Neurogenic Thoracic Outlet Syndrome—Presentation, Diagnosis, and Treatment

Abstract

Background: Thoracic outlet syndrome (TOS) refers to a group of disorders in which there is compression of and/or damage to the neurovascular structures at the thoracic outlet, i.e., at the transition from chest to neck. The incidence of neurogenic thoracic outlet syndrome (nTOS) is estimated to be 2-3 / 100 000 / year, with an estimated prevalence of 10 / 100 000. Patients present with upper extremity sensorimotor symptoms that are often related to movement. The aim of the present article is to highlight the clinical presentation patterns of nTOS and to provide an overview of its diagnosis and treatment.

Methods: Selective literature search for prospective observational studies and RCTs, including systematic reviews and metaanalyses.

Results: There is no multicenter randomized controlled trial available on the treatment of nTOS. Prospective observational studies with a hierarchical study design report a positive effect of physiotherapy in 27-59% of cases. After unsuccessful conservative treatment, up to 56-90% benefit from surgical management. Patients with nTOS are more severely affected compared with those with other forms of TOS and benefit less from transaxillary first rib resection. nTOS patients who underwent supraclavicular decompression without rib resection had excellent surgical outcomes in 27%, good outcomes in 36%, acceptable outcomes in 26%, and poor surgical outcomes in 11% of cases. There is no systematic comparison available of the types of surgical management involved. Also, there is currently no uniform classification available for all medical sub-disciplines. Therefore, interpretation, and comparability of the study results are limited.

Conclusion: Although nTOS is the most common form of TOS, studies on its treatment are currently limited in terms of numbers and quality. The type of surgical management varies according to the experience and preference of the surgeon, treating specialty, special anatomic features, and clinical symptoms.

Figure

The supraclavicular approach to the neurovascular bundle of the thoracic outlet a) The skin is incised parallel to the clavicle lateral to the sternocleidomastoid m. The omohyoid m. is then exposed and lateralized (and ligated and divided if necessary) and the anterior scalene m. is dissected with careful sparing of the phrenic n. The brachial plexus can now be gently dissected free between the anterior and middle scalene mm. b) The division and, if necessary, partial resection of the anterior scalene m. decompresses the neural structures. The brachial plexus is circumferentially exposed under the operating microscope, and its course is followed under the clavicle. This enables the exposure and, if necessary, resection of other potentially compressing structures (middle scalene m. from the dorsal side, accessory muscles, Sibson‘s fascia, bony elements, etc.). A final check by palpation is recommended, including a check with the arm in the position that triggers the symptoms (abduction and retroversion). Modified from König et al. (e15)