Family screening for abdominal aortic aneurysms: a systematic review and meta-analysis.

Background: International guidelines recommend screening of first-degree relatives of patients with abdominal aortic aneurysm (AAA). However, the prevalence of AAA amongst screened relatives is uncertain. Methods: Medline, Embase, and the Cochrane Library were searched from inception to 4 March 2026 for studies screening relatives of patients with AAA. Data were analysed using a random-effects model meta-analysis in Stata. Risk of bias was assessed using a validated tool for prevalence studies. Evidence quality was assessed using GRADE. Aims and analyses to be performed were pre-specified and recorded with PROSPERO: CRD42024566370. Findings: Twenty-six studies were included with 4166 AAA index patients and 4530 screened relatives, providing moderate-certainty evidence. The prevalence of AAA amongst relatives overall was 14.4% (95% CI 10.7%-18.4%) (24 studies), 21.9% (95% CI 15.9%-28.6%) in male relatives (19 studies), and 6.3% (95% CI 3.6%-9.5%) in female relatives (17 studies). The prevalence of familial AAA, where AAA index patients had at least one affected relative, was 16.9% (95% CI 12.7%-21.6%) (13 studies). The odds of finding an AAA amongst male relatives was about 4 times greater than in female relatives (OR 3.69, 95% CI 2.89-4.71). Screened female relatives had a 5 times greater risk of having AAA compared to age- and sex-matched controls, whereas the comparable figure for male relatives was about 3. The risk of bias was low for all studies. Interpretation: Relatives of patients with AAA are a highly enriched population for AAA, occurring in 1 in 5 males and 1 in 16 females, with 1 in 6 AAA index patients having at least one affected relative. These findings support screening strategies that encompass all first-degree relatives, both male and female, irrespective of reported family history in the AAA index patient. Funding: None.