A Experimental Study of Microcirculation and Electrophysiology in Rabbit of Tractive Iumbar-sacral Nerve Root Injury

Objective To establish an animal model of graded tractive lumbar-sacral nerve root injury in rabbits,discuss the CSEP and MVD after lumbar-sacral nerve root injury.Methods 40 rabbits were randomly divided into 4 groups: control group without traction,light traction group,middle traction group and serious traction group.The model was induced by dragging the first left sacral nerve root in different degrees of traction with a special retractor after exposing the spinal cord entirely via bilateral laminectomy,then neurophysiologic evaluation was performed and tissue samples were harvested for histological analyses.Results The neural electrophysiological changes and MVD were correlated with traction.The larger the traction,the longer the latency of SEP P1 wave and the more severe of the MVD change.The light traction group showed no significant difference compared with the control group throughout the experimental period. For the middle traction group,the latency of SEP P1 waves were significantly longer than the control nerve roots during the traction,but not significant after the traction.The latency of SEP P1 wave was significantly longer.Conclusion This animal model of tractive lumbar-sacral nerve root injury was based on different degrees of trction.It has stable and repetitive characters for research on basic pathophysiologic mechanisms and on the effects of various interventions on nerve root injury.MVD and CSEP can measure injury degree of spinal cord and nerve root better.