Kidney accelerated placement project: Outcomes and lessons learned

Expanding Access to High KDPI Kidney Transplant for Recipients Aged 60 y and Older: Cost Utility and Survival

Background

Modern organ allocation systems are tasked with equitably maximizing the utility of transplanted organs. Increasing the use of deceased donor organs at risk of discard may be a cost-effective strategy to improve overall transplant benefit. We determined the survival implications and cost utility of increasing the use of marginal kidneys in an older adult Canadian population of patients with end-stage kidney disease.

Methods

We constructed a cost-utility model with microsimulation from the perspective of the Canadian single-payer health system for incident transplant waitlisted patients aged 60 y and older. A kidney donor profile index score of ≥86 was considered a marginal kidney. Donor- and recipient-level characteristics encompassed in the kidney donor profile index and estimated posttransplant survival scores were used to derive survival posttransplant. Patients were followed up for 10 y from the date of waitlist initiation. Our analysis compared the routine use of marginal kidneys (marginal kidney scenario) with the current practice of limited use (status quo scenario).

Results

The 10-y mean cost and quality-adjusted life-years per patient in the marginal kidney scenario were estimated at $379 485.33 (SD: $156 872.49) and 4.77 (SD: 1.87). In the status quo scenario, the mean cost and quality-adjusted life-years per patient were $402 937.68 (SD: $168 508.85) and 4.37 (SD: 1.87); thus, the intervention was considered dominant. At 10 y, 62.8% and 57.0% of the respective cohorts in the marginal kidney and status quo scenarios remained alive.

Conclusions

Increasing the use of marginal kidneys in patients with end-stage kidney disease aged 60 y and older may offer cost savings, improved quality of life, and greater patient survival in comparison with usual care.

Expanding the access to kidney transplantation: Strategies for kidney transplant programs

Kidney transplantation is the most successful kidney replacement therapy available, resulting in improved recipient survival and societal cost savings. Yet, nearly 70 years after the first successful kidney transplant, there are still numerous barriers and untapped opportunities that constrain the access to transplant. The literature describing these barriers is extensive, but the practices and processes to solve them are less clear. Solutions must be multidisciplinary and be the product of strong partnerships among patients, their networks, health care providers, and transplant programs. Transparency in the referral, evaluation, and listing process as well as organ selection are paramount to build such partnerships. Providing early culturally congruent and patient-centered education as well as maximizing the use of local resources to facilitate the transplant work up should be prioritized. Every opportunity to facilitate pre-emptive kidney transplantation and living donation must be taken. Promoting the use of telemedicine and kidney paired donation as standards of care can positively impact the work up completion and maximize the chances of a living donor kidney transplant.

The Kidney Not Taken: Single-Kidney Use in Deceased Donors

BACKGROUND

The nonuse rate for kidneys recovered from deceased donors is increasing, rising to 27% in 2023. In 10% of these cases, 1 kidney is transplanted but the mate kidney is not.

STUDY DESIGN

We conducted a retrospective, single-center cohort study from December 2001 to May 2023 comparing single kidneys transplanted at our center (where the contralateral kidney was not used) to kidneys where both were transplanted separately, at least 1 of which was at our center.

RESULTS

We performed 395 single deceased-donor kidney transplants in which the mate kidney was not transplanted. Primary reasons for mate kidney nonuse were as follows: no recipient located or list exhausted (33.4%), kidney trauma or injury or anatomic abnormalities (18.7%), biopsy findings (16.7%), and poor renal function (13.7%). Mean donor and recipient ages were 51.5 ± 14.2 and 60 ± 12.6 years, respectively. Mean kidney donor profile index was 73% ± 22%, and 104 donors (26.3%) had kidney donor profile index >85%. Mean cold ischemia was 25.6 ± 7.4 hours, and 280 kidneys (70.7%) were imported. Compared with 2,303 concurrent control transplants performed at our center, primary nonfunction or thrombosis (5.1% single vs 2.8% control) and delayed graft function (35.4% single vs 30.1% control) were greater with single-kidney use (both p < 0.05). Median patient and death-censored graft survival were shorter in the single group (11.6 vs 13.5 years, p = 0.03 and 11.6 vs 19 years, p = 0.003), although the former was at least double median survival on the waiting list. In patients with functioning grafts in the single-kidney group, 1-year mean serum creatinine was 1.77 ± 0.8 mg/dL and estimated glomerular filtration rate was 44.8 ± 20 mL/min/1.73 m 2 .

CONCLUSIONS

These findings suggest that many mate kidneys are being inappropriately rejected, given the acceptable outcomes that can be achieved by transplanting the single kidney in appropriately selected recipients.

Evaluation of Opening Offers Early for Deceased Donor Kidneys at Risk of Nonutilization

BACKGROUND

Reducing nonutilization of kidneys recovered from deceased donors is a current policy concern for kidney allocation in the United States. The likelihood of nonutilization is greater with a higher kidney donor risk index (KDRI) offer. We examine how opening offers for organs with KDRI >1.75 to the broader waitlist at varying points of time affects usage rates.

METHODS

We simulate kidney allocation using data for January 2018 to June 2019 from Organ Procurement and Transplantation Network. For the simulation experiment, allocation policy is modified so that KDRI >1.75 organs are offered to all local candidates (same donation service area) after a set amount of cold time simultaneously. Open offers to candidates nationally are similarly examined.

RESULTS

Simulation results ( n =50 replications) estimate that opening offers locally for KDRI >1.75 after 10 hours yields a nonutilization rate of 38% (range: 35%-42%), less than the prevailing rate of 55% of KDRI >1.75 kidneys. Opening offers after 5 hours yields 30% (range: 26%-34%), reducing the prevailing nonutilization rate by 45%. Opening offers nationally after 10 and 5 hours yields nonutilization rates of 11% (range: 8%-15%) and 6% (range: 4%-9%) for KDRI >1.75 kidneys, respectively.

CONCLUSIONS

Simulation findings indicate that opening offers and adjusting their timing can significantly reduce nonutilization of high-KDRI kidneys.

Single center experience and literature review of kidney transplantation from non-ideal donors with acute kidney injury: Risk and reward

INTRODUCTION

There is limited experience transplanting kidneys from either expanded criteria donors (ECD) or donation after circulatory death (DCD) deceased donors with terminal acute kidney injury (AKI).

METHODS

AKI kidneys were defined by a donor terminal serum creatinine level >2.0 mg/dL whereas non-ideal deceased donor (NIDD) kidneys were defined as AKI/DCD or AKI/ECDs.

RESULTS

From February 2007 to March 2023, we transplanted 266 single AKI donor kidneys including 29 from ECDs, 29 from DCDs (n = 58 NIDDs), and 208 from brain-dead standard criteria donors (SCDs). Mean donor age (43.7 NIDD vs. 33.5 years SCD), KDPI (66% NIDD vs. 45% SCD), and recipient age (57 NIDD vs. 51 years SCD) were higher in the NIDD group (all p < .01). Mean waiting times (17.8 NIDD vs. 24.2 months SCD) and dialysis duration (34 NIDD vs. 47 months SCD) were shorter in the NIDD group (p < .05). Delayed graft function (DGF, 48%) and 1-year graft survival (92.7% NIDD vs. 95.9% SCD) was similar in both groups. Five-year patient and kidney graft survival rates were 82.1% versus 89.9% and 82.1% versus 75.2% (both p = NS) in the NIDD versus SCD groups, respectively.

CONCLUSIONS

The use of kidneys from AKI donors can be safely liberalized to include selected ECD and DCD donors.

Long-term outcomes of kidney transplantation from deceased donors with terminal acute kidney injury: Single center experience and literature review

INTRODUCTION

Long-term outcomes of kidney transplantation from deceased donors (DDKTs) with terminal acute kidney injury (AKI) are not well defined.

METHODS

Single center retrospective review of DDKTs from 1/31/07-12/31/19. AKI kidneys were defined by a doubling of the donor's admission serum creatinine (SCr) level AND a terminal SCr ≥2.0 mg/dl.

RESULTS

A total of 188 AKI DDKTs were performed, including 154 from brain-dead standard criteria donors (SCD). Mean donor age was 36 years and mean Kidney Donor Profile Index was 50%; mean admission and terminal SCr levels were 1.3 and 3.1 mg/dl, respectively. With a mean follow-up of 94 months (median 89 months), overall patient (both 71.3%) and graft survival (54% AKI vs. 57% non-AKI) rates were comparable to concurrent DDKTs from brain-dead non-AKI SCDs (n = 769). Delayed graft function (DGF) was higher in AKI kidney recipients (47% vs. 20% non-AKI DDKTs, p < .0001). DGF was associated with lower graft survival in recipients of both AKI and non-AKI SCD kidneys but the impact was earlier and more pronounced in non-AKI recipients.

CONCLUSIONS

Despite having more than twice the incidence of DGF, kidneys from deceased donors with terminal AKI have long-term outcomes comparable to non-AKI SCD kidneys and represent a safe and effective method to expand the donor pool.

Early Effect of the Circular Model of Kidney Allocation in the United States

BACKGROUND

In March 2021, the United States implemented a new kidney allocation system (KAS250) for deceased donor kidney transplantation (DDKT), which eliminated the donation service area-based allocation and replaced it with a system on the basis of distance from donor hospital to transplant center within/outside a radius of 250 nautical miles. The effect of this policy on kidney discards and logistics is unknown.

METHODS

We examined discards, donor-recipient characteristics, cold ischemia time (CIT), and delayed graft function (DGF) during the first 9 months of KAS250 compared with a pre-KAS250 cohort from the preceding 2 years. Changes in discards and CIT after the onset of COVID-19 and the implementation of KAS250 were evaluated using an interrupted time-series model. Changes in allocation practices (biopsy, machine perfusion, and virtual cross-match) were also evaluated.

RESULTS

Post-KAS250 saw a two-fold increase in kidneys imported from nonlocal organ procurement organizations (OPO) and a higher proportion of recipients with calculated panel reactive antibody (cPRA) 81%-98% (12% versus 8%; P <0.001) and those with >5 years of pretransplant dialysis (35% versus 33%; P <0.001). CIT increased (mean 2 hours), including among local OPO kidneys. DGF was similar on adjusted analysis. Discards after KAS250 did not immediately change, but we observed a statistically significant increase over time that was independent of donor quality. Machine perfusion use decreased, whereas reliance on virtual cross-match increased, which was associated with shorter CIT.

CONCLUSIONS

Early trends after KAS250 show an increase in transplant access to patients with cPRA>80% and those with longer dialysis duration, but this was accompanied by an increase in CIT and a suggestion of worsening kidney discards.

Kidney utility and futility

Changes in kidney allocation coupled with the COVID-19 pandemic have placed tremendous strain on current systems of organ distribution and logistics. Although the number of deceased donors continues to rise annually in the United States, the proportion of marginal deceased donors (MDDs) is disproportionately growing. Cold ischemia times and kidney discard rates are rising in part related to inadequate planning, resources, and shortages. Complexity in kidney allocation and distribution has contributed to this dilemma. Logistical issues and the ability to reperfuse the kidney within acceptable time constraints increasingly determine clinical decision-making for organ acceptance. We have a good understanding of the phenotype of "hard to place" MDD kidneys, yet continue to promote a "one size fits all" approach to organ allocation. Allocation and transportation systems need to be agile, mobile, and flexible in order to accommodate the expanding numbers of MDD organs. By identifying "hard to place" MDD kidneys early and implementing a "fast-track" or open offer policy to expedite placement, the utilization rate of MDDs would improve dramatically. Organ allocation and distribution based on location, motivation, and innovation must lead the way. In the absence of change, we are sacrificing utility for futility and discard rates will continue to escalate.

Deceased donor kidneys allocated out of sequence by organ procurement organizations

Deceased donor kidney allocation follows a ranked match-run of potential recipients. Organ procurement organizations (OPOs) are permitted to deviate from the mandated match-run in exceptional circumstances. Using match-run data for all deceased donor kidney transplants (Ktx) in the US between 2015 and 2019, we identified 1544 kidneys transplanted from 933 donors with an OPO-initiated allocation exception. Most OPOs (55/58) used this process at least once, but 3 OPOs performed 64% of the exceptions and just 2 transplant centers received 25% of allocation exception Ktx. At 2 of 3 outlier OPOs these transplants increased 136% and 141% between 2015 and 2019 compared to only a 35% increase in all Ktx. Allocation exception donors had less favorable characteristics (median KDPI 70, 41% with history of hypertension), but only 29% had KDPI ≥ 85% and the majority did not meet the traditional threshold for marginal kidneys. Allocation exception kidneys went to larger centers with higher offer acceptance ratios and to recipients with 2 fewer priority points-equivalent to 2 less years of waiting time. OPO-initiated exceptions for kidney allocation are growing increasingly frequent and more concentrated at a few outlier centers. Increasing pressure to improve organ utilization risks increasing out-of-sequence allocations, potentially exacerbating disparities in access to transplantation.

Early Assessment of National Kidney Allocation Policy Change

BACKGROUND

The new kidney allocation changes with elimination of donor service areas (DSAs) and Organ Procurement and Transplantation Network regions were initiated to improve equity in organ allocation. The aim of this evaluation was to determine the operational, financial, and recipient-related effect of the new allocation system on a large rural transplantation program.

STUDY DESIGN

A retrospective, cross-sectional analysis of organ offers, allograft outcomes, and attributed costs in a comparative time cohort, before (December 16, 2020 to March 14, 2021) and after (March 15, 2021 to June 13, 2021) the allocation change was performed. Outcomes were limited to adult, solitary, deceased donor kidney transplantations.

RESULTS

We received 198,881 organ offers from 3,886 organ donors at our transplantation center from December 16, 2020 to June 31, 2021: 87,643 (1,792 organ donors) before the change and 111,238 (2094 organ donors) after the change, for a difference of +23,595 more offers (+302 organ donors). This resulted in 6.5 more organs transplanted vs a predicted loss of 4.9 per month. Local organ offers dropped from 70% to 23%. There was a statistically significantly increase in donor terminal serum creatinine (1.2 ± 0.86 mg/dL vs 2.2 ± 2.3 mg/dL, p < 0.001), kidney donor profile index (KDPI) (39 ± 20 vs 48 ± 22, p = 0.017), cold ischemia time (16 ± 7 hours vs 21 ± 6 hours, p < 0.001), and delayed graft function rates (23% vs 40%, p = 0.020).

CONCLUSION

The new kidney allocation policy has led to an increase in KDPI of donors with longer cold ischemia time, leading to higher delayed graft function rates. This has resulted in increasing logistical and financial burdens on the system. Implementing large-scale changes in allocation based predominantly on predictive modeling needs to be intensely reassessed during a longer follow up.