167 Threshold for Intervention in Females with Asymptomatic Abdominal Aortic Aneurysm (AAA)- a Literature Review

Abstract

Abstract Introduction UK Small Aneurysm Trial, a study conducted in the late 90s, showed that the threshold for asymptomatic abdominal aortic repair in females would be < 5.5 cm. However, this threshold remained debatable. Our aim is to search for the most recent evidence in regard to the AAA repair threshold in females, and factors affecting the decision to intervene. Method PRISMA Flow from 2011–2021 was utilized using keywords on PubMed resulted in 913 articles. Upon further review by and full paper, 2 Cohort studies (n = 10102) and 11 narrative and retrospective reviews were found. Results 2 cohort studies (n = 10102), as well as 2 other studies, showed that the threshold should be 5 cm. There was a split in opinions between another retrospective (n = 4) reviews which argued for a cut-off between < 5 cm and 5.2 cm. The others, showed evidence of better outcomes repairing asymptomatic AAA at a threshold < 5 cm. Meanwhile, 3 studies recommended using ASI diameter < 5.5 cm^2. Overall, the Intervention threshold being 5 cm or less is reasonable for females since they have a 4-fold men risk of rupture rates at 5.5 cm in addition to significant physiologically smaller aortic diameter (1.75 cm) compared with males (2.4 cm). Conclusions The threshold for operating on female asymptomatic AAA should be lower than males, with some evidence suggesting < 5 cm compared to 5.5 in men. Patient tailored and risk assessment approach is recommended. Hence, this will be our standard for upcoming clinical audit.