The importance of surgeon volume and training in outcomes for vascular surgical procedures

Mortality and morbidity rates after vascular surgical procedures have been related to hospital volume. Hospitals in which greater volumes of vascular surgical procedures are performed tend to have statistically lower mortality rates than those hospitals in which fewer procedures are performed. Only a few studies have directly assessed the impact of the surgeon's volume on outcome. Therefore, the purpose of this study was to review a large state data set to determine the impact of surgeon volume on outcome after carotid endarterectomy (CEA), lower extremity bypass grafting (LEAB), and abdominal aortic aneurysm repair (AAA).

The Florida Agency for Health Care Administration state admission data from 1992 to 1996 were obtained. The data included all nonfederal hospital admissions. Frequencies were calculated from first-listed International Classification of Diseases-9 codes. Multiple logistic regression was used to test the significance on outcome of surgeon volume, American Board of Surgery certification for added qualifications in general vascular surgery, hospital size, hospital volume, patient age, and gender.

During this interval, there were 31,172 LEABs, 45,744 CEAs, and 13,415 AAAs performed. The in-hospital mortality rate increased with age. A doubling of surgeon volume was associated with a 4% reduction in risk for adverse outcome for CEA (P =.006), an 8% reduction for LEAB, and an 11% reduction for AAA ( P =.0002). However, although hospital volume was significant in predicting better outcomes for CEA and AAA procedures, it was not associated with better outcomes for LEAB. Certification for added qualifications in general vascular surgery was a significant predictor of better outcomes for CEA and AAA. Certified vascular surgeons had a 15% lower risk rate of death or complications after CEA (P =.002) and a 24% lower risk rate of a similar outcome after AAA (P =.009). However, for LEAB, certification was not significant.

Surgeon volume and certification are significantly related to better patient outcomes for patients who undergo CEA and AAA. In addition, surgeons with high volumes demonstrated consistently lower mortality and morbidity rates than did surgeons with low volumes. Hospital volume for a given procedure also is correlated with better outcomes.