The quintessential question in liver transplant practice is whether a living donor liver is better than a cadaver liver option! Most live donor programs in India are vociferous in their support for living liver donation and claim living donor liver transplants are superior to cadaveric liver transplants. While living donor livers may be better in quality than a cadaver liver in India, the donor related risk and the higher technical complication rate negate this advantage. In view of the risks to living donors, I have personally opted to wait for cadaver transplants unless the patient is too sick to wait.
Having said that, there is an element of uncertainity with the cadver liver function. Particularly in India where standards of critical care, infection control and lack of awareness about donor maintenance protocols, this issue takes the center stage. There is no gold standard test to ascertain the viability of a cadver liver or the degree of damage sustained by it in the donor and ability to predict optimal function after transplantation.
All in all around 20 - 30% of cadaver livers fail to function optimally after transplantation in India and this condition is termed early allograft dysfunction (EAD). There are certain known associations for EAD, which are- older donors, prolonged ICU stay of donors, fatty liver (>30%), larger livers, those donors who sustain cardiac arrest during their ICU stay, longer cold preservation of the liver, excessive blood loss during recipient liver removal, high MELD score of the recipient and if the recipient was on a ventilator at the time of transplant.
By defenition EAD is present when the PT-INR is more than 1.6 after 7 days of transplant, AST/ ALT levels are higher than 2000 iu within the first 7 days and serum Bilurubin > 10 mg/ dl after 1 week of liver transplant.
A study 1930 cadver liver transplants published from Mayo clinic (Annals of Hepatology, Vol-15, No.1, 2016:53-60) clearly establishes the poor graft survival in EAD group. The 1 year, 3 year and 5 year survival for non EAD vs those with EAD was 91.4% vs 78.6%, 83.5% vs 67.9% and 74.8% vs 57.2% respectively. Clearly the graft failure rate and patient mortality continued into the fifth year after liver transplant.
This revelation raises a number of ethical issues in choosing marginal livers for liver transplant. Should the patient’s be given the choice to reject marginal livers? Which group of recipients can be transplanted with marginal livers? How does one decide on the issue of marginality?….. currently there are no guidelines and are left to individual surgeons or the center policy. Centers with larger number of waitlisted ptients assume this responsibility and are aggressive in using almost all livers. the big question is how ethical is this decision making process….moreover usually the junior members of a team is sent to assess and retrieve livers and their assessment may be questionable.
Taking cognisance of the fact that cadaver organ resource is scarce, one should be able to utilize this resource with minimum discard rate. Few options come to the fore, define degree of marginality based on the known risk factors and transplant livers with percieved risk of bad outcome only to those with higher risk (eg; HCC, high MELD, retransplants, those with living donor choice as a back up). Next the marginal livers could be maitained on pulsatile organ perfusion machines to study their function before transplantation (currently in expeimental stage). Yet another option that is gaining momentum is therapeutic plasma exchange in those with EAD. early repots indicate a statistical benefit in graft and patient survival.