Dynamic impact of liver allocation policy change on donor utilization

Determinants of Long Waiting Time to Kidney Transplantation

BACKGROUND

Disparity in waiting time to kidney transplantation led to new policy (KAS250). Our aims were to identify variables associated with long wait time (LWT); assess the impact of KAS250 on WT; and analyze modifiable transplant center behaviors correlated with WT.

METHODS

SRTR data for adult deceased donor kidney transplants were analyzed. Time-periods from 8/1/2018-7/31/2019 and 5/1/2021-4/30/2022 were chosen for pre- and post-KAS250 analyses. Transplant centers were categorized as LWT or SWT centers depending on whether pre-KAS250 median center waiting times were greater or less than the national pre-KAS250 median waiting time of 57.8 months.

RESULTS

In multivariate analysis, transplantation with HCV NAT negative kidneys was associated with an additional 21.3 months of WT (CI: 18.5-24.2, P < .0001), and transplantation with KDPI <85% kidneys was associated with an additional 10.8 months (CI: 8.2-13.3, P < .0001). Post-KAS250 national kidney transplant waiting time decreased from 61-58 months (P < .0001) and waiting time at LWT centers decreased from 74-69 months (P < .0001). Cold ischemic times (CIT) increased (20.2 hours vs 18.3 hours, P < .0001) and DGF rates also increased (32.7% vs 31.0%, P < .0001). Centers generally displayed more aggressive transplantation practices post-KAS250 however significant differences in DCD utilization, organ offer acceptance ratios and tolerance for long CIT persist between SWT and LWT centers.

CONCLUSION

KAS250 has reduced waiting time disparities between SWT and LWT centers at the cost of increased CIT and DGF and reduced allocation efficiency. Significant differences in transplant practice persist between SWT and LWT centers.

Role of Doppler Trasonography in Predicting Recovery From Early Allograft Dysfunction in Liver Postoperative Patients

OBJECTIVE

The aim of this study was to observe the recovery of liver function in patients with early allograft dysfunction (EAD) at one month postoperatively and explore whether early postoperative ultrasonic hemodynamic parameters can predict this outcome.

METHODS

Patients with EAD postoperatively, who underwent orthotopic liver transplantation (OLT) in our hospital from December 2012 to June 2021, were retrospectively collected. Based on the recovery of liver function within one month, patients were divided into two groups: the recovery group (FR-1M) and the non-recovery group (Non-FR-1M). Ultrasonic hemodynamic parameters within the first seven days postoperatively were compared between the two groups.

RESULTS

Among the 254 EAD patients included in this study, 158 (62%) patients recovered their liver function within one month. Of the 96 (38%) patients who did not recover, The RI of the non-FR-1M group was significantly lower than that of the FR-1M group on postoperative day 6 (POD6) and POD7. In the high resistance interval (RI all > 0.7), Group FR-1M represents a significant proportion (29/3, ratio 12/1), while in the low resistance interval (RI < 0.5 at least once), Group non-FR-1M accounts for a relatively high proportion (12/27, ratio 5/11). In the middle resistance interval (more than 1 time ≤ 0.7 and all ≥ 0.5), the proportions of the two groups are balanced (85/88, ratio 1/1).

CONCLUSION

Liver function typically recovers within 1 month in most patients with EAD. The high resistance state of the hepatic artery in the early postoperative period is illustrative an important role in its recovery. Low-resistance state is most unfavorable for the recovery of liver function.

Liver Transplant Costs and Activity After United Network for Organ Sharing Allocation Policy Changes

Importance

A new liver allocation policy was implemented by United Network for Organ Sharing (UNOS) in February 2020 with the stated intent of improving access to liver transplant (LT). There are growing concerns nationally regarding the implications this new system may have on LT costs, as well as access to a chance for LT, which have not been captured at a multicenter level.

Objective

To characterize LT volume and cost changes across the US and within specific center groups and demographics after the policy implementation.

Design, Setting, and Participants

This cross-sectional study collected and reviewed LT volume from multiple centers across the US and cost data with attention to 8 specific center demographics. Two separate 12-month eras were compared, before and after the new UNOS allocation policy: March 4, 2019, to March 4, 2020, and March 5, 2020, to March 5, 2021. Data analysis was performed from May to December 2022.

Main Outcomes and Measures

Center volume, changes in cost.

Results

A total of 22 of 68 centers responded comparing 1948 LTs before the policy change and 1837 LTs postpolicy, resulting in a 6% volume decrease. Transplants using local donations after brain death decreased 54% (P < .001) while imported donations after brain death increased 133% (P = .003). Imported fly-outs and dry runs increased 163% (median, 19; range, 1-75, vs 50, range, 2-91; P = .009) and 33% (median, 3; range, 0-16, vs 7, range, 0-24; P = .02). Overall hospital costs increased 10.9% to a total of $46 360 176 (P = .94) for participating centers. There was a 77% fly-out cost increase postpolicy ($10 600 234; P = .03). On subanalysis, centers with decreased LT volume postpolicy observed higher overall hospital costs ($41 720 365; P = .048), and specifically, a 122% cost increase for liver imports ($6 508 480; P = .002). Transplant centers from low-income states showed a significant increase in hospital (12%) and import (94%) costs. Centers serving populations with larger proportions of racial and ethnic minority candidates and specifically Black candidates significantly increased costs by more than 90% for imported livers, fly-outs, and dry runs despite lower LT volume. Similarly, costs increased significantly (>100%) for fly-outs and dry runs in centers from worse-performing health systems.

Conclusions and Relevance

Based on this large multicenter effort and contrary to current assumptions, the new liver distribution system appears to place a disproportionate burden on populations of the current LT community who already experience disparities in health care. The continuous allocation policies being promoted by UNOS could make the situation even worse.

Exception Policy Change Increased the Simultaneous Kidney-Liver Transplant Probability of Polycystic Disease in the Centers With High Median MELD at Transplantation

BACKGROUND

In 2019, Organ Procurement and Transplantation Network/United Network for Organ Sharing changed the exception policy for liver allocation to the median model for end-stage liver disease at transplantation (MMaT). This study evaluated the effects of this change on-waitlist outcomes of simultaneous liver-kidney transplantation (SLKT) for patients with polycystic liver-kidney disease (PLKD).

METHODS

Using the Organ Procurement and Transplantation Network/United Network for Organ Sharing registry, 317 patients with PLKD listed for SLKT between January 2016 and December 2021 were evaluated. Waitlist outcomes were compared between prepolicy (Era 1) and postpolicy (Era 2) eras.

RESULTS

One-year transplant probability was significantly higher in Era 2 than in Era 1 (55.7% versus 37.9%; P  = 0.001), and the positive effect on transplant probability of Era 2 was significant after risk adjustment (adjusted hazard ratio, 1.76; 95% confidence interval, 1.22-2.54; P  = 0.002 [ref. Era 1]), whereas waitlist mortality was comparable. Transplant centers were separated into the high and low MMaT groups with a score of 29 (median MMaT) and transplant probability in each group between eras was compared. In the high MMaT transplant centers, the 1-y transplant probability was significantly higher in Era 2 (27.5% versus 52.4%; P  = 0.003). The positive effect remained significant in the high MMaT center group (adjusted hazard ratio, 2.79; 95% confidence interval, 1.43-5.46; P  = 0.003 [ref. Era 1]) but not in the low MMaT center group. Although there was a difference between center groups in Era 1 ( P  = 0.006), it became comparable in Era 2 ( P  = 0.54).

CONCLUSIONS

The new policy increased 1-y SLKT probability in patients with PKLD and successfully reduced the disparities based on center location.

2023 Clinical Update in Liver Transplantation

Liver transplantation continues to provide life-saving treatment for patients with end-stage liver disease. Advances in the field of transplant anesthesia continue to support the care of more complex patients. The use of extracorporeal membrane oxygenation has been described in critical care settings and cardiac surgery but may be a valuable option for specific conditions for patients undergoing liver transplantation. Changes to the allocation process for liver grafts now focus on acuity circles to reduce regional disparities. As the number of life-saving transplant surgeries increases, so does the need for specialty knowledge in the anesthetic considerations of these procedures. The specialty of transplant anesthesia continues to grow and develop to meet the demands of complex patients and the increased number of transplants performed. Liver transplantation can be a resource-demanding procedure, and predicting the need for massive transfusion can aid in planning and preparing for significant blood loss.

Association of procurement technique with organ yield and cost following donation after circulatory death

Donation after circulatory death (DCD) could account for the largest expansion of the donor allograft pool in the contemporary era. However, the organ yield and associated costs of normothermic regional perfusion (NRP) compared to super-rapid recovery (SRR) with ex-situ normothermic machine perfusion, remain unreported. The Organ Procurement and Transplantation Network (December 2019 to June 2023) was analyzed to determine the number of organs recovered per donor. A cost analysis was performed based on our institution's experience since 2022. Of 43 502 donors, 30 646 (70%) were donors after brain death (DBD), 12 536 (29%) DCD-SRR and 320 (0.7%) DCD-NRP. The mean number of organs recovered was 3.70 for DBD, 3.71 for DCD-NRP (P < .001), and 2.45 for DCD-SRR (P < .001). Following risk adjustment, DCD-NRP (adjusted odds ratio 1.34, confidence interval 1.04-1.75) and DCD-SRR (adjusted odds ratio 2.11, confidence interval 2.01-2.21; reference: DBD) remained associated with greater odds of allograft nonuse. Including incomplete and completed procurement runs, the total average cost of DCD-NRP was $9463.22 per donor. By conservative estimates, we found that approximately 31 donor allografts could be procured using DCD-NRP for the cost equivalent of 1 allograft procured via DCD-SRR with ex-situ normothermic machine perfusion. In conclusion, DCD-SRR procurements were associated with the lowest organ yield compared to other procurement methods. To facilitate broader adoption of DCD procurement, a comprehensive understanding of the trade-offs inherent in each technique is imperative.

The Public Health Service "Increased Risk" 2020 Policy Change Has not Improved Organ Utilization in the United States: A Nationwide Cohort Study

Objective

To assess the effects of the 2020 United States Public Health Service (PHS) "Increased Risk" Guidelines update.

Background

Donors labeled as "Increased Risk" for transmission of infectious diseases have been found to have decreased organ utilization rates despite no significant impact on recipient survival. Recently, the PHS provided an updated guideline focused on "Increased Risk" organ donors, which included the removal of the "Increased Risk" label and the elimination of the separate informed consent form, although the actual increased risk status of donors is still ultimately transmitted to transplant physicians. We sought to analyze the effect of this update on organ utilization rates.

Methods

This was a retrospective analysis of the Organ Procurement and Transplantation Network database which compared donor organ utilization in the 2 years before the June 2020 PHS Guideline update for increased-risk donor organs (June 2018-May 2020) versus the 2 years after the update (August 2020-July 2022). The organ utilization rate for each donor was determined by dividing the number of organs transplanted by the total number of organs available for procurement. Student t test and multivariable logistic regression models were used for analysis.

Results

There were 17,272 donors in the preupdate cohort and 17,922 donors in the postupdate cohort; of these, 4,977 (28.8%) and 3,893 (21.7%) donors were considered "Increased Risk", respectively. There was a 2% decrease in overall organ utilization rates after the update, driven by a 3% decrease in liver utilization rates and a 2% decrease in lung utilization rates. After multivariable adjustment, donors in the postupdate cohort had 10% decreased odds of having all organs transplanted.

Conclusions

The 2020 PHS "Increased Risk" Donor Guideline update was not associated with an increase in organ utilization rates in the first 2 years after its implementation, despite a decrease in the proportion of donors considered to be at higher risk. Further efforts to educate the community on the safe usage of high-risk organs are needed and may increase organ utilization.

Decreased Utilization Rate of Grafts for Liver Transplantation After Implementation of Acuity Circle-based Allocation

BACKGROUND

The allocation system for livers began using acuity circles (AC) in 2020. In this study, we sought to evaluate the impact of AC policy on the utilization rate for liver transplantation (LT).

METHODS

Using the US national registry data between 2018 and 2022, LTs were equally divided into 2 eras: pre-AC (before February 4, 2020) and post-AC (February 4, 2020, and after). Deceased potential liver donors were defined as deceased donors from whom at least 1 organ was procured.

RESULTS

The annual number of deceased potential liver donors increased post-AC (from 10 423 to 12 259), approaching equal to that of new waitlist registrations for LT (n = 12 801). Although the discard risk index of liver grafts was comparable between the pre- and post-AC eras, liver utilization rates in donation after brain death (DBD) and donation after circulatory death (DCD) donors were lower post-AC ( P  < 0.01; 79.8% versus 83.4% and 23.7% versus 26.0%, respectively). Recipient factors, ie, no recipient located, recipient determined unsuitable, or time constraints, were more likely to be reasons for nonutilization after implementation of the AC allocation system compared to the pre-AC era (20.0% versus 12.3% for DBD donors and 50.1% versus 40.8% for DCD donors). Among non-high-volume centers, centers with lower utilization of marginal DBD donors or DCD donors were more likely to decrease LT volume post-AC.

CONCLUSIONS

Although the number of deceased potential liver donors has increased, overall liver utilization among deceased donors has decreased in the post-AC era. To maximize the donor pool for LT, future efforts should target specific reasons for liver nonutilization.

The short and long-term prognostic influences of liver grafts with high bilirubin levels at the time of organ recovery

BACKGROUND

Donors with hyperbilirubinemia are often not utilized for liver transplantation (LT) due to concerns about potential liver dysfunction and graft survival. The potential to mitigate organ shortages using such donors remains unclear.

METHODS

This study analyzed adult deceased donor data from the United Network for Organ Sharing database (2002-2022). Hyperbilirubinemia was categorized as high total bilirubin (3.0-5.0 mg/dL) and very high bilirubin (≥5.0 mg/dL) in brain-dead donors. We assessed the impact of donor hyperbilirubinemia on 3-month and 3-year graft survival, comparing these outcomes to donors after circulatory death (DCD).

RESULTS

Of 138 622 donors, 3452 (2.5%) had high bilirubin and 1999 (1.4%) had very high bilirubin levels. Utilization rates for normal, high, and very high bilirubin groups were 73.5%, 56.4%, and 29.2%, respectively. No significant differences were found in 3-month and 3-year graft survival between groups. Donors with high bilirubin had superior 3-year graft survival compared to DCD (hazard ratio .83, p = .02). Factors associated with inferior short-term graft survival included recipient medical condition in intensive care unit (ICU) and longer cold ischemic time; factors associated with inferior long-term graft survival included older donor age, recipient medical condition in ICU, older recipient age, and longer cold ischemic time. Donors with ≥10% macrosteatosis in the very high bilirubin group were also associated with worse 3-year graft survival (p = .04).

DISCUSSION

The study suggests that despite many grafts with hyperbilirubinemia being non-utilized, acceptable post-LT outcomes can be achieved using donors with hyperbilirubinemia. Careful selection may increase utilization and expand the donor pool without negatively affecting graft outcome.

Impact of Median MELD at Transplant Minus 3 National Policy on Quality of Transplanted Livers for Patients With and Without Hepatocellular Carcinoma

BACKGROUND

Patients with hepatocellular carcinoma (HCC) have been overprioritized in the deceased donor liver allocation system. The United Network for Organ Sharing adopted a policy in May 2019 that limited HCC exception points to the median Model for End-Stage Liver Disease at transplant in the listing region minus 3. We hypothesized this policy change would increase the likelihood to transplant marginal quality livers into HCC patients.

METHODS

This was a retrospective cohort study of a national transplant registry, including adult deceased donor liver transplant recipients with and without HCC from May 18, 2017, to May 18, 2019 (prepolicy) to May 19, 2019, to March 1, 2021 (postpolicy). Transplanted livers were considered of marginal quality if they met ≥1 of the following: (1) donation after circulatory death, (2) donor age ≥70, (3) macrosteatosis ≥30% and (4) donor risk index ≥95th percentile. We compared characteristics across policy periods and by HCC status.

RESULTS

A total of 23 164 patients were included (11 339 prepolicy and 11 825 postpolicy), 22.7% of whom received HCC exception points (prepolicy versus postpolicy: 26.1% versus 19.4%; P = 0.03). The percentage of transplanted donor livers meeting marginal quality criteria decreased for non-HCC (17.3% versus 16.0%; P < 0.001) but increased for HCC (17.7% versus 19.4%; P < 0.001) prepolicy versus postpolicy. After adjusting for recipient characteristics, HCC recipients had 28% higher odds of being transplanted with marginal quality liver independent of policy period (odds ratio: 1.28; confidence interval, 1.09-1.50; P < 0.01).

CONCLUSIONS

The median Model for End-Stage Liver Disease at transplant in the listing region minus 3 policy limited exception points and decreased the quality of livers received by HCC patients.

The history of ethical principles in liver transplant organ allocation in the United States: how historical and proposed allocations system fare in balancing utility vs. urgency and justice vs. pragmatism

PURPOSE OF REVIEW

The United States (US) liver transplant community is processing changes to the allocation system and developing a new proposal that will result in even greater change. This review evaluates the ethical implications of these decisions, focusing on two sets of competing ethical principles (Urgency vs. Utility and Justice vs. Pragmatism).

RECENT FINDINGS

About four years ago, the Organ Procurement and Transplantation Network (OPTN) implemented the Acuity Circle Model to replace the geographic boundaries of organ procurement organizations (OPOs). Here, we review how effectively this model reduced regional variation in access and improved waitlist survival. Likewise, the OPTN is planning to transition to a continuous distribution model which will redefine the scoring systems for allocation. We will discuss how the ethical priorities discussed above should be considered while developing the new system.

SUMMARY

Every change in organ allocation policy must balance competing ethical imperatives. Although our community's emphasis on urgency over utility is appropriate, we should study the potential benefits of considering utility in the system. Meanwhile, our push for more Justice in the system should remain our imperative and Pragmatism should only be considered to minimize the costs of these changes.

Expanding Liver Transplant Opportunities in Older Patients With Nonconventional Grafts

INTRODUCTION

Broader use of donation after circulatory death (DCD) and nonconventional grafts for liver transplant helps reduce disparities in organ availability. Limited data, however, exists on outcomes specific to nonconventional graft utilization in older patients. As such, this study aimed to investigate outcomes specific to conventional and nonconventional graft utilization in recipients > 70 y of age.

METHODS

1-to-3 matching based on recipient sex, Model for End-Stage Liver Disease score, and donor type was performed on patients ≥70 and <70 y of age who underwent liver transplant alone at Mayo Clinic Arizona between 2015 and 2020. Primary outcomes were posttransplant patient and liver allograft survival for recipients greater than or less than 70 y of age. Secondary outcomes included grafts utilization patterns, hospital length of stay, need for reoperation, biliary complications and disposition at time of hospital discharge.

RESULTS

In this cohort, 36.1% of grafts came from DCD donors, 17.4% were postcross clamp offers, and 20.8% were nationally allocated. Median recipient ages were 59 and 71 y (P < 0.01). Recipients had similar Intensive care unit (P = 0.82) and hospital (P = 0.14) lengths of stay, and there were no differences in patient (P = 0.68) or graft (P = 0.38) survival. When comparing donation after brain death and DCD grafts in those >70 y, there were no differences in patient (P = 0.89) or graft (P = 0.71) survival.

CONCLUSIONS

Excellent outcomes can be achieved in older recipients, even with use of nonconventional grafts. Expanded use of nonconventional grafts can help facilitate transplant opportunities in older patients.

Outcomes after liver transplantation using deceased after circulatory death donors: A comparison of outcomes in the UK and the US

BACKGROUND AND AIMS

Identifying international differences in utilization and outcomes of liver transplantation (LT) after donation after circulatory death (DCD) donation provides a unique opportunity for benchmarking and population-level insight.

METHODS

Adult (≥18 years) LT data between 2008 and 2018 from the UK and US were used to assess mortality and graft failure after DCD LT. We used time-dependent Cox-regression methods to estimate hazard ratios (HR) for risk-adjusted short-term (0-90 days) and longer-term (90 days-5 years) outcomes.

RESULTS

One-thousand five-hundred-and-sixty LT receipts from the UK and 3426 from the US were included. Over the study period, the use of DCD livers increased from 15.7% to 23.9% in the UK compared to 5.1% to 7.6% in the US. In the UK, DCD donors were older (UK:51 vs. US:33 years) with longer cold ischaemia time (UK: 437 vs. US: 333 min). Recipients in the US had higher Model for End-stage Liver Disease (MELD) scores, higher body mass index, higher proportions of ascites, encephalopathy, diabetes and previous abdominal surgeries. No difference in the risk-adjusted short-term mortality or graft failure was observed between the countries. In the longer-term (90 days-5 years), the UK had lower mortality and graft failure (adj.mortality HR:UK: 0.63 (95% CI: 0.49-0.80); graft failure HR: UK: 0.72, 95% CI: 0.58-0.91). The cumulative incidence of retransplantation was higher in the UK (5 years: UK: 11.9% vs. 4.6%; p < .001).

CONCLUSIONS

For those receiving a DCD LT, longer-term post-transplant outcomes in the UK are superior to the US, however, significant differences in recipient illness, graft quality and access to retransplantation were seen between the two countries.

Decreasing Significance of Early Allograft Dysfunction with Rising Use of Nonconventional Donors

Background and Objectives: Early allograft dysfunction (EAD) is considered a surrogate marker for adverse post-liver transplant (LT) outcomes. With the increasing use of nonconventional donors, EAD has become a more frequent occurrence. Given this background, we aimed to assess the prevalence and impact of EAD in an updated cohort inclusive of both conventional and nonconventional liver allografts. Materials and Methods: Perioperative and one-year outcomes were assessed for a total of 611 LT recipients with and without EAD from Mayo Clinic Arizona. EAD was defined as the presence of one or more of the following: bilirubin > 10 mg/dL on day 7, INR > 1.6 on day 7, or ALT and/or AST > 2000 IU/L within the first 7 days of LT. Results: Within this cohort, 31.8% of grafts (n = 194) came from donation after circulatory death (DCD) donors, 17.7% (n = 108) were nationally shared, 16.4% (n = 100) were allocated as post-cross clamp, and 8.7% contained moderate steatosis. EAD was observed in 52.2% (n = 321) of grafts in the study cohort (79% in DCD grafts and 40% in DBD grafts). EAD grafts had higher donor risk index (DRI) scores (1.9 vs. 1.6, p < 0.0001), were more likely to come from DCD donors (48% vs. 13.8%, p < 0.0001), were regionally allocated (p = 0.003), and had higher cold ischemia times (median 6.0 vs. 5.5 h, p = 0.001). Primary nonfunction events were rare in both groups (1.3% vs. 0.3%, p = 0.22). Post-LT acute kidney injury occurred at a similar frequency in recipients with and without EAD (43.6% vs. 30.3%, p = 0.41), and there were no differences in ICU (median 2 vs. 1 day, p = 0.60) or hospital (6 vs. 5 days, p = 0.24) length of stay. For DCD grafts, the rate of ischemic cholangiopathy was similar in the two groups (14.9% EAD vs. 17.5% no EAD, p = 0.69). One-year patient survival for grafts with and without EAD was 96.0% and 94.1% (HR 1.2, 95% CI 0.7−1.8; p = 0.54); one-year graft survival was 92.5% and 92.1% (HR 1.0, 95% CI 0.7−1.5; p = 0.88). Conclusions: In this cohort, EAD occurred in 52% of grafts. The occurrence of EAD, however, did not portend inferior outcomes. Compared to those without EAD, recipients with EAD had similar post-operative outcomes, as well as one-year patient and graft survival. EAD should be managed supportively and should not be viewed as a deterrent to utilization of non-ideal grafts.