Neuroanatomy of cervical sympathetic trunk: a cadaveric study

Abstract

To reduce the risk of iatrogenic injury to sympathetic chain during anterior and anterolateral approaches to the cervical spine, its location has to be well defined and known by surgeons. We analyzed the course of sympathetic chain and its ganglia from C7 up to its entry into the cranial base and its relationship mainly with the longus colli (LC). Formalin fixed 20 human cadavers were dissected under operating microscope. Measurement of the dimensions of the ganglia, distance of the trunk to the LC, and the angles identifying the course of the chain were performed. Superior and inferior cervical/cervicothoracic ganglion were observed in all specimens, the middle cervical ganglion was observed in 48% of the specimens. The middle ganglion consisted of two ganglia in 10% of the dissected sides. Forty percent of the inferior cervical/cervicothoracic ganglion was at the C7 level, 25% was at C7-Th1 disc level, and 35% was at Th1 level. Vertebral ganglion was detected in only 8% of the specimens. The course of the sympathetic trunk converges medially descending from upper cervical levels to the lower levels. Anterior surgical approach to the cervical spine is a commonly used procedure. Although Horner syndrome due to sympathetic injury is not a common sequence of cervical operations, our findings support the current few reports on the subject and should be useful to any surgeon who operates in the cervical region to avoid this uncommon complication.