Effect Of Mild Hypothermic Circulatory Arrest On Brain Function In Patients With Stanford A Aortic Dissection

Objective:To compare whether the mild hypothermic circulatory arrest(mild hypothermic group)temperature(30-32℃)compared with the moderate hypothermic circulatory arrest(moderate hypothermic group)temperature(26-28℃)has less brain injury and whether it can better protect the postoperative brain function of patients with Standford A aortic dissection.Methods:A total of 120 patients with Standford A aortic dissection who were treated in the Department of Cardiovascular surgery,the second Hospital of Jilin University from January 2017 to July 2022 were randomly selected.The inclusion criteria will be met: 1.patients with Stanford A aortic dissection;2.All surgical procedures are ascending aorta and aortic arch replacement,distal stent implantation,stent elephant trunk;3.There were no neurological complications before operation;4.The age is between 45 and 75 years old.5.Patients who are without surgical contraindications,including those with severe hepatic and renal insufficiency and pulmonary insufficiency,or patients with a history of coma.According to the difference in nasopharyngeal temperature during circulatory arrest during operation,those with a nasopharyngeal temperature of 30-32℃ during circulatory arrest were set as the mild hypothermia group,and those with a nasopharyngeal temperature of 26-28℃ during circulatory arrest were set as the moderate-low temperature group.Sixty patients were randomly selected in each group,to analyze and study the general condition of patients before operation,Intraoperative time,cardiopulmonary bypass time,hypothermia time,rewarming time,ascending aortic occlusion time,circulatory arrest time,postoperative awakening time,postoperative mechanical ventilation time more than 72 hours,perioperative red blood cell transfusion,number of postoperative ECMO cases,postoperative thoracic drainage volume and hospitalization time,postoperative ICU stay time and the most important postoperative nervous system outcome observation index that the number of cases of temporary neurological dysfunction and the number of cases of postoperative permanent neurological dysfunction.The data were collected and statistically analyzed.Results:There was no significant difference in preoperative age,sex,body weight,hypertension and other general data between the two groups.There was no significant difference in ascending aortic occlusion time and circulatory arrest time between the two groups.The cardiopulmonary bypass time,operation time,cooling time and rewarming time in the mild hypothermia group were shorter than those in the moderate hypothermia group,and there was statistical difference.There was no significant difference in postoperative ventilation time > 72 hours,awakening time,permanent neurological dysfunction rate,postoperative ECMO cases and postoperative 30-day mortality between the two groups(P > 0.05).The number of24 h postoperative thoracic drainage volume,ICU stay time,hospital stay time and the case of temporary neurological dysfunction in the mild hypothermia group were significantly lower than those in the moderate hypothermia group.Conclusions:Mild hypothermic circulatory arrest(30-32 ℃)combined with bilateral selective antegrade cerebral perfusion is safe and effective in Stanford type A aortic dissection,especially to reduce the incidence of temporary neurological dysfunction after operation.In the case of avoiding moderate hypothermic circulatory arrest,it is helpful to reduce the side effects of cardiopulmonary bypass and moderate hypothermic circulatory arrest,which is more beneficial to the prognosis of patients.