Comparative Study Of Aortic Remodeling And Therapeutic Effect After TEVAR In Acute And Subacute Stanford B Thoracic Aortic Dissection

Background:At present,Thoracic endovascular aortic repair(TEVAR)has become the first choice for the treatment of type B thoracic aortic dissection(TBTAD).However,the medical reports are mainly focus on the comparison and difference of the patients in acute phase and chronic stage.With the introduction of the concept of subacute stage of dissection,the characteristics of TBTAD in each period under the new staging system has gradually become a research hotspot.The purpose of this study is to compare the aortic remodeling before and after TEVAR in patients with acute and subacute TBTAD and to provide clinical evidences for diagnosis and treatment of the disease.Materials and Methods:The data of acute and subacute TBTAD patients who received TEVAR treatment for the first time in Subei People’s Hospital of Jiangsu province from January 2013 to December 2018 were collected and analyzed.According to the CTA images of the patients,the average internal diameters of true and false lumen in S1-S5section,thoracic aorta,thoracic aorta and thoracic aorta were measured before and after TEVAR treatment.Total aortic volume,total aortic true lumen volume and total aortic pseudocavity volume were measured before and after operation in both FLP and FLT groups.Using SPSS 26.0 statistical software(IBM SPSS Statistics.Version 26.0)analyze the data.According to the normality test of continuous numerical variables,the statistical results of those who obey normal distribution are expressed by mean±standard deviation(M±SD),those who do not obey normal distribution are expressed by median and upper and lower quartile,and classified variables are described by median and mode.Comparing the differences among different groups,those who obey normal distribution in continuous numerical variables are tested by independent sample T test,those who do not obey normal distribution are tested by nonparametric test,and the classified variables are analyzed byχ~2 test or Fisher exact test.P<0.05 was considered to have statistical difference.Results:A total of 65 patients were included in the study.There were 38 male patients and 27 female patients with an average age of 58.69±11.59 years.Among them,35patients(53.85%)in acute stage,the average time from onset to operation was 8.27±3.12 days,and 30 patients in subacute stage(46.15%),the average time from onset to operation was 19.81±4.62 days.The internal diameter of TL was enlarged and the diameter of FL decreased in both acute and subacute groups after operation,especially in the thoracic aorta segments(S1,S2,S3)(P<0.001).After TEVAR treatment,there were significant differences in the average diameter of thoracic aorta and FL between the two groups(P<0.05).After TEVAR treatment,there were significant differences in the average diameter of thoracic aorta and FL between the two groups(P=0.037 and P=0.027).After TEVAR,the average internal diameter of TA-TL increased significantly,while the average internal diameter of TA-FL decreased significantly in acute and subacute groups(P<0.001,P<0.003),and the average internal diameter of TA in acute group decreased significantly(P<0.001).For the patients with TA-FLT,the postoperative AA-TL volume increased and the AA-FL volume decreased in both the acute and subacute phase groups(P=0.004;P=0.003;P=0.017,P=0.002),and in the patients with TA-FLP,the AA-TL volume increased after operation(0.041 and 0.038).Conclusion:The results of this study show that TEVAR is an ideal method for the treatment of TBTAD.Aortic remodeling is more obvious in acute patients after TEVAR,which may help to choose the best operation time.