Hemodialysis Access-Associated Venous Thoracic Outlet Syndrome

Venous thoracic outlet syndrome (VTOS) is a less-recognized cause of hemodialysis access malfunction but one that can lead to loss of access if inadequately treated. Unlike classic VTOS where compression of the subclavian vein results from anatomic abnormalities alone, the underlying cause of access-associated VTOS is hemodynamic as well as anatomic-with the increased flow disturbances at the costoclavicular space creating a vicious cycle of stenosis. Patients mainly present with symptoms of venous hypertension and physical examination shows signs of central venous obstruction. Duplex ultrasound is indispensable for measuring flow volumes to guide the choice of treatment option, while cross-sectional imaging with computerized tomographic venography is very helpful for demonstrating the bone compression and for preoperative planning. The main goal of treatment is to maintain or restore access functionality and relieve venous hypertension symptoms. Although endovascular treatment with balloon angioplasty and stenting is the most common therapy for venous outflow obstruction, angioplasty tends to be of transient value only and stenting is doomed to fail in the costo-clavicular space. The anatomic issues must be addressed for durable relief. Just as with conventional VTOS, bony decompression by first rib resection or medial claviculectomy is highly recommended prior to any endovascular treatment.