you work at a keyboard or do other work that involves repeated movements of your hands and arms. Stretch and rest your arms during these breaks.

General instructions

• Stay at a healthy weight. Lose weight as told by your provider.
• Maintain good posture.
• Keep all follow-up visits. Your provider will check to see if your symptoms are improving with treatment.

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 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.