Clinical Anatomy and Variations of the Supraclavicular Veins

Abstract

Clavicular fractures are now increasingly treated surgically. Therefore, the anatomical relationships of neurovascular structures to the clavicle assume major importance. Here we describe anatomical variants to the external jugular vein (EJV). We dissected two adult cadavers and displayed the EJV bilaterally. In both cases the EJV was found to be the inferior continuation of the retromandibular vein emerging from the inferior pole of the parotid gland. It crossed the sternocleidomastoid (SCM) muscle obliquely and pierced the deep cervical fascia to drain into the subclavian vein in the inferior medial angle of the posterior triangle. The distal end received two veins: a lateral vein about 2.00 mm in diameter crossed vertically at the anterior surface of the middle of the clavicle and drained into EJV just before the later penetrated the deep fascia; a second vein, found only on the right side arose from a network of veins at the medial edge of the sternal head of SCM, traversed laterally on the anterior surface of the clavicle and opened into the vertical vein. The inferior belly of the omohyoid and trunks of the brachial plexus were found to pass behind the EJV and posterior to the clavicle. The veins running in physical contact with the anterior surface of the clavicle might be a source of bleeding in surgical procedures involving fractures of the clavicle or procedures that use the clavicle as an anatomical landmark.