LIVING DONOR LIVER TRANSPLANT
Until the 1970s, there was no perspective of treatment for patients with end-stage liver disease. The only treatment available were palliative measures just to mitigate the patient´s suffering until the final phase of the natural course of the disease. However, liver transplantation opened increasingly exciting perspectives, and probably represents the greatest progress of modern hepatology. Centers with greater degree of experience report 90% of discharge and 70% of survival at five years after transplantation.
These fine results, achieved in a population without another therapeutic alternative, account for why the number of grafts is not enough to help every transplant candidate. Consequently, in all countires where this procedure is carried out, it is necessary to organize waiting lists and adopt criteria so as to establish a sequence of assistance. In Brazil, in 1997, a law was enacted creating one sole listing of recipients for each region, determining a chronological criterion according to the order of register on the list. In São Paulo, the waiting list includes around 3,000 patients. As the transplantation is performed only about 4 years after registering, a high mortality during the waiting period is reported. This problem is particularly important regarding pedriatic transplantation, since graft availability is smaller for this group.
With the purpose to find solution to the shortage of organs and its consequences, in 1988, we described, with colleagues Sérgio Mies and José Roberto Néri, a technique for pedriatic purposes, which uses a volunteer donor´s graft, called intervivos (living donors) transplant. The left lobe from an adult donor (20-25% of the organ) is transplanted into a child recipient. The surgery implies a very low risk for the donor, since resection of the segment employed as a graft infers a mortality rate of only 3% and requires no blood transfusion. Additionally, the regeneration process, peculiar to the liver, adds a significantly attractive element to the procedure. In 30 days, the donor has his/her liver original mass restored, while the transplanted segment grows until attaining the normal size, compatible with the recipient. Currently, this technique employed in the majority of the pediatric liver transplant centers has reduced the mortality on the waiting list reported in the literature from 50% to 5% .
From the 1990s on, in countries where harvesting of cadaver organs is prohibited, some medical teams have started to apply this technique in adults as well. The graft used is the right lobe (50-60% of the organ), of which the removal from the donor implies a greater risk, with a mortality rate estimates around 2%. However, since living donor transplant avoids the waiting list, its acceptance has been enormous also in countries where cadaver grafts are used. Over 4,000 cases of this surgery have already been reported in 30 centers in the USA, 15 in Asia and 5 in Europe.
In 1999, due to the high mortality rate of patients on the waiting list, the Liver Unit began to apply the living donor technique in adults. A 148 living-donor transplantations have already been carried out, the last 100 being performed at Hospital Israelita Albert Einstein, with which the Liver Unit established a partnership for transplant surgeries, including in public health system (SUS) patients. There was no mortality among donors, whose average hospital stay was 3,8 days. The outcome for the recipients has been similar to that obtained by other groups with great casuistry, that is, similar to those with cadaver grafts. The difficulties result from the smaller graft size and the smaller diameter of the vessels and the bile duct to be anastomosed. The anatomic variation of the bile duct pratically demands that a different type of reconstruction be carried out for each case. Despite these obstacles, adult living donor liver transplant has been the greatest progress in this specialty for the past years, deserving special attention in every congress where the topic is discussed.
Essentialy, a major attractive issue in the living donor technique is that it spares recipients awaiting transplantatioin, and opens perspectives for patients that otherwise would die before being transplanted. However, to depend on volunteer donation leads to scenarios never seen before with respect to ethics, which must be widely discussed. It is necessary to guard the donor´s autonomy, who is subject to unavoidable emotional strain, since the life of a beloved one depends on his/her decision.
We must stress that only centers with high degree of experience in hepatic resection and traditional transplants can carry out the living donor technique. Only under these circumstances may the the donor rely on the guarantee of graft removal at an ethically acceptable risk.
More specifically, the procedure must be evaluated with a view to the basic medical ethics. Is the modality based on volunteer donation of the right lobe useful? Yes, it is, because it´s the last resource for patients that cannot wait as long as established for cadaver organ transplantation. Is it fair? Yes, because it increases the chances of the recipíents on the waiting list. Finally, concerning the primo non nocere (do-no-harm) principle, we must consider two antagonistic trends. One of them, forbids the physician to do their patients any harm, while the other one guarantees every human being the regard to their right to autonomy. This principle confers the donor the right to running a known risk in order to save a patient´s life to whom he/she is emotionally connected. This binomial leads to the concept of "informed consent", based on a decision free from influences of any kind, whether they are emotional, family or others. In a context where the life of someone dear depends on a decision such as this one, there is no way to avoid influences that may restrain the donor´s freedom of choice.
It falls to the medical team involved to comply with a system which is able to guarantee the donor´s free will to its fullest . At the liver Unit, once there is an indication, the recipient and his/her family is informed of the existence of the living donor liver transplantation program and its results. Should the recipient agree, and provided there is a potential donor, the evaluation is carried out by another medical team, always in the absence of the recipient and his/her family. It begins with the thorough description of the risks inherent to the graft removal. Next, a procedure divided into three stages is followed, every stage including tests able to progressively elucidate whether the potential donor can actually be useful. After each one of these stages, the donor is asked to sign an informed consent. Prior to signing it, even if the tests demonstrate the surgery is feasible, the donor is informed that if he/she quits, the cancellation will be communicated to the recipient and his/her family as a result of anatomic incompabilities or any other type of inconsistency. If after these procedures, the donor confirms his/her inicial decision, his/her agreement is interpreted as "legimate consent".
By conducting this process, the medical team that indicates and performs the living donor transplantation provides a good example of what one expects from a modern physician, who represents the interface between the quick evolution of today´s medicine and the patient´s actual benefit.
In order to play this role well, he must develop and use more discernment and ethical principles, which tend to adapt to this very progress, not foreseeable until a few years ago.