Commentary: Comments on Thoracic Outlet Syndrome

74 Thoracic outlet syndrome (TOS) is a comprehensive term used to describe symptomatology due to compression of neurovascular bundle in the thoracic outlet region of upper extremity. The term TOS was used for the first time in the literature by Rob and Standeven.[1] It had also been termed costoclavicular syndrome, cervical rib syndrome, scalenus anticus syndrome, subclavius tendon syndrome, or musculus pectoralis major syndrome by various authors.[2,3] Depending on the predominant structure involved in compression, it is further divided into three subtypes, namely, neurogenic TOS (n‐TOS, compression of brachial plexus), arterial TOS (a‐TOS, compression of subclavian artery), and venous TOS (v‐TOS, compression of subclavian vein). The most common form by far is nTOS, which accounts for >90% of all TOS cases.[4] Brachial plexus and subclavian artery pass through the scalene triangle which is formed by the borders of anterior scalene and middle scalene muscle along with the first rib whereas subclavian vein compression occurs while passing through the costoclavicular space formed by clavicle, first rib, and costoclavicular ligament.