Chapter 116 - Thoracic Outlet Syndrome

Abstract

Thoracic outlet syndrome is a group of distinct disorders resulting from compression of the brachial plexus and/or the subclavian vessels as the structures travel from the thoracic outlet to the axilla. There are five types of thoracic outlet syndrome: arterial, venous, traumatic neurovascular, true neurogenic, and disputed. Any anatomic anomaly in the thoracic outlet has the potential to dispose a patient to thoracic outlet syndrome. Clinical presentation of thoracic outlet syndrome is highly variable; symptoms associated with thoracic outlet syndrome are usually divided into vascular and neurogenic categories, based on the underlying structures implicated. True neurogenic thoracic outlet syndrome typically involves the lower trunk of the brachial plexus. Approximately 85% of patients diagnosed with thoracic outlet syndrome are believed to have the disputed type, which usually present with inconsistent symptomatology in the absence of a consistent anatomic abnormality. Diagnosis for thoracic outlet syndrome includes a thorough history and physical examination, pertinent provocative tests, and imaging studies. Nerve conduction studies and electromyography are helpful to support neurogenic thoracic outlet syndrome, because the electrodiagnostic manifestations are essentially pathognomonic. Conservative treatment includes relative rest, nonsteroidal anti-inflammatory medications, and physiotherapy is indicated for most patients in the acute phase; surgery is reserved for patients with acute vascular insufficiency and progressive neurologic dysfunction.