The effect of surgical volume and the provision of residency and fellowship training on complications of major hepatic resection

Abstract

Background: Positive volume-outcomes relationships have been demonstrated for hepatic resection using arbitrary criteria to define high-volume centers. The safety of training programs has not been evaluated. The association of surgical volume, as a continuous variable and the influence of a surgical residency and a fellowship program on outcomes after major hepatectomy were determined.

Methods: The Nationwide Inpatient Sample (NIS) was queried from 1998 to 2006. Quantification of patients' comorbidities was made using the Charlson index, and mortality, and complication rates were determined. Institutions' annual case volumes were correlated with risk-adjusted outcomes over time, as well as presence or absence of residency or fellowship training program using logistic regression modeling.

Results: A total of 5,298 major hepatectomies were recorded, representing a weighted nationwide total of 26,396 cases. In-hospital unadjusted mortality for the study period was 6%. Adjusting for comorbidities, greater major hepatectomy volume was associated with improvements in the incidence of most measured complications, with plateauing of mortality of between 2% and 3% at approximately 50 cases per year. The mortality rate increased once greater than approximately 70 cases were performed per annum. Hospitals supporting a surgical residency program had lower overall morbidity and mortality. A fellowship program however was not associated with overall lower morbidity and mortality and appeared to result in a higher rate of certain complications.

Conclusions: Greater annual major hepatectomy volume improves outcomes with reduced mortality up to a certain point. The presence of surgical residency program but not a fellowship program is associated with reduced predicted morbidity and mortality.