Importance of the Second Thoracic Segment for the Sympathetic Denervation of the Hand

Abstract

The alternative pathways of the thoracic sympathetic nerve are inconstant. Ascending and descending communicating rami can bypass the sympathetic chain. The inconstant, intrathoracic nerve of Kuntz is one of the most important parts of the sympathetic innervation of the hand. With the combination of cold exposure test, sweating test, and ulnar nerve block, the difference in sympathectomy effect on the vasomotor and on the sudomotor function can be demonstrated. A positive ulnar nerve block test makes the persistence of the intrathoracic nerve probable. The thoracodorsal sympathectomy en bloc offers a real chance of complete sympathetic denervation of the hand as demonstrated in patients in 106 operative procedures. A complete sympathetic denervation of the hand requires the intradural excision of the total outflow of the 3rd and especially the 2nd segments.