The need for quality assurance in vascular surgery can be deduced from the variability in unruptured abdominal aneurysm operative death rates in a group of patients large enough that factors influencing mortality rates other than quality of care can be controlled. Operative mortality rate for 3570 patients undergoing unruptured abdominal aortic aneurysm repair was determined for all non-Veterans Administration surgeons and hospitals in New York State from 1985 to 1987. The average annual number of aneurysm operations per surgeon was 3.6, and per hospital it was 10.2. Unruptured aneurysm repair mortality for surgeons performing 1 to 5 aneurysm operations per year was 10% whereas for surgeons performing more than 26 aneurysm operations per year it was 6% (p < 0.0001). Unruptured aneurysm repair mortality for hospitals performing 1 to 5 aneurysm operations per year was 14% and for hospitals performing more than 38 aneurysm operations per year it was 5% (p < 0.0001). Even when these mortality rates were adjusted for differences in patient age, severity of illness, secondary diagnoses and admission status, significant mortality rate differences persisted: 9% versus 4% for low and high volume surgeons, respectively (p < 0.001), and 12% versus 5% for low and high volume hospitals, respectively (p < 0.001). Surgeons who performed more than 7 aneurysm operations per year devoted more of their practice to aortic (11%) and vascular operations (52%) than did surgeons who performed 7 or fewer aneurysm operations per year (2% and 19%, respectively). These data support the need for quality assurance in vascular surgery and indicate that the quality of care for unruptured abdominal aortic aneurysms is improved when operations are performed by surgeons who (1) specialize in vascular surgery, (2) perform comparatively large numbers of aneurysm operations, and (3) operate in hospitals where these procedures were relatively common. The need for more widespread referral of patients with unruptured abdominal aortic aneurysms to surgeons who specialize in their care and work in hospitals where such operations are performed frequently is thereby supported.
