The morphology of lumbar sympathetic trunk in humans: a cadaveric study

The vasospastic diseases and chronic pain related to lower limb have been successfully treated by surgical ablation of lumbar sympathetic trunk for last 80 years. Precise knowledge of anatomy of lumbar sympathetic trunk and its adjoining structures is mandatory for safe and uncomplicated lumbar and spinal surgeries. We aim to study the detailed anatomy of entry and exit of lumbar sympathetic trunk, the number, dimensions and location of lumbar ganglia in relation to lumbar vertebra. Thorough dissection was carried out in 30 formalin embalmed cadavers available in the Department of Anatomy, Pravara Institute of Medical Sciences (PIMS), Rural Medical College (RMC), Loni, Maharashtra. A total of 238 ganglia were observed in 60 lumbar sympathetic trunks. The sympathetic trunk traversed dorsal to the crus of diaphragm in 72.6% and in 13.3% it entered dorsal to the medial arcuate ligament. The most common site of the location of lumbar ganglia was in relation to the second lumbar vertebra, sometimes extending up to the L2-L3 vertebral disc. There was a medial shift of sympathetic trunk in lumbar region and it coursed over sacral promontory to reach the pelvic region in 96% of specimens. These variations should be kept in mind in order to prevent hazardous complications like accidental avulsion of first lumbar ganglia and genitofemoral neuritis.