ANATOMY OF THE LUMBAR SYMPATHETIC CHAIN

Background and Objectives. To acquire an accurate knowledge of the rel ationship of the sympathetic chain to the vertebral column. Methods. I n dissections on 65 cadavers the authors located the sympathetic chain and its ganglia in three dimensions with respect to the vertebral col umn: cephalad-caudad in the sagittal plane; ventrally and laterally in the horizontal (axial) plane. The relationship of the sympathetic cha in to the psoas muscle and that of the psoas muscle to the vertebral c olumn was also established. Transparent markers were placed at each di sk space and colored markers at each grossly recognizable ganglion. Ph otographs and measurements were then made. Results. In the sagittal pl ane, the lumbar ganglia were most often present opposite the middle of the body of the third vertebra and at the disks above and below. In t he horizontal plane, the ganglia lay from 0 to 0.5 cm posterior to the anterior border of the third lumbar vertebra and 1.8 to 3.0 cm latera lly from the center of the third lumbar vertebra. The sympathetic chai n always lay anterior to the psoas muscle. Conclusions. Although the l ocation of the ganglia is quite variable, the best approach for sympat hetic block is to advance the needle paravertebrally through the fasci a of the psoas muscle slightly cephalad to the midpoint of the body of L3.