Atmospheric pressure and infra-renal abdominal aortic aneurysm rupture: a single observational study and a comprehensive review of literature

Abstract

Introduction: There have been various suggestions that abdominal aortic aneurysm rupture (rAAA) might have a seasonal variation depending on atmospheric pressure (AP) alteration. Despite above suggestions no study has yet examined the effect of fluctuation in AP on daily, seasonal, monthly, AAA size and co-morbidities to reach a conclusive outcome.

Methods: A total of fifty (n = 50) ruptured AAA over a 5-year period were retrospectively studied. Local meteorological data on AP were obtained from UK Meteorological Office. The data was subjected to statistical analysis using Student's t-test, linear regression (Pearson correlation Coefficient) and Coefficient of determination to establish any casual link between AP and incidences of rAAA on daily, seasonal and monthly basis. The casual link was also assessed between AP, AAA size and co-morbidities. The outcome is presented in a format of comprehensive review of literature that detected only 6 papers in MEDLINE and EMBASE from 1951 to 2012 in UK.

Conclusion: There appears to be a significant correlation between mean monthly pressures and mean monthly rupture incidence (Pearson)(n = 12; r = -0.61; p < 0.034; rsq = 0.37). The periods of low AP are associated with higher incidence of rupture (rAAA n = 29 at mean atmospheric pressure 1012 mB Vs rAAA n = 12 at mean atmospheric pressure 1016 mB Vs rAAA n = 9 at mean atmospheric pressure of 1020 mB) in our study and all reviewed literature. In addition, no casual link between AP to co-morbidities (diabetes mellitus, hypertension ischaemic heart disease, chronic obstructive pulmonary disease) and AAA size could be established or found in the literature.