Spinal Cord Blood Flow Change Of Primary Experimental Study In Canine Spinal Cord Injury

Background and Objective: Current, acute spinal cord injury(SCI) is one of the emergency trauma common disability diseases. The emergency department more attention to life support, spinal fixation and prevent secondary damage of SCI. But a large number of literatures have shown that it does not reduce the morbidity of SCI patients, and puts forward the closely associated with stroke SCI secondary to spinal cord injury. SCI secondary injury processes is the central gray bleeding, spinal cord blood flow plummeted and ischemia-reperfusion injury leads to lipid peroxidation, free radical formation, cell lysis and inflammation grade- linking reaction, and ultimately apoptosis. The change of Spinal Cord Blood Flow(SC BF) is one of the important factors involved in SCI secondary injury processes, so the study of SCBF change is an important part of the pathophysiology of SCI. Spinal cord structure consisting of central neurons mainly for butterfly gray region, surrounded by white matter area of myelinated fibers cells. Currently SCBF monitoring methods commonly used detector is located in the surface of the spinal cord, real time monitoring blood flow to the area hasn’t reported, blood flow to different parts of the gray and white matter in the changing rule of the impact after SCI is not very clear. So this topic aiming at the shortcomings of the SCBF monitoring method, using a needle type probe laser doppler blood flow monitor(NP- LDF) monitoring of SCBF in different regions of spinal cord, which primary observe its change rule after SCI, provide theoretical basis for clinical treatment SCI.Methods: 8 canines were divided into 2 groups at random. Control group : 2 canines exposure to thoracic 12-13(T12-13) segmental spinal; SCI group:6 canines not only exposure to T12-13 segmental spinal, but also have traumatic SCI。Canines have monitoring of central gray regions, ventral white regions and back white regions of the SCI areas by needle probe—laser doppler flowmetry( NP-LDF) at SCIpreoperative,postoperative 5minutes(5min), 60minutes(60min), 7days(7d), 3w(3weeks). The somatosensory evoked potentials(SEP) and motor evoked potentials(MEP) were administered and TSCIS method to evaluate behavior of hindlimb function at postoperative 1d,7d,3w.SCI group 3canines were death at postoperative 7d,3w,spinal cord have haematoxylin and eosin(HE) staining.Results:1.SCI group all animals model successful and enters the experimental.2.SC BF: SCI preoperative: central gray regions base value compared with ventral white regions base value and back white regions base value had significantly statistical difference(P<0.05); SCI group compared with control group in each region of the spinal cord SCBF value in the postoperative each time node corresponding had significantly statistical difference(P<0.05);SCI group central gray regions, ventral white regions and back white regions which postoperative 5min compared with postoperative 60 min,7d,3w had significantly statistical difference( P < 0.05);Postoperative 60 min compared with postoperative 7d,3w had significantly statistical difference(P<0.05).Preoperative compared with postoperative 5min,60 min,7d,3w had significantly statistical difference(P<0.05).3. TSCIS: Control group compared with SCI group had significantly statistical difference(P<0.05) at postoperative 1d,7d,3w. 4. SCI group’s SEP and MEP were not found any wave record, double leg gradually contracture, only on forelimbs. 5. HE: Postoperative 7d: spinal cord part of the loss of normal tissue, the central gray regions necrosis, cystic cavity formation; Postoperative 3w: Spinal cord is completely normal tissue, no obvious boundaries between gray and white regions, glial cells was discovered.Conclusion:1. The NP- LDF can accurately measure the SCBF of central gray regions,ventral white regions and back white regions; 2.The SC BF of central gray regions, ventral white regions and back white regions have a few time ascend after SCI, and with time pass, its have decreased significantly, eventually reach a steady state. Description of the spinal cord secondary injury processes after primary damage ensued;3.The experiment used NP- LDF into spinal cord to monitor the quality of SCBF, although for invasive monitoring method, but the research shows the probe intothe spinal cord to the spinal cord function has no effect, and can more accurately reflect changes in spinal cord blood flow after SCI.