Skip to main content

Split liver variance

Proposal Overview

Status: Implemented

Sponsoring Committee: Liver and Intestinal Organ Transplantation

Strategic Goal: Increase the number of transplants

Read the modified proposal (PDF; 12/2019)

View the policy notice (PDF; 691 K; 6/2019)

View the Board report (PDF - 538 K; 6/2019)

Read the proposal (PDF; 1/2019)

Contact: Elizabeth Miller

Executive summary

This proposal would create a variance to permit participating liver programs to split a liver and transplant the first segment into the candidate to whom it was allocated, and then transplant the remaining segment into another candidate at the same transplant hospital or an affiliated hospital after offering the remaining segment to the most urgent candidates within 500 nautical miles. The goal is to increase the number of livers that are split and thereby increase the number of liver transplants available from the same donor pool. It aims to reduce the logistical and technical challenges currently associated with splitting a liver. The variance would be used to determine whether it would in fact increase the number of transplants by increasing the number of livers that are split.

This variance was initially proposed by transplant hospitals and OPOs in region eight, who requested it as a regional variance. However, transplant hospitals in other regions expressed interest, and the Committee proposes that this be an open variance that other OPTN members can also join.

Feedback requested

The Committee encourages all interested individuals to comment on the proposal in its entirety. Members are asked to comment on both the immediate and long-term impact on budgets and other resources that may be required if this proposal is approved; this information assists the Board in considering the proposal and its impact on the community. The Committee requests specific feedback on the following items:

  1. Members are asked to comment on whether this variance should only be available to region eight, or if it should be available to other OPTN members that would like to participate.
  2. Members are also asked to comment on whether they would be interested in participating in this variance so that the Committee can gauge the level of interest in the variance.


 | 03/26/2019

Vote with amendment: 4-strongly support, 17-support, 2-abstain, 0-oppose, 0-strongly oppose Amendment: If the primary recipient receives the left lateral segment, then the right tri-segment has to be offered using the full match run. If the primary recipient receives the right tri-segment, then the accepting program or their affiliated hospital can use the left lateral segment.

Joseph Hillenburg | 03/22/2019

This proposal would seem to have strong benefits overall, but specifically to pediatric centers. All regions should participate.

Society for Pediatric Liver Transplantation (SPLIT) | 03/22/2019

The Society of Pediatric Liver Transplantation is strongly in favor of effective measures to increase overall number of transplants and increase utilization of appropriate grafts. Previous research has shown that when appropriate livers are allocated to small children first and required to be split, the right lobe is transplanted, typically into an adult recipient. The changes in prioritization of all pediatric livers for pediatric patients may prompt increased utilization of split grafts. This variance, which we support, allows the receiving program or center to incentivize the utilization of that graft for more than one patient. It is intended to allow for facilitating increased number of adult and pediatric transplants overall.

 | 03/22/2019

The American Society for Histocompatibility and Immunogenetics (ASHI) strongly supports this proposal.

 | 03/22/2019

0 strongly support, 1 support, 4 abstain, 7 oppose, 14 strongly oppose Amendment: As proposed, remove first offer going to remaining segment to Status 1 and MELD >32 within 500NM - 15 strongly support, 6 support, 3 abstain, 0 oppose, 0 strongly oppose Comments: The region was supportive of increasing the number of transplants, and making this an open variance. However, they noted that if a program accepts a whole organ, what is the incentive to split, even if the program ultimately keeps both segments? Members concurred that if a program determined a liver could be split, the program should be permitted to keep both segments, and there should not be a requirement to first offer a segment to a high MELD candidate. In a straw poll, 7 programs indicated they might participate if it was an open variance. The region opposed the variance requirements as proposed, but supported an amendment removing the requirement that the accepting program only gets to keep the split portion of liver after it has been offered to Status 1A and 1B candidates within 500 nautical miles of the donor and candidates with a MELD or PELD of 33 or higher that are within 500 nautical miles of the donor first.

 | 03/22/2019

4 strongly support, 11 support, 6 abstain, 4 oppose, 5 strongly oppose Proposed Amendment: Split liver variance should only apply to adult candidate splits with two adult recipients – 7 strongly support, 13 support, 9 abstain, 3 oppose

 | 03/22/2019

4 strongly support, 20 support, 8 abstain, 5 oppose, 3 strongly oppose The region commented the reason splitting livers is not more common is because there aren’t many adult programs that will accept them. Programs associated with a pediatric program have more motivation to split.

Carolina Donor Services | 03/22/2019

Carolina Donor Services supports this proposal to increase organ utilization through wider implementation of the Region 8 split liver variance.

American Society of Transplant Surgeons | 03/21/2019

The American Society of Transplant Surgeons (ASTS) thanks the OPTN Liver and Intestinal Committee for their work on this policy proposal. ASTS supports the Region 8 variance as written but only for Region 8 until data is collected during the 3 year demonstration project.

American Society of Transplantation | 03/19/2019

The American Society of Transplantation could not come to clear agreement within its membership to either support or oppose this proposal, but offers the following comments for consideration: The Society’s pediatric members strongly support any strategy that seeks to increase opportunities for small children to benefit from transplantation but wishes to clarify that a similar variance was created for Region 2 and an OPO in Region 5, and the unpublished data demonstrated no significant increase in split liver utilization. It is believed that the under-utilization of split liver transplants stems from a national gap in surgical expertise to safely perform the technical operation and an overweighting of programmatic penalization for complications or poor outcomes related to these procedures. Surgeon experience, and organ selection decision-bias continue to limit broader voluntary use of split liver practices for the smallest waitlisted patients despite improving surgical techniques and era-controlled studies demonstrating the contemporary statistically similar outcomes of technical variant grafts vs. whole organs. The highest pediatric liver waitlist mortality rate is still the neonatal (90% of those cases, the aggregate adult transplant waitlist was not disadvantaged because the right lobe was typically transplanted into an adult recipient. The Society’s pediatric members support this present proposal as an intermediary step to encourage more split liver transplants but further advocate for development of an allocation system that mandates a liver be split from any donor that meets current criteria for potential to be split and that the left lateral segment be allocated first to the highest priority small pediatric liver recipients within the designated concentric circle. We view this strategy as a path to eliminating liver waitlist mortality. This practice in other countries has yielded a higher split graft utilization. (Hsu and Mazariegos, Liver Transplantation 23:86-95, 2017). A number of the Society’s liver members were not in agreement on this proposal. Some members felt that the remaining segment should be offered to Status 1 and MELD >32 to avoid disparity in organ allocation, as there are programs that are currently accepting these segments for transplantation into their recipients. They proposed that if the split is decided upon prior to the recovery of the donor organ, then the remaining segment should be offered back to the allocation scheme within 250 NM distance first and then expanded out to 500 NM. If there is no acceptance for the second segment prior to the recovery, the primary center should be allowed to use the second segment for a recipient at the same center. If a split transplant is decided upon after recovery based on the size of the organ, the primary center should be allowed to use the other half for use on another recipient in the same center. Expedited placement for a split liver under these circumstances with prolonged cold ischemic time is not practical. Other members of the Society’s liver community proposed that the remaining segment is allowed to be transplanted into a second recipient in the same transplant center without returning to the match run in order to incentivize splitting livers. AST also recommends consideration of separate monitoring of outcomes from these split liver transplants from the total deceased donor transplant outcomes so as not to disincentivize centers from splitting livers.

 | 03/19/2019

The Pediatric Transplantation Committee (Pediatric Committee) commends the Liver Committee for their effort in creating this public comment proposal and thanks them for the presentation on the document. A Pediatric Committee member asked what the incentive would be for a primary adult program to split a right trisegment. Another Pediatric Committee member was curious if Region 8 had any issues with the requirement to offer the second segment to Status 1 and high MELD candidates within 500 NM. The Pediatric Committee member felt that this requirement may reduce some of the incentive of the variance. Another Pediatric Committee member asked if it would be possible to target pediatric programs with the variance. The Pediatric Committee also inquired about how participation in the variance would happen given the new allocation system.

Association of Organ Procurement Organizations (AOPO) | 03/18/2019

The Association of Organ Procurement Organizations (AOPO) appreciates the opportunity to provide comment on the proposed Split Liver Variance. The Split Liver Variance, as proposed, is intended to increase the use of Split Liver segments and thus potentially increase the number of liver transplants. This variance would be available to all transplant centers that apply for the variance and the variance will expire in three years. UNOS data demonstrate that less than 1.5% of donor livers are split for transplant. Also, not all the remaining segments from a split liver are transplanted because of logistical reasons related to the current allocation policy. AOPO supports organ allocation policies that have as a goal, the increase in number of transplants and the reduction in organ discards. AOPO supports the proposed variance and making it available nationally with these caveats: A. The variance must not negatively impact the availability of left lateral segments for pediatric liver transplant candidates. B. UNOS must aggressively monitor the variance to ensure that participating liver transplant programs are accepting livers to split for the appropriate patients and transplanting both segments in the appropriate candidates.

Donor Alliance | 03/15/2019

Donor Alliance supports extending the split liver variance beyond Region 8 to centers choosing to opt- in. The overall goal of split liver usage is to transplant more individuals. The proposal strikes a balance between meeting the medically urgent needs of recipients within a 500 NM radius with incentive to the original center of allocation to voluntarily split the liver in order to transplant two patients.

 | 03/15/2019

Region 4 vote-1 strongly support, 14 support, 4 abstain, 3 opposed, 0 strongly opposed Comments: There was concern raised that sharing for MELD >32 would not help to increase sharing. There was some support for the recipient center keeping both segments. There was also some support for sharing the remaining segment more broadly for Status 1’s only

 | 03/14/2019

The Organ Procurement Organization (OPO) Committee discussed this proposal and offer the following responses: o The Committee supports this proposal to increase splitting of livers but there is some concern about this process bypassing candidates on the waiting list and the disadvantages it can present in other regions. OPO Committee Vote: • What is your opinion of this proposal? Vote: 2 strongly support, 1 support, 3 oppose • Should this variance only be available to Region 8 or should it be available to other members? Vote: Unanimously (9 votes) support this variance should permit other members to participate.

Warren Maley | 03/08/2019

This proposal would preferentially direct the right portion of liver to programs with an associated pediatric program as the majority of splits are done where the pediatric recipient is primary. Effectively, this would limit access to the right portion for patients listed at a program not having a pediatric liver center. One would anticipate that support for this variance would be limited to those centers having an associated pediatric liver program.

Anonymous | 03/07/2019

this proposal is blatantly unfair to programs without pediatric component. The adult/small child splits are routinely used. It disadvantages those patients who are in adult only transplant programs.

Joseph Magliocca | 03/07/2019

Transplant hospitals that are perform split liver transplants can most efficiently tailor grafts to patients with the utmost regard for both grafts. At this point, it is difficult to accept a split graft that was split at a different center as it is not possible to be present when the organ is split to optimize the graft for each recipient. I believe this policy would increase the use of split organs and increase the number of transplants.

 | 02/28/2019

Region 10 Vote: Proposal as written: 3 strongly support, 3 support, 7 neutral/abstain, 0 oppose, 9 strongly oppose Hemiliver split in adults only amendment: 7 strongly support, 6 support, 7 neutral/abstain, 1 oppose, 0 strongly oppose Members voiced concern over the lack of standardization in how to split livers in the proposal. They proposed an amendment that would only allow for hemi-liver splits in adults to be used in the proposed variance.

UPMC Children's Hospital of Pittsburgh | 02/28/2019

The UPMC Children’s Hospital of Pittsburgh strongly supports the split liver variance proposal sponsored by the Liver and Intestinal Organ Transplantation Committee. Technical variant liver transplantation has been shown to have equivalent outcomes to whole liver transplantation and can be utilized to decrease not only waitlist mortality and time to transplant, but also provide an influx of additional opportunities for transplantation by splitting livers for multiple recipients that would otherwise have been transplanted into one individual, as a whole liver. We wholly agree, with other public comments posted, that programs choosing to participate in the split liver variance are electing to invest additional time and resources to transplant multiple patients with one allocated graft. The stated goal of the variance is to increase the number of livers that are split and thereby increase the number of liver transplants available from the same donor pool. Inherently, more programs can be expected to split an allocated liver if they know that they will be provided the opportunity to transplant the remaining segment into another candidate at their transplant hospital or an affiliated children’s hospital after offering the remaining segment to the most urgent candidates within 500 nautical miles. Hsu and Mazariegos noted that of 581 children listed on the national liver transplant waiting list in 2013 only 541 underwent liver transplantation and an additional 49 were removed because of death or being too ill to transplant (Liver Transplantation 23:86-95, 2017). The proposed split liver variance is an attempt by the liver and intestinal transplantation committee to eliminate or significantly decrease the occurrence of death on the waitlist while also increasing the number of overall transplants by increasing the number of whole, allocated livers that are split. We also support the language in the proposal allowing each individual transplant center the ability to opt-in to this variance.

Anonymous | 02/26/2019

The proposal is fundamentally flawed since the liver allograft has been allocated according to UNOS to a deserving adult patient. The process of denying that adult the full liver and consent process for this is highly questionable. Programs will state that their patients are consented for split livers, however, are they are really consented to donate their left later segment. The proper way to accomplish this goal would be to first allocate all splittable livers to pediatric patients. This way the left lateral segment would be allocated a child and then triseg graft could be allocated to the adults as a according to UNOS allocation policy.

 | 02/25/2019

Region 8 vote: 5 strongly support, 14 support, 3 neutral/abstain, 1 oppose, 1 strongly oppose Comments: One member verbalized the proposed sharing threshold of a MELD score of 32 was too low. This score is within reach of some candidates with malignancy and a high exception-based score. An alternative sharing threshold of 35 was suggested as this is more in-keeping with sharing for sicker liver transplant candidates.

 | 02/21/2019

Region 2 Vote: 4 strongly support, 1 support, 2 neutral/abstain, 15 oppose, 5 strongly oppose The comments from Region 2 were split on the proposal. A few members noted that this has the potential to increase the number of livers split and therefore increase the number of patients that are transplanted. By allowing both segments of the liver to remain at one center, it potentially increases the likelihood that both segments will be transplanted. On the other hand, centers that do not opt into the variance will miss out on the livers that are split at those centers; which puts patients not in the variance at a disadvantage. Several in the audience felt that the remaining segment should continue to be allocated to the patient on the list as current allocation demands.

 | 02/21/2019

Region 5 Vote: 4 strongly support, 3 support, 3 abstain, 6 oppose, 19 strongly oppose Several members commented that the incentive to split livers should come from the ability to transplant a sick child and not from policy. This would disadvantage adults listed at programs that are not affiliated with a pediatric center. Multiple members also contributed to the conversation that this is based on a practice variation in a particular region that does not split many livers and is not representative of the country. They asked if region 8 implements this, how would it impact surrounding centers when DSA/region is eliminated form allocation? Also, how would it work if only one center opted in as this would decrease sharing and go against the Final Rule. Another question was how the cutoff of 32 was determined as this could exclude a large population of region 5. One member stated this should be two proposals: one for pediatric splits and the split should go back to the list and one for adults that if the program splits, they should be able to use the other segment.

Region 1 | 02/18/2019

Region 1 vote-1 strongly support, 4 support, 3 abstain,4 opposed, 1-strongly opposed Comments: Members from pediatric programs commented that this variance will not help to increase splits. When centers split a liver for a pediatric candidate, the remaining segment is always placed. This is targeted at adult centers for an adult to adult split. Some in the region thought this might make sense in Region 8 due to OPOs having operating rooms. There was little support for offering this variance beyond Region 8 or participating in an open variance.

Ryutaro Hirose | 02/13/2019

I agree completely with HB Kim. I would, however, support this proposal if it were modified to include left lobe/right lobe splits (not left lateral segment/trisegment splits) . When a whole adult organ is allocated to a child, it is/should be split. I would favor an allocation change that directed young adult splittable livers to small pediatric patients. I also believe that pediatric liver centers should be held accountable for not accepting and not splitting appropriate offers for their pediatric candidates. I agree with Dr. Mathur's comments as well, that adult programs who happen not to be affiliated with a pediatric program are greatly disadvantaged, if this variance were to be allowed, and these adult programs ought to have the same access to the trisegment graft as those with an affiliation. It does seem a bit odd to need to be able to keep the right trisegment graft for a center to split. Many of our centers seem to be able to split livers without this 'incentive'. If allocation policy were to direct these livers more often to centers that split livers for their pediatric , more livers would be split and two candidates would benefit, the pediatric candidate and an adult candidate (that would not necessarily be listed at the same/or affiliated center).

Amit Mathur | 02/11/2019

I am strongly opposed to this proposal for several reasons. 1. Access to transplant for pediatric recipients: The language in the proposal implies that its purpose is to encourage more splitting of deceased donor livers. The by-and-far majority of splits occur as left lateral segment for a child, and a right trisegmentectomy graft for an adult. In my mind, the only incentive you need to split a liver for a child is the presence of a sick child on the list for transplant. Sick children are the primary recipients in these scenarios, and if a program needs further incentive to split livers to manage a child who is dying on the list than already exist, than those programs are doing a disservice to their patients. 2. Access to transplant for adult candidates: Adult candidates who are listed at programs without an institutionally affiliated pediatric program are disadvantaged by this policy in a significant way. Right trisegmentectomy grafts should be offered to ALL CANDIDATES on the list in order of allocation priority, not just those who happen to be in hospitals with a pediatric program. Adult programs that have an institutional affiliation with a pediatric program DO NOT have more deserving adult candidates than adult candidates in programs without a pediatric affiliation. This is simply inequitable, against the spirit of NOTA, and precipitates a form of geographic disparity. 3. Precedent: Region 8 proposed this variance and splits among the least numbers of livers compared to other Regions in the US. Other Regions have developed systems to make splitting work efficiently and place both grafts. In Region 5, we have all types of programs: free standing pediatric programs, multiple pediatric programs with affiliated adult programs, and multiple adult programs without affiliated pediatric programs. We share right triseg grafts regularly and there is an understanding and trust of the competence of the splitters to do service to both grafts. Why should it be different for Region 8? This is a policy that is unwarranted and should be opposed.

 | 02/08/2019

Region 7 vote-5 strongly support, 8 support, 3 abstain, 1 opposed. Several members commented that by making offers using the proposed MELD threshold and status 1 the variance may do very little to increase splitting and transplants. It is likely that the second segment will be accepted by someone in the 500 NM circle. Some recommended that the MELD threshold be higher or the circle size be smaller. There was support for having be incentive for adult programs to offer out the left lateral segment to pediatrics. Doing this would increase the number of pediatric transplants. The OPOs raised a concern about allowing any program to participate rather than an entire region. Since the OPO will be responsible for allocating the split to the medically urgent candidates, they would need to know which programs in their DSA/region are participating and should be a participant in the variance. Overall the region was supportive of having this be a regional variance, but would consider participating as either a region or as individual programs.

Zakiyah Kadry | 02/05/2019

This policy limits the utilization of split livers exclusively to pediatric liver transplant centers or teams that perform the split for one of their candidates. This proposal was voted against in our Region 2 meeting because we have several adult centers that utilize these match run offered extended right split livers for their adult patients. As a transplant center that accepts these split livers, we strongly oppose this proposal as it will exclude our patients from receiving these offers if they are not status 1 or if they have a MELD less than 32. Also, although we do not perform the split liver procurement, our center does send a procuring surgeon who supervises the split to ensure that no injury occurs to the extended right graft that we have accepted. I also want to point out that this policy provides an unfair advantage to pediatric centers that have an adult liver transplant program because these extended right grafts can be used on any MELD patient by the center performing the split while the other centers are being limited to utilizing these split livers in patients with a Status 1 designation or a MELD greater than 32 requirement. This is an unfair process in liver distribution. If UNOS decides at some point to proceed with this variance nationally regardless of a negative regional vote, then there should be an opt in process for centers that do not perform these splits but have a history of accepting and transplanting split liver grafts.

James Pomposelli | 02/04/2019

As one of the sponsors of the Split Liver Variance I strongly support making the variance available for any member who wants to participate. In that case they will need to participate in a national database to collect data. Some members have argued that this variance "is not fair" as the split portion stays with the splitting center or can go to an affiliated Children's hospital. They ignore the provisions for sharing for the most needy candidates where appropriate. The purpose of the variance is to incentivize more transplants and the arguments about fairness are not legitimate. If a liver is allocated to the top candidate of a program they have the right to transplant that liver into that candidate without question. There are no UNOS rules to compel a program to split a liver unvoluntarily and share it. Therefore, if the program is willing to take the extra time and risk to get two of their candidates transplanted with one liver, that should be encouraged. The spirit of the variance as we developed it is to try to get 2 adults transplanted with one liver but does not preclude splitting for children as is already done nationally.

LifeGift | 01/30/2019

LifeGift strongly supports this proposal and supports the intent to increase utilization of both segments of split livers as well described in the policy document.

Heung Bae Kim | 01/25/2019

I strongly support policy development that will increase the utilization of split liver transplantation as a means to increase the overall number of transplants and decrease waitlist mortality. However, the approach outlined in this proposal has already been attempted in the past using a variance in Region 2 as well as a single OPO in Region 5 and data from this variance demonstrated almost no increase in split liver utilization. It is disappointing to see that this historical information was absent from this proposal and I wonder if the committee was aware of this data? The main issue that has prevented broader voluntary use of split liver transplantation is the well justified behavior of surgeons working to minimize the complications in their individual patients. UNOS/SRTR data clearly shows that the majority of splits occur when the index offer is to a small pediatric recipient that requires the liver to be split. In >90% of those cases, the right lobe graft is transplanted, usually into an adult recipient. Therefore, one method that has been proven to increase split liver utilization would be to allocate "splittable" livers to small children first - a system that has been used in other countries as described in a paper by Hsu and Mazariegos (Liver Transplantation 23:86-95, 2017). This type of approach would be preferable to another attempt at "incentivized volunteerism" where the incentive is simply allowing the splitting center to keep both organs - a system that has already been tested and failed.

Chris Sonnenday | 01/22/2019

I strongly support the Split Liver Variance Proposal, and believe that it should be implemented nationally. Split liver transplantation is an underutilized tool to increase the number of liver transplants performed annually, and a good portion of the disincentives for splitting are logistical. Limiting the allocation of the two liver segments to a single transplant center (with exception for the most urgent candidates, as the variance allows) will facilitate more efficient split liver allocation and procurement.