Arterial TOS (subclavian/axillary arterial compromise)
What is it?
- Compression of the subclavian/axillary artery within the thoracic outlet.
What is the cause?
- Arterial TOS occurs because the subclavian artery is repeatedly compressed in the scalene triangle at the level of the first rib and in the costoclavicular space, damaging its wall.
- Documented structural factors related to subclavian arterial compression include cervical ribs and anomalous first ribs.
- Overdeveloped scalene muscles have also been described to compromise blood flow through the subclavian artery as it traverses the interscalene triangle proximally.
- More distally, the axillary artery may undergo compression as it passes beneath the tendon of the pectoralis minor muscle.
Signs and symptoms:
- Onset-overuse-related and position dependent
- Symptoms-vague pain, claudication, parasthesias
- Signs-diminished radial pulse, blood pressure, and/or delayed capillary refill
Diagnostic Tool to rule in/out:
- Contrast angiography, MRA
Presentation of Disease:
- Pain, coldness, and pale discoloration of the hand.
- Cramps occur when using the arm for activity.