A case of neurogenic thoracic outlet syndrome for which cervical rib resection was effective

The patient was a 34-year-old American woman who taught English at a high school. In year X-1, she noticed severe pain in her right upper limb and visited the orthopedic department of Hospital A. The imaging findings obtained at Hospital A ruled out cervical disc herniation and cervical spondylosis. Cervical radiography revealed the presence of a right cervical rib. In the physical findings, the Morley and Roos test results were positive, and the Wright and Eden test results were negative. The patient was diagnosed with thoracic outlet syndrome (TOS) caused by the cervical rib and was referred to our department. Contract-enhanced computed tomography (CT) revealed slight stenosis of the right subclavian artery at the post-attachment site of the anterior scalene muscle and at the anterior site of the cervical rib. Three-dimensional CT revealed that the cervical rib compressed the subclavian artery from the dorsal side. Considering the course of the brachial plexus, we assumed that it was also compressed at this site. We treated the patient with pharmacotherapy with neuropathic pain relievers, provided lifestyle and occupational advice to limit forced movement of the upper limbs and exercise tolerance, and instructed her to perform thoracic outlet exercises to strengthen the muscles around the scapula. Although she was treated with these treatments for 3 months, they were ineffective. As the pain was severe and interfered with daily life and work performance, surgery (cervical rib resection) was scheduled in year X. Surgery was performed by the right supraclavicular approach. The platysma muscle and adipose tissue were incised to expose the brachial plexus, which was further divided into the upper to middle and lower trunks and taped. The subclavian artery was slightly compressed on the dorsal side of the anterior scalene muscle. The anterior scalene muscle was resected at the site of attachment to the first rib to release the compression of the subclavian artery. A cervical rib was detected on the dorsal side of the brachial plexus and the subclavian artery. This rib compressed the brachial plexus. The cervical rib was then morselized using the Luer forceps. No abnormal cord-like materials were found connected to the cervical rib. After cervical rib resection, the absence of tissues compressing the brachial plexus and subclavian artery was confirmed, and the surgery was completed. Postoperatively, the worst pain in the right upper limb was alleviated, and the patient returned to work. Although the cervical rib is a congenital anomaly that may cause TOS, it itself is rarely a direct cause of TOS. TOS is diagnosed based on clinical symptoms and physical tests. Surgical indications should be carefully determined for patients who are unresponsive to conservative treatment.