Continuous Distribution of Kidneys Update, Summer 2024
At a glance
Current policy
This paper builds upon the Kidney Transplantation Committee’s previous request for feedback, and on the Committee’s Continuous Distribution (CD) updates. This update provides the Committee’s progress to date on the continuous distribution project, including their discussions regarding efficiency objectives. This includes reducing non-use of kidneys, reducing out of sequence allocation for kidneys, and consideration of an expedited placement pathway in the continuous distribution of kidneys. This update also includes Committee discussions on continued modeling and optimization.
Supporting media
Presentation
Project update
- The Committee has been discussing trends in non-use of donor kidneys and identifying key drivers of non-use
- Committee has also established specific goals to define efficiency in continuous distribution, and is working in collaboration with the OPTN Expeditious Task Force on Efficiency
- The Committee is also working to develop a data-driven definition of “hard to place” kidneys
- Additionally, this update details the efforts of the Kidney Expedited Placement Workgroup, which is working with the Expeditious Task Force towards the development of an expedited kidney placement policy
Project goals
- Provides a more equitable approach to matching kidney candidates and donors
- Removes hard boundaries between classifications that prevent kidney candidates from being prioritized further on the match run
- Considers multiple patient attributes simultaneously through a composite allocation score instead of within categories
- Establishes a system that is flexible enough to work for each organ type
- Creates a uniform system that will make future policy changes faster
- Consider how CD would impact the goals of decreasing non-use and non-utilization of kidneys
Anticipated impact
- What it's expected to do
- Prioritize candidates in a more flexible manner
- Allow the transplant community to see how much weight is placed on each attribute
- Improve equity in access to organ transplantation
- Improve efficiency of kidney allocation in a continuous distribution framework
- What it won't do
- This paper is not a proposed policy change, but is an update on the project
Terms to know
- Attribute: Criteria used to classify then sort and prioritize candidates. For example, in kidney allocation, criteria include medical urgency, blood type compatibility, HLA matching, and others.
- Composite Allocation Score: Combines points from multiple attributes together. This concept paper proposes the use of composite allocation scores in a points-based framework.
- Match run: The list of potential recipients printed by the OPO or Organ Center for each organ recovered for the purpose of transplantation from each donor.
- Modeling: Calculations the Scientific Registry of Transplant Recipients (SRTR) uses to create model predictions on the different attributes and their effect on organ allocation.
- Rating Scale: Describes how much preference is given to candidates within each attribute.
- Weights: Reflect the relative importance or priority of each attribute toward our overall goal of organ allocation. Combined with the ratings scale and each candidate’s information, this results in an overall composite score for prioritizing candidates.
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Comments
Region 1 | 08/29/2024
A comment was submitted stating that kidney allocation should be based on best use and efficiency, since kidney transplants are not as life-saving as heart or liver transplants. The commenter supports exhausting the list of patients who are “local” before considering any patients at further distances. They added that the single largest barrier to kidney allocation is programs who express interest in a kidney, only to turn it down after cross-clamp and that this must be addressed. Another comment suggested looking at kidney offer filters to help define “hard to place”. A virtual attendee stated that programs differ in their tolerance to cold ischemic time limits, so using that alone to define a “hard to place” kidney would not be useful. The attendee also does not believe there are specific anatomy characteristics that should be included in a “hard to place” definition.
During the meeting, attendees participated in group discussions and provided the following feedback:
· Cold ischemic time (CIT) should be major factor in defining hard to place kidneys. Attendees commented that their OPO allocates kidneys 12-24 hours pre-recovery, so if these were “easy to place” they should be accepted right after recovery.
· A member suggested that if programs thoroughly review the offers, there might not be a need for expedited or rescue pathways. Creatinine, age of donor are examples of things to be evaluated related to offers.
· An attendee remarked that many times their program doesn’t hear about kidney until 12-15 hours post-procurement. CIT is a major consideration but not the only one – they would also consider factors like KDPI and location of donor. For example, if there is a high KDPI kidney in New York and the program is notified it at 12 hours, they may not take it. Other important factors to consider would be biopsy, pump pressure, and anatomy.
· The group felt that determining allocation thresholds for defining “hard to place” is difficult. They remarked that it would be helpful to see the data within each KDPI group to see how far it goes. They said that once a kidney starts getting turned down, it develops a reputation based more on assumptions than actual organ quality, so attendees felt initially that “hard to place” should be stringently defined.
UAMS Medical Center | 08/28/2024
After reviewing the Summer 2024 update to the continuous distribution of kidneys proposal, we appreciate the additional information provided and offer the following feedback. When an organ is classified as “hard to place”, we feel that the transplant center should receive an additional SRTR risk adjustment or waiver. This would allow centers to use “hard to place” organs and receive accurate risk adjustment for SRTR releases. Transplant centers are expected to carry the burden of the additional cost these organs incur such as increased length of stay, readmissions, long term care needs and frequent clinic/lab visits. The financial burden this places on transplant centers needs to be considered and solutions need to be identified before additional regulations are added. To classify an organ as “hard to place”, we feel a variety of factors should be considered including donor comorbidities, prior HD/CRRT, Cold Ischemic Time, Biopsy results, etc. We agree that the creation of clear and consistent definitions for “hard to place” organs will be beneficial to transplant centers and OPOs. While we support the creation of an expedited kidney placement policy, we firmly believe that this should not take away a surgeon/OPOs ability to quickly place organs. It is important that OPOs are allowed to “skip the list” and place organs with known aggressive centers quickly and efficiently versus requiring time consuming and tedious documentation.
Region 8 | 08/27/2024
Online members pointed out that as more centers decline a kidney, others become skeptical. A member suggested the number of 50 declines is the number at which an organ should be considered “hard to place” or at risk of non-use. The number of transplant center programs that have declined for all recipients is a very good indicator of kidney non-use. More specifically kidney centers who have been deemed "aggressive", if they decline it is more likely for non-use.
· An attendee explained there are many factors that make a kidney difficult to place. Kidney biopsy being one large factor in non-utilization.
· For specific anatomy characteristics or considerations that should be included in the “hard to place” kidney or kidney at increased risk of non-use, attendees suggested the following: plaque, stripped or multiple ureters, and biopsy results.
· An attendee commented that they did not recommend reducing the pediatric weight (even slightly) to reduce median travel distance.
· Another attendee commented how continuous distribution has greatly increased transportation logistics. For organs such as lungs, hearts, and even livers, charter jets are more mainstream. For kidneys, there is a real risk of increased non-use due to extended CITs by using commercial aircraft unless CMS makes an announcement that charter jets can be used as standard of care in transportation logistics over longer distances.
During the meeting, in-person attendees participated in group discussions and provided feedback on the following questions:
· Should a cold ischemic time (CIT) threshold alone be used to define a kidney as “hard to place” or at increased risk of non-use?
o The group reported that no, we should not use CIT threshold alone. Twenty hours of CIT may mean something very different in one donor than another. They suggested to consider factors in conjunction with CIT.
· Are there specific anatomy characteristics or considerations that should be included in a definition of a “hard to place” kidney, or a kidney at increased risk of non-use?
o Regarding specific anatomy characteristics - not biopsy but gross anatomy inspection, i.e. multiple arteries, presence of plaque in arterial veins, and overall kidney size.
· Allocation thresholds are based on the progress of allocation, specifically in terms of increasing numbers of declines. For example, allocation efforts reaching sequence number 200 means that the organ offer has been declined for 199 candidates. Alternatively, another allocation indicator under consideration could be the number of programs who have declined for all of their candidates. Is there a number of candidate or program declines at which an organ could be considered harder to place or at risk of non-use?
o Programs may be more reflective of when a kidney is getting harder to place. For example, if five programs pass, then OPOs may start getting nervous. It also depends on where you are/transplant program density.
OPTN Organ Procurement Organization Committee | 08/22/2024
The six-hour mark is indeed critical, as it significantly increases the risk of non-use for kidneys. The group seems to agree that decisions should be made more quickly, ideally before this point.
- Regarding moving through allocation better and identifying high-risk kidneys:
- There's a suggestion to create specific pathways for hard-to-place kidneys, especially those with high KDP scores.
- Consider cold ischemic time as a key factor in decision-making, starting from the cross-clamp time.
Develop clearer definitions and consistent language across OPOs and transplant centers to improve communication and decision-making.
On the issue of clear definitions:
- The group agrees this is necessary, both for OPOs and transplant centers.
- It's suggested that everyone should use the same language to ensure consistency.
- This standardization could help in making quicker, more informed decisions about organ allocation.
Region 4 | 08/19/2024
The kidney and pancreas group commented that continuous distribution should not take away the discretion of OPOs and surgeons to place kidneys quickly and efficiently. One attendee strongly advocated for giving priority to prior living donors noting that over the past 25 years, the number of prior living donors who are listed for transplant is very low but has a high impact on promoting trust in the system and is important for how the transplant community connects with the community at large. There was also a recommendation that the committee collaborate with the Expeditious Task Force as there is much work being done to assess kidney allocation and continuous distribution will directly affect the allocation policies as they are updated.
Virtual attendees also provided feedback on key questions. Several attendees commented that cold ischemic time should not be used as the sole definition of hard-to-place kidneys. They added that there are multiple reasons behind increased cold ischemic time including anatomical issues, hypertension, age, serologies, glomerular function, en bloc, etc., that need to be considered. Specific to anatomy characteristics, attendees commented that the following kidney characteristics should be included in hard-to-place kidney definition: trauma to kidney/parenchyma or vasculature, greater than 3 arteries, dual or enbloc kidneys, cysts, surgical injury, discoloration/mottling, mass, excessive dense fat or plaque. There were also on-line comments that hard-to-place kidneys should include decline thresholds of 25 centers and 250NM.
Region 2 | 08/16/2024
Feedback submitted online highlighted the need to limit penalties for transplant centers that accept organs with unadjusted risks, emphasizing that many donor organs now carry significant risks not accounted for in standard SRTR risk adjustments or KDPI. Examples include donors on dialysis before donation or with a history of acute kidney injury/renal failure. Once an organ is deemed "hard to place" after multiple centers decline it, it should not be scrutinized under standard SRTR criteria, and recipients of such organs should receive priority if the organ fails early. Additionally, there was support for giving patients a greater role in decision-making and transparency regarding organ preferences, as well as agreement on the importance of optimizing outcome modeling for hard-to-place organs.
During the meeting, attendees participated in group discussions and provided feedback on the following questions:
- Should a cold ischemic time threshold alone be used to define a kidney as “hard to place” or at increased risk of non-use?
- Cold ischemia time (CIT) should not be the sole factor in decision-making for kidney transplants, as there are many other important considerations, such as medical comorbidities, the reliability of virtual crossmatch, and biopsy results, especially for hard-to-place organs. While some agreed that CIT is important, they noted that its definition varies, and for some, CIT should ideally be less than 24 hours from cross-clamp to departure from the OPO.
- Are there specific anatomy characteristics or considerations that should be included in a definition of a “hard to place” kidney, or a kidney at increased risk of non-use?
- The discussion highlighted key anatomical and medical factors that can make a kidney difficult to place, including multiple vessels, suspicious cysts or nodules, and specific vascular anomalies or damage, such as renal artery surgical injuries and poor flush quality. Additionally, medical comorbidities like a history of diabetes (DM), hypertension (HTN), and the use of continuous renal replacement therapy (CRRT) or hemodialysis (HD) during admission were noted as new challenges in kidney placement.
- Allocation thresholds are based on the progress of allocation, specifically in terms of increasing numbers of declines. For example, allocation efforts reaching sequence number 200 means that the organ offer has been declined for 199 candidates. Alternatively, another allocation indicator under consideration could be the number of programs who have declined for all of their candidates. Is there a number of candidate or program declines at which an organ could be considered harder to place or at risk of non-use?
- The discussion emphasized that the allocation of kidneys should consider not only the number of declines but also the specific centers that decline them, as surgeon behavior can significantly impact placement. Geographic factors and reasons for declines were acknowledged as driving influences in the process. A kidney should not be deemed hard to place based solely on decline numbers; rather, if five different programs decline offers to standard adult single organ candidates—excluding high CPRA, pediatric cases, or other organ transplant priorities—the organ should be flagged as at risk. The proposed distance for evaluating placements was noted as 150 to 200 nautical miles. Overall, both the quantity and reasons behind declines are critical in assessing a kidney's placement challenges.
George Bayliss | 08/12/2024
The Kidney Committee has produced a thorough examination of the continuous distribution of kidneys and efforts to include increased use of kidneys and decreased waste of organs in this new point-based system of matching donated organs and recipients.
Continuous distribution always has always intended to decrease waste by using each patient's composite allocation score to match kidneys and potential recipients more closely. Adding a specific mandate to decrease non-use of organs while developing a transparent system for expedited placement of organs at risk of discard acknowledges that this may be difficult to do in the new allocation system.
The Kidney Committee has made useful suggestions on ways to reduce delays while individual programs exam offers, such as the shift to virtual cross matches; standardization of biopsy and pump data and closer examination of whether they are necessary; simultaneous allocation; expanded use of organ allocation filters to help reduce risk of programs becoming overwhelmed with the need to examine many orders simultaneously.
The Kidney Committee writes about the need for flexibility in determining what donor and organ characteristics, and logistical aspects will define hard to place and need to offer a kidney for expedited placement or a rescue pathway. They note the difficulty OPOs might have in deciding which centers are able to take such a challenged kidney. Universal use of offer filters would help create an initial screen, in addition to past OPO experience with centers.
Another idea would be to include as part of the composite score an indicator of whether a candidate is willing to take a rescue kidney. This would only come into play when a kidney has hit the threshold of “hard to place.” It would allow ranking according to the standard composite allocation score but identify candidates for one of these kidneys early.
The Kidney Committee’s future updates on continuous distribution should consider what effect new efforts to assess programs on organ acceptance as a function of expected acceptance and the Department of Health and Human Services “Increasing Organ Transplant Access” model will have on allocating “hard-to-place” organs.
Lydia Clipper | 07/31/2024
The anti a1 question of yes or no for eligibility in the UNOS system is flawed. When an answer is updated, the system automatically uses the date of entry. Because being eligible for anti a1 is date specific the system should ask to document the date the specimen was obtained so the timeframes may be figured appropriately according to the date of the blood draw that makes them eligible.
She Gay | 07/31/2024
I am excited we have more living donors stepping up than in the past. I believe this will help reduce the numbers of kidney candidates. Sadly, the kidney wait time is too long. I am a strong proponent of our state candidates first considered if all the criteria is equal.
Keith Plummer | 07/31/2024
I would like to see a system that centers can use to convey current placement on “the list”. My surgeon has mentioned to me that some kidneys are shipped with the recipients then needing a blood transfusion to accept the kidney. He claims most of these type fail and the organs are wasted.