Arterial thoracic outlet syndrome

Abstract

Thoracic outlet syndrome (TOS) is used to describe the constellation of symptoms arising from neurovascular compression of the thoracic outlet. The structures passing through the thoracic outlet include the subclavian artery, subclavian vein and trunks of the brachial plexus. Patients may experience symptoms related to compression of any one or various combinations of these structures. Arterial pathology as the cause of TOS is rare, though repetitive overhead arm motion, such as seen in athletes, is a risk factor for developing arterial TOS (aTOS). Symptoms include chronic findings, such as pallor, arm claudication or cool arm. Currently diagnosis of aTOS is made using clinical and imaging parameters which include focused history and physical including provocative maneuvers and imaging follow-up ranging from angiography to MRI. Occasionally, acute thrombosis can result in limb threatening ischemia requiring emergent catheter directed thrombolysis. Outside of acute limb ischemia, management of aTOS is variable, however typically begins with conservative measures such as physical therapy. In patients who do not respond or progress on conservative management, surgical decompression may be performed. Open or endovascular treatment of subclavian artery pathology may be necessary for recalcitrant cases. In this article, the aim is to review the elements involving diagnosis and management of aTOS.

Anatomy and Pathogenesis of Vascular Thoracic Outlet Syndrome

“…General symptoms of vascular compression in the arm are paresthesia and numbness [ 13 ]. ATOS can be subcategorized based on the way of its pathogenesis in acute thrombosis, chronic stenosis, non-thrombotic ischemia, distal embolization, and total occlusion [ 14 ]. The main symptoms include claudication and pain during the arm’s activity, which slowly subsides after the end of the movement.…”

“…Furthermore, TOS causes upper extremity pain because of the acute distal upper extremity ischemia, caused by the embolization [ 16 ]. A TOS can rarely present itself with non-limb-related consequences such as strokes [ 14 ].…”

“…It consists of provocative physical exam maneuvers and radiographic and vascular studies [ 16 ]. Frequently, patients will present a mix of symptoms with concurrent NTOS, ATOS, and VTOS occurring simultaneously [ 14 ]. The diagnosis is made by confirming the compromised circulation of a vessel and identifying the anatomical factor that is responsible for the obstruction [ 15 ].…”

“…In patients with continuing or progressing symptoms, surgical decompression may be used to treat a TOS. In cases of acute thrombosis, thrombolysis is sometimes necessary to counteract ischemia that constitutes a danger to a limb [ 14 ]. There are generally three main principles that should be followed intraoperatively: decompression, vascular resection, and distal revascularization.…”

A Hypertrophic Anterior Scalene Muscle and the Passage of a Subclavian Artery Through its Fibres: The Location of Possible Entrapment

“…The presence of some anatomical variants, such as cervical ribs, 1 st rib anomalies, hypertrophy of the cervical muscles in combination with repetitive motion, as well as fibrocartilaginous bands (1-3) may cause subclavian artery (SCA) entrapment and/or compression (2,(4)(5)(6)(7)(8). In addition, the atypical passage of the SCA through the anterior scalene muscle (ASM) or posterior to it (9,10) may cause compression on the SCA.…”