Anatomical variations of the upper thoracic sympathetic chain: a review.

OBJECTIVES The objective of this study is to provide a thorough overview of the anatomical variations of the upper thoracic sympathetic trunk to improve clinical results of upper thoracic sympathectomy. In addition, this study strives for standardization of future studies regarding the anatomy of the upper thoracic sympathetic chain. METHODS The Web of Science, PubMed and Google Scholar databases were searched using keywords, alone or combined, regarding the anatomy of the thoracic sympathetic chain. The search was limited to studies performed in humans. RESULTS Fifteen studies were finally included. Cervicothoracic ganglion and nerve of Kuntz were present in 77% and 53%, respectively. The upper thoracic ganglia were predominantly located in their corresponding intercostal space with a relatively downwards shift at the lower thoracic levels. The right sympathetic trunk is prone to have more communicating rami then the left. The lower levels of ganglia tend to have more normal rami. No clear pattern was found concerning the presence of the ascending rami and there was a decrease in the number of descending rami as the chain runs caudally. The intercostal rami remain a rare anatomical variation. CONCLUSIONS This study presents an overview of the anatomy of the upper thoracic sympathetic chain. Its results may guide upper thoracic sympathectomy to improve clinical results. This review also provides a baseline for future studies on anatomical variations of the thoracic sympathetic trunk. More uniform reporting is necessary to compare different anatomical studies.