Supraclavicular Approach to First Rib Resection for Thoracic Outlet Syndrome

Abstract

Thoracic outlet syndrome (TOS) refers to compression of the subclavian vessels and brachial plexus in the region of the superior aperture of the chest, with most compression of these structures directed against the first rib. Historically, the diagnosis and treatment of TOS have been difficult and controversial topics. Symptoms may be vascular or neural, depending on the predominant target of compression. Neurologic signs and symptoms can range from mild paresthesia and numbness to intrinsic hand muscle atrophy, and many times there will be more than one site of nerve compression. Often, particularly in neurogenic TOS, there is no reliable objective test to identify the cause. Nerve conduction studies are useful for detecting sites of concomitant distal compression, such as the median nerve at the carpal tunnel or the ulnar nerve at the elbow, but neither they nor somatosensory-evoked potentials are universally accepted as helpful in the diagnosis of TOS. In these cases, the diagnosis is suggested by physical examination. Though many provocative tests exist, we have found the most logical and reliable to be the reproduction of symptoms within 1 minute of arm elevation, with the wrist neutral and elbow extended. This positionpreventstheconfoundingincitementofperipheralnerve compression at the elbow or wrist. Symptoms may occur more briskly with concomitant digital pressure on the supraclavicular brachial plexus. Most patients with neurogenic TOS will achieve relief with specific and directed physical therapy. However, those with an easily identifiable cause of vascular or nervous compression, and some of those without an identifiable cause and incomplete relief from conservative management, may benefit from surgical decompression. The supraclavicular approach to relieve thoracic outlet syndrome by decompression of the brachial plexus and excision of the first rib releases structures that compress soft tissue in the region of the interscalene portion of the brachial plexus.ThelowernervetrunkandC8andT1nerverootscan be completely identified and protected as the most posterior aspect of the first rib is resected under direct vision. Any cervical ribs or prolonged transverse processes are easily removed by this supraclavicular approach.