UNOS Liver Registry: ten year survivals

1. This is a retrospective study using the UNOS database to examine the effects of various recipient, donor and transplant factors on 10-year liver graft survivals. A total of 68,776 adult liver transplants were reported to OPTN/UNOS from September 1987 to July 2006. Recipient, donor and transplant characteristics were compared using the paired t test for continuous variables. The chi-square tests were used to compare categorical variables. We calculated actual liver graft survival rates using the Kaplan-Meier methods. For statistical comparisons of survival curves, we used log-rank analysis. 2. The number of recipients who were older than 65 years of age has been steadily increasing each year. Since 1998, more than 10% of all recipients were over 65 years old, and in 2003 it reached 15.3%. The 1-, 5- and 10-year graft survival rates of liver transplant recipients who were younger than 65 years were 82.1%, 67.8% and 52.6%, respectively; for recipients who were 65 years or older they were 77.5%, 59.7% and 41.2%, respectively. 3. The impact of recipient, donor and transplant factors on liver graft survivals changed over time after liver transplantation. Recipient age, sex, having diabetes or angina and being positive against HCV antibody had both short- and long- term effects on transplant grafts. Pre-transplant dialysis and cold ischemia time had only short-term effects. 4. Our results showed that the transplants from older donors, DCD donors, HCV antibody-positive donors and diabetic donors had poorer graft survival than the transplants from other types of donors. 5. When the grafts which failed within one year were excluded from analyses, recipients whose serum total bilirubin at transplantation was higher than 7 mg/dL or recipients who were on mechanical ventilation at transplantation had better liver graft survival compared to other recipients. The better prognosis among recipients with higher total bilirubin or recipients on mechanical ventilation is partially explained by younger recipient age in these recipient groups. 6. The present allocation policy, the MELD-based deceased donor liver allocation system, mainly assigns a donor to a recipient depending on recipient pre-transplant medical status. However, to optimize the use of limited organs, not only pre-transplant recipient status but also expected liver graft outcome based donor assignment to recipients should be incorporated. 7. In conclusion, our study on ten-year liver graft survival showed that impacts of recipient, donor and transplant factors on liver graft survivals changed over time after liver transplantation.