Predicting Risk in Elective Abdominal Aortic Aneurysm Repair: A Systematic Review of Current Evidence

ObjectiveTo examine and compare existing pre-operative risk prediction methods for elective abdominal aortic aneurysm (AAA) repair.DesignSystematic review.MethodsMedline, EMBASE and the Cochrane library were searched for articles that related to risk prediction models used for elective AAA repair.Results680 abstracts were reviewed and after exclusions 28 articles encompassing 10 risk models were identified. The most frequently studied of these were the Glasgow Aneurysm Score (GAS), the Physiological and Operative Severity Score for enUmeration of Mortality (POSSUM) predictor equation and the Vascular Biochemistry and Haematology Outcome Model (VBHOM). All models had strengths and weaknesses and some had unique features which were identified and discussed.ConclusionThe GAS appeared to be the most useful and consistently validated score at present for open repair. Other systems were either not validated fully or were not consistently accurate. Some had significant drawbacks which appeared to severely limit their clinical application. Recent work has shown that no scores consistently predicted the risk associated with endovascular aneurysm repair (EVAR). Pre-operative risk stratification is a vital component of modern surgical practice, and we propose the need for a comprehensive new risk scoring method for AAA repair incorporating anatomical and physiological data.