Combined extravasal compression of the right subclavian artery caused by stellate ganglion schwannoma and additional rudimentary cervical rib. Clinical case and literature review.

Unlike widespread and well-studied atherosclerosis of supra-aortic arteries, non-atherosclerotic vascular diseases are less common. Of these, one of the most unusual is extravasal compression by additional structures between scalene muscles. Close topographic and anatomical connections of scalene muscles, vertebral and subclavian arteries, brachial plexus and stellate ganglion can lead to complex syndrome including impaired blood supply to the arm, brachial plexus compression and vertebrobasilar circulatory disorders. The main treatment method for supraclavicular compression syndromes is surgery. However, differential diagnosis, indications for surgical treatment and optimal technique are still discussable due to small incidence of disease. The key factor in determining treatment strategy is the cause of compression (congenital or acquired scalene muscle hypertrophy, age-related ptosis of the shoulder girdle; neck injuries; cervical spine degeneration). One of the rarest causes of compression is rudimentary additional cervical rib («cervical rib syndrome») and vessels. Combination of these factors is a casuistic etiology. The authors present a 25-year-old patient with stellate ganglion schwannoma whose mass effect caused dislocation and compression of subclavian artery by rudimentary additional cervical rib and scalene muscle. Surgical treatment including resection of tumor, release of the artery and scalenotomy restored arterial patency and eliminated clinical symptoms.