Clinical Anatomy Study Of Autonomic Nerves And Vascular Of The Anterior Approach Lumbar Surgery

Objective: To understand the location characteristics and the anatomical relationshipbetween lumbosacral autonomic nerve plexus and vascular,the morphological changeswere observed in the lumbosacral autonomic nerve plexus and vascular.The purpose ofthis study is to provide anatomic theoretical basis for the protection of autonomic nerveand vessel on the lower lumbar anterior approach operation.Methods:1. A random investigation on19formalin-treated adult cadavers (15male and4female).2. Cutting rectal on the level of peritoneal invagination and removeintestine,Open the parietal peritoneum,Complete exposure spinal region below the levelof L2.Dissection the following organizational structure:abdominal aortic plexus(AAP)、Lumbar splanchnic nerve(LSN)、Inferior mesenteric plexus(IMP)、Superior hypogastricplexus(SHP)、Sympathetic trunk(SC).3.Exposure of lumbar side:remove the psoasmuscle and exposure of lumbar side to intervertebral foramen.Exposure Intervertebraldisc and the segmental artery and vein of the lateral face of low lumbar,from their originto the processus transversus.4.Determined anterior midline line and observe thecharacteristics of AAP, IMP and SHP.Measure and record the relationship betweenAutonomic nerve,vessel and the anterior median line.Results:1.Nerve fibers of AAP,LSN and IMP mainly distribute in ahead of theabdominal aorta.The left side of the abdominal aorta has more nerve fibers than theright side.There are four types of the SHP nerve trunk:the type I of a single thinrounded nerve(21.1%);The type II of a broadened band-like nerve trunk (36.8%);The type III of two distinct nerves in close proximity with each other(15.8%);the typeIV of a wide plexiform formation(26.3%).The trunk of SHP with a mean length of59.38±12.86mm and mean width of11.25±2.92mm.SHP trunk were found located onthe left side of the anterior median line,and the distance from anterior median line to right border of SHP trunk was6.82±3.41mm.2.On the level of lower lumbar,intervertebral space existed in "safe region" which wasconstituted by segmental vessels,sympathetic trunk,lumbar plexus.On the left side,thearea of each "safe region"of L2-3、L3-4、L4-5level was followed by29.23mm×29.11mm、31.15mm×30.41mm、31.15mm×30.41mm.On the right side,it was followed by28.48mm×29.51mm、30.18mm×30.86mm、28.60mm×28.26mm， there was nosignificant difference in the bilateral "safe region".Conclusions:1:This research observed the anatomical characteristic of autonomic nerveplexus.Nerve fibers of AAP,LSN and IMP mainly distribute in ahead of the abdominalaorta.The left side of the abdominal aorta has more nerve fibers than the right side. TheSHP trunk were found located on the left side of the anterior median line.There are fourtypes of the SHP nerve trunk with a mean length of59.38±12.86mm and mean width of11.25±2.92mm.Further more,the SHP trunk has a mean width of19.49±5.10mm on thelevel of Sacral promontory.2:On the level of lower lumbar,intervertebral space existed in "safe region" without anyimportant vessels and neves.Must spaces can be provided during the anterior surgicaloperation for lumbar fusion or internal fixation.There was no significant difference inthe bilateral "safe region".3:According to the autonomic nerve plexus anatomical features of AAP, IMP andSHP,there are some suggestions for the less interference to autonomic nerve plexus onlumbar anterior approach operation.It should be exposure of the spine between L2andL5from the right side of the vertebral and remove autonomic nervous and vessels as awhole.This method is also be applied to exposure the L5-S1intervertebral in order toprotect autonomic nerve fiber on the lower lumbar anterior approach operation.