Regarding “A new metric for centralization of ruptured abdominal aortic aneurysm repair in large territories”

Abstract

With great interest we read the article on the method to measure the door-to-door time as a metric for ruptured abdominal aneurysms. 1 This article described 2 remarkable observations, the first one being the introduction of door-to-door time as a quality parameter, the second being the absence of difference in mortality between low-and high-volume hospitals.One of the cornerstones of their argument for centralization is the suggestion that by using endovascular aneurysm repair (EVAR), the mortality of ruptured abdominal aneurysms can be reduced. As an argument for this hypothesis the authors present their own data, where the 6.3% of patients with EVAR had a mortality of almost 18%, whereas the remaining group of open patients had a mortality of >35%.Clearly these retrospective data do not support this thesis. On the contrary, the variation in volume of patients according to center suggests that the EVAR group is highly selected, specifically that there might exist a bias in which EVAR is only undertaken for less complicated cases. Although there is some potentially biased evidence that EVAR offers a mortality benefit over open repair, there are also randomized controlled trials that did not show any statistical difference in mortality between EVAR and open repair. 2 Because of such inherent potential bias in the registry presented, this study provides insufficient data to support the authors' conclusion of improved survival after EVAR with centralization of repair.