Effects Of Different Cerebral Perfusion On Postoperative Cognitive Function In Patients With Stanford Type A Dissection

BackgroundDeep hypothermic circulatory arrest（DHCA）is needed in Stanford type A aortic dissection.In order to protect brain tissue during circulatory arrest,perfusion doctors will carry out selective cerebral perfusion to the brain,but too low flow will lead to insufficient perfusion,and too high flow can lead to excessive perfusion hydrocephalus.Therefore,finding appropriate cerebral perfusion is an urgent problem to be solved in clinic.ObjectiveTo observe and compare the effects of antegrade selective cerebral perfusion of（ASCP）with different flow rates during deep hypothermic circulatory arrest（DHCA）on cognitive impairment in patients undergoing cardiovascular surgery.MethodsA total of 78 patients with Stanford type A dissection were selected from The First Affiliated Hospital of Xinxiang Medical College and Fuwai Huazhong Cardiovascular Hospital from September 2019 to May 2021.All patients underwent DHCA+ASCP operation.According to the difference of ASCP flow,they were divided into three groups:low flow group（L group,3ml/kg·minn）,medium flow group（M group,5ml/kg·min）and high flow group（H group,7ml/kg·min）.Venous blood was collected before operation（T₀）,circulatory arrest for 5 minutes（T₁）,rewarming to 36℃（T₂）,24 hours（T₃）,48 hours（T₄）and 72 hours（T₅）after operation to determine the concentration of NSE and S-100?protein in serum,and 1 day（T₆）,3 days（T₇）and 7 days（T₈）after extubation.The discharged patients returned to the hospital for reexamination or telephone follow-up（T₉）one month after discharge.The cognitive function was evaluated with the Mini Mental State Scale（MMSE）and Montreal Assessment Scale（Mo CA）.Intraoperative cerebral oxygen saturation r SO₂was monitored by NIRS,blood gas analysis was monitored intermittently,and lactate level and postoperative POCD incidence were recorded.Results1.There was no significant difference in demographic characteristics of different flow selective cerebral perfusion（P>0.05）;2.MMSE and MOCA scores of three groups of TAAD patients at each time point:the scores of medium flow group were significantly higher than those of low flow group and high flow group;And the score at T₈is significantly lower than that at T₇;3.Comparison of the incidence of POCD:the incidence of patients in the medium flow group was significantly lower than that in the low flow group and high flow group;4.r SO₂level,blood lactate level,S100-βProtein level and NSE level:repeated measurement analysis of variance was conducted among the three groups,and there was significant interaction between groups and time（F=15.59,P=0.001）.The results of simple effect analysis showed that the time effect and inter group effect were statistically significant（P<0.01）.The level of r SO₂in group M was significantly higher than that in group L and group H at T₂（P<0.05）.The level of blood lactic acid in group M was significantly lower than that in group L and group H at T₅（P<0.01）,S100-βof patients in group M.The protein level was significantly lower than that of group L and group H at T₄and T₅（P<0.01）.5.Spearman correlation analysis showed that blood lactate level,NSE level and S100-β.There was a significant positive correlation between protein level and POCD in patients with aortic dissection（P<0.05）;6.Logistic regression analysis showed that S100-β.It was an independent risk factor for POCD in patients with aortic dissection（P<0.05）.ConclusionsSelective cerebral perfusion with 5ml/kg·min does not increase neurological complications,can satisfy cerebral perfusion under deep hypothermic circulatory arrest,has brain protective effect,and will not increase the incidence of postoperative cognitive dysfunction.