Infra-renal abdominal aortic aneurysm dilation ratio (AADR): A different measurement technique for intervention

Abstract

Introduction

To test the null hypothesis that the proposed abdominal aortic aneurysm (AAA) dilation ratio (AADR) obtained by dividing the widest diameter of the infra-renal AAA by the immediate native (normal) infra-renal aorta in millimetres, fails to provide accurate information about the risk of rupture in the female population, small or various sizes of infra-renal AAAs.

Methods

A retrospective study of 112 patients that underwent an infra-renal AAA repair on elective, urgent and or immediate basis with prior computed tomography angiogram (CTA) or computed tomography (CT).

Results

The mean AADR was 2.3 for asymptomatic group (n=73) and 3.3 for symptomatic group (n=28) (p<0.0001). The mean AADR was 2.88 for the tender AAA group (n=14) and 3.78 for the ruptured group (n=14) (p<0.0042).

Conclusion

Study suggests a lower threshold for female population that do not meet the interventional size. AADR≤2.8 could be a reasonable criteria for intervention irrespective of the aneurysm size. AADR can assist in doubtful or borderline scenarios, especially during the management of symptomatic patients as higher AADR>2.8 warrants an immediate operation. Finally, the AADR can be important in less privileged centres where ultrasonography (USS) and not repeated CT scan is permissible.