Clinical Identification of the Vertebral Level at Which the Lumbar Sympathetic Ganglia Aggregate.
BACKGROUND
The location and the number of lumbar sympathetic ganglia (LSG) vary between individuals. The aim of this study was to determine the appropriate level for a lumbar sympathetic ganglion block (LSGB), corresponding to the level at which the LSG principally aggregate.


METHODS
Seventy-four consecutive subjects, including 31 women and 31 men, underwent LSGB either on the left (n = 31) or the right side (n = 43). The primary site of needle entry was randomly selected at the L3 or L4 vertebra. A total of less than 1 ml of radio opaque dye with 4% lidocaine was injected, taking caution not to traverse beyond the level of one vertebral body. The procedure was considered responsive when the skin temperature increased by more than 1℃ within 5 minutes.


RESULTS
The median responsive level was significantly different between the left (lower third of the L4 body) and right (lower margin of the L3 body) sides (P = 0.021). However, there was no significant difference in the values between men and women. The overall median responsive level was the upper third of the L4 body. The mean responsive level did not correlate with height or BMI. There were no complications on short-term follow-up.


CONCLUSIONS
Selection of the primary target in the left lower third of the L4 vertebral body and the right lower margin of the L3 vertebral body may reduce the number of needle insertions and the volume of agents used in conventional or neurolytic LSGB and radiofrequency thermocoagulation.
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Ji Won
JW
An
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Jae Chul
JC
Koh
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Jong Min
JM
Sun
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Ju Yeon
JY
Park
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Jong Bum
JB
Choi
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Myung Ju
MJ
Shin
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.; Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Youn Woo
YW
Lee
Clinical identification; Lumbar; Neurolytic; Radiofrequency; Sympathetic ganglia; Vertebral level