Simultaneous Liver-Kidney Transplants - The Argument for Standardized Allocation Rules.

Abstract

Background. There are currently minimal allocation rules for simultaneous liver-kidney (SLK) transplants (txs) and a lack of standardized allocation rules for these txs may be diverting donated kidneys (KIs) from candidates in medical need to those who could regain KI function with a solitary liver (LI) tx. The Organ Procurement and Transplantation Network (OPTN) KI Committee is in the early stages of considering a policy proposal to address SLK allocation. This abstract is to inform the tx community of the need for equitable allocation rules for SLK txs. Data. The OPTN database was analyzed for clinical/donor characteristics of SLK txs and KI listings after LI txs to determine the number of recipients who had clinical factors that suggest they may not have needed the KI at time of LI tx. Results. During 1/1/05-6/30/13, 510 (15%) of 3,431 SLK recipients did not receive pre-tx dialysis and had a serum creatinine of <2.5 mg/dl at tx, which suggests that some of these patients may not have needed the KI. Of these 510 SLK txs, 237 (47%) had a Kidney Donor Profile (KDPI) of <35%. Among recipients of solitary LI tx, on average 200 patients are listed for a KI tx after LI tx yearly. The median time to listing for these patients was 9 yrs for those with a KI diagnosis of CNI toxicity, 6.5 yrs for hypertension, and 5 yrs for diabetes; additionally, only 19% were listed within a year of the LI tx. Summary. These findings suggest that approximately 500, or 60 SLK recipients per year, may not have needed the KI. They also suggest that the fear of chronic KI insufficiency rapidly leading to ESRD after LI tx for a large number of solitary LI patients may be unfounded. KIs utilized in SLK txs also tend to have a lower KDPI score, suggesting that the lack of standardized clinical criteria for SLK txs will, in the new kidney allocation system, divert some KIs away from pediatric candidates and adults with estimated post-tx survival (EPTS) scores in the top 20%. The Committee continues to review data and discuss new SLK allocation policy to achieve equity and best use of donated organs as specified in the Final Rule.