Thoracic outlet syndrome is not the name of a single entity but rather a collective title for a variety of conditions attributed to the compression of neurovascular structures as they traverse the thoracic outlet.
The thoracic outlet is bordered by the scalene muscles, first rib, and clavicle. Neurovascular structures pass from the neck and thorax into the axilla through this space. Thoracic outlet syndrome remains one of the most controversial clinical entities in medicine.
See the image below.
Thoracic outlet syndrome in a 16-year-old volleyball player with a stenotic right subclavian vein (arrow) secondary to fibrosis.
Diagnosis and management
To exclude systemic disease and inflammation, a few simple blood tests may refine the differential diagnosis for thoracic outlet syndrome, including a blood glucose level, complete blood cell (CBC) count, erythrocyte sedimentation rate (ESR), basic metabolic panel, thyrotropin level, and rheumatologic workup, if indicated.
Imaging studies that can be used in the diagnosis of thoracic outlet syndrome include the following:
Computed tomography (CT) scanning and magnetic resonance imaging (MRI) – Useful for identifying other conditions that might cause similar symptoms
Magnetic resonance angiography (MRA)
Venography and duplex scanning
Electrodiagnostic studies can be helpful in classic cases of neurogenic thoracic outlet syndrome. However, many symptoms are intermittent in this disorder; therefore, negative test results do not rule out the diagnosis.
Surgery in cases of thoracic outlet syndrome is indicated for acute vascular insufficiency and progressive neurologic dysfunction. Other patients should receive nonoperative treatment that, in the acute phase, includes relative rest, nonsteroidal anti-inflammatory medications (NSAIDs), cervicoscapular strengthening exercises, and modalities such as ultrasound, transcutaneous nerve stimulation, and biofeedback. Physiotherapy in the acute phase focuses on pain control and range of motion with specific stretching exercises.