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Kuntz A: Distribution
of the Sympathetic Rami to the Brachial Plexus: Its Relation to Sympathectomy
Affecting the Upper Extremity. Arch. Surg., 15, 871-877, 1927.
OF THE SYMPATHETIC RAMI
TO THE BRACHIAL PLEXUS
ITS RELATION TO SYMPATHECTOMY AFFECTING THE
ALBERT KUNTZ, Ph.D., M.D.
of the stellate ganglion or section of the gray rami which connect
this ganglion with the brachial plexus has become a recognized surgical
procedure, especially in diseases involving the blood vessels of the
upper extremity. The aim of this procedure in diseases of the blood
vessels is vasomotor denervation of the extremity. Extirpation of the
stellate ganglion alone, or section of the gray rami which connect
it with the brachial plexus, however, does not completely eliminate
the sympathetic nerves of the upper limb in a large percentage of cases.
The operation has failed to produce the desired results in certain
cases, probably because of incomplete sympathetic denervation of the
blood vessels which were involved.
During the progress of studies involving the gray rami associated with the
brachial plexus and the distribution of sympathetic fibers in the upper extremity,
my attention was called to the inconstant intra thoracic ramus that connects
the first and second thoracic nerves as a possible pathway through which sympathetic
fibers that leave the sympathetic trunk below the stellate ganglion might enter
the first thoracic nerve and become incorporated in nerves arising from the
brachial plexus. Accordingly, the present study of the lower cervical and upper
thoracic portions of the sympathetic trunks and the communicating rami joining
the spinal nerves which contribute to the innervation of the upper extremity
was undertaken in order to obtain more exact knowledge regarding the sources
of the sympathetic innervation of the upper limb and, if possible, to afford
a rational basis for an operative procedure that will in all cases effectively
deprive the blood vessels of this limb of their vasomotor nerves.
The chief sources of sympathetic fibers to the upper extremity are the middle
cervical and stellate ganglions. These ganglions, as well as the upper thoracic
sympathetic ganglions, are extremely variable. Not infrequently the middle
cervical ganglion is absent; when it is present, it is generally located about
the level of the body of the sixth cervical vertebra. It is usually connected
through the gray rami with the fifth and sixth cervical nerves; in some instances,
also with the fourth and seventh cervical nerves (Potts, 1925).1 In some instances
the middle cervical ganglion lies close to the stellate ganglion. In such cases,
the communicating rami arising from the cervical sympathetic trunk may join
the fifth and sixth and possibly the fourth and seventh cervical nerves.
A discrete, inferior, cervical sympathetic ganglion occurs but rarely, if at
all, in man. This ganglion commonly fuses with the first thoracic sympathetic
ganglion to form a stellate ganglion. In some instances the second thoracic
sympathetic ganglion is also incorporated in the stellate ganglion. This ganglion
varies greatly in size and form. It commonly lies about the level of the neck
of the first rib, but it may occupy a somewhat lower position. Gray rami arising
from the stellate ganglion join the seventh and eighth cervical and the first
thoracic nerves. Not infrequently, especially if the middle cervical ganglion
is absent, a gray ramus from the stellate ganglion joins the sixth cervical
nerve. At times the stellate ganglion sends a gray ramus to the second thoracic
nerve. The first thoracic nerve also sends a white ramus into the stellate
Although an intrathoracic ramus of the second thoracic nerve joins the first
thoracic nerve in a large percentage of cases, the second thoracic nerve is
not commonly regarded as contributory to the brachial plexus. In forty-eight
cadavers examined during the present study, an intra thoracic ramus connecting
the first and second thoracic nerves was present bilaterally in twenty-one
and unilaterally in nine. In the twenty-one cadavers in which it was present
bilaterally, this ramus was described as large in ten, of medium size in seven
and as small in four. In the nine cadavers in which it was present on only
one side, it was described as of medium size in five and as small in four.
According to statements in the textbooks regarding this inconstant ramus of
the second thoracic nerve, it may join only the intercostal ramus of the first
thoracic nerve or only the brachial plexus, or it may contribute fibers to
both the first intercostal nerve and the brachial plexus. In the cadavers examined
in the present study, this ramus joined the first intercostal nerve distal
to its origin from the first thoracic nerve in only six cases, in all of which
it was described as medium or small. In all the other cases it joined the first
thoracic nerve proximal to the origin of the first intercostal nerve. If the
ramus in question is small, all of its fibers may still be incorporated in
the first intercostal nerve, although a contribution of fibers from the second
thoracic nerve to the brachial plexus is not precluded. Not infrequently this
ramus is actually larger than the first intercostal nerve. In such instances
the second thoracic nerve clearly contributes fibers to the brachial plexus.
* From the St. Louis University School of Medicine.
1. Potts, T. K.: The Main Peripheral Connections of the Human Sympathetic Nervous
System, J. Anat. 59:129, 1925.