Age and liver transplantation

Summary

The average age of liver transplant donors and recipients has increased over the years. Independent of the cause of liver disease, older candidates have more comorbidities, higher waitlist mortality and higher post-transplant mortality than younger patients. However, transplant benefit may be similar in older and younger recipients, provided older recipients are carefully selected. The cohort of elderly patients transplanted decades ago is also increasingly raising issues concerning long-term exposure to immunosuppression and aging of the transplanted liver. Excellent results can be achieved with elderly donors and there is virtually no upper age limit for donors after brain death liver transplantation. The issue is how to optimise selection, procurement and matching to ensure good results with elderly donors. The impact of old donor age is more pronounced in younger recipients and patients with a high model for end-stage liver disease score. Age matching between the donor and the recipient should be incorporated into allocation policies with a multistep approach. However, age matching may vary depending on the objectives of different allocation policies. In addition, age matching must be revisited in the era of direct-acting antivirals. More restrictive limits have been adopted in donation after circulatory death. Perfusion machines which are currently under investigation may help expand these limits. In living donor liver transplantation, donor age limit is essentially guided by morbidity related to procurement. In this review we summarise changing trends in recipient and donor age. We discuss the implications of older age donors and recipients. We also consider different options for age matching in liver transplantation that could improve outcomes.

Introduction

The face of liver transplantation has changed in the last decades. Significant improvements have been achieved in terms of post-transplant survival and quality of life. The number of liver transplants performed each year increased up to 2005 in the United States[1], [2] and up to 2010 in Europe,[3], [4], [5], [6] before becoming relatively stable thereafter. The steady increase in donation after circulatory death (DCD) has contributed to the expansion of the donor pool. However, less stringent criteria in the selection of donation after brain death (DBD) donors along with a growing number of DCD donors has not covered the gap between the number of organs and the number of patients who could derive a benefit from transplantation.[7], [8], [9], [10] Due to this imbalance between donors and recipients, there is a clear incentive to push the age limits for donation in liver transplantation. Indeed, good results have been extensively reported with older DBD donors.[11], [12], [13] In the current context of organ shortage, the issue is not whether older donors should be used, rather how to use them and in which recipients.

In parallel with improvements in post-transplant results, more liberal policies have been adopted allowing transplantation as an option in recipients older than 65. The proportion of registrants older than 60 has already increased significantly in the United States and in Europe.[9], [10], [14] Age at registration will probably continue to increase as decompensated hepatitis C virus (HCV)-related cirrhosis represents a lower proportion of candidates, while non-alcoholic steatohepatitis (NASH) has become a leading indication for transplantation.[15], [16] Indeed, patients with decompensated cirrhosis or NASH-related hepatocellular carcinoma (HCC) tend to be older than patients with other causes of liver disease.[10], [17]

The aims of this review are to present and summarise data concerning trends in age at registration for liver transplantation according to different aetiologies, impact of aging in candidates for transplantation and recipients, impact of older donors, interactions between older donors and older recipients and how to optimise the management in this population. This review is based on both a systematic review of the literature and expert opinion.