High volume of AAA repairs associated with lower mortality

Clinical Question

Are patients with abdominal aortic aneurysms better off if they go to institutions with higher surgical volumes?

Bottom Line

Patient survival after repair of abdominal aortic aneurysms (elective or urgent) is higher when the patient is treated in an institution with a high surgical volume. This argues in favor of a central approach to managing patients with abdominal aortic aneurysms. Additionally clinicians who diagnose these patients may wish to consider altering their referral process taking these data into account. (LOE = 1a)


Holt PJ, Poloniecki JD, Gerrard D, Loftus IM, Thompson MM. Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery. Br J Surg 2007;94:395-403.  [PMID:17380547]

Study Design

Systematic review


Unknown/not stated


Inpatient (any location)


These authors used multiple databases to find articles reporting the relationship between volume of abdominal aortic aneurysm repair and outcomes. Although they reviewed the reference lists of included articles, they don't describe searching for unpublished articles. The authors report that each article was assessed for quality, but they don't report how this was done. Although a single author extracted the data from the included studies, the authors don't report assessing the quality of this researcher's work. When this was reported, the authors used the case-mix adjusted complication rates. Finally, they supplemented the data from the published studies with data from the United Kingdom Hospital Episode Statistics. They included 21 studies of elective repair and 12 studies of repair for ruptured aneurysms. When supplemented with the national registry information, this resulted in 421,299 elective surgeries and 45,796 surgeries for ruptured aneurysms. They used 43 elective surgeries per year and 15 for ruptures to distinguish high- and low-volume hospitals. For elective surgery, the overall mortality rate was 9.5% and the mortality rate declined as the annual volume of surgery increased. High-volume hospitals had lower mortality rates (odds ratio [OR] = 0.66; 95% CI, 0.65-0.67). The overall mortality rate for repair of ruptured aneurysms was 37.1%. High-volume hospitals also had lower mortality rates then low-volume hospitals (OR = 0.78; 95% CI, 0.73-0.82).