1310 - Arterial Thoracic Outlet Syndrome in a Patient with Thyroid Cancer

Differential diagnosis for this patient included neurogenic/vascular thoracic outlet syndrome (TOS), cervical radiculopathy, peripheral neuropathy, brachial plexopathy, subclavian steal syndrome, and Pancoast tumor. CT of the Larynx was notable for an incidental right cervical rib. MRI of cervical spine revealed minimal degenerative changes. Dynamic arterial ultrasound was highly suggestive of arterial thoracic outlet syndrome, and CTA neck showed compression of the right subclavian artery between the anterior scalene muscle and right cervical rib. More than 90% of TOS cases are of neurogenic origin, 3-5% are of venous origin, and 1-2% are of arterial origin. A cervical rib is the etiology of about 5% of TOS cases.

Conclusions: Arterial TOS involves compression of the subclavian artery, and may cause pain, pallor, coolness, ischemia, thrombosis, or embolism of the upper extremity. Ultimately, a multidisciplinary team involving cardiology, vascular surgery, physiatry, and physical therapists offers the best outcomes for treatment of arterial TOS. For this patient, lifestyle modifications (postural correction, avoiding sleeping in overhead arm positions/avoiding repetitive overhead movements) were emphasized and she was referred to vascular surgery. While surgery remains a more controversial option for neurogenic TOS, small scale studies have reported good short and long-term outcomes with performing cervical rib transection in arterial TOS.