In a study of over 100,000 intact abdominal aortic aneurysm (AAA) repairs, an increase in the proportion of patients undergoing endovascular aneurysm repair (EVAR) over time has been demonstrated. This recent research, published in the European Journal of Vascular and Endovascular Surgery and authored by Jonathan R Boyle (Cambridge Vascular Unit, Cambridge University Hospitals NHS Trust and Department of Surgery, University of Cambridge, Cambridge, UK) et al, also reported that perioperative mortality rates are falling for both EVAR and open surgical repair. However, Boyle and colleagues also state that outcomes are poorer in women and octogenarians, and advise that future efforts should be focused on improving outcomes for these patients.
Given that outcomes after surgery vary between different healthcare systems and by country, the investigators set out to analyse perioperative mortality for intact AAA repair in contemporary data collected by the International Consortium of Vascular Registries (ICVR) in 11 countries and compare outcomes by gender, age, and geographical location during two different time periods.
Outlining the significance of this work, Boyle and co-authors write: “The importance of monitoring outcomes following AAA repair has been underlined by the recommendation in the European Society for Vascular Surgery (ESVS) AAA guidelines that vascular units performing aortic surgery should enter cases into a validated prospective registry to allow for monitoring of changes in practice and outcomes.
“The reporting of variation in outcomes after AAA repair is important for both patients and surgeons and is vital to drive quality improvement. The identification of high performing of units, regions, or countries enables them to share best practice principles and provides benchmark data for lower performing institutions to strive towards.”
In 2008, a VASCUNET report demonstrated that the UK had a higher elective AAA mortality rate (7.5%) than any country in Europe or Australasia. According to Boyle et al’s recounting, this publication was the catalyst for the Vascular Society of Great Britain and Ireland (VSGBI) to implement a Quality Improvement Programme in 2009, with the aim of halving the elective AAA mortality rate to 3.5% by 2014. As of 2012, mortality had fallen to 2.4% in the UK.
The present study utilised prospectively-collected ICVR data on primary repair of intact AAA from 11 countries, and included a total of 103,715 patients, analysed for two time periods: 2010–2013, and 2014–2016. The primary outcome was perioperative mortality after EVAR and open surgical repair. Multivariable logistic regression models were used to adjust for differences in patient characteristics.
The percentage of patients undergoing EVAR increased from 63.6% to 71.2% (p<0.001) over the study period. This proportion varied by country, from 35% in Hungary to 81% in the USA. Overall, perioperative mortality decreased from 2.1% to 1.6 % (p<0.001). Mortality also declined significantly over time for both open surgical repair (4.2% to 3.6%; p<0.002) and EVAR (1% to 0.7%; p<0.002).
Furthermore, the investigators found that mortality was significantly higher for women than men (3% vs. 1.6%; p<0.001). The percentage of patients under 80 years old undergoing AAA repair remained constant at 23.6% (p=0.91). perioperative mortality was higher for patients over 80 years than for those over 80 years old (2.7% vs. 1.6%; p<0.001). In total, 46% (n=275) of all EVAR deaths occurred in the over 80s.
Commenting on these findings, Boyle et al say: “Although some of this reduction may reflect an increase in the proportion of patients undergoing endovascular repair, it is clear that mortality has decreased for both open surgical repair (4.2–3.6%) and EVAR (1–0.7%). Within this large cohort, there was significant variation in both practice and outcomes by country. Not surprisingly, those countries that performed a higher proportion of open surgical repair had greater overall mortality rates. It is interesting that despite eight of the countries in this study being European, practice is clearly not standardised and there remain significant variations in the interpretation of the ESVS AAA guidelines in clinical practice.”