1. Characteristics Associated with Liver Graft Failure: The Concept of a Donor Risk Index American Journal of Transplantation 2006; 6: 783–790 S. Fenga, N.P. Goodrich, J.L. Bragg-Gresham, D.M. Dykstra, J.D. Punch, M.A. DebRoy, S.M. Greenstein R.M. Merion Ri 張立禹

2. Introduction Increasing organ utilization / Progressive shortage of donor organs Increasing awareness of potential impact of aggressive organs utilization The Model for End-Stage Liver Disease (MELD): solely based upon transplant candidate Quantitative descriptions of organ quality, solely based upon donor characteristics

3. Materials & Methods (Data source) Data source: the Scientific Registry of Transplant Recipients (SRTR) Duration: 1998/1/1-2002/12/31 20,023 transplants Deceased donor Multiple organ transplants: excluded

4. Materials & Methods (Analytic methods) Cox regression models Time to graft failure: Transplantation to Retransplantation/ Recipient death The median follow-up time: 3 years Age, sex, race, ethnicity…… Recipient and transplant factors: adjusted to isolate the impact of donor characteristics.

5. Results - Donor and recipient characteristics -

7. Results -Risk factors for graft failure- 7 risk factors has significant association with liver graft failure: 1. Age 2. Race 3. Height 4. Cause of death (COD): CVA 5. COD: Other (not trauma/ CVA/ anoxia) 6. Donation after cardiac death (DAD) 7. Split/ Partial graft

8. “ Donor Demographic Characteristics ” Age: >40 years- increased risk of graft failure >60 years– the strongest risk factor for graft failure Race: African-American– 19% higher than white donor Height: Stronger than body weight

9. “Cause and Type of Donor Death” COD CVA: COD Other: Both have higher risk of graft failure (16% and 20%) DCD: 51% higher risk of graft failure Split/ Partial graft : 52% higher risk of graft failure

10. --Two Transplant Factors-- Cold ischemia time: ↑ 1% risk of graft failure/ addition hour Sharing outside of the local donor service area: Outside the local area: ↑ 11% Nationally shared: ↑ 28%

11. Results - Transplants according to donor risk index- RR of graft failure vs donor factor alone

12. Donor risk index = exp[(0.154 if 40≤ age <50) + (0.274 if 50≤ age <60) + (0.424 if 60≤ age <70) + (0.501 if 70 ≤ age) +(0.079 if COD = anoxia) + (0.145 if COD = CVA) + (0.184 if COD = other) + (0.176 if race = African American) + (0.126 if race = other) +(0.411 if DCD)+(0.422 if partial/split)+(0.066 ((170–height)/10))+(0.105 if regional share)+(0.244 if national share)+(0.010×cold time)].

13. Results - Recipient characteristics associated with utilization of grafts with higher donor risk index - More likely to receive higher risk donor index organs Older Youngest Woman Recipient without HCV Low disease severity (MELD score 10-14)

14. Results -Liver disposition by donor risk index categories- ↑Risk index,↑Higher discard rate Discard rate: Risk index > 1.5 twice than risk index ≤ 1.1

15. Discussion 7 donor & graft characteristics are significantly and independently associated with graft failure. Could compare the relative risk and the candidate’s disease severity at the time of organ offer

16. Age: A negative factor Donor age > 40 years are increasing (1988: 13%; 2003: 54%) Reflect the increasing disparity of organ demand and supply

17. Split/partial or DCD grafts: Associated with >50% risk of graft failure Only 2.0% and 1.1% of all transplantation now, but will likely continue to increase

18. -Other Risk Factor- Not achieve significance in this study: Female sex, Obesity,↑Liver function test (AST/ALT), hypotension/ increased pressor use, and ↑[Na+] Macrosteatosis and Cold ischemia time Both strongly associate with outcome in other study Macrosteatosis: Not easily detect while organ offering (frozen section) Not significantly associate with outcome in this study Cold ischemia time Estimated while organ offer Included in this study’s donor risk index

19. Ideal graft (ex: from donor <40 years, brain death secondary to trauma or anoxia) A relatively homogenous outcome group Non-ideal graft A heterogeneous outcome group The multitude of possible risk factor combinations presented by the donor pool

20. The risk continues to increase: Age of donor↑, Frequency of DCD donor↑, Split/ partial grafts↑ Ironic, split graft have been seen as ideal if transplanted as a whole organ Split graft: increased the patient transplanted & the net gain of life year

21. -The candidate who have the greatest risk without graft transplantation- Have the greatest survival benefit form transplantation May have disproportionately poorer outcomes with higher risk graft Compare to delayed transplantation, immediate transplantation with graft bearing a 50% risk of primary liver failure provide a higher 1-year survival rate

22. -Discard Rate- Higher discard rate for organs with higher donor risk index, but modest (3.1% in risk index of 1.0 to 12.5% in risk of 2.0 or greater) → the willingness to accept increased risk from suboptimal donor quality (more imminent consideration of candidate mortality in the absence of transplantation)

23. The decision to accept either the risk of transplantation or the risk of waiting must be decide rationally. The risk posed by the graft offering The risk of death from progressive liver disease This study provides an important quantitative assessment of relative risk of every potential graft, based upon donor and graft characteristics

24. Thanks For Your Attention