Gender Differences in Aortic Anatomic Severity Grade and Long-Term Survival Following Elective Abdominal Aortic Aneurysm Repair at a Single Tertiary Center

Abstract

Anatomic severity grade (ASG) score is utilized to assess preoperative abdominal aortic aneurysms (AAA) and provide a quantitative data on its anatomic complexity. The aim of this study is to determine the anatomical differences and long-term survival between male and female patients undergoing elective AAA repair. All patients undergoing intact AAA repair from 2007 to 2014 were included. ASG scores were calculated based on preoperative anatomical characteristics including aortic neck, aneurysm, and iliac artery. Standard univariate analysis was used to evaluate patient and anatomical characteristics. Kaplan-Meier survival curves were used to evaluate long-term survival at 1 and 5 years. A total of 379 patients were identified, of which, majority of them were males (80%). Females were on average 3years older (mean [SD]: 74.32 [8.63] vs. 71.92 [8.64] years) and were more likely to undergo open repair (29.7% vs. 17.5%) (both P<0.05). Both groups had similar comorbidities. The mean long-term follow-up (S.D.) was 6.21 (3.81) years. No significant difference was seen between males versus females in long-term survival at both 1 year (86.3% vs. 92.8, P=0.06) and 5 year (68.5% vs. 72.7%, P=0.38). In regard to the anatomical characteristics, females had shorter aortic neck length (mean in mm [S.D.]: 17.67 [1.41] vs. 27.20 [15.76]), increased tortuosity index [mean (S.D.): 1.11 (0.07) vs. 1.09 (0.07)]) and higher calcification [mean % (S.D.): 17.12 (21.17) vs. 10.59 (16.82)] (All P<0.05). In contrast, males had larger aortic neck (mean in mm (S.D.): 23.81 (4.17) vs. 22.41 (4.16)] and iliac artery [mean in mm (S.D.): 7.70 (1.91) vs. 6.28 (1.67)] diameter (both P<0.05). The mean total ASG score was significantly higher among females versus males [mean (S.D.): 17.23 (4.01) vs. 15.67 (3.96), P=0.003]. After stratifying by ASG score ≥15, females had significantly lower survival at 1 year compared to males (82.6% vs. 92.1%, P=0.04). However, this difference disappeared at 5 years. The data demonstrate that females present at an older age with more complex AAA anatomy than males. Based on anatomical complexities, females were more likely to undergo open repair, with a corresponding increase in 1-year mortality, but not at 5 year. The data suggest that care processes for optimization of aortic surgery in females are needed to improve 1-year survival.