Single-center analysis of organ offers and workload for liver and kidney allocation

Referral and Beyond: Restructuring the Kidney Transplant Process to Support Greater Access in the United States

Advocates for improved equity in kidney transplant in the US have recently focused efforts on initiatives to increase referral for transplant evaluation. However, because donor kidneys remain scarce, increased referrals are likely to result in an increasing number of patients proceeding through the evaluation process without ultimately receiving a kidney. Unfortunately, the process of referral and evaluation can be highly resource-intensive for patients, families, transplant programs, and payers. Patients and families may incur out-of-pocket expenses and be required to complete testing and treatments that they might not have chosen in the course of routine clinical care. Kidney transplant programs may struggle with insufficient capacity, inefficient workflow, and challenging programmatic finances and payers will need to absorb the increased expenses of upfront pretransplant costs. Increased referral in isolation may risk simply transmitting system stress and resulting disparities to downstream processes in this complex system. We argue that success in efforts to improve access through increased referrals hinges on adaptations to the pretransplant process more broadly. We call for an urgent reevaluation and redesign at multiple levels of the pretransplant system in order to achieve the aim of equitable access to kidney transplantation for all patients with kidney failure.

Missing the Match: A National Survey Investigating Education in Renal Donor-Recipient Matching

PURPOSE

Clinical judgment in renal donor organ and recipient selection is gained through fellowship and mentorship in early career. We aim to understand the past and current state of organ acceptance education.

METHODS

We developed and distributed an anonymous, national survey to American Society of Transplant Surgeons faculty members and transplant surgery fellows in 2022. Survey questions explored in detail the evaluation of organ offers, the extent of formal education in organ evaluation, and attitudes regarding training adequacy.

FINDINGS

Ninety-eight attending surgeons (65 men, 25 women, and 3 nonbinary) and 38 fellows (25 men, 6 women, and 2 nonbinary) responded. Seventy-eight percent of attending surgeons and 6% of fellows take primary organ offers. Forty-four percent of fellows report no didactic education in donor evaluation and recipient selection. Fellows report that discussion with attending surgeons (37.2%) and independent study of the literature (35.4%) are their primary modes of learning. Fellows call for additional clinical decision-making experience (47.3%), further didactic sessions (44.7%), and additional discussions with faculty (44.7%). Sixty-four percent of fellows and 55% of attendings felt their training provided adequate education about donor selection.

CONCLUSION

Our responses suggest gaps in education regarding donor and recipient selection. Increased clinical experience and standardized education at the national level represent opportunities for improvement.

Non-invasive evaluation of hepatic macrosteatosis in deceased donors

INTRODUCTION

Liver allocation changes have led to increased travel and expenditures, highlighting the need to efficiently identify marginal livers suitable for transplant. We evaluated the validity of existing non-invasive liver quality tests and a novel machine learning-based model at predicting deceased donor macrosteatosis >30%.

METHODS

We compared previously-validated non-invasive tests and a novel machine learning-based model to biopsies in predicting macrosteatosis >30%. We also tested them in populations enriched for macrosteatosis.

RESULTS

The Hepatic Steatosis Index area-under-the-curve (AUC) was 0.56. At the threshold identified by Youden's J statistic, sensitivity, specificity, positive, and negative predictive values were 49.6%, 58.9%, 14.0%, and 89.7%. Other tests demonstrated comparable results. Machine learning produced the highest AUC (0.71). Even in populations enriched for macrosteatosis, no test was sufficiently predictive.

CONCLUSION

Commonly used clinical scoring systems and a novel machine learning-based model were not clinically useful, highlighting the importance of pre-procurement biopsies to facilitate allocation.

Increased volume of organ offers and decreased efficiency of kidney placement under circle-based kidney allocation

The newest kidney allocation policy kidney allocation system 250 (KAS250) broadened geographic distribution while increasing allocation system complexity. We studied the volume of kidney offers received by transplant centers and the efficiency of kidney placement since KAS250. We identified deceased-donor kidney offers (N = 907,848; N = 36,226 donors) to 185 US transplant centers from January 1, 2019, to December 31, 2021 (policy implemented March 15, 2021). Each unique donor offered to a center was considered a single offer. We compared the monthly volume of offers received by centers and the number of centers offered before the first acceptance using an interrupted time series approach (pre-/post-KAS250). Post-KAS250, transplant centers received more kidney offers (level change: 32.5 offers/center/mo, P < .001; slope change: 3.9 offers/center/mo, P = .003). The median monthly offer volume post-/pre-KAS250 was 195 (interquartile range 137-253) vs. 115 (76-151). There was no significant increase in deceased-donor transplant volume at the center level after KAS250, and center-specific changes in offer volume did not correlate with changes in transplant volume (r = -0.001). Post-KAS250, the number of centers to whom a kidney was offered before acceptance increased significantly (level change: 1.7 centers/donor, P < .001; slope change: 0.1 centers/donor/mo, P = .014). These findings demonstrate the logistical burden of broader organ sharing, and future allocation policy changes will need to balance equity in transplant access with the operational efficiency of the allocation system.

Beyond donation to organ utilization in the USA

PURPOSE OF REVIEW

The deceased donor organ pool has broadened beyond young, otherwise healthy head trauma victims. But an abundance of donated organs only benefits patients if they are accepted, expeditiously transported and actually transplanted. This review focuses on postdonation challenges and opportunities to increase the number of transplants through improved organ utilization.

RECENT FINDINGS

We build upon recently proposed changes in terminology for measuring organ utilization. Among organs recovered for transplant, the nonuse rate (NUR REC ) has risen above 25% for kidneys and pancreata. Among donors, the nonuse rate (NUR DON ) has risen to 40% for livers and exceeds 70% for thoracic organs. Programme-level variation in offer acceptance rates vastly exceeds variation in the traditional, 1-year survival benchmark. Key opportunities to boost utilization include donation after circulatory death and hepatitis C virus (HCV)+ organs; acute kidney injury and suboptimal biopsy kidneys; older and steatotic livers.

SUMMARY

Underutilization of less-than-ideal, yet transplant-worthy organs remains an obstacle to maximizing the impact of the U.S. transplant system. The increased risk of inferior posttransplant outcomes must always be weighed against the risks of remaining on the waitlist. Advanced perfusion technologies; tuning allocation systems for placement efficiency; and data-driven clinical decision support have the potential to increase utilization of medically complex organs.

The New Distance-Based Kidney Allocation System: Implications for Patients, Transplant Centers, and Organ Procurement Organizations

Purpose of Review

The goal of deceased donor kidney allocation policy is to provide objective prioritization for donated kidneys, and policy has undergone a series of revisions in the past decade in attempt to achieve equity and utility in access to kidney transplantation. Most recently, to address geographic disparities in access to kidney transplantation, the Kidney Allocation System changed to a distance-based allocation system—colloquially termed “KAS 250”—moving away from donor service areas as the geographic basis of allocation. We review the early impact of this policy change on access to transplant for patients, and on complexity of organ allocation and transplantation for transplant centers and organ procurement organizations.

Recent Findings

Broader sharing of kidneys has increased complexity of the allocation system, as transplant centers and OPOs now interact in larger networks. The increased competition resulting from this system, and the increased operational burden on centers and OPOs resulting from greater numbers of organ offers, may adversely affect organ utilization. Preliminary results suggest an increase in transplant rate overall but a trend toward higher kidney discard and increased cold ischemia time.

Summary

The KAS 250 allocation policy changed the geographic basis of deceased donor kidney distribution in a manner that is intended to reduce geographic disparities in access to kidney transplantation. Close monitoring of this policy’s impact on patients, transplant center behavior, and process measures is critical to the aim of maximizing access to transplant while achieving transplant equity.