Liver Transplant Recipient Characteristics Associated With Worse Post-Transplant Outcomes in Using Elderly Donors

Expanding the Liver Donor Pool: Promise and Peril

Liver transplantation remains a life-saving therapy for a growing list of indications. Although 10,660 adult liver transplants were performed in the United States in 2023, a 50% increase over the preceding decade, the demand continues to far exceed the supply. Efforts to expand the liver donor pool by using donors that were previously considered unsuitable have remained an important strategy to help overcome shortages. We discuss the progress that has been made over the past decade, as well as potential future barriers that will need to be overcome to help successfully expand the liver donor pool.

Elderly Ages in Liver Transplantation: Are Older Donors Really Higher Risk?

Background

There is currently a supply and demand mismatch in liver transplantation, with more patients needing transplants than grafts available. The use of older donors is one potential way of expanding access to viable grafts. No national study has yet reported on outcomes of liver transplants with donors ≥70 y.

Methods

The US Scientific Registry of Transplant Recipients registry was queried for deceased donor LT (1988-2021). Balance-of-risk (BAR) score was calculated for each patient. The primary outcome was graft survival. Cubic spline curves were used to evaluate the full spectrum of donor ages.

Results

A total of 148 960 livers met inclusion criteria: 5414 (3.6%) from donors ≥70 y and 4291 (2.9%) recipients ≥70 y. Within the overall cohort, graft survival decreased with increased donor and recipient age. Median graft survival within donors ≥70 y improved over time from 2.2 y (interquartile range [IQR] 0.2-9.8 y) in 1987-1999 to 9.6 y (IQR 3.2-11.6 y) in 2010-2019 (P < 0.0001). Elderly donors had equivalent outcomes to donors <70 y when transplanted in elderly recipients (≥70 y). Outcomes for young recipients that received grafts from elderly donor improved with time, with median survival of 10.1 y (IQR 3.9-11.5 y) in 2010-2019. BAR and survival outcomes following liver transplant (SOFT) scores predicted improved graft survival on time-to-event analysis in all donors aged >70 y. In low-risk recipients, evidenced by preallocation SOFT score <5, elderly donors had comparable outcomes to young (<40 y) and middle-aged donors (40-69 y). Increasing donor age was not associated with worse graft survival in transplants performed between 2010 and 2019.

Conclusions

Donors aged ≥70 y may be more comfortably considered for deceased donor liver transplantation, especially within low-risk recipients. The BAR and SOFT scores may be a useful guide for safely expanding the use of these theoretically riskier liver grafts.

Survival benefit of liver transplantation utilizing marginal donor organ according to ABO blood type

The current liver transplantation (LT) allocation policy focuses on the MELD scores, often overlooking factors like blood type and survival benefits. Understanding blood types' impact on survival benefits is crucial for optimizing the MELD 3.0 classification. This study used the United Network for Organ Sharing national registry database (2003-2020) to identify LT characteristics per ABO blood type and to determine the optimal MELD 3.0 scores for each blood type, based on survival benefits. The study included candidates of LT aged 18 years or older listed for LT (total N=150,815; A: 56,546, AB: 5841, B: 18,500, O: 69,928). Among these, 87,409 individuals (58.0%) underwent LT (A:32,156, AB: 4,362, B: 11,786, O: 39,105). Higher transplantation rates were observed in AB and B groups, with lower median MELD 3.0 scores at transplantation (AB: 21, B: 24 vs. A/O: 26, p <0.01) and shorter waiting times (AB: 101 d, B:172 d vs. A: 211 d, O: 201 d, p <0.01). A preference for donation after cardiac death (DCD) was seen in A and O recipients. Survival benefit analysis indicated that B blood type required higher MELD 3.0 scores for transplantation than A and O (donation after brain death transplantation: ≥15 in B vs. ≥11 in A/O; DCD transplantation: ≥21 in B vs. ≥11 in A, ≥15 in O). The study suggests revising the allocation policy to consider blood type for improved post-LT survival. This calls for personalized LT policies, recommending higher MELD 3.0 thresholds, particularly for individuals with type B blood.

Longitudinal analysis of social and community factors effective in increasing the number of liver donors in the United States

In this research, it was aimed to evaluate of social and community factors effective in increasing the number of liver donors. Descriptive and relational scanning models were used to conduct the research. Data on liver donors was gathered from the USA Health Resources & Services Administration's Organ Procurement and Transplantation Network between 1988 and 2023. The United States (USA) World Bank Country Reports provided the mortality rates. The data was analyzed using Spearman rho correlation, year-controlled partial correlation, and Generalized Linear Model-Logit analysis. Deceased donor numbers were significantly and negatively correlated with government health expenditure (r = -0.816; P < .01), current health expenditure (r = -0.768; P < .01), female education attainment (r = -0.804; P < .01) and Gini index (r = 0.434; P < .05). Living donor numbers were significantly and negatively correlated with government health expenditure (r = -0.731; P < .01), current health expenditure (r = -0.781; P < .01), male percentage (r = -0.786; P < .01), female education attainment (r = -0.640; P < .05), employment (r = 0.751; P < .01), GDP (r = -0.792; P < .01) and Gini index (r = -0.486; P < .01). Living donor numbers were significantly and positively correlated with age dependency (r = 0.815; P < .01). Generalized Linear Model-Logit (GLM-L) results showed that effect of female education attainment had significant contribution on deceased liver donor (B = -3290.605; P < .01). Effects of significantly correlated community factors on living liver donor numbers were found to be statistically insignificant (P > .05). Research findings reveal that among community factors, especially women's participation in education has a statistically significant effect on liver donors. These results show that the health expenditures made over the years do not provide any added value for liver donors, and role of women on liver donor is significantly dominant.

Current Understanding of Marginal Grafts in Liver Transplantation

End-stage liver disease (ESLD), stemming from a spectrum of chronic liver pathologies including chronic liver failure, acute cirrhosis decompensation and hepatocellular carcinoma, imposes a significant global healthcare burden. Liver transplantation (LT) remains the only treatment for ESLD. However, the escalating mortality on transplant waitlists has prompted the utilization of marginal liver grafts in LT procedures. These grafts primarily encompass elderly livers, steatotic livers, livers from donation after circulatory death, split livers and those infected with the hepatitis virus. While the expansion of the donor pool offers promise, it also introduces concomitant risks. These encompass graft failure, biliary and cardiovascular complications, the recurrence of liver disease and reduced patient and graft survival. Consequently, various established strategies, ranging from improved donor-recipient matching to surgical interventions, have emerged to mitigate these risks. This article undertakes a comprehensive assessment of the current landscape, evaluating the viability of diverse marginal liver grafts. Additionally, it synthesizes approaches aimed at enhancing the quality of such marginal liver grafts. The overarching objective is to augment the donor pool and ameliorate the risk factors associated with the shortage of liver grafts.

Survival after LDLT in recipients ≥70 years old in the United States. An OPTN/UNOS liver transplant registry analysis

BACKGROUND

Living donor liver transplantation (LDLT) in the elderly population is currently not well studied. There are single-center studies indicating that patient age should not be a barrier to LDLT, with similar outcomes compared to younger recipients.

METHODS

Using UNOS/STAR data from 2010 to 2022 we retrospectively analyzed patients ≥70 years old receiving a living donor graft (LDLT ≥70y group) versus a deceased donor graft (DDLT ≥70y group). In addition, we compared recipients ≥70 years old undergoing LDLT versus patients 18-69 years old also undergoing LDLT. Donor and recipient baseline characteristics, as well as postoperative outcomes including graft and patient survival were analyzed and compared between groups.

RESULTS

Recipients in the LDLT ≥70y group showed less disease burden and spent significantly less time on the waitlist when compared to recipients in the DDLT ≥70y group (102 [49-201] days versus 170 [36-336] days) respectively; p = .004. With the exception of a longer length of stay (LOS) in the LDLT ≥70y group (p ≤ .001), postoperative outcomes were comparable with recipients in the DDLT ≥70y group, including similar graft and patient survival rates at 1-, 3-, and 5-years. When compared to younger recipients of a graft from a living donor, patients in the LDLT ≥70y group had similar post-transplant functional status, re-transplant rates and similar causes contributing to graft failure. However, significantly lower graft and patient survival rates were observed.

CONCLUSION

LDLT for recipients aged 70 or greater represents a faster access to transplantation in a safe and feasible manner when compared to similar- aged recipients undergoing DDLT.

Beyond the Concepts of Elder and Marginal in DCD Liver Transplantation: A Prospective Observational Matched-Cohort Study in the Italian Clinical Setting

Donation after circulatory determination of death (DCD) is a valuable strategy to increase the availability of grafts for liver transplantation (LT). As the average age of populations rises, the donor pool is likely to be affected by a potential increase in DCD donor age in the near future. We conducted a prospective cohort study to evaluate post-transplantation outcomes in recipients of grafts from elderly DCD donors compared with younger DCD donors, and elderly donors after brainstem determination of death (DBD). From August 2020 to May 2022, consecutive recipients of deceased donor liver-only transplants were enrolled in the study. DCD recipients were propensity score matched 1:3 to DBD recipients. One-hundred fifty-seven patients were included, 26 of whom (16.6%) were transplanted with a DCD liver graft. After propensity score matching and stratification, three groups were obtained: 15 recipients of DCD donors ≥75 years, 11 recipients of DCD donors <75 years, and 28 recipients of DBD donors ≥75 years. Short-term outcomes, as well as 12 months graft survival rates (93.3%, 100%, and 89.3% respectively), were comparable among the groups. LT involving grafts retrieved from very elderly DCD donors was feasible and safe in an experienced high-volume center, with outcomes comparable to LTs from younger DCD donors and age-matched DBD donors.