The anatomical rationale for an upper limb sympathetic blockade: preliminary report.

Stellate ganglion blockade (SGB) has long been considered pivotal in the diagnosis, determination of prognosis and management of chronic regional pain syndrome (CRPS) by sympathectomy. To date a variety of SGB techniques have been described. An inaccurate SGB may mislead clinicians and deny patients a potentially beneficial procedure. In order to obtain a predictable and readily reproducible blockade of the upper limb, a modified anterior technique was evaluated. This modified sympathetic block was performed in 10 adult cadavers (n=19 sides). Toluidine blue solution (10 ml) was injected and, following median sternotomy, the extent of spread of dye was evaluated. In one cadaver a dual block using both the modified and the standard techniques was performed. Proximal spread to the seventh cervical vertebra was noted in all blocks; distal spread extended to the neck of the third rib (n=3), neck of the fourth rib 7 (n=15) and neck of the seventh rib (n=1). Medial spread was greater than lateral spread and extended to the vertebral bodies (vagus nerve was also stained) while lateral spread in all cases "blocked" lower roots of the brachial plexus and was consistently noted beyond the usual location of the nerve of Kuntz. This modified technique demonstrated that the lower cervical ganglia and proximal thoracic sympathetic trunk were consistently stained. It should be noted that the spread was sufficiently lateral to block the nerve of Kuntz. The pitfalls of this technique aside, we suggest that this technique be reserved for therapeutic purposes, particularly when sympathectomy is not possible.