The Effect Of Preoperative Anatomical Factors On Postoperative Aneurysm Behavior In Patients With Abdominal Aortic Aneurysm Undergoing EVAR Surgery

Objective(s):To explore the preoperative basic data and anatomical factors related to the reduction of abdominal aortic aneurysm after endovascular aneurysm repair(EVAR),there is currently almost no research summary specifically targeting the relevant factors affecting the reduction of abdominal aortic aneurysm in the area where the center is located.This study will provide a summary of the relevant experience of the center,It helps to understand the factors that are conducive to the occurrence of aneurysm contraction after EVAR surgery in patients with abdominal aortic aneurysm in the area where our center is located,,and provide reference and reference for domestic cases in preoperative evaluation of such patients for surgical teams in China and even Asia.Methods:The baseline and imaging data of 72 patients with abdominal aortic aneurysm undergoing EVAR treatment in our center were retrospectively analyzed.The age,gender,smoking status,BMI,and underlying disease status of the patients were recorded.The preoperative CTA aortic diameter,proximal aneurysm neck diameter,proximal aneurysm neck length,preoperative maximum aneurysm diameter,inferior mesenteric artery diameter,lumbar artery diameter,lumbar artery number,and percentage of thrombus and calcification were measured and recorded.The percentage of aortic calcification and the distortion of the iliac artery were measured using Photoshop software to assist in obtaining the percentage of thrombus and calcification.The maximum diameter of the abdominal aortic aneurysm was measured before,3 months after,and 1 year after EVAR surgery,and compared to observe whether the aneurysm had shrunk during the follow-up process.The standard grouping was based on the reduction of the diameter of the abdominal aortic aneurysm after surgery by more than 5mm compared to that before surgery.Cases with a reduction of more than 5mm were divided into AAA reduction groups,and cases with a reduction of less than 5mm were divided into AAA non reduction groups.To compare the differences between patients in the shrinking group and patients in the non shrinking group after EVAR surgery in terms of the basic data collected above and the anatomical conditions of the aneurysm.Results:The results of the 3-month follow-up cases and the 1-year follow-up cases were approximately the same.(1)In the comparison results,there was no significant difference between the groups in terms of age,gender,smoking factors,BMI,and underlying diseases(P>0.05).(2)There was no significant difference between the groups in terms of the preoperative CTA aortic diameter,proximal aneurysm neck diameter,proximal aneurysm neck angulation,preoperative maximum aneurysm diameter,inferior mesenteric artery diameter,lumbar artery diameter,and number of lumbar arteries.There was no difference in whether the iliac artery was twisted or not(P>0.05).(3)In the results of comparison between the two groups of patients during the two follow-up periods,it was found that there was statistical significance in the length of the AAA neck before surgery(P<0.05).Through logistic regression analysis,it was found that in the cases with two follow-up cases,the preoperative AAA neck length was closely related to the postoperative aneurysm size reduction(P<0.05).The area under the ROC curve of the regression equation for 3-month follow-up cases was 0.835(95%CI 0.736～0.934,P<0.01),and the area under the ROC curve of the regression equation for 1-year follow-up cases was 0.884(95%CI 0.742～1.000,P<0.01).Conclusion:1.There is a significant correlation between preoperative neck length and AAA size reduction after EVAR.The longer the preoperative neck length,the greater the probability of postoperative aneurysm reduction.For patients with abdominal aortic aneurysm undergoing elective endovascular repair(EVAR),a longer neck may indicate a greater probability of postoperative AAA reduction in preoperative evaluation,and may also predict a relatively good prognosis.When the length of the aneurysm neck is larger before surgery,the aneurysm is more likely to shrink after surgery,and the postoperative contraction behavior of the aneurysm body can also be observed at an earlier stage.