Will Improved Donor Safety Increase Liver Donations?

The advent of liver transplantation using living donor has ushered in a new era for the liver surgeon as well as the transplant surgeon. For the transplant surgeon, it has meant the initiation of liver transplantation in countries that cannot have a structured cadaveric organ donation due to lack of infrastructure or religious concerns. For the liver surgeon, it has profoundly enhanced the knowledge in terms of the functional anatomy. The importance of adequate venous drainage in reducing postoperative complications along with a better comprehension of the mechanism of liver regeneration are the substantial contributions of living donor liver transplantation (LDLT) to liver surgery. On similar lines, the transplantation of partial grafts led to the discovery of the “small for size” syndrome which describes the liver parenchymal injury due to hyperportal flow. Liver surgeons from Asia—who are the pioneers of this procedure—remain world leaders in the domain of LDLT because of the high quality of their surgery, extensive knowledge of the anatomy, meticulous surgical approach resulting in minimal blood loss, and their excellent assessment of postoperative vascular dynamics.

Results of the study published in this issue reaffirm the superiority of the Japanese surgeons in the field of LDLT (¹). Despite being a multicentric study, they have published the lowest mortality among all the nationwide surveys in the Europe and the United States (^{2, 3}) with a commendable low morbidity rate with 2.5% biliary fistula and 0.3% blood transfusion rate. This study confirms that the left lateral segment graft which is used for the pediatric liver transplantation has a low complication rate among the donors. This re-emphasizes the notion that LDLT for pediatric recipients is a reasonably safe option as regards the donor risk wherein the parents easily accept the risk of donation for their children without adverse psychological consequences.

There is a declining trend of adult-to-adult LDLT in European and US centers (^{2, 3}). The donor safety is the “credo” of the transplant team. This survey reported a remarkably low morbidity and only one death. It is surprising and interesting to note that the incidence of pulmonary complications is so low. Even if pulmonary embolisms are more frequent in the Western population than the Asian population, they are not mentioned in this survey whereas five cases were reported in the first one including 1841 donors (⁴). Moreover, beyond the actual classification of morbidity, the life long impact of some complications, such as portal vein thrombosis or biliary stenosis, still need to be better addressed.

Japanese donors are motivated by their strong social identity; this could explain the tiny number of psychological problems reported in this survey. Western donors who are more individualistic could be more often disappointed by an insufficient follow-up of the medical team who do not pay enough attention to their postoperative pain or difficult recovery. Some donors also undergo significant psychological trauma when they are disillusioned at the insufficient gratitude of the recipient for whom they risked their life in compulsive familial and ethical circumstances. These along with the physical quality of life issues among live liver donors need to be addressed with greater zeal in future surveys.

Would this new benchmark of donor safety overcome our reluctance to develop adult LDLT programs in the Western world? The answer is probably no …

Although most of the European and American states have well-established cadaveric organ donation programs and legislations, there is still a substantial scope to improve the number of livers procured with an increased use of marginal grafts and nonheart-beating donors.

With the allocation of organs now performed in accordance with the MELD score, those with an increased risk of mortality will no longer need a living donation. The question that now arises is whether it is ethical to subject a donor to risk for a patient who is not in imminent danger of dying and can await his liver? In addition, the progressive reduction of LDLT in Western countries does not allow most centers to reach the minimum number of procedures per year to ensure sufficient technical expertise.

The world’s largest LDLT center frequently use a “double” graft technique with two left lobes from two donors for adults to minimize the rate of right graft use (⁵). This strategy in a group who had performed more than 1500 LDLT procedures during the last decade indicates that the morbidity of right graft harvesting remains significant even after the learning curve is overcome (⁵). This suggests that there are certain factors beyond technical proficiency, which play a role in the occurrence of complications in these “patients.” If we analyze the causes of reported liver donor deaths, what is striking is that most of them have died—not due to common causes such as hemorrhage, sepsis or liver insufficiency—but often due to uncommon or unexplained causes (⁶). Is the healthy liver of the donor physiologically less prepared to tolerate the major hepatectomy and the subsequent rapid regeneration mechanism than the “sick” liver with a benign or malignant lesion? The remnant liver of the donor probably has to suddenly “work” much more to maintain the physiological status and is therefore more vulnerable and pays a much greater price than the liver with a pathological lesion.

Every country performing LDLT must take a cue from the Japanese surgeons and maintain a registry on donor morbidity and mortality, which at present is mandatory in France with a central governing body. This will not only help maintain standards of surgical expertise but also enable the analysis of complications and further minimize the adverse outcomes of living donor hepatectomy. The promotion and development of cadaveric organ donation program in countries that do not presently have one in place should be a priority. This will also improve the outcome of recipients who have less biliary complications and less poor liver function when they received a whole graft.