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Marginal Donors: ethical considerations patient or centre oriented allocation systems?

Marginal Donors: ethical considerations patient or centre oriented allocation systems?. Background. There is an increasing disparity between the number of potential liver allograft recipients and the availability of donor livers Therefore there needs to be a system of organ allocation that is

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Marginal Donors: ethical considerations patient or centre oriented allocation systems?

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  1. Marginal Donors: ethical considerationspatient or centre oriented allocation systems?

  2. Background • There is an increasing disparity between the number of potential liver allograft recipients and the availability of donor livers • Therefore there needs to be a system of organ allocation that is • Transparent • Equitable • Just • Ethical • Supported by all stake-holders

  3. Expansion of donor pool • Maximise use of optimal donor pool • Splitting livers • Increased use of marginal livers • Living donors • Non-heart beating donors • Xenografts • Reduce contra-indications • e.g.Intracerebral malignancy, HCV positive and HBcAb positive donors

  4. Approaches to liver allocation • Selection of the sickest patient • Selection of the patient most likely to benefit • Selection of the patient who has waited longest • Giving everyone an equal chance • Consideration to the well-being of others • Priority to those who have already been transplanted • Ability to pay

  5. The US Approach • Priority to status 1 patients • Allocation to sickest candidate • Most likely to die • Assessed by MELD (or PELD) score

  6. UK approach • Priority to those with fulminant hepatic failure and early post-transplant graft failure • Selection by the local transplant centre • Common policy • >50% probability of survival at 5 years post transplant • Quality of life acceptable to the patient

  7. Benefits and Limitations • UNOS • Introduction of MELD has reduced mortality of patients on the waiting list • Based on objective and validated criteria • Needs adjustment for cancers, metabolic diseases • Problems for patients with symptomatic disease (such as intractable pruritus, encephalopathy)

  8. Benefits and Limitations • UK • Utility • Allows local centre to consider a variety of factors – donor, recipient, institution and logistical • Little evidence to justify or validate criteria • Could inhibit research and expansion of criteria

  9. Marginal Donors • No common or objective criteria • A graft a risk of • Primary graft non-function • Initial poor function

  10. Variable approaches to marginal donors(Mirza 1994) • 30 of 213 organs met the criteria for marginal donor livers • 16 refused by other centres (11 on medical grounds) • Graft survival not-affected (72% and 73%) • Questionnaire to various European Transplant Centres • 7/30 refused • 11/30 outright acceptance • Larger centres less likely to refuse

  11. Predictors of early allograft dysfunction(Deschenes et al, 1998) • Early Allograft Dysfunction (EAD) • Serum bilirubin >10 mg/dl • PT>17 secs prolonged • encephalopathy • Predictors of EAD • Outcome of EAD

  12. Predictors of early allograft dysfunction(Deschenes et al, 1998) • Early Allograft Dysfunction (EAD) • Donor Predictors of EAD and OR • Older age (>50years) 3.61 • Hospital stay >3 days 1.92

  13. What is a marginal liver • Donor • Technical

  14. Donor factors associated with liver graft dysfunction Age Gender Ethnicity Weight/BMI Steatosis in graft Cause of brain stem death Duration of ITU stay Use of pressors High serum sodium

  15. Technical factors associated with liver graft dysfunction Split livers Non-heart beating donors Cold ischaemia time

  16. Non-heart beating donors(Abt 2004) • Retrospective analysis of graft and patient survival between 1993 and 2001 from UNOS database • 144 NHBD and 26856 cadaveric donors 1yr Pt SPNFRe-graft NHBD 70.2% 11.8% 13.9% HBD 80.4% 6.4% 8.5%

  17. Split livers(Roberts, 2004) Risk of graft failure Age DD-F DD-S LD <2 1.64 2.06 1.02 2-10 1.01 1.16 1.48 11-16 0.99 1.68 3.82 17-29 1.0 2.28 0.96

  18. Surgeons are good at assessing marginal donors! • Zamir (2000) examined outcome of livers exported from OPO (13.3% of 555 livers over 3 years) • Objective reasons • No appropriate recipient, serology, malignancy • Subjective reasons • Medical/social history, abnormal liver tests, older age, organ appearance

  19. 1yr PS 1yr GS PNF Objective 79% 83% 0% Subjective 59% 68% 17%

  20. A scoring system for donor livers(Atli et al, 2004) • Retrospective study of 758 primary allografts done 1994-2001 • Multivariate analysis

  21. Donor Factors Age Macrosteatosis >30% BMI Peri-operative factors Cold ischaemic time FFP transfusion Cryoprecipitate

  22. Formula to predict early graft dysfunction 20.06 x steatosis 0.44 x donor age Cut off: 23.1

  23. The need to match donor and recipient • Gender mis-matching • Graft failure with gender mis-match 12.2% cf 11.3% match, p=0.013, mis-match associated with a 6.9% increased risk of graft failure (Rustgi, 2002, Neugarten 1994) • Ethnicity mis-matching • Mis-match increases risk of graft failure by 27% (p<0.001) (Rustgi, 2002) • ABO matching • Donor age and HCV

  24. Principles of medical ethics • Non-maleficence • Beneficence • Patient autonomy

  25. Ethical issues • Marginal livers • Split livers • Steatotic livers • Patient consent and autonomy • HCV positive recipients

  26. Split livers • Splitting livers has benefited the children • What expense to the adult potential recipient?

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