Vascular thoracic outlet syndrome (vascular TOS) occurs when the blood vessels between the collar bone and the first rib (the top rib) are compressed. The thoracic outlet is the small opening just below the collarbone that allows the blood vessels and nerves to serve the arms. Vascular TOS involving the subclavian vein (carries oxygen poor blood back from the arm) makes up about 4% of all TOS cases. Arterial TOS involving the subclavian artery (carries oxygen rich blood to the arm) only accounts for 1% of all TOS cases. Most TOS involves the nerves (neurogenic TOS).
Symptoms may include bluish colored or pale hands. In the arms, there may be pain, swelling, or discoloration. The fingers, hands, or arms may feel cold or numb. Arm cramps may also occur. Additionally, people with the syndrome may feel weakness in the arms or neck and a painful lump near the collarbone (clavicle).
Vascular TOS can be caused by poor posture, obesity, pregnancy, severe trauma – like a car accident – or a repetitive activity at work or while playing sports. Certain birth defects, like being born with an extra rib or abnormal first rib, increase the risk of arterial TOS.
The syndrome may be difficult to diagnose. With venous TOS, your doctor will look for swelling, check the prominent veins where your shoulder and chest join, and perform a venography. In arterial TOS, your doctor will look for a weak wrist pulse, compare colors of your hands and perform pulse volume recordings and arteriography. Other tests may include Doppler ultrasounds, CT scans, and MRIs. Treatments for TOS may include physical therapy, medications, or surgery. If you or a family member has been diagnosed with vascular TOS, talk to your doctor and specialist(s) about the most current treatment options. Support groups are also a good source of information and can help connect you with others affected by TOS.