[The effect of the ratio of aneurysm sac diameter to patient age on the long-term efficacy of different surgical methods for infrarenal abdominal aortic aneurysm].

Objective: To investigate the effect of the ratio of the maximum diameter of aneurysm sac to age (R) on the long-term efficacy of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) in patients with infrarenal abdominal aortic aneurysm (IAAA). Methods: This is a retrospective cohort study.The clinical data of 317 patients with IAAA who underwent surgical repair in the Department of Vascular Surgery,the Third Affiliated Hospital of Sun Yat-Sen University from January 2016 to October 2022 were retrospectively collected.There were 266 males and 51 females,aged (69.7±8.3) years (range:37 to 87 years).The R value of the patient was calculated and the receiver operating characteristic(ROC) curve was used to establish a model to calculate the optimal cut-off value.The propensity score matching method was used to match the baseline data of patients in the EVAR and OSR group by 3∶1 (the caliper value was 0.05),and the patients were stratified according to the cutoff value of R, and the postoperative efficacy and survival of the patients were analyzed.The primary endpoint was the total mortality rate,and the secondary endpoints included the occurrence of postoperative complications and reintervention.Pearson χ2 or Fisher 's exact test was used for categorical variables, and independent sample t test or Wilcoxon rank sum test was used for continuous variables to compare differences between groups.The survival curves of the two groups were described by Kaplan-Meier method. Results: After propensity score matching,198 cases were in the EVAR group and 66 cases were in the OSR group.The ROC model showed that the best cut-off value of R value was 0.90,and the two groups were divided into two layers:R<0.90 and R≥0.90.Among them,112 patients with R<0.90 (84 cases of EVAR,28 cases of OSR);there were 152 patients with R≥0.90 (114 cases of EVAR and 38 cases of OSR).The follow-up time was (23.6±1.6) months (range:1 to 70 months).In the R≥0.90 stratification,the total mortality (26.3% vs.5.3%,χ2=7.600，P=0.006),complication rate (44.7% vs.26.3%, χ2=4.025，P=0.045), and secondary intervention rate (31.6% vs.13.2%, χ2=4.910，P=0.027) in the EVAR group were higher than those in the OSR group.In the R<0.90 stratification,there was no significant difference in the total mortality rate (13.1% vs.10.7%, χ2=0.109，P=0.741), complication rate (28.6% vs.35.7%, χ2=0.507，P=0.477) and secondary intervention rate (14.3% vs.21.4%, χ2=0.353，P=0.552) between the two groups. Conclusions: When R≥0.90 in IAAA patients,OSR maybe more beneficial to patients in terms of survival rate,postoperative complication rate and secondary intervention rate than EVAR.When R<0.90,there are no significant differences in survival rate,complication rate and secondary intervention rate between the two surgical methods.