RECENT advances in surgery make approaches to the sympathetic nervous system more feasible than ever before. Indications for sympathetic nerve surgery and the results of operations depend on fundamental knowledge of the anatomy and physiology of the sympathetic nerves. This morphologic study of the thoracolumbar sympathetic chains and rami was carried out to compare the findings with descriptions in standard anatomy textbooks and to contribute knowledge leading toward effective sympathetic denervation and prevention of nerve regeneration. The thoracic and lumbar sympathetic chains were carefully dissected and drawn in detail in adult human cadavers, 41 of the best bilateral dissections being used as the basis for this paper.
The embryology of the sympathetic chain is reflected in adult anatomy. The solid mass of neural crest cells does not consistently differentiate into a ganglion for each body segment, and sympathetic ganglions sometimes supply more than one segmental nerve in the thoracic and