Study On The Reconstruction Of Rectal Function In Rats With Spinal Nerve Cross Anastomosis

[Objective] To investigate the effective of reconstructing rectal physiological reflexarc by cross anastomosis nerve root.[Methods] From30three months age male SD rats, weighing about250gram; theright side as the experimental side, the left side as control side. Rats right L5spinalnerve were cut at foramen2mm，Right L6spinal nerves were amputated at the levelL5spinal cord level，Separating out L5, L6posterior roots，Then the far ends of L6roots （Ventral roots and Dorsal root） corresponding to coincide the line L5rootsnearly around the stump；Then，establish artificial the rectal reflex arc model owingcomplete sensory and motor pathways; All rats， the left are not processing.12weeksafter operation, we truncated spinal cord below the level of the L5segment toEstablish the complete paraplegia model of rats; then We conducted HRP retrogradetracing, detected the anterior and posterior horns of spinal cord CGRP content,determinated the intrarectal pressure;[Results]21rats survived to12weeks after operation,11rats were successfullyisolated nerve root anastomose, get the result of the experiment. Stimulation of L6DRof anastomotic distal rectum, by the artificial reflex arc new leads to the intrarectalpressure are respectively (19.2±1.33) cmH2O（before truncating）and (18.9±1.27)cmH2O（after truncating）, no significant difference (P>0.05). Before paraplegia,stimulating The control side L6DR, internal rectal pressure was (45.23±1.78)cmH2O, were greater than the experimental side (P <0.01) before and afterparaplegia. Immunohistochemistry showed L5segment of the right posterior horn ofthe spinal cord visible brown CGRP immune positive afferents end, followed by theangle of positive fibers IOD value close to the normal control group, the differencewas not statistically significant (t=1.05, P>0.05); and the visible L5root CGRPpositive axons with different thickness, through the DREZ into the horn of the spinalcord. HRP retrograde tracing show that experiments side establish new neuralpathways by axonal regeneration, the axonal regeneration transport functionrecovered well. Histological observations revealed that rat walking gait, Musculi- quadriceps femoris average weight of experimental side was (0.702±0.058g), thecontrol side weight (0.710±0.061g), t=1.01, p=0.233>0.05, no significant difference.[Conclusion] With VR and DR anastomosing can create artificial rectal reflex arccomplete, provide laboratory evidence for clinical paraplegia patients autonomydefecation.