The relationship between outcome of liver transplantation and experience in new centers

For several medical interventions, increasing experience results in improved outcome. This finding may result from better patient selection or increased skill levels. This report examines whether there is a relationship between center experience and patient outcome for liver transplantation, and if so, whether the relationship is explained by patient or donor selection or level of experience required to obtain optimal results. The United Network for Organ Sharing Scientific Liver Transplant Registry includes all procedures performed in the United States since October 1987. The date of the first transplantation and the number of operations performed were used to define 42 new and 27 experienced centers. Within new centers, experience was quantified by the sequence number of each transplantation. Characteristics of 6,180 recipients and donors were compared between new and experienced centers using the chi 2 test for association. A linear trend test identified whether these characteristics varied with experience within new centers. The independent association between experience in new centers and perioperative mortality was examined using logistic regression. Patient and donor selection criteria differ between experienced and new centers and change within new centers as experience is gained. Adjusting for calendar year and various patient and donor characteristics, perioperative mortality rates decrease in new centers as experience is gained. After 20 transplantations are performed, perioperative mortality in new centers is not significantly different than that in experienced centers. Criteria for recipient and donor selection change as centers gain experience. Despite these differences and improvements that have occurred over time, increasing experience in centers performing liver transplantations is associated with reduced perioperative mortality.