Volume versus outcome when treating abdominal aortic aneurysm electively--is there evidence to centralise?

To identify evidence for the minimum annual case load of open repairs of abdominal aortic aneurysms compatible with an acceptable perioperative mortality rate.

A PubMed search resulted in 137 references, sixteen articles with original data on volume and mortality not older than ten years were identified and selected for review.

Three studies found no volume-mortality relationship when controlled for age, sex and medical risk. Six studies verified volume thresholds of 20 procedures per year or more. In seven studies hospital volumes of 7-17 elective abdominal aortic aneurysm (AAA) repairs per year were sufficient to reach a mortality rate of a national average or similar to that of higher volume centres. No studies were published on the minimum annual case-load of EndoVascular Aneurysm Repair (EVAR), or of a combination of EVAR and open repair.

Recent studies in North America and in Europe indicate that 10-15 procedures annually can be sufficient to safely perform open AAA repairs. Centres regularly performing less should consider referral. Continuous monitoring and audit of risk-adjusted perioperative mortality rates should be practiced in all centres.