| Part one:Research monkey brain selective ultra-deep hypothermic blood flow recovery in animal model and EEG changesObjective:To establish a monkey brain after severe ischemia of the ultra-selective cerebral perfusion during deep hypothermic animal model to investigate the severe cerebral ischemia underwent selective cerebral perfusion during deep hypothermic effect on EEG.Materials and Methods:Healthy adult rhesus 8 (provided by the Kunming institute of Zoology, Chinese Academy of Sciences), male, responsive, normal nerve function, aged 5-8 years, with an average 6.43 persons 1.58 years old, weighing 6.73-9.86Kg, average 7.42 disabilities 2.51 Kg, were randomly divided into three groups:four-vessel (bilateral carotid artery and vertebral artery) blocking cold perfusion group (four-vessel group, n=3), two vessels (bilateral common carotid artery) resistance breaking cold perfusion group (two vascular group, n= 3), two vessels (bilateral common carotid artery) blocked isothermal perfusion group (isothermal perfusion group, n= 2). Preparation of ultra-deep hypothermia selective blocking blood flow recovery in an animal model of security:(1) before cooling to prepare:anesthetized, intubated to maintain spontaneous breathing animal. Inguinal incision area exposed left femoral vein to connect the output of the ultrafiltration device rewarming, revealing the right femoral vein to connect the input of an ultrafiltration device rewarming, revealing the right femoral artery was cannulated to monitor mean arterial pressure; cut bilateral carotid sheath to expose the internal carotid artery distal end connected to the right side of rewarming ultrafiltration device input, the right internal jugular vein connected to the distal end of rewarming ultrafiltration unit outputs, in order to establish cerebral cardiopulmonary bypass and right carotid vein proximal catheter central venous pressure monitoring. Separation with bilateral external jugular vein, left common carotid artery and jugular vein spare. Group 4-vessel occlusion in carotid sheath behind, isolated bilateral vertebral artery spare under the front neck 6 transverse process nodules. Through the right frontal craniotomy, in the frontal brain temperature sensors placed needle and EEG electrodes. Preparatory temperature (4.00±0.50)℃ in Ringer 4000 ml; (2) cooling methods:cool down before measuring EEG, systemic heparin, clipping bilateral external jugular vein, the left carotid artery and jugular vein, four-vessel occlusion blocking cold perfusion group shall bilateral vertebral artery, after 10 min ischemia through cooling system (Ringer-arterial infusion pressurizer) into the right carotid artery input Ringer maintain arterial pressure and groin artery pressure equal while from the right internal jugular vein and the left side of the head end distal femoral vein blood reflux. After removing excess water reflux rewarming to 38℃, via the right femoral vein proximal to reinfusion circulation, cooling 19.03 disabilities 4.72min, to be lowered brain temperature< 16℃ slowing the infusion rate, brain temperature is maintained at 14.70-16.00℃, a total of 60 min. (3) rewarming and restore normal blood supply:stop cold perfusion perfusion, restore normal blood flow is blocked vessels, natural rewarming to normal brain temperature. Breathing animal to be stable after the removal of endotracheal intubation, close monitoring of vital signs 72 h, let it restore the natural state. Two vessel occlusion room temperature perfusion group animals other infusion 37℃ Ringer’s solution, no measures to reduce brain temperature, the rest of the model building process with the other two groups the same.Results:The two-vessel occlusion cold perfusion group 3 animals were successfully established selective blocking blood flow ultra-deep hypothermia security recovery in animal models, the normal long-term survival after resuscitation; after four vessel occlusion cold perfusion group 3 animals difficult recovery, surgery unstable blood pressure, continued use of vasopressors to maintain blood pressure, all died within 24 h after surgery (2 h after the death of two perfusion, respectively, survived a 6h); two-vessel occlusion room temperature perfusion group 2 animals died immediately after reperfusion. EEG before and after surgery:three groups of animals were obtained before surgery EEG activity in the normal state image, regular rhythm, mainly to a wave amplitude is normal. (1) two-vessel occlusion cold perfusion group:bilateral carotid artery occlusion, brain surgery with the temperature drop, showed normal EEG a wave background disappeared, EEG wave amplitude decreased, increased slow wave; when the brain EEG≤18℃ when temperature dropped to a linear state without EEG activity, low voltage or equipotential; when rewarming to 33℃ EEG returned to normal (Fig.1). (2) two-vessel occlusion room temperature perfusion group:bilateral carotid artery occlusion, in perfusion during normal a wave background weakened or disappeared, irregular rhythm was low-medium-high amplitude slow waves, a moderate amount-the high amplitude spike slow wave, was rhythmic outbreak; EEG waveform is not restored to a normal state after injury, continued to show a low-medium-high amplitude slow waves, visible-the high amplitude spike slow wave rhythm of the outbreak was (figure 2). (3) 4-vessel occlusion cold perfusion group:4 animals are whole brain vessel occlusion, the EEG changes with two-vessel occlusion cold perfusion group is asically the same operation as the brain temperature dropped, EEG reduce volatility, dropped to≤18℃ when the brain waves almost in a straight line; rewarming to 33℃ brain wave returned to normal.Conclusion:The continuous monitoring during perfusion and after perfusion showed that compared with normal body temperature, ultra-low temperature of deep cerebral cortex have a significant protective effect; total blockade after bilateral carotid artery did not cause hypothermia group of animals hypoxic-ischemic injury, increased intracranial pressure without significant changes, ultra-deep hypothermia proved safe and effective in neurosurgery; and bilateral carotid artery occlusion of blood flow in animal models of experimental monkeys no neurological recovery after adverse effects, does not cause ischemia, hypoxic injury, showed good neuroprotective effect.Part two:Effect of monkey brain selective ultra-deep hypothermic blood flow recovery on EEG power spectrumObjective:To establish a monkey brain after severe ischemia of the ultra-selective cerebral perfusion during deep hypothermic animal model to investigate the severe cerebral ischemia reperfusion underwent selective cerebral profound hypothermia on EEG power spectrum.Materials and Methods:Healthy adult rhesus monkeys 3 (provided by the Kunming Institute of Zoology, Chinese Academy of Sciences), male, responsive, normal nerve function, aged 6-8 years, with an average 6.73 persons 1.18 years old, weighing 7.68-9.26Kg, average 8.22 disabilities 1.32Kg. Preparation of ultra-deep hypothermia selective blocking blood flow recovery in an animal model of security: (1) before cooling to prepare:anesthetized, intubated to maintain spontaneous breathing animal. Inguinal incision area exposed left femoral vein to connect the output of the ultrafiltration device rewarming, revealing the right femoral vein to connect the input of an ultrafiltration device rewarming, revealing the right femoral artery was cannulated to monitor mean arterial pressure; cut bilateral carotid sheath to expose the internal carotid artery distal end connected to the right side of rewarming ultrafiltration device input, the right internal jugular vein connected to the distal end of rewarming ultrafiltration unit outputs, in order to establish cerebral cardiopulmonary bypass and right carotid vein proximal catheter central venous pressure monitoring. Separation with bilateral external jugular vein, left common carotid artery and jugular vein spare. Preparatory temperature (4.00±0.50)℃ in Ringer 4000 ml; (2) cooling methods:cool down before measuring EEG, systemic heparin, clipping bilateral external jugular vein, the left carotid artery and jugular vein, after 10 min ischemia through cooling system (Ringer-arterial infusion pressurizer) into the right carotid artery input Ringer maintain arterial pressure and arterial pressure equal to the groin, while the right internal jugular vein from the head end and the left femoral vein distal venous reflux. After removing excess water reflux rewarming to 38℃, via the right femoral vein proximal to reinfusion circulation, cooling 19.03 disabilities 4.72min, to be lowered brain temperature≤16℃ slowing the infusion rate, brain temperature is maintained at 14.70-16.00℃, a total of 60 min. (3) re warming and restore normal blood supply:stop cold perfusion perfusion, restore normal blood flow is blocked vessels, natural rewarming to normal brain temperature. Breathing animal to be stable after the removal of endotracheal intubation, close monitoring of vital signs 72 h, let it restore the natural state. Monitor the preparation of animal model during EEG tracings to the conventional EEG electrode signals sampled randomly selected without interference or artifacts 30 seconds into the computer processing of the four bands namely 8 wave (0.5-3.9Hz),θ wave (4.0-7.9Hz), α-wave (8.0-13.9Hz),β wave (14-30Hz) the absolute power value. DB calculated using the absolute power values(dBm).Statistical analysis:SPSS 17.0 statistical software for statistical analysis, all data are expressed±standard deviation, number of groups were compared using repeated measures ANOVA design, showed statistically significant when, then LSD-t test pairwise comparison, P<0.05 explain the difference was significant statistically. Specifically described as follows:Fl, P1 represents the change of power leads of the same value with time, when P1<0.05 when the power value of four periods of the same failure, the difference was statistically significant. At this point again pairwise comparison to anesthesia as a control group, the other three power values are compared with the period of anesthesia, when the difference was statistically significant by*. F2, P2 Pairing leads comparison, namely about the corresponding leads (such as 01/02) of LSD-t test, when P2<0.05 when the legend about the corresponding leads (such as 01/02) power value in four different periods can be considered different power values of the left and right brain.Results:4 Period (anesthesia, infusion of low temperature maintenance phase, rewarming period) 4 brain waves (δ,θ, α, β) the absolute value of the power band of the same failure, the difference was statistically significant (P1<0.05). At this point then pairwise comparisons, compared with the anesthesia, the absolute power level perfusion period and low maintenance phase of their significant differences (* indicates P<0.05), the contrary, the absolute power level rewarming of its no significant difference (P> 0.05). Description With the monkey brain perfusion cold start, the absolute power level 4 brain wave bands are different brain regions began to decline, to a low temperature in Brain absolute power values are the lowest maintenance period. When rewarming of the absolute power level of each brain region is restored to the level before the low perfusion. Corresponding to the left and right leads (such as O1/O2) absolute power value LSD-t test, four brain wave frequencies corresponding to the absolute value of each time around was no significant difference between the leads (P2> 0.05), suggesting that low perfusion during about four bands brain regions brainwave absolute power values change no difference.Conclusions:(1)in low temperature maintenance period (lowered brain temperature≤18℃ when) EEG power spectrum band four waves (δ,θ, α,β) of the absolute power level, although there is still the lowest EEG activity and slow wave (δ, 0) based;(2) low perfusion during cerebral metabolic rate decreases nerve function was inhibited, rewarming brain metabolism and nerve function gradually returned to the level before cooling, confirmed the protective effect of low temperature of the brain from the EEG physiological point of view;(3) cold infusion process the left and right brain metabolism may be no difference in the cold infusion process. |
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