The anatomical approach in stellate ganglion injection.

T H E sympathetic outflow to the head and neck and the greater part of that to the upper limbs passes on each side through the relatively small confines of the stellate ganglion and is here subject to interruption by stellate ganglion block. This block will cut off all efferent sympathetic impulses to the head and neck and most, if not all, of those to the upper limb and may be of value for example in estimating the likely improvement in blood supply that would follow a cervical sympathectomy in Raynaud's or other vascular diseases and also as a therapeutic measure temporarily increasing the blood supply in cerebral thrombosis or embolism pending the opening up of collateral circulation. In addition certain visceral afferent fibres pass through the stellate ganglion, for example, cardiac pain impulses are believed to pass by the middle and inferior cervical cardiac branches of the sympathetic to the cervical sympathetic trunk and so through the stellate ganglion (Peterson, 1938; Mitchell, 1953). Stellate ganglion block, especially if combined with block of the upper thoracic ganglia of the trunk, may relieve the pain (White, 1940). The outflow to the head and neck leaves the spinal cord through the first thoracic nerve and passes by the white ramus communicans to the first thoracic or the stellate ganglion of the sympathetic trunk. The fibres turn upwards and after synapse here or in the middle or superior cervical ganglia are distributed by grey rami to the cervical nerves, by communications to the last four cranial nerves, by visceral branches to cervical viscera and to the heart, and by the vertebral and internal carotid nerves to the interior of the cranium. The outflow to the upper limb leaves the spinal cord through the white rami of the second to the sixth or seventh thoracic nerves (Foerster, 1939). The fibres turn upward and after synapse in the thoracic, stellate, vertebral or middle cervical ganglia pass through grey rami for distribution through the brachial plexus. Kuntz (1927) has shown that there is a frequent though inconstant intrathoracic connection between the second and first thoracic nerves and Kirgis and Kuntz (1942) have demonstrated a similar connection between the third and second thoracic nerves. These connections would allow sympathetic fibres destined for the brachial plexus to leave the sympathetic trunk at the level of the second and third thoracic ganglia and these fibres would not pass through the stellate ganglion. Therefore to be certain of complete sympathetic denervation of the upper limb stellate ganglion block would be insufficient and it would be necessary to block the sympathetic trunk down to the level of the third thoracic ganglion.