K. Washburn1,*, K. Olthoff2
Article first published online: 28 MAR 2012
DOI: 10.1111/j.1600-6143.2011.03960.x
American Journal of Transplantation
Volume 12, Issue 4, pages 799–800, April 2012
© Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons
Truth and Consequences: The Challenge of Greater Transparency in Liver Distribution and Utilization
The system for distribution of deceased donor liver allografts has undergone relatively minor modifications over the past 15 years. The local-regional-national algorithm has been modified with small changes for discrete patient groups that impact a minor percentage of the total liver transplant volume. The proliferation of transplant centers has contributed to an entrenchment of the local donation service area as the primary distribution unit, with an amplified level of competition between centers. This has resulted in the relatively infrequent occurrence where a liver is placed nationally with a center outside the region of origin of the donor.
For a liver to make it to the national level of sharing, it must presumably first be denied by centers at the local and regional level. In this issue of American Journal of Transplantation, Lai et al. (1) examine the characteristics of nationally placed livers and the patients that receive them. Several findings are important to highlight. Nationally placed livers comprise 6% of the total transplant volume for the 5-year period. Large proportions (64%) of these nationally placed livers are utilized by just six centers. The MELD score at transplant for the recipients of these organs is significantly lower than that of locally placed livers (20 vs. 24). Fewer patients with hepatocellular cancer (HCC) and other exceptions are transplanted with national livers. After adjusting for a number of donor and recipient variables, the authors conclude that nationally placed livers can be transplanted with no increased risk of patient or graft loss compared to locally placed livers.
We think this study brings to light some important issues in regards to distribution and liver transplantation. Notably, using these less than ideal organs can result in acceptable outcomes in selected patients. In addition, these organs traveled considerably further (528 vs. 26 miles) with a longer cold ischemic time (9 vs. 7 h) than the local organs, without what appears to be significant detrimental consequences, all other things being equal. These results help support the concept that broader distribution of liver allografts is possible without paying a huge penalty in patient outcomes. However, it is important to note there is still a cost. The unadjusted results showed a significantly higher rate of graft loss, and lower patient and graft survival with nationally shared livers. National livers simply are not the same as locally placed livers.
Of interest and pointed out by the authors is the average MELD at transplant is significantly lower in nationally placed livers, with 25% being placed in MELD<15, and fewer recipients had HCC or other exceptions. The authors hypothesize, and we would concur, that it is likely that centers are using these organs in lower MELD score patients who might not otherwise have a chance at transplant, bypassing a large number of patients on their waiting list with presumably higher waitlist mortality, and probably outside the UNOS/OPTN allocation scheme.
These data highlight significant differences in behavior between centers, which cannot be entirely explained by geography. The data indicate that there are just a handful of programs attracting a large percentage of these nationally placed livers. This small group of centers is clearly willing to consider and use livers that others are hesitant to transplant, despite a higher chance of graft loss. It is possible that they feel a great need due to higher waitlist deaths, or perhaps they are more comfortable and better at utilizing these livers than others (2). The authors state they are looking into center specific parameters that may explain some of this behavior. We also do not have the data on other potential downstream outcomes from the use of these livers, such as length of stay, need for dialysis, and other issues associated with poor graft function.
What remains unclear is the process by which these organs are being offered and questions the methods by which these events might be allowed to occur. Are organ procurement organizations (OPO) proceeding systematically through the match run or are they making local and /or regional offers and if no takers moving on to an expedited placement to a center they know will likely accept the offer? If so, is this really a problem as organs are being utilized that otherwise might not be placed. Are other, equally desperate patients being passed over? Or are these OPOs and centers just demonstrating that expedited placement can work?
The system itself (DonorNet) may be inadequate to deal with these unwanted livers. Centers can put broad acceptance criteria in place for offers, and also place a provisional yes, with no obligation or negative consequence to such a response. Yet, multiple affirmative responses can slow down a process to expeditiously place a liver that is not wanted locally. An OPO may move to an expedited placement of a liver by calling a center they are confident will use the liver and obviate the need to go through the entire national list, saving critical minutes. At this time, there is no down side for an OPO to engage in this activity. The problem that we see is that many patients and centers are skipped over with this process. It would be interesting to know in the report from Lai et al. how often this short-circuited process was utilized, and the match list bypassed. OPOs have an incentive to place as many organs as possible for transplant and this system allows them to have “go to” or “speed dial” centers that allow them to maximize their yield. We think the system should be more transparent and fair to patients and centers. Developing a scoring system for centers that use a national liver when they put in a provisional yes may allow more centers to participate in this currently opaque process without slowing it down.
The current report illustrates that it is possible to utilize lower quality organs distributed nationally. The challenge is whether other centers of varying sizes can replicate these results (3), and second, developing a system that is more transparent in how these organs are distributed. Another challenge is to make transplant centers accountable, and to actually abide by the acceptance criteria that they put into DonorNet. The UNOS Liver and Intestine Committee is systematically tackling the issue of expedited placement and distribution with the help of analyses such as Lai et al. Breaking down old paradigms, learning from present experience and challenging our current system may allow the community to move toward a more equitable system for patients.
Disclosure
The opinions expressed here are those of the authors and do not necessarily reflect those of the UNOS Liver and Intestine Committee. The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation.
References
- , , , , . Patient, center, and geographic characteristics of nationally placed livers. Am J Transplant. this issue.
- 2 , , , et al. Utilization of extended donor criteria liver allografts maximizes donor use and patient access to liver transplantation. Ann Surg 2005; 242: 556–563.
- 3 , , , et al. Impact of center volume on outcomes of increased-risk liver transplants. Liver Transpl 2011; 17: 1191–1199.
No comments:
Post a Comment