Kidney After Liver Transplantation Matched-pair Analysis: Are Kidneys Allocated to Appropriate Patients to Maximize Their Survival?

Improved outcomes of kidney after liver transplantation after the implementation of the safety net policy

The number of kidney after liver transplants (KALT) increased after the implementation of the United Network of Organ Sharing (UNOS) safety net policy, but the effects of the policy on KALT outcomes remain unknown. Using the UNOS database, we identified KALT between 60 and 365 days from liver transplant from January 1, 2010, to December 31, 2020. The main outcome was 1- and 3-year patient, liver, and kidney graft survival. Secondary outcomes included 6-month and 1-year acute rejection (AR) of liver and kidney, and 1-year kidney allograft function. Of the 256 KALT, 90 were pre-policy and 166 post-policy. Compared to pre-policy, post-policy 1- and 3-year liver graft survival was higher (54% and 54% vs. 86% and 81%, respectively, p <0.001), while 1- and 3-year kidney graft survival (99% and 75% vs. 92% and 79%, respectively, p =0.19), and 1- and 3-year patient survival (99% and 99% vs. 95% and 89%, respectively, p =0.11) were not significantly different. Subgroup analysis revealed similar trends in patients with and without renal failure at liver transplant. Liver AR at 6 months was lower post-policy (6.3% vs. 18.3%, p =0.006) but was similar (10.5% vs. 13%, p =0.63) at 1 year. Kidney AR was unchanged post-policy at 6 months and 1 year. Creatinine at 1 year did not differ post-policy versus pre-policy (1.4 vs. 1.3 mg/dL, p =0.07) despite a higher proportion of deceased donors, higher Kidney Donor Profile Index, and longer kidney cold ischemia time post-policy ( p <0.05 for all). This 3-year follow-up after the 2017 UNOS policy revision demonstrated that the safety net implementation has resulted in improved liver outcomes for patients who underwent KALT with no increased AR of the liver or the kidney allografts.

Supervivencia del injerto y pacientes postrasplante renal de un hospital de Yucatán, México

Introducción: El trasplante de órganos es considerado como uno de los mayores avances de la medicina, no solo por recuperar la salud, sino por mejorar la calidad de vida de las personas con enfermedades crónicas o terminales.Objetivo: Identificar la supervivencia del injerto y pacientes sometidos a trasplante renal, así como los factores asociados en un Hospital de Alta Especialidad de Mérida, Yucatán, México.Material y Método: Estudio epidemiológico, observacional, longitudinal y retrospectivo donde se analizó el 100% de los expedientes disponibles de pacientes con trasplante renal, cuyo procedimiento se realizó a partir de enero de 2010 a diciembre de 2018.Resultados: La supervivencia global de los pacientes, fue de 96,7% a 1 año (IC:95%: 0,92-0,99) y 90,7% a 5 años (IC:95%: 0,75-0,97). La administración de terapia inmunosupresora previa al trasplante es un factor independiente de protección frente al desenlace de mortalidad o fallo del injerto (p=0,02). La supervivencia del injerto fue de 79,2% a 1 año (IC:95%: 0,71-0,85), y 41,37% a 5 años (IC:95%: 0,27-0,54). La dislipidemia (p=0,01), la Diabetes Tipo 2 (p=0,09), la isquemia fría (p=0,01), la isquemia caliente (p=0,02), la edad (p=0,03), y el Índice de Masa Corporal (p=0,01) fueron determinantes de la supervivencia del injerto.Conclusiones: La supervivencia del paciente y del injerto son distintas. La administración de inmunosupresor previo al trasplante afecta la supervivencia del paciente; mientras que factores de riesgo cardiovascular y los tiempos de isquemia estuvieron ligados a la supervivencia del injerto.

Pros and Cons of the Safety Net Rule for Prioritization of Liver Transplant Recipients Who Receive Liver Alone Transplant but Develop End-Stage Renal Disease

The number of patients presenting with cirrhosis with kidney injury and the potential need for SLKT is increasing. In 2017, standardized criteria were implemented to identify candidates for SLKT as well as criteria for prioritizing LTA recipients for kidney transplant if they developed kidney failure, which is referred to as the 'safety net rule.' Goal of the safety net rule is to provide a pathway that provides increased priority to LTA recipients with renal failure who may have previously undergone SLKT. This article reviews the pros and cons of the safety net rule for liver transplant recipients who develop ESRD.

Early Outcomes With the Liver-kidney Safety Net

BACKGROUND

A safety net policy was implemented in August 2017 giving liver transplant alone (LTA) recipients with significant renal dysfunction posttransplant priority for subsequent kidney transplantation (KT). This study was undertaken to evaluate early outcomes under this policy.

METHODS

Adults undergoing LTA after implementation of the safety net policy and were subsequently listed for KT between 60 and 365 days after liver transplantation contained in United Network for Organ Sharing data were examined. Outcomes of interest were receipt of a kidney transplant and postliver transplant survival. Safety net patients were compared with LTA recipients not subsequently listed for KT as well as to patients listed for simultaneous liver-kidney (SLK) transplant yet underwent LTA and were not subsequently listed for KT.

RESULTS

There were 100 patients listed for safety net KT versus 9458 patients undergoing LTA without subsequent KT listing. The cumulative incidence of KT following listing was 32.5% at 180 days. The safety net patients had similar 1-year unadjusted patient survival (96.4% versus 93.4%; P = 0.234) but superior adjusted survival (hazard ratio0.133, 0.3570.960; P = 0.041) versus LTA recipients not subsequently listed for KT. Safety net patients had superior 1-year unadjusted (96.4% versus 75.0%; P < 0.001) and adjusted (hazard ratio0.039, 0.1260.406; P < 0.001) survival versus SLK listed patients undergoing LTA without subsequent KT listing.

CONCLUSIONS

The safety net appears to provide rapid access to KT with good early survival for those able to take advantage of it. Survival of patients unable to qualify for KT listing after LTA needs to be better understood before further limitation of SLK, however.