Thoracic origin of a sympathetic supply to the upper limb: the ‘nerve of Kuntz’ revisited

Abstract

An understanding of the origin of the sympathetic innervation of the upper limb is important in surgical sympathectomy procedures. An inconstant intrathoracic ramus which joined the 2nd intercostal nerve to the ventral ramus of the 1st thoracic nerve, proximal to the point where the latter gave a large branch to the brachial plexus, has become known as the ' nerve of Kuntz ' (Kuntz, 1927). Subsequently a variety of sympathetic interneuronal connections down to the 5th intercostal space were reported and also described as the nerve of Kuntz. The aim of this study was to determine : (1) the incidence, location and course of the nerve of Kuntz ; (2) the relationship of the nerve of Kuntz to the 2nd thoracic ganglion ; (3) the variations of the nerve of Kuntz in the absence of a stellate ganglion ; (4) to compare the original intrathoracic ramus with sympathetic variations at other intercostal levels ; and (5) to devise an appropriate anatomical classification of the nerves of Kuntz.Bilateral microdissection of the sympathetic chain and somatic nerves of the upper 5 intercostal spaces was undertaken in 32 fetuses (gestational age, 18 wk to full term) and 18 adult cadavers. The total sample size comprised 99 sides.Sympathetic contributions to the first thoracic nerve were found in 60 of 99 sides (left 32, right 28). Of these, 46 were confined to the 1st intercostal space only. The nerve of Kuntz (the original intrathoracic ramus) of the 1st intercostal space had a demonstrable sympathetic connection in 34 cases, and an absence of macroscopic sympathetic connections in 12. In the remaining intercostal spaces, intrathoracic rami uniting intercostal nerves were not observed. Additional sympathetic contributions (exclusive of rami communicantes) were noted between ganglia, interganglionic segments and intercostal nerves as additional rami communicantes. The eponym nerve of Kuntz should be restricted to descriptions of the intrathoracic ramus of the 1st intercostal space. Any of these variant sympathetic pathways may be responsible for the recurrence of symptoms after sympathectomy surgery.

Sympathectomy for Palmar Hyperhidrosis

“…In six of 12 patients, we found additional thin sympathetic chain under the clipped chain, which could not be seen without complete dissection and lifting of sympathetic chain between second and fourth ribs. Sympathetic chain variations are very important for the success rate of operation [15,16]. Surgical failure and recurrence of hyperhidrosis after operation probably may be resulted from the anatomical variations as seen in our study.…”

Anatomical variations of the upper thoracic sympathetic chain

“…Ramsaroop et al (2001) reported an incidence of 61%, while Chung et al, (2002) reported an incidence of 68.2%. Our study found an incidence of 40%(20/50).…”

“…The first intercostal ramus or Kuntz nerve (Ramsaroop et al, 2001) (Fig. 2), connecting the second intercostal nerve to the ventral ramus of the first thoracic nerve was observed in 20 of 50 sides (40%) and was present bilaterally in 16%(4/25)of cadavers.…”

Sympathetic Blockade

“…It may also be slightly lateral within the intercostal space at the level of the intervertebral space near the upper border of the third rib [ 16,17 ] .…”