Skip to main content

Split liver variance

Proposal Overview

Status: Public Comment

Sponsoring Committee: Liver & Intestinal Organ Transplantation Committee

Strategic Goal 1: Increase the number of transplants

Read the proposal (PDF; 1/2019)

Contact: Elizabeth Miller

Please use this form to provide your feedback. Your comments relating to the proposal will be displayed in the comment section below (within 24 hours).

No other identifying information will be displayed unless you choose to display your name with the comment. You can also submit a comment anonymously. You may submit comments by email, fax or mail.

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/UNOS 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/UNOS 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.


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.

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.

Kevin Myer | 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.

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.

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.

Region 7 | 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.

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.

Ryutaro Hirose | 02/14/2019

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).

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.