Relation of Paralumbar Nerves and Conus Medullaris to the Vertebrae of Swamp Buffaloes

Abstract

                The last thoracic (T13) and the first three lumbar spinal nerves (L1-L3) of the 20 adult swamp buffaloes specimens were dissected and observed the relation of their crossing to the tip of transverse processes of first five lumbar vertebrae (TL1-TL5). Their dorsal and ventral branches crossed obliquely caudolaterally on the dorsal and ventral surface of the lumbar transverse processes, respectively. The T13 crossed the anterior border of TL1 tip (20 specimens). Most of L1 (8 specimens and two of the right side) crossed the posterior border of TL2 tip. The L1 of 6 specimens crossed the anterior border of TL3 tip. Some variations of L1 crossed the anterior border of TL2 tip and the posterior border of TL3 tip. The L2 crossed the anterior (10 specimens and one of the right side) and the posterior (7 specimens) border of the TL4 tip, and a few specimens variably crossed the posterior border of TL3 tip. Most of ventral branch of L3 were lining caudolaterally under psoas muscles. The ventral branch of L3 in some specimens (4 specimens and two of only right and left side) have a branch on the dorsal surface of the psoas muscles and crossed the posterior border of TL5 tip. The conus medullaris of spinal cord of all specimens were taper to filum terminale at the caudal part of the first sacral vertebra.

                 This study showed the variation in the course of the lumbar spinal nerves. It might be recommended that the effective paravertebral anesthesia nerve blocks in swamp buffaloes will be injected to the tip of the first five lumbar transverse processes, and infiltrated to anterior and posterior of them for the last thoracic and the first three lumbar spinal nerves blocks, respectively. The epidural anesthesia in swamp buffaloes will be safe for the spinal cord by injection at sacrococcygeal foramen since the spinal cord is taper to filum terminale in the first sacral vertebra.