Thromboangiitis obliterans

**Definition:** Thromboangiitis obliterans (TAO), or Buerger's disease, is a segmental occlusive inflammatory condition of arteries and veins, with thrombosis and recanalization of the affected vessels. It is a nonatherosclerotic inflammatory disease affecting small and medium sized arteries and veins of upper and lower extremities. TAO can be distinguished from other types of vasculitis based on its tendency to occur in young male subjects. The etiology and pathogenesis of TAO remains unknown; however, tobacco consumption plays a key role in the initiation and persistence of the disease.