Difference Analysis Of Imaging Factors Of Intraluminal Thrombus Between Ruptured And Intact Abdominal Aortic Aneurysm

ObjectiveThe purpose of this study is to compare the parameter difference of intraluminal thrombus between diameter-matched ruptured and intact abdominal aortic aneurysms(AAAs)MethodsWe collected 996 cases who were diagnosed as "abdominal aortic aneurysm" in vascular surgery department from 2010 to 2018 through the case database of China-Japan Union Hospital of Ji Lin University.We selected datas of 93 cases by means of browsing the abdominal and lower limb enhanced scans(CTA),and we choosed ruptured AAAs and diameter-matched intact AAAs among them in a proportion of 1:2 into the experimental group and control group respectively.There were 15 cases in ruptured AAA group and 30 cases in intact AAA group.We got informations from the relevant cases,compared the demographic information and comorbidities of the patients in groups,including age,gender,smoking,hypertension,diabetes,hyperlipidemia;the variables that were recorded were the normal and maximum diameter,ILT thickness,lumen and AAA cross-sectional areas,lumen and AAA volumes,which were measured through three-dimensional vascular reconstruction,and the ILT area and ILT volume were indirectlycalculated.These datas were divided into one-dimensional parameters,two-dimensional parameters and three-dimensional parameters according to the spatial geometry.We wanted to find out whether the difference in parameters between the intact AAAs group and the ruptured AAAs group was statistically significant;and found out whether the difference from patients’ demographic information and comorbidities subgroup analyses on AAA was statistically significant.Results1.Comparison of demographic information and comorbidities between patients in ruptured AAAs group and intact AAAs group:compared with intact AAAs group,patients in ruptured AAAs group were significantly younger in age(p=0.005),and the proportion of rupture in AAA patients with diabetes was significantly lower than that without diabetes mellitus(p= 0.008).At the same time,there were statistically significant differences between the two groups in smoking status(p= 0.001).On the contrary,there was no significant statistical difference between the two groups in gender,hypertension,hyperlipidemia,etc.(P>0.05)2.Comparison of differences in AAA diameters between different genders: compared with females,males had larger normal diameters(28.46±2.90 mm VS 26.04±3.65 mm,P=0.033),and the diameter ratio of males was also significantly greater than that of females(44.37±6.20%VS 39.27±8.5%,P=0.041).3.Comparison of CTA 1d parameters between the ruptured AAAs group and the intact AAAs group: the normal diameter of the ruptured AAAs group was significantly smaller than that of the intact AAAs group(25.99±1.95 mm VS 28.89±3.29 mm,P= 0.003),and the diameter ratio of the ruptured AAAs group was also smaller than that of the intact AAAs group(40.22±6.00% VS 44.74±7.10%,P=0.04).Comparatively speaking,the ruptured AAAs group had a thinner ILT thickness(13.47±8.96 mm VS 22.95±11.41 mm,P= 0.007).There was no significant difference in the maximum diameter between the two groups(P>0.05).4.Comparison of two-dimensional parameters of CTA between the ruptured AAAs group and the intact AAAs group: the proportion of ILT area in the ruptured AAAs group was significantly smaller than that in the intact AAA group(43.25±22.40% VS 60.68±23.77%,P=0.023),and the lumen area of ruptured AAAs was significantly larger than that in the intact AAAs group(20.96±13.44cm2 VS 14.83±13.02cm2,P= 0.036).However,there was no significant difference in the cross-sectional area of AAAs between the two groups(P>0.05).5.Comparison of three-dimensional parameters of CTA between the ruptured AAAs group and the intact AAAs group: there was no significant difference in the ILT volume,AAA volume and lumbar volume between the two groups,but in terms of the ILT volumeproportion,the ruptured AAAs group was significantly smaller than the intact AAAs group(44.22±15.04% vs.54.73±16.95%,P=0.048).6.Comparison of the influence of diabetes on ILT load :compared with AAA patients without diabetes mellitus,AAA patients with diabetes mellitus had greater ILT thickness(23.27±12.21 mm VS 16.16±9.63 mm,P=0.036),ILT area(21.04±9.08cm2 VS 14.91±7.50cm2,P=0.018),and larger ILT volume(176.14±75.38cm3 VS 125.82cm3,P=0.016),and so were the larger ILT area ratio(61.89±22.54% VS 47.53±24.83%,P=0.048)and volume ratio(56.45±15.18% VS 45.76±17.25%,P= 0.033).Conclusion1.Compared with intact AAAs,ILT load(ILT thickness,ILT volume ratio and ILT area ratio)of ruptured AAAs was significantly reduced,and ILT load could be used as a potential imaging index to improve prediction of rupture risk in AAAs;2.The ILT load of AAA individuals with diabetes was significantly increased,and the rupture tendency of AAA was smaller,which showed a negative correlation between diabetes and the progression of AAA to some extent.