Title: Thoracic Outlet Decompression.
Published: 5/17/2011, Updated: 5/17/2011.
Author(s): Susan E. Mackinnon MD, Andrew Yee BS, Osvaldo Laurido-Soto BS.
Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St. Louis, MO.
Thoracic outlet syndrome (TOS) is controversial and difficult to diagnose due to the wide-range of symptomology (vascular and/or neurogenic) that are involved, may it be vascular and/or neurogenic, and there not being a distinct examination method (1). The superior thoracic outlet, anatomically known as the thoracic inlet, is composed of the anterior and middle scalene between which the brachial plexus, subclavian artery, and subclavian vein courses distal, superior to the 1st rib and passes obliquely and inferiorly to the clavicle. Impingement of the brachial plexus can involve these structures. As there can be a neurogenic, arterial, and/or venous component of TOS, the most common is neurogenic and constitute the majority of patients with complaints of diffuse shoulder weakness, postural abnormalities, and pain/numbness in the affected upper extremity. Non-invasive treatment for TOS can involve posture correction, shoulder muscles strengthening, and stretching to promote nerve gliding and relieve pressure off of the brachial plexus through the thoracic outlet. Therefore, diagnosis of TOS is made frequently; rarely do these patients require surgical decompression (1). If conservation management fails, our institution’s preferred approach for decompression of the brachial plexus for neurogenic TOS is a supraclavicular approach to release the scalene muscles. Initially, the procedure included a first rib resection, but over the last two decades, literature has shown that the release of the scalene muscles is as satisfactory in results as with the first rib resection. Resection of the first rib is not necessary, unless there is a vascular component to the thoracic outlet syndrome or an underlining pathology in the bony structures. Decompression of the brachial plexus for neurogenic TOS primarily involves dividing the anterior and middle scalene muscles and inspecting the brachial plexus and its nerve branches for possible compression points by adjacent structures.