Supraclavicular Approach

Abstract

The supraclavicular approach is the oldest one which attempted to deal with the neurogenic thoracic outlet syndrome, even though removal of a normal first thoracic rib to relieve compression of the brachial plexus was reported earlier by Brickner [1]. The operation begins with a transverse incision made above the clavicle on the affected side. After entering the subcutaneous tissue and dividing the platysma muscle the sternocleidomastoid muscle is then partially divided. Some advocate that the muscle be divided totally in order to expose the posterior space, but others only divide part of the muscle. The posterior space, consisting solely of subcutaneous tissue, is reflected laterally; the external jugular vein does not need to be divided. At the bottom of the space lies the anterior scalene muscle. This is carefully exposed, paying particular attention to protecting the phrenic nerve which runs anterior to the muscle. As the nerve gradually reaches the clavicle it tends to migrate medially towards the mediastinum, thereby separating itself from the muscle. This approach does not allow dissection of the first rib in its entire length. The field does permit the first rib to be visualized in its superior portion anteriorly, but as the dissection is carried out posteriorly it becomes possible to dissect the rib circumferentially. The subclavian vein can now be visualized as it lies exactly in front of the anterior scalene muscle; this vessel must be retracted off the first rib. The course of the vein can be followed towards the mediastinum and then down behind the manubrium of the sternum. Dividing the sternocleidomastoid muscle allows the surgeon to see the junction of the innominate and internal jugular veins, but the portion of innominate vein so exposed which can be isolated is limited.