Systematic Review and Meta-analysis on the Use of Aortic Size Index in Women with Infrarenal Abdominal Aortic Aneurysms

Objective:
The aim of this study was to compare aortic size index (ASI) (aortic diameter/body surface area) with aortic diameter (AD) in patients with infrarenal abdominal aortic aneurysms (AAAs) for screening, diagnosis, and outcomes, focusing on women.

Methods:
Cochrane, MEDLINE, and Web of Science Core Collection databases were searched (last update 14 May 2024) for reports on ASI in patients with AAA reporting sex disaggregated data. A systematic review and meta-analysis was performed following the PRISMA guidelines.

Results:
Eleven studies with 150 028 cases (19.8% women) were included. The reported outcomes exhibited considerable heterogeneity. Three studies evaluated incidence and or prevalence rates, seven reported on AD and ASI at the time of repair, three considered rupture risk, and five evaluated peri-operative outcomes. In one study, AAA prevalence was 5.7% in men and 4.5% in women with a cutoff ASI ≥ 1.5 cm/m2 (corresponding to a 30 mm AD in men and 26 mm AD in women), compared with 5.7% in men vs. 2.4% in women using an AD ≥ 30 mm cutoff. ASI ≥ 2.7 cm/m2 was found to be associated with a distribution of ruptured repairs of 12% in both sexes, corresponding to 55 mm AD in men and 49 mm AD in women. A meta-analysis of aneurysm size at the time of surgical repair found that women were intervened at an estimated 3.05 mm smaller diameter but 0.32 cm/m2 higher ASI. Higher ASI was associated with worse clinical outcomes in women, but not consistently so in men.

Conclusion:
Women undergo AAA repair at lower AD but higher ASI than men. Use of ASI suggests that women undergo diagnosis and treatment at a later stage of disease. This warrants reconsideration of current AD threshold recommendations and further in depth studies assessing the impact of ASI standardisation.