Vascular Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a collection of upper extremity symptoms that result from compression of the neurovascular bundle by various structures in the area just above the first rib and behind the clavicle. Although vascular TOS (venous and arterial) account for only 5% of all TOS cases, leaving the majority for neurogenic cases, it is associated with the most serious complications, including limb ischemia. The main pathophysiology is based on a mechanism of chronic compression over the subclavian artery or vein and then stenosis, which results in further intimal injury with fibrosis, thickening, and arterial luminal narrowing or complete or partial venous occlusion and thrombosis. Arm swelling, cyanosis, and other symptoms of primary venous thromboses represent the clinical picture of venous TOS. With arterial TOS, an ischemic hand in various pictures represents an advance stage, whereas asymptomatic cases are the majority. Various invasive and non-invasive examination tests can help in diagnosing and distinguishing among the etiologies of TOS; however, conventional arteriography and venography remains the gold standard for vascular investigation testing. Of note, this method has gradually been replaced by advanced CT angiography/venography. In terms of vascular TOS treatment, the role of conservative management is limited and the main target of treatment, which includes relieving the compression over the neurovascular structures, is mainly achieved by surgical option with superior results with early intervention.