Thoracic outlet syndrome (TOS) constitutes a group of disorders resulting from compression of the neurovascular bundle exiting through the thoracic outlet. The vessels from the chest and the nerves from the spinal column pass between the scalene muscles above the rim of the superior thoracic aperture. They then go on to pass through the triangle formed by the first rib, clavicle, and scapula and run underneath the coracoid process to the brachium. Along this route, there are three spaces within the thoracic outlet that can cause compression of the neurovascular structures, which include the scalene triangle, costoclavicular space, and subcoracoid space.1

TOS can be classified based on the etiology of the pathophysiology: neurogenic (nTOS), venous (vTOS), arterial (aTOS), and mixed (mTOS). These can be further subdivided on congentital, traumatic, or functionally acquired caused. The constellation of symptoms a patient may experience vary depending on the structures involved. Most commonly, these symptoms include: paresthesias, pain, weakness, muscle atrophy, pallor, or swelling.2

The diagnosis of TOS requires a thorough physical exam in addition to other adjuncts. The physical exam should focus on the upper extremity and cervical spine while making comparisons between the affected and unaffected extremities. There are certain characteristic findings depending on the etiology of TOS.3 For example, aTOS can have large differences in blood pressure readings; whereas, vTOS can present with edema, discoloration, and chest wall varicosities (if chronic). nTOS, when severe, can present with muscular atrophy of the hand and forearm. Duplex, CT, and MRI can assist with the diagnosis of aTOS and vTOS which may reveal arterial/venous stenosis or thrombus. Diagnostic angiography can also be helpful with the use of intraoperative provocative maneuvers. Nerve conduction and EMG studies are indicated for patients suspected of having nTOS. While the majority of patients will have normal or negative results, electrophysiological evaluation can help rule out cervical radiculopathy and myopathies.2

Due to the wide range of etiologies and presenting symptoms, treatments surrounding TOS also differ. Management options for TOS can include: lifestyle modifications, physical therapy, pain management, anticoagulation, and surgery. Surgical options can also differ depending on the etiology of the TOS.2 For example, the presence of a cervical rib will require removal or arterial reconstruction may be needed in the setting of aTOS. The majority of the literature published on surgical decompression for TOS focuses on perioperative and short-term outcomes. This systematic review aimed to provide a pooled analysis of studies to better understand the intermediate and long-term outcomes of surgical decompression for TOS.