Differential Analysis Of Distal Aortic Remodeling After Surgery For Acute Type A Aortic Dissection

Background and Objective:Type A aortic dissection is a fatal disease in cardiovascular surgery.Although the treatment effect of Sun’s Procedure currently recognized in China is relatively good,the 5-year survival rate of patients is still low,which may be attributed to the adverse remodeling of distal lumen after surgery.In recent years,more and more scholars have focused on analyzing the related factors affecting lumen remodeling.However,there are few studies on the difference in the effect of distal lumen remodeling after acute type A aortic dissection.There is no unified standard on how to make distal remodeling better and the selection of intraoperative stent size.Therefore,the purpose of this study was to explore the differences in distal lumen remodeling at four representative levels after acute type A aortic dissection,and analyze the influence and correlation of different stents and distal fractures on the remodeling effect at different levels.Method:Data of 63 patients with acute Stanford A aortic dissection admitted to the Department of Cardiovascular Surgery of Southern Hospital of Southern Medical University from January 1,2018 to August 31,2022 were retrospectively collected.Statistical analysis was conducted to obtain the remodeling effect of the distal aortic lumen at four levels before and after surgery(that is,the change of total diameter,the change of true and false cavity diameter,and the change of true and false cavity index).The difference of remodeling effect of the distal lumen at each level in patients with acute type A aortic dissection after surgery was compared,and the influence of different stent and distal rupture conditions on the difference was analyzed.Results:1.From the perspective of changing trend,the 63 patients had the best remodeling effect at the A level(descending aorta and pulmonary artery bifurcation level)after surgery(true cavity index 88.89%higher than before,the change was statistically significant,p<0.001),and good remodeling effect at the B level(10th thoracic vertebra level)(true cavity index 63.49%higher than before,The changes were statistically significant,p=0.002),and the effect of aortic remodeling at C and D levels(abdominal stem level and iliac artery bifurcation level)was relatively poor(true cavity index 52.38%increased compared with the previous level,the change was not statistically significant,p c=0.614,p D=0.616).2.Among the four levels A,B,C and D,there were significant differences in the effect of aortic remodeling between A and the other three levels(ZAB=-3.253,p=0.001;ZAC=-4.642,p<0.001;ZAD=-4.583,p<0.001),there was no significant difference among B,C and D(ZBC=-1.397,p=0.163;ZBD=-1.420,p=0.156;ZCD=0.056,p=0.955).3.At the B level,the remodeling effect of T8 was better than that of T5(X2=20.257,p=0.009).However,for levels A,C and D,there was no significant difference in lumen remodeling effect between different end levels of scaffolds.(X2A=5.820,p=0.121;X2C=6.030,p=0.110;X2D=3.215,p=0.360).However,there were differences in the degree of thrombus in the A-level pseudolumen with different stent widths(X2=11.325,p=0.023).4.Among the four layers,there was no significant correlation between the remodeling effect of lumen at the A and B layers and the existence of distal rupture(RA=0.102,pA=0.422;RB=0.047,pB=0.710),there was a negative correlation between the effect of lumen remodeling at the C and D layers and whether there was a distal fracture,and the D layer was more significant than the C layer(RC=-0.431,p c=0.001;RD=-0.532,pD<0.001).There were significant differences in the remodeling effects of different number of holes in C and D layers(X2C=12.754,p=0.002;X2D=15.385,p<0.001),and the remodeling effect of 3 or more holes was the worst.Conclusions:Sun’s Procedure can greatly promote the benign remodeling of aortic lumen.It is reasonable to believe that in the uncovered segment above the level of T10,the lower the level of the end of the stent,the better the effect of lumen remodeling.In the segment of stent coverage above T10 level,large and wide diameter stents were more likely to promote postoperative pseudolumen thrombosis than small and wide diameter stents.Whether there is still a tear in the distal end only affects the remodeling of the distal active vasculature below the abdominal trunk,and the lower the level,the more obvious the influence,and the more the number of holes,the worse the remodeling effect.