Thoracic Outlet Syndrome
Findings:
3D TOF MRA of the aortic arch great vessels shows abrupt
termination of flow signal in the bilateral subclavian arteries with arm
abduction.
Discussion:
Thoracic outlet syndrome is caused by rib anomalies or
musculofibrous bands between the clavicle, cervical spine, and first rib.
Alternatively, this may be an acquired condition due to malunited clavicle
fracture or body habitus (thin or muscular). An anomalous anterior scalene
muscle is the most common cause. Any condition which narrows the costoclavicular
space may cause the symptom complex. These patients experience ischemic
symptoms in the arms with abduction, associated with loss of the radial
pulse and possibly a subclavian bruit. Complications include poststenotic
aneurysm, subclavian artery thrombosis, mural thrombus with distal embolization,
or venous thrombosis. Surgery can be curative.