Controlled Decompression For The Treatment Of Severe Traumatic Brain Injury:An Experimental Study Of Necroptosis In Rabbits

Part Ⅰ:Establishment of Rabbit Model of Acute Intracranial Hypertension for Basic Research of Controlled DecompressionObjective A stable rabbit model of acute intracranial hypertension was established by epidural balloon compression,which lays a foundation for the basic research of controlled decompression.Methods The model of acute intracranial hypertension was made by epidural balloon compression.70 New Zealand rabbits were randomly divided into 7 groups(16mm Hg,26 mm Hg,36 mm Hg,38 mm Hg,39 mm Hg,41 mm Hg,46 mm Hg;n=10).The changes of intracranial pressure in each group were dynamically monitored to determine the stable limit intracranial hypertension.After that,12 New Zealand rabbits were selected as the experimental group and the control group(n=6).The neurological score,the degree of brain edema,the number of Nissl staining positive cells and the expression of apoptotic factors were compared between the two groups 24 hours after the experiment.Results After injection of(1.21±0.88)ml normal saline into the balloon,the increase of intracranial pressure to 38 mm Hg could be used as a stable limit of intracranial hypertension in New Zealand rabbits.CT scanning and gross specimens showed that the brain tissue was obviously compressed,and the brain water content was significantly higher than that of the control group(80.79 ±1.49 > 78.75 ±1.10).The neurological score increased significantly(4.17±0.98>0.67±0.82).The number of Bax positive cells increased significantly(45.83±7.17 > 25.33±7.50),while the number of Bcl-2positive cells decreased significantly(29.67±6.47<54.83±11.41),The differences were statistically significant.Conclusion A stable and reliable rabbit model of acute intracranial hypertension with 38mm Hg was established,which lays a foundation for the basic research of controlled decompression.Part Ⅱ:Controlled Decompression for the Treatment of Traumatic Brain Injury: An Experimental Study of Necroptosis in RabbitsObjective The protective effect and specific mechanism of controlled decompression in the treatment of severe craniocerebral injury in rabbits were explored by comparing the two different surgical modes of controlled decompression and rapid decompression.Methods 24 New Zealand white rabbits were randomly divided into the Sham group,the Controlled group and the Rapid group.After the establishment of acute intracranial hypertension model,the degree of brain edema,animal behavior score,imaging and Nissl staining of cortical tissue were observed and compared 24 hours later.The expression of RIP1,RIP3 and Caspase-3 was detected by Western blot method.Results Neurological score,brain water content,and the expressions of RIP1,RIP3 and Caspase-3 in the Control group and the Rapid group were significantly higher than the Sham group(P<0.01),and the Control group were significantly lower the Rapid group(P<0.05).The amount of positive cells of Nissl’s body in the Control group and the Rapid group were both significantly higher than that in the Sham group(P<0.01),but there was no significant difference between the Control group and the Rapid group(P >0.05).Conclusion Controlled decompression can effectively reduce neuronal damage and Cerebral edema after craniocerebral injury,alleviate ischemia-reperfusion injury,and consequently protect brain tissue.