Effects of hospital preference for endovascular repair on postoperative mortality after elective abdominal aortic aneurysm repair: analysis of the Dutch Surgical Aneurysm Audit. Issue 3 (22nd May 2021)

• Record Type: Journal Article
• Authors: Lijftogt, N; Vahl, A C; Karthaus, E G; van der Willik, E M; Amodio, S; van Zwet, E W; Hamming, J F
• Is Part Of: BJS open. Volume 5:Issue 3(2021)
• Publication Date: 2021-05-22
• Subjects: Surgery -- Periodicals; 617.005
• DOI: 10.1093/bjsopen/zraa065
• Languages: English
• ISSNs: 2474-9842

Abstract

Abstract: Background: Increased use of endovascular aneurysm repair (EVAR) and reduced open surgical repair (OSR), has decreased postoperative mortality after elective repair of abdominal aortic aneurysms (AAAs). The choice between EVAR or OSR depends on aneurysm anatomy, and the experience and preference of the vascular surgeon, and therefore differs between hospitals. The aim of this study was to investigate the current mortality risk difference (RD) between EVAR and OSR, and the effect of hospital preference for EVAR on overall mortality. Methods: Primary elective infrarenal or juxtarenal aneurysm repairs registered in the Dutch Surgical Aneurysm Audit (2013–2017) were analysed. First, mortality in hospitals with a higher preference for EVAR (high-EVAR group) was compared with that in hospitals with a lower EVAR preference (low-EVAR group), divided by the median percentage of EVAR. Second, the mortality RD between EVAR and OSR was determined by unadjusted and adjusted linear regression and propensity-score (PS) analysis and then by instrumental-variable (IV) analysis, adjusting for unobserved confounders; percentage EVAR by hospital was used as the IV. Results: A total of 11 997 patients were included. The median hospital rate of EVAR was 76.6 per cent. The overall mortality RD between high- and low-EVAR hospitals was 0.1 (95 per cent −0.5 to 0.4) per cent. The OSR mortality rate was significantly higher among high-EVAR hospitals than low-EVAR hospitals: 7.3 versus 4.0 per cent (RD 3.3 (1.4 to 5.3) per cent). The EVAR mortality rate was also higher in high-EVAR hospitals: 0.9 versus 0.7 per cent (RD 0.2 (−0.0 to 0.6) per cent). The RD following unadjusted, adjusted, and PS analysis was 4.2 (3.7 to 4.8), 4.4 (3.8 to 5.0), and 4.7 (4.1 to 5.3) per cent in favour of EVAR over OSR. However, the RD after IV analysis was not significant: 1.3 (−0.9 to 3.6) per cent. Conclusion: Even though EVAR has a lower mortality rate than OSR, the overall effect is offset by the high mortality rate after OSR in hospitals with a strong focus on EVAR. Abstract : Mortality after abdominal aortic aneurysm surgery may have changed owing to the increased application of endovascular aneurysm repair (EVAR) at the expense of open surgical repair (OSR), along with hospital preference. This study investigated the effect of hospital preference for EVAR on mortality by using an instrumental variable (IV): a hospital's preference for EVAR. Although overall mortality rates were similar in hospitals carrying out a high and low percentage of EVAR procedures, the mortality rate following OSR was significantly higher in high-EVAR than in low-EVAR hospitals. This will need special attention in the future.