On the complexity of screening detected abdominal aortic aneurysms: A retrospective observational multicenter cohort study

BACKGROUND: Ultrasound screening for abdominal aortic aneurysms (AAA) has been shown to decrease aneurysm related mortality. Likely by providing an opportunity to intervene while the aneurysm is still intact, but possibly also when and the anatomy still relatively uncomplicated which would provide a less complex procedure. Our aim was to retrospectively investigate the complexity of repair for screening-detected AAAs in a cohort of 65-year-old men. METHODS: All screening detected AAA cases that underwent repair between Sept 2010 and June 2014 in the most southern region of Sweden were included. Procedures were classified as either standard or complex. A standard procedure was defined as either standard EVAR (endovascular aneurysm repair) within the manufacturers Instructions For Use (IFU) or open repair with infrarenal clamping followed by a tube graft repair. All other types of procedures were defined as complex. The prevalence rate of AAA, screening compliance, short-and midterm outcome of the operations were reported. RESULTS: From the 35513 men invited to screening, 27 951 (78.7%) attended screening with ultrasound. AAA30 mm was found in 561 cases, yielding a prevalence rate of 2.0%. Forty-eight patients underwent AAA repair. A percentage of 43.8% of these were classified as complex procedures. These consisted mostly of branched/fenestrated EVAR or EVAR with simultaneous exclusion of common iliac aneurysm. CONCLUSIONS: Our study confirms contemporary prevalence rates of AAA. Almost half (43.8%) of screening-detected AAA required complex operations, a significant proportion. The complex aneurysms were, on average, larger than the non-complex cases and they were more likely to be cases that required surgery immediately after screening detection. Our data suggests that the nature of AAA is heterogenous, even in the screening-detected group requiring operation. This should spur interest in more studies to investigate this issue.