Impact of Centralisation on Abdominal Aortic Aneurysm Repair Outcomes: Early Experience in Catalonia

Objective: Several studies have revealed high volume centres have better outcomes in the treatment of abdominal aortic aneurysms (AAAs), thus supporting centralisation of this procedure into selected centres based on volume. To date however, the real benefit of centralisation of this pathology has not been well demonstrated. The aim of this study was to analyse the impact of centralisation in to high volume centres (defined as those performing more than 30 cases per year) on AAA treatment outcomes carried out in Catalonia (Spain). Methods: Data were collected from official national registries (HDMBD) for AAA treated by endovascular aneurysm repair (EVAR) or open repair (OR) over a nine year period. Two time periods were selected for comparison: before centralisation (2009-2014) and after complete centralisation (2015-2017). The primary objective was to determine short term mortality (in hospital and 30 day mortality) and length of stay (LOS) after intact AAA (iAAA) and ruptured AAA (rAAA) repair, before and after centralisation. Uni- and multivariable analyses were performed in order to identify independent outcomes predictors. Results: A total of 3 501 iAAAs, including 1 124 (32.1%) OR and 2377 (67.9%) EVAR, and 409 rAAAs, including 218 (53.3%) OR and 191 (46.7%) EVAR, were identified. After centralisation, there was a significant decrease in overall mortality in iAAA repair (4.7% vs. 2.0%, p < .001) and rAAA repair (53.1% vs. 41.9%, p = .028). Mortality reduction in iAAAs was significant for OR (8.7% vs. 3.6%, p = .005), but not for EVAR (2.2% vs. 1.5%, p = .25). Overall LOS decreased as well, mainly in iAAAs (9.49 +/- 10.84 vs. 7.44 +/- 12.23 days, p < .001), and in particular in elective EVAR (7.32 +/- 7.73 vs. 6.00 +/- 8.97 days, p < .001). Multivariable analysis was identified before the centralisation period as an independent predictor for both mortality (odds ratio 1.484, 95% CI 1.098-2.005, p = .010) and LOS (B coefficient 1.146, 95% CI 0.218-2.073, p = .016). Conclusion: The implementation of a country based centralisation programme for AAA treatment led to a significant reduction in short term mortality, for both iAAA and rAAA, and mainly for elective OR. LOS also significantly decreased, mainly for elective EVAR. These results support the benefit of centralisation of AAA repair procedures