[Compression Syndromes: New Insights into the Arterial Thoracic Outlet Syndrome]

The arterial Thoracic Outlet Syndrome (aTOS) is a rare condition affecting approximately 4 per 100000 individuals per year, predominantly young and active patients. It results from compression of the subclavian or axillary artery at one of three anatomical predilection sites within the thoracic outlet. Recent expert consensus has introduced a clinically important nomenclature distinguishing asymptomatic compression (TOC), symptomatic syndrome (TOS), and compression with complications (TOX/TOCs), with the primary aim of avoiding overtreatment.

Congenital bony anomalies such as cervical ribs, atypical ligaments, and post-traumatic changes - particularly callus formation after clavicular fracture - are the most relevant risk factors for aTOS. Turbulent flow distal to the compression site promotes the formation of local aneurysm with consecutive thrombus development and peripheral embolization, potentially leading to limb-threatening ischemia.

Diagnosis of aTOS relies on a combination of clinical examination, provocation maneuvers, and vascular imaging. Color-coded duplex ultrasound has emerged as the first-line imaging modality. In recent studies color-coded duplex ultrasound demonstrated superiority over both conventional angiography and CT angiography, while avoiding radiation and contrast medium exposure. CT retains its role in preoperative planning of complex bony pathology.

Given the risk of limb loss in untreated aTOS, surgical decompression is indicated in the majority of cases. The transaxillary approach remains the most commonly used technique and should be performed in high-volume centers, which have demonstrated up to 30% fewer severe complications. Minimally invasive video- and robot-assisted thoracoscopic techniques show promising results but are currently associated with higher recurrence rates and require further validation.