Invited commentary
Article Outline
Dr Schermerhorn and colleagues have documented the changes in procedural volume and in-hospital mortality for abdominal aortic aneurysm (AAA) repair in the United States after the introduction of endovascular aneurysm repair (EVAR) using the National Inpatient Sample. They reported that the introduction of EVAR was associated with approximately a 40% reduction in the number of AAA-related deaths encompassing patients undergoing repair of intact aneurysms, ruptured aneurysms, and those with ruptured aneurysms that were not repaired. Somewhat surprisingly, the total number of repairs performed annually (both open and EVAR) has not increased significantly, but there has been an increase in the number of intact repairs and a corresponding decrease in ruptured repairs. The authors have documented that most intact AAA repairs are currently performed using the endovascular approach and that this transition from the open approach is largely responsible for the decreases in procedural-related mortality even though the average patient age is significantly greater in the post-EVAR era.
The reported results are very encouraging, and we should all take some measure of pride in the fact that the aneurysm-related mortality rate appears to be decreasing. However, the results need to be interpreted with some caution given the limitations of the study and the administrative database.
First, it is important to remember that the primary outcome measure is in-hospital, procedural-related mortality. Similar to the early results of the Dutch Randomised Endovascular Aneurysm Management (DREAM)1 and EVAR-12 trials, the observed benefits in procedural-related mortality may not actually translate into a longer-term survival benefit.
Second, the true effect on the population as a whole in terms of aneurysm-related mortality remains unknown because it is likely that a significant number of patients die with ruptured aneurysms outside of the hospital setting and, therefore, would not be accounted for in the current report.
Third, the study is a retrospective analysis that uses an administrative database of nonfederal hospitals. Despite their utility, these administrative databases are not designed specifically to answer clinical questions and are fraught with problems in terms of the accuracy and reliability of the data. Indeed, it was somewhat surprising that the survival rate for nonrepaired, ruptured aneurysms was 30%.
Fourth, the indications for the procedures are not available. Although unlikely, it is conceivable that the post-EVAR reduction in mortality resulted from a more widespread application of the technique to better-risk patients or those with smaller aneurysms (eg, <5 cm), or both. It has clearly been our anecdotal impression that the patients undergoing open repair in the post-EVAR era are more complicated both in terms of comorbidities and anatomy.
Ideally, these exciting results should serve as stimuli to further clarify the observations and continue to improve the overall care for patients with AAAs. The latter objective is contingent upon the identification of the presence of an aneurysm, refining the indications for repair, and improving the perioperative and longer-term outcomes. The Screening Abdominal Aortic Aneurysm Very Efficiently Act (SAAAVE) established a screening protocol for Medicare beneficiaries, but the indications are narrower than those recommended by the position statement of the Society for Vascular Surgery and its impact remains uncertain. The national and international randomized trials comparing open repair vs expectant management and open repair vs EVAR have begun to define the appropriate treatment paradigms. However, it is contingent upon us to incorporate the evidence from these trials in to our own practices.
References
- A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med. 2004;351:1607–1618
- . Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial. Lancet. 2004;364:843–848
PII: S0741-5214(08)01679-0
doi:10.1016/j.jvs.2008.10.009
© 2009 The Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Refers to article:
- Decrease in total aneurysm-related deaths in the era of endovascular aneurysm repair , 12 January 2009
