IN APRIL 1953, we developed and began to use an anterior transthoracic transpleural approach through the third intercostal space for an upper thoracic (dorsal) sympathectomy. This provided, for the first time, a direct and easy approach to this segment of the sympathetic chain and associated ganglia. With the excision of the sympathetic chain and ganglia from the first through the fifth thoracic ganglia, a complete and permanent sympathetic denervation of the structures of the head, neck, shoulder, and anterior and posterior aspects of the chest to the fifth thoracic somatic intercostal levels, upper extremity, mediastinal, and thoracic contents (including the esophagus, heart, coronary vessels, bronchi, lungs, and great vessels) can be accomplished. The extent of this resection is considered essential to ablate all of the visceral afferent and efferent pathways to the areas and structures listed above. This exposure makes it possible for the surgeon to readily visualize the thoracic