Screening for abdominal aortic aneurysm in 65-year-old men in Oslo – outcomes and benefits

An abdominal aortic aneurysm (AAA) is a focal dilatation of the abdominal aorta, most commonly seen in elderly men, smokers and in individuals with a first degree relative with AAA. The condition is usually asymptomatic, but large AAAs are at risk of rupture. Ruptured AAAs are lethal without emergency repair, and the overall mortality is up to 80%. In comparison, the mortality after preventive elective repair is less than 5%. It is therefore crucial to detect and monitor individuals with AAAs, to intercept those with high-risk aneurysms and offer them preventive repair. An ongoing research project at Oslo University Hospital, started in 2011, offers AAA screening with ultrasound to 65-year-old men living in Oslo. The purpose of this doctoral work was to evaluate the outcomes and benefits of the screening project. From 2011 to 2019, 12810 men have been screened, uncovering a AAA prevalence of 2.6%. Annual attendance rates have been 60-80%. Eleven-year follow-up through hospital records and the Norwegian Cause of Death Registry, of individuals with a screen-detected AAA, revealed a rupture rate and AAA-related mortality of less than 1%. One fifth of these individuals had undergone preventive AAA repair, thus representing a group with aneurysms that could have ruptured had they not been detected. There was a non-negligible incidence of ruptures among non-attenders to screening, indicating a group that could especially benefit from screening. Exploring socioeconomic factors as well as self-reported reasons for non-attendance, suggested that socioeconomic deprivation is a determinant for non-attendance and that reminder invitations could increase the attendance rate. In conclusion, the AAA screening project in Oslo is relevant and effective in the effort to reduce the incidence of rupture AAAs and AAA-related mortality. In the future, on may consider offering screening to other high risk populations than 65-year-old men.