A meta-analysis of the association of primary abdominal wall hernia with abdominal aortic aneurysm

Aim. Aim of the study was to determine whether primary abdominal wall hernia (AWH) is associated with abdominal aortic aneurysm (AAA) presence, we performed a meta-analysis of studies investigating the association with primary AWH and AAA. Methods. Medline and Embase were searched through January 2014 using Web-based search engines (PubMed and OVID). Studies considered for inclusion met the following criteria: the design was a comparative study; the study population was patients with AAA and subjects without AAA or patients with primary AWH and subjects without primary AWH; and outcomes included primary AWH incidence in both the AAA and control groups or AAA incidence in both the primary AWH and control groups. For each study, data regarding primary AWH incidence in both the AAA and control groups were used to generate unadjusted odds ratio (OR) and 95% confidence intervals (CIs). Results. Of 151 potentially relevant articles screened initially, 14 eligible studies were identified and included. A pooled analysis of all the 14 studies demonstrated significantly higher primary AWH incidence in the AAA group than that in the control group in the random-effects model (OR 2.32; 95% CI, 1.72 to 3.14; P for effect <0.00001; P for heterogeneity <0.00001). When data from 5 studies reporting adjusted ORs and other 9 studies were combined separately, primary AWH was significantly associated with AAA presence. Eliminating 3 large-size population-based studies did not substantially change the pooled estimate. Conclusion. Primary AWH appears to be associated with AAA presence.