Topographical considerations under video-scope guidance in the T3,4 levels sympathetic surgery

Anatomical variation of the sympathetic nervous system is known to be one of the main causes of failure and dissatisfaction after sympathetic surgery. However, there are only few reports on the descriptive analysis of sympathetic nerve variants. The purpose of this study is to investigate the anatomical variations of the sympathetic trunk at the levels of T3 and T4 ganglia considered in a topographic approach for sympathetic procedures and to further improve the postoperative outcome.

From June 2003 to January 2004, 44 patients with palmar hyperhidrosis underwent bilateral T3,4 ramicotomy via video-assisted thoracoscopic surgery. The anatomy of T3 and T4 sympathetic ganglia, pathway of sympathetic trunk, and rami-communicantes were recorded on video and still cut images for descriptive analysis.

The thoracic sympathetic trunks were mostly lying against the heads of the ribs, but there were variants of sympathetic trunk running along the medial side of the rib heads of 3rd, 4th and 5th ribs, respectively in 9.0%, 18.0% and 37.5% of the cases. There were also variants running along the lateral side of rib heads near the neck portion in 12.5%, 10.2% and 8.0% of the cases. The 3rd ganglion was located within the intercostal space (59.1%) or at the level of the upper border of the 4th rib (36.4%) or upon the 4th rib (4.5%). The location of the 4th ganglion was in the intercostal space (18.2%), the upper border of the 5th rib (44.3%) or upon the 5th rib (37.5%). The ascending rami were found at the level of the 3rd ganglion in 48.8% and the 4th ganglion in 45.5% of the cases. The descending rami were located at the level of 3rd and the 4th ganglion in 8.0% and 6.8%, respectively. And the middle rami were found in all cases except one.

It may be difficult to localize the sympathetic trunk in some cases of severe obesity; a careful inspection has to be performed from the medial side of the rib heads to the neck portion. The obvious 'downward shift of ganglion' in the position shown as the thoracic sympathetic trunk descends is to be deliberated in T4 sympathetic surgery. Many ascending and descending accessory pathways of sympathetic nerve were observed; therefore, a lateral extension of electrocoagulation at the level of upper and lower rib border is necessary to impose a complete blockage of sympathetic nerve stimulus.