Outcomes of liver transplantation alone after listing for simultaneous kidney: comparison to simultaneous liver kidney transplantation. Transplantation. 2015;99:823-828. [PMID: 25250648 DOI: 10.1097/tp.0000000000000438]

Simultaneous liver-kidney transplantation: future perspective

BACKGROUND

The aims of this narrative review were (i) to describe the current indications of SLKT, (ii) to report evolution of SLKT activity, (iii) to report the outcomes of SLKT, (iv) to explain the immune-protective effect of liver transplant on kidney transplant, (v) to explain the interest of delay kidney transplantation, using hypothermic machine perfusion (HMP), (vi) to report kidney after liver transplantation (KALT) indications and (vii) to describe the value of the increase in the use of extended criteria donors (ECD) and particular controlled donation after circulatory death (cDCD) transplant, thanks to the development of new organ preservation strategies.

METHOD

Electronic databases were screened using the keywords "Simultaneous", "Combined", "kidney transplantation" and "liver transplantation". The methodological and clinical heterogeneity of the included studies meant that meta-analysis was inappropriate.

RESULTS

 A total of 1,917 publications were identified in the literature search. Two reviewers screened all study abstracts independently and 1,107 of these were excluded. Thus, a total of 79 full text articles were assessed for eligibility. Of these, 21 were excluded. In total, 58 studies were included in this systematic review.

CONCLUSIONS

 Simultaneous liver-kidney transplantation has made a significant contribution for patients with dual-organ disease. The optimization of indication and selection of SLKT patients will reduce futile transplantation. Moreover, increasing the use of transplants from extended criteria donors, in particular cDCD, should be encouraged, thanks to the development of new modalities of organ preservation.

Waitlist and post-transplant outcomes among candidates listed for liver transplant: Liver alone versus simultaneous liver kidney listings

BACKGROUND

Data comparing waitlist and post-transplant outcomes of liver transplantation (LT) alone (LTA) versus simultaneous liver kidney (SLK) listings are limited.

AIM

To examine 90-days waitlist and 1-year post-transplant outcomes of LT listings since Organ Procurement Transplant Network (OPTN) policy for SLK, who had cirrhosis with eGFR <30 mL/min or on dialysis at listing.

METHODS

Adults (08/2017-03/2021) with first LT listing (2628 SLK) were stratified on renal function from listing: acute kidney injury (AKI): rise of serum creatinine by ≥0.3 mg/dL or <42 days hemodialysis; chronic kidney disease (CKD): eGFR <60 mL/min for ≥90 days or ≥42 days hemodialysis.

RESULTS

Among 7094 adults analyzed, 90-days competing cumulative waitlist mortality was 18.2% in LTA + CKD (n = 37), 15.3% in LTA + AKI (n = 3337), 15% in SLK + AKI (n = 2070), and 11% in SLK + CKD (n = 403), p < 0.001. On fine and gray model, compared to SLK + CKD, LTA + AKI had 1.4-fold waitlist mortality. On a median post-transplant follow up of 1 year, patient survival was similar comparing LTA versus SLK for AKI (89% each, p = 0.83), for CKD (93 vs. 86%, p = 0.55), but lower in recipients listed for SLK with no AKI or CKD (93 vs. 88%, p = 0.02), adjusted hazard ratio (95% CI) of 0.7 (0.4-1.2). Among 1024 LTA recipients without AKI or CKD from listing, 117 were listed for SLK, and their 1-year survival was poorer compared to LT alone listings (79 vs. 95%, p < 0.002, adjusted HR 3.6 (1.3-10.3); p = 0.015).

CONCLUSIONS

Among candidates with renal dysfunction at listing for LT, those listed for LT alone should receive transplant promptly to optimise waitlist outcomes. Those listed for SLK should wait to receive both organs to optimise post-transplant outcomes.

Recent advances in pathophysiology, diagnosis and management of hepatorenal syndrome: A review

Hepatorenal syndrome with acute kidney injury (HRS-AKI) is a form of rapidly progressive kidney dysfunction in patients with decompensated cirrhosis and/or acute severe liver injury such as acute liver failure. Current data suggest that HRS-AKI occurs secondary to circulatory dysfunction characterized by marked splanchnic vasodilation, leading to reduction of effective arterial blood volume and glomerular filtration rate. Thus, volume expansion and splanchnic vasoconstriction constitute the mainstay of medical therapy. However, a significant proportion of patients do not respond to medical management. These patients often require renal replacement therapy and may be eligible for liver or combined liver-kidney transplantation. Although there have been advances in the management of patients with HRS-AKI including novel biomarkers and medications, better-calibrated studies, more widely available biomarkers, and improved prognostic models are sorely needed to further improve diagnosis and treatment of HRS-AKI.

Vasoconstrictor Therapy for Acute Kidney Injury Hepatorenal Syndrome: A Meta-Analysis of Randomized Studies

Background and Aims

Type 1 hepatorenal syndrome (HRS) is a rapid deterioration in kidney function in patients with cirrhosis. Data on efficacy of vasoconstrictors for type 1 HRS have shown mixed results.

Methods

Literature searched for randomized controlled trials comparing pharmacological therapy for HRS vs placebo or another drug for HRS. Primary outcome was HRS reversal (serum creatinine <1.5mg/dL on 2 readings), and secondary outcomes were liver transplant (LT) free survival and serious adverse events (SAE).

Results

Sixteen studies on 1244 patients (mean age 50.3 yrs., 67.5% males, serum creatinine of 3.07 mg/dL, serum sodium 127.2 mEq/liter, and Model for End-stage Liver Disease (MELD) score of 30.9, and Child-Pugh score 11) with type 1 HRS treated with vasoconstrictors vs placebo or another drug were analyzed. All the patients received intravenous albumin infusion. (A) terlipressin vs placebo: Odds of HRS reversal were 3.3 folds with terlipressin without difference on LT-free patient survival. Terlipressin was associated with higher odds of SAE. (B) Nor-epinephrine (NE) vs terlipressin: No difference on HRS reversal, LT-free survival, and SAE. (C) Terlipressin or NE vs midodrine and octreotide: 91% lower odds of HRS reversal with midodrine and octreotide. There were no differences on SAE (10 of 64 vs 10 of 58, P = .812). Non-responders vs responders had higher mean MELD score (29 vs 27.8), P = .014 and serum creatinine (3.5 vs 3.1), P = .027.

Conclusion

Terlipressin and NE are similar and superior to midodrine octreotide combination for HRS reversal. No therapy improves LT-free patient survival. Response to treatment is better with lower baseline serum creatinine and MELD score. The risk of adverse effects is similar with terlipressin and NE. Studies are needed as basis to identify candidates with best response to treatment with excellent safety profile.

Healthcare burden and outcomes of hepatorenal syndrome among cirrhosis-related hospitalisations in the US

BACKGROUND

Hepatorenal syndrome (HRS) contributes to significant morbidity and mortality in hospitalised patients with cirrhosis.

AIMS

To examine recent trends, magnitude and outcomes of HRS in the National Inpatient Sample (NIS) database METHODS: Among the NIS database on cirrhosis hospitalisations (2016-2019) due to alcohol (ALD), chronic viral hepatitis (CVH), or NASH and complicated by acute kidney injury (AKI) were analyzed.

RESULTS

Of 113,454 hospitalisations, 18,735 (16.5%) had HRS (mean age 56 years, 36% females, 68% whites, 80% ALD, 7% NASH) with a stable trend over time. Among 1:1 propensity-matched 36,090 hospitalisations, the odds of HRS were 12% higher in NASH versus CVH. Based on weighted national estimates, there were 27,180 (8.3 per 100,000 US population) HRS hospitalisations in 2019, with economic burden of $4.2 billion USD. Mean hospitalisation and total charges (ALD vs. CVH vs. NASH) were 11 versus 10.8 versus 9.2 days and 151,000 versus 157,000 versus 120,000 USD, respectively; p < 0.001. In-hospital mortality was 18.9%, higher in HRS (25.8 vs. 12%, p < 0.001), and decreased by 15% annually. Survivors were more likely to be discharged to short- or long-term care facilities (HRS vs. non-HRS [42 vs. 27%, p < 0.001]); only 28.7% received palliative care.

CONCLUSION

HRS was the cause of AKI in 16.5% of patients hospitalised with cirrhosis and conferred significant healthcare burden with 27,180 HRS hospitalisations in 2019 and requiring an estimated 4.2 billion USD for hospital care. While there has been a decrease in in-hospital mortality over time, it remained high at 23.7% in 2019 in those with HRS.

Evaluation of liver transplant candidates with non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is anticipated to become the leading indication for liver transplantation (LT) in the United States in the near future. LT is indicated in patients with NASH-related cirrhosis who have medically refractory hepatic decompensation, synthetic dysfunction, and hepatocellular carcinoma (HCC) meeting certain criteria. The objective of LT evaluation is to determine which patient will derive the most benefit from LT with the least risk, thus maximizing the societal benefits of a limited resource. LT evaluation is a multidisciplinary undertaking involving several specialists, assessment tools, and diagnostic testing. Although the steps involved in LT evaluation are relatively similar across different liver diseases, patients with NASH-related cirrhosis have unique demographic and clinical features that affect transplant outcomes and influence their LT evaluation. LT candidates with NASH should be assessed for metabolic syndrome and obesity, malnutrition and sarcopenia, frailty, and cardiovascular disease. Interventions that treat cardiometabolic co-morbidities and improve patients' nutrition and functionality should be considered in order to improve patient outcomes in the waitlist and after LT.

Impact of medical eligibility criteria and OPTN policy on simultaneous liver kidney allocation and utilization

BACKGROUND

Organ Procurement and Transplantation Network (OPTN) implemented medical eligibility and safety-net policy on 8/10/17 to optimize simultaneous liver-kidney (SLK) utilization. We examined impact of this policy on SLK listings and number of kidneys used within 1-yr. of receiving liver transplantation (LT) alone.

METHODS AND RESULTS

OPTN database (08/10/14-06/12/20) on adults (N = 66 709) without previous transplant stratified candidates to listings for SLK or LT alone with pre-LT renal dysfunction at listing (eGFR < 30 mL/min or on dialysis). Outcomes were compared for pre (08/10/14-08/09/17) vs. post (08/10/17-06/12/20) policy era. SLK listings decreased in post vs. pre policy era (8.7% vs. 9.6%; P < .001), with 22% reduced odds of SLK listing in the postpolicy era, with a decrease in all OPTN regions except regions 6 and 8, which showed an increase. Among LT-alone recipients with pre-LT renal dysfunction (N = 3272), cumulative 1-year probability was higher in post vs. prepolicy period for dialysis (5.6% vs. 2.3%; P < .0001), KT listing (11.4% vs. 2.0%; P < .0001), and KT (3.7% vs. .25%; P < .0001). Sixty-seven (2.4%) kidneys were saved in post policy era, with 18.1%, 16.6%, 4.3%, and 2.9% saving from regions 7, 2, 11, and 1, respectively.

CONCLUSION

Medical eligibility and safety-net OPTN policy resulted in decreased SLK use and improved access to LT alone among those with pre-LT renal dysfunction. Although decreased in postpolicy era, regional variation of SLK listings remains. In spite of increased use of KT within 1-year of receiving LT alone under safety net, less number of kidneys were used without impact on patient survival in postpolicy era.

Simultaneous Liver-Kidney Transplantation

End-stage kidney disease (ESKD) after liver transplantation is associated with high morbidity and mortality. This increase in mortality can be offset by performing a kidney transplant at the time of the liver transplant in select cases. Accordingly, Margreiter and colleague; s performed the first simultaneous liver-kidney (SLK) transplant in 1983. The number of SLK transplants has increased by more than 300% since then. In 1990%, 1.7% of all liver transplants in the United States were SLK transplants which increased to 9.9% by 2016. This steep increase was likely due to the implementation of the model of end-stage liver disease (MELD) scoring system in 2002, which is heavily weighted by serum creatinine.

Chronic Kidney Disease After Liver Transplantation

Improved survival after liver transplantation has led to an aging cohort of recipients at risk of renal dysfunction. The etiology of renal dysfunction is typically multifactorial; calcineurin inhibitors nephrotoxicity, pretransplant renal dysfunction, and perioperative acute kidney injury are important risk factors. Metabolic complications such as hypertension, diabetes mellitus, and metabolic-associated fatty liver disease also contribute to the development of renal disease. Most LT recipients will eventually develop some degree of renal dysfunction. Criteria to select candidates for simultaneous liver and kidney transplantation have been established. Both delayed introduction of CNIs and renal-sparing immunosuppressive regimens may reduce progression of renal dysfunction.

[Kidney failure after liver transplantation]

One third of cirrhotic patients present impaired kidney function. It has multifactorial causes and has a harmful effect on patients' morbi-mortality before and after liver transplant. Kidney function does not improve in all patients after liver transplantation and liver-transplant recipients are at high risk of developing chronic kidney disease. Causes for renal dysfunction can be divided in three groups: preoperative, peroperative and postoperative factors. To date, there is no consensus for the modality of evaluation the risk for chronic kidney disease after liver transplantation, and for its prevention. In the present review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease to determine a risk stratification for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this setting, and highlight the indications of combined liver-kidney transplantation.

Utilization and effectiveness of the organ procurement and transplantation network "safety-net" policy

BACKGROUND

Liver transplant recipients with persistent renal dysfunction may be prioritized on the kidney transplant waitlist based on the Organ Procurement and Transplantation Network "safety-net" policy implemented in 2017. The aim of this study was to evaluate the utilization of kidney transplant and posttransplant outcomes, of liver transplant recipients with persistent renal dysfunction before and after implementation of the Organ Procurement and Transplantation Network kidney safety-net policy and standardization of simultaneous liver-kidney requirements.

METHODS

Using the United Network for Organ Sharing database from January 2015 to March 2019, outcomes of liver transplant recipients listed for kidney transplant and the subset who received kidney after liver transplants were compared before and after policy implementation.

RESULTS

Liver transplant recipients listed for kidney transplant increased from 58 to 200, and kidney after liver transplants increased from 29.3% to 42.5% after safety-net policy implementation. Post-policy kidney after liver transplants received more local organs (91.8% vs 70.6%, P = .03) and trended toward shorter waitlist time (47 [17-123] vs 84 [37-226] days, P = .051). The pre- and post-policy cohorts had similar (P > .05) kidney donor profile index (0.43 [0.27-0.69] vs 0.42 [0.28-0.58]) and delayed graft function (11.8% vs 14.1%). Patient, kidney graft, and liver graft survival were similar (P > .05) between pre and post-policy cohorts. Patient and kidney graft survival were similar between kidney after liver transplants and propensity score-matched kidney transplant alone recipients. Patient, kidney, and liver graft survival were similar between kidney after liver transplants and propensity score-matched simultaneous liver-kidney transplant recipients.

CONCLUSION

This study demonstrates that after Organ Procurement and Transplantation Network "safety-net" policy implementation, there has been an increase in liver transplant recipients with renal dysfunction who are listed for and undergo kidney transplant with excellent short-term results.

Kidney Failure after Liver Transplantation

One-third of patients with cirrhosis present kidney failure (AKI and CKD). It has multifactorial causes and a harmful effect on morbidity and mortality before and after liver transplantation. Kidney function does not improve in all patients after liver transplantation, and liver transplant recipients are at a high risk of developing chronic kidney disease. The causes of renal dysfunction can be divided into three groups: pre-operative, perioperative and post-operative factors. To date, there is no consensus on the modality to evaluate the risk of chronic kidney disease after liver transplantation, or for its prevention. In this narrative review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease in order to establish a risk categorization for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this context, and highlight the indications of combined liver–kidney transplantation.

Current and Evolving Indications for Simultaneous Liver Kidney Transplantation

This review will discuss the etiologies of kidney disease in liver transplant candidates, provide a historical background of the prior evolution of simultaneous liver-kidney (SLK) transplant indications, discuss the current indications for SLK including Organ Procurement and Transplantation Network policies and Model for End Stage Liver Disease exception points, as well as provide an overview of the safety net kidney transplant policy. Finally, the authors explore unanswered questions and future research needed in SLK transplantation.

Need for improvements in simultaneous heart-kidney allocation: The limitation of pretransplant glomerular filtration rate

The incidence of simultaneous heart-kidney transplant (SHK) has increased markedly in the last 15 years. There are no universally agreed upon indications for SHK vs. heart alone (HA) transplant, and center evaluation processes vary widely. We utilized Scientific Registry of Transplant Recipients data from 2003 to 2017 to quantify changes in the practice of SHK, examine the survival of SHK vs. HA, and identify patients with marginal benefit from SHK. We used Kaplan-Meier curves and Cox proportional hazards to assess differences in survival. The incidence of SHK increased more than fourfold between 2003 and 2017 from 1.6% to 6.6% of total hearts transplanted, while the proportion of dialysis-dependent patients undergoing SHK has remained constant. SHK was associated with increased survival in dialysis-dependent patients (Median Survival SHK: 12.6 vs. HA: 7.1 years p < .0001) but not with nondialysis-dependent patients (Median Survival SHK: 12.5 vs. HA 12.3, p = .24). The marginal effect of SHK in decreasing the hazard of death diminished with increasing eGFR. Delayed graft function occurred in 26% of SHK recipients. Posttransplant chronic dialysis was similar for both operations (6.4% of HA and 6.0% of SHK). Further study is needed to define patients who benefit from SHK.

Position paper on liver and kidney diseases from the Italian Association for the Study of Liver (AISF), in collaboration with the Italian Society of Nephrology (SIN)

Liver and kidney are strictly connected in a reciprocal manner, in both the physiological and pathological condition. The Italian Association for the Study of Liver, in collaboration with the Italian Society of Nephrology, with this position paper aims to provide an up-to-date overview on the principal relationships between these two important organs. A panel of well-recognized international expert hepatologists and nephrologists identified five relevant topics: 1) The diagnosis of kidney damage in patients with chronic liver disease; 2) Acute kidney injury in liver cirrhosis; 3) Association between chronic liver disease and chronic kidney disease; 4) Kidney damage according to different etiology of liver disease; 5) Polycystic kidney and liver disease. The discussion process started with a review of the literature relating to each of the five major topics and clinical questions and related statements were subsequently formulated. The quality of evidence and strength of recommendations were graded according to the GRADE system. The statements presented here highlight the importance of strong collaboration between hepatologists and nephrologists for the management of critically ill patients, such as those with combined liver and kidney impairment.

Delayed Graft Function in Simultaneous Liver Kidney Transplantation

BACKGROUND

Delayed graft function (DGF) is associated with inferior posttransplant outcomes in kidney transplantation. Given these adverse outcomes, we sought to determine the incidence, unique risk factors, and posttransplant outcomes for simultaneous liver kidney (SLK) transplant recipients developing DGF.

METHODS

We studied 6214 adult SLK recipients from March 2002 to February 2017 using the Scientific Registry of Transplant Recipients. We determined associations between risk factors and DGF using Poisson multivariate regression and between DGF and graft failure and mortality using Cox proportional hazard analysis.

RESULTS

The overall rate of DGF was 21.8%. Risk factors for DGF in the hepatitis C virus (HCV)-negative recipient population included pretransplant dialysis (adjusted incident rate ratio [aIRR] 3.26, P = 0.004), donor body mass index (aIRR 1.25 per 5 kg/m, P = 0.01), and transplantation with a donation after circulatory death (aIRR 5.38, P = 0.001) or imported donor organ (regional share aIRR 1.69, P = 0.03; national share aIRR 4.82, P < 0.001). DGF was associated with a 2.6-fold increase in kidney graft failure (adjusted hazard ratio [aHR] 2.63, P < 0.001), 1.6-fold increase in liver graft failure (aHR 1.62, P < 0.001), and 1.6-fold increase in mortality (aHR 1.62, P < 0.001).

CONCLUSIONS

In HCV-negative SLK recipients, recipient pretransplant dialysis and components of kidney graft quality comprise significant risk factors for DGF. Regardless of HCV status, DGF is associated with inferior posttransplant outcomes. Understanding these risk factors during clinical decision-making may improve prevention of DGF and may represent an opportunity to improve posttransplant outcomes.

Defining a Willingness-to-transplant Threshold in an Era of Organ Scarcity: Simultaneous Liver-kidney Transplant as a Case Example

BACKGROUND

Organ scarcity continues in solid organ transplantation, such that the availability of organs limits the number of people able to benefit from transplantation. Medical advancements in managing end-stage organ disease have led to an increasing demand for multiorgan transplant, wherein a patient with multiorgan disease receives >1 organ from the same donor. Current allocation schemes give priority to multiorgan recipients compared with single-organ transplant recipients, which raise ethical questions regarding equity and utility.

METHODS

We use simultaneous liver and kidney (SLK) transplant, a type of multiorgan transplant, as a case study to examine the tension between equity and utility in multiorgan allocation. We adapt the health economics willingness-to-pay threshold to a solid organ transplant setting by coining a new metric: the willingness-to-transplant (WTT) threshold.

RESULTS

We demonstrate how the WTT threshold can be used to evaluate different SLK allocation strategies by synthesizing utility and equity perspectives.

CONCLUSIONS

We submit that this new framework enables us to distill the question of SLK allocation down to: what is the minimum amount of benefit we require from a deceased donor kidney to allocate it for a particular indication? Addressing the above question will prove helpful to devising a rational system of SLK allocation and is applicable to other transplant settings.

Delayed Implantation of Pumped Kidneys Decreases Renal Allograft Futility in Combined Liver-Kidney Transplantation

BACKGROUND

Combined liver-kidney transplantation (CLKT) improves survival for liver transplant recipients with renal dysfunction; however, the tenuous perioperative hemodynamic and metabolic milieu in high-acuity CLKT recipients increases delayed graft function and kidney allograft failure. We sought to analyze whether delayed KT through pumping would improve kidney outcomes following CLKT.

METHODS

A retrospective analysis (University of California Los Angeles [n = 145], Houston Methodist Hospital [n = 79]) was performed in all adults receiving CLKT at 2 high-volume transplant centers from February 2004 to January 2017, and recipients were analyzed for patient and allograft survival as well as renal outcomes following CLKT.

RESULTS

A total of 63 patients (28.1%) underwent delayed implantation of pumped kidneys during CLKT (dCLKT) and 161 patients (71.9%) received early implantation of nonpumped kidneys during CLKT (eCLKT). Most recipients were high-acuity with median biologic model of end-stage liver disease (MELD) score of, 35 for dCLKT and 34 for eCLKT (P = ns). Pretransplant, dCLKT had longer intensive care unit stay, were more often intubated, and had greater vasopressor use. Despite this, dCLKT exhibited improved 1-, 3-, and 5-year patient and kidney survival (P = 0.02) and decreased length of stay (P = 0.001), kidney allograft failure (P = 0.012), and dialysis duration (P = 0.031). This reduced kidney allograft futility (death or continued need for hemodialysis within 3 mo posttransplant) for dCLKT (6.3%) compared with eCLKT (19.9%) (P = 0.013).

CONCLUSIONS

Delayed implantation of pumped kidneys is associated with improved patient and renal allograft survival and decreased hospital length of stay despite longer kidney cold ischemia. These data should inform the ethical debate as to the futility of performing CLKT in high-acuity recipients.

Kidney Rejection Following Simultaneous Liver-kidney Transplantation

Background.

Donor-specific antibodies are reported to increase the risk of rejection and reduce allograft survival following simultaneous liver-kidney transplantation. Optimal immunosuppression regimens to reduce this risk and to treat rejection episodes are underinvestigated.

Methods.

Cohort analysis of the first 27 simultaneous liver-kidney transplant recipients, between 2014 and 2018 at our unit, is performed under a new risk stratification policy. Those with donor-specific antibodies to class II HLA with a mean fluorescence intensity >10 000 are considered high risk for antibody-mediated rejection (AMR). These patients received immunosuppression, which consisted of induction therapy, tacrolimus, mycophenolate mofetil, and prednisolone. All other patients are considered low risk and received tacrolimus and prednisolone alone.

Results.

Three patients were high risk for rejection, and 2 of these patients developed AMR, which was treated with plasma exchange and intravenous immunoglobulin. At 1 y, their estimated glomerular filtration rate (eGFR) were 50 and 59 mL/min. Two other patients developed AMR, which was similarly treated, and their 1-y eGFR was 31 and 50 mL/min. The overall histologically proven acute rejection rate within the first year was 33%, and median eGFR, for the 27 patients, at 1 y was 52 mL/min and at 2 y was 49 mL/min.

Conclusions.

This study confirms that there is a risk of AMR following simultaneous liver-kidney transplantation despite increased immunosuppression. This can be effectively treated with plasma exchange and intravenous immunoglobulin.

Racial/Ethnic Disparities in Access and Outcomes of Simultaneous Liver-Kidney Transplant Among Liver Transplant Candidates With Renal Dysfunction in the United States

BACKGROUND

Since the Model for End-stage Liver Disease (MELD) allocation system was implemented, the proportion of simultaneous liver-kidney transplantation (SLKT) has increased significantly. However, whether racial/ethnic disparities exist in access to SLKT and post-SLKT survival remains understudied.

METHODS

A retrospective cohort of patients aged ≥18 years with renal dysfunction on the liver transplant (LT) waiting list was obtained from Organ Procurement and Transplantation Network. Renal dysfunction was defined as estimated glomerular filtration rate <60 mL/min/1.73 m at listing for LT. Multilevel time-to-competing-events regression adjusting for center effect was used to examine the likelihood of receiving SLKT. Inverse probability of treatment weighted survival analyses were used to analyze posttransplant mortality outcomes.

RESULTS

For patients with renal dysfunction at listing for LT, not listed for simultaneous kidney transplant, non-Hispanic black (NHB) and Hispanic patients were more likely to receive SLKT than non-Hispanic white (NHW) patients (NHB: multivariable-adjusted hazard ratio [aHR] 2.57; 95% confidence interval [CI], 1.42-4.65; Hispanic: aHR, 2.03; 95% CI, 1.14-3.60). For post-SLKT outcomes, compared to NHW patients, NHB patients had a lower mortality risk before 24 months (aHR, 0.80; 95% CI, 0.65-0.97) but had a higher mortality risk (aHR, 2.00; 95% CI, 1.59-2.55) afterward; in contrast, Hispanic patients had a lower overall mortality risk than NHW patients (aHR, 0.61; 95% CI, 0.51-0.74).

CONCLUSIONS

In the MELD era, racial/ethnic differences exist in access and survival of SLKT for patients with renal dysfunction at listing for LT. Future studies are warranted to examine whether these differences remain in the post-SLK allocation policy era.

Similarities and Differences Between Nonalcoholic Steatohepatitis and Other Causes of Cirrhosis

Nonalcoholic fatty liver disease includes a spectrum of liver disorders that range from simple steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Risk factors such as obesity, hypertension, hyperlipidemia, chronic kidney disease, and smoking status increase risk of progression to cirrhosis among patients with NASH. Cirrhosis derived from non-NASH causes may share similar features with patients with NASH but embody distinct pathogenetic mechanisms, genetic associations, prognosis, and outcomes. This article discusses in detail the comparison of clinical, genetic, and outcome characteristics between patients with NASH cirrhosis as opposed to alternative causes of chronic liver disease.

Arterial Blood Pressure at Liver Transplant Evaluation Predicts Renal Histology in Candidates With Renal Dysfunction

Renal dysfunction is common in liver transplantation (LT) candidates, but differentiating between reversible and irreversible renal injury can be difficult. Kidney biopsy might be helpful in differentiating reversible from irreversible renal injury, but it is associated with significant complications. We aimed to identify pre-LT predictors of potentially reversible renal injury using histological information obtained on pre-LT renal biopsy. Data on 128 LT candidates who underwent pre-LT kidney biopsy were retrospectively collected and correlated with renal histological findings. Indications for kidney biopsy were iothalamate glomerular filtration rate (iGFR) ≤40 mL/minute, proteinuria >500 mg/day, and/or hematuria. According to the biopsy diagnosis, patients were grouped into the following categories: normal (n = 13); acute tubular necrosis (ATN; n = 25); membranoproliferative glomerulonephritis (n = 19); minimal histological changes (n = 24); and advanced interstitial fibrosis (IF) and glomerulosclerosis (GS) (n = 47). Compared with patients having advanced IF/GS, patients with normal biopsies and those with ATN had lower systolic blood pressure (SBP) and diastolic blood pressure (DBP) and higher international normalized ratio and total bilirubin levels (<0.05 for all). Both SBP and DBP directly correlated with the degree of IF and GS (R = 0.3, P ≤ 0.02 for all). SBP ≤90 mm Hg was 100% sensitive and 98% specific in correlating with normal biopsies or ATN, whereas SBP ≥140 mm Hg was 22% sensitive and 90% specific in correlating with advanced IF/GS. Model for End-Stage Liver Disease score, serum creatinine, iGFR, urinary sodium excretion, and renal size did not correlate with biopsy diagnosis or degree of IF or GS. In conclusion, SBP at the time of LT evaluation correlates with renal histology, and it should be included along with other clinical and laboratory markers in the decision-making process to list patients with renal dysfunction for LT alone versus simultaneous liver-kidney transplantation.

Outcomes of Liver Transplantation in Patients on Renal Replacement Therapy: Considerations for Simultaneous Liver Kidney Transplantation Versus Safety Net

As the liver transplant (LT) waiting list continues to outpace organ availability, many patients require renal replacement therapy (RRT) before LT. It is unclear which patients will benefit from simultaneous liver kidney (SLK) transplant as opposed to awaiting a Safety Net kidney transplant (KT) post-LT.

Methods

In this study, a retrospective analysis of the United Network for Organ Sharing dataset was performed to identify risk factors associated with poor outcome for patients on RRT before LT who were listed for SLK and received either SLK vs LT alone (LTA).

Results

Between January 2003 and December 2016, 8971 adult LT recipients were on RRT at the time of LT. 5359 were listed for and received LTA (Group 1). Of 3612 patients listed for SLK, 3414 (38.1%) received SLK (Group 2) and 198 (2.2%) received LTA (Group 3). Overall, Group 3 had lower graft and patient survival post-LT when compared with Groups 1 and 2 (P < 0.001). Serum creatinine at 1 year post-LT and cumulative incidence for KT at 3 years post-LT were higher for Group 3 (P < 0.001). On multivariate analysis, pre-LT diabetes (P = 0.002), Model of End-Stage Liver Disease score (P = 0.01), and donor kidney donor profile index (P = 0.025) were significant in Group 2. Recipient age >60 (P < 0.001) and RRT pre-LT (>90 days; P = 0.001) were associated with lower patient survival in Group 3.

Conclusions

Among LT recipients on RRT before LT who were listed for SLK, RRT >90 days, and age >60 were associated with poor outcome following LTA. This suggests that programs should carefully weigh the decision to proceed with LTA vs waiting for SLK in this patient population. Future access to Safety Net KT will be an important consideration for these patients moving forward.

Renal function after combined liver-kidney transplantation: A longitudinal study of pediatric and adult patients

It has been proposed that the liver protects the kidney in CLKT. However, few studies have examined long-term renal function after CLKT and contrasted renal function of CLKT patients to KT patients beyond one year after transplantation. We studied long-term renal function of CLKT patients and compared renal function of CLKT patients to KT patients between one and five years after transplantation. Patients who underwent CLKT between 1993 and 2011 were included (n = 34; 11 children and 23 adults). Ninety-six (27 children and 69 adults) KT patients were selected as controls. GFR was estimated (eGFR) and measured (mGFR) with ⁵¹ Cr-EDTA clearance. Mean mGFR was 63 at one and 70 at ten years after pediatric CLKT. Mean eGFR was 75 at one and 50 at ten years after adult CLKT. Difference in mean mGFR between pediatric CLKT and KT patients was 8 (95% CI -7 to 23) and 11 (95% CI -4 to 26) at one and five years after transplantation, respectively. Difference in mean eGFR between adult CLKT and KT patients was 8 (95% CI -5 to 20) and 1 (95% CI -10 to 12) at one and five years after transplantation, respectively. Longitudinal changes in GFRs were somewhat similar in CLKT and KT patients in both age-groups but pediatric CLKT patients had on average higher GFRs than pediatric KT patients. In long-term follow-up, renal function remains stable in pediatric CLKT patients but declines in adult CLKT patients.

Comparing Simultaneous Liver-Kidney Transplant Strategies: A Modified Cost-Effectiveness Analysis

BACKGROUND

The proportion of patients with kidney failure at time of liver transplantation is at a historic high in the United States. The optimal timing of kidney transplantation with respect to the liver transplant is unknown.

METHODS

We used a modified cost-effectiveness analysis to compare 4 strategies: the old system ("pre-OPTN"), the new Organ Procurement Transplant Network (OPTN) system since August 10, 2017 ("OPTN"), and 2 strategies which restrict simultaneous liver-kidney transplants ("safety net" and "stringent"). We measured "cost" by deployment of deceased donor kidneys (DDKs) to liver transplant recipients and effectiveness by life years (LYs) and quality-adjusted life years (QALYs) in liver transplant recipients. We validated our model against Scientific Registry for Transplant Recipients data.

RESULTS

The OPTN, safety net and stringent strategies were on the efficiency frontier. By rank order, OPTN > safety net > stringent strategy in terms of LY, QALY, and DDK deployment. The pre-OPTN system was dominated, or outperformed, by all alternative strategies. The incremental LY per DDK between the strategies ranged from 1.30 to 1.85. The incremental QALY per DDK ranged from 1.11 to 2.03.

CONCLUSIONS

These estimates quantify the "organ"-effectiveness of various kidney allocation strategies for liver transplant candidates. The OPTN system will likely deliver better liver transplant outcomes at the expense of more frequent deployment of DDKs to liver transplant recipients.

Baseline and Center-Level Variation in Simultaneous Liver-Kidney Listing in the United States

BACKGROUND

The Organ Procurement and Transplantation Network has implemented medical criteria to determine which candidates are most appropriate for simultaneous liver-kidney (SLK) transplantation in comparison to liver-alone transplantation. We investigated prepolicy center-level variation among SLK listing practice, in light of such criteria.

METHODS

We identified 4736 SLK-eligible candidates after Share-35 in the United States. We calculated the proportion of candidates at each center who were listed for SLK transplantation within 6 months of eligibility. Multilevel logistic regression and parametric survival model was used to estimate the center-specific probability of SLK listing, adjusting for patient and center-level characteristics.

RESULTS

Among 4736 SLK-eligible candidates, 64.8% were listed for SLK within 6 months of eligibility. However, the percentage of SLK listing ranged from 0% to 100% across centers. African American race, male sex, transplant history, diabetes, and hypertension were associated with a higher likelihood of SLK listing. Conversely, older age was associated with a lower likelihood of SLK listing. After adjusting for candidate characteristics, the percentage of SLK listing still ranged from 3.8% to 80.2% across centers; this wide variation persisted even after further adjusting for center-level characteristics.

CONCLUSIONS

There was significant prepolicy center-level variation in SLK listing for SLK-eligible candidates. Implementation of standardized SLK listing practices may reduce center-level variation and equalize access for SLK candidates across the United States.

Acute Kidney Injury Before and After Liver Transplant

The development of acute kidney injury in the setting of liver disease is a significant event both before and after liver transplant. Whether acute kidney injury is the cause of or merely associated with worse outcomes, the development of renal failure is significant from a prognostic as well as from a diagnostic and therapeutic standpoint. Although not every etiology is reversible, there are number of etiologies that are correctable, to include hypovolemia, nephrotoxic medications, and acute tubular necrosis. In the post-liver transplant period, renal failure is associated with graft failure as well as worse outcomes overall. Prompt recognition, workup, and intervention can significantly impact outcomes and survival both before and after liver transplant.

Effect of transplant center volume on post-transplant survival in patients listed for simultaneous liver and kidney transplantation

AIM

To examine the effect of center size on survival differences between simultaneous liver kidney transplantation (SLKT) and liver transplantation alone (LTA) in SLKT-listed patients.

METHODS

The United Network of Organ Sharing database was queried for patients ≥ 18 years of age listed for SLKT between February 2002 and December 2015. Post-transplant survival was evaluated using stratified Cox regression with interaction between transplant type (LTA vs SLKT) and center volume.

RESULTS

During the study period, 393 of 4580 patients (9%) listed for SLKT underwent a LTA. Overall mortality was higher among LTA recipients (180/393, 46%) than SLKT recipients (1107/4187, 26%). The Cox model predicted a significant survival disadvantage for patients receiving LTA vs SLKT [hazard ratio, hazard ratio (HR) = 2.85; 95%CI: 2.21, 3.66; P < 0.001] in centers performing 30 SLKT over the study period. This disadvantage was modestly attenuated as center SLKT volume increased, with a 3% reduction (HR = 0.97; 95%CI: 0.95, 0.99; P = 0.010) for every 10 SLKs performed.

CONCLUSION

In conclusion, LTA is associated with increased mortality among patients listed for SLKT. This difference is modestly attenuated at more experienced centers and may explain inconsistencies between smaller-center and larger registry-wide studies comparing SLKT and LTA outcomes.

The donor risk index: A decade of experience

In 2006, derivation of the donor risk index (DRI) highlighted the importance of donor factors for successful liver transplantation. Over the last decade, the DRI has served as a useful metric of donor quality and has enhanced our understanding of donor factors and their impact upon recipients with hepatitis C virus, those with low Model for End-Stage Liver Disease (MELD) score, and individuals undergoing retransplantation. DRI has provided the transplant community with a common language for describing donor organ characteristics and has served as the foundation for several tools for organ risk assessment. It is a useful tool in assessing the interactions of donor factors with recipient factors and their impact on posttransplant outcomes. However, limitations of statistical modeling, choice of donor factors, exclusion of unaccounted donor and geographic factors, and the changing face of the liver transplant recipient have tempered its widespread use. In addition, the DRI was derived from data before the MELD era but is currently being applied to expand the donor pool while concurrently meeting the demands of a dynamic allocation system. A decade after its introduction, DRI remains relevant but may benefit from being updated to provide guidance in the use of extended criteria donors by accounting for the impact of geography and unmeasured donor characteristics. DRI could be better adapted for recipients with nonalcoholic fatty liver disease by examining and including recipient factors unique to this population. Liver Transplantation 23 1216-1225 2017 AASLD.

Utility in Treating Kidney Failure in End-Stage Liver Disease With Simultaneous Liver-Kidney Transplantation

Background

Simultaneous liver-kidney (SLK) transplantation plays an important role in treating kidney failure in patients with end-stage liver disease. It used 5% of deceased donor kidney transplanted in 2015. We evaluated the utility, defined as posttransplant kidney allograft lifespan, of this practice.

Methods

Using data from the Scientific Registry of Transplant Recipients, we compared outcomes for all SLK transplants between January 1, 1995, and December 3, 2014, to their donor-matched kidney used in kidney-alone (Ki) or simultaneous pancreas kidney (SPK) transplants. Primary outcome was kidney allograft lifespan, defined as the time free from death or allograft failure. Secondary outcomes included death and death-censored allograft failure. We adjusted all analyses for donor, transplant, and recipient factors.

Results

The adjusted 10-year mean kidney allograft lifespan was higher in Ki/SPK compared with SLK transplants by 0.99 years in the Model for End-stage Liver Disease era and 1.71 years in the pre-Model for End-stage Liver Disease era. Death was higher in SLK recipients relative to Ki/SPK recipients: 10-year cumulative incidences 0.36 (95% confident interval 0.33-0.38) versus 0.19 (95% confident interval 0.17-0.21).

Conclusions

SLK transplantation exemplifies the trade-off between the principles of utility and medical urgency. With each SLK transplantation, about 1 year of allograft lifespan is traded so that sicker patients, that is, SLK transplant recipients, are afforded access to the organ. These data provide a basis against which benefits derived from urgency-based allocation can be measured.

This analysis of the UNOS data demonstrated that SLK patients had decreased long term renal graft function that SPK patients. This analysis demonstrates the difficult policy choices epitomized by prioritizing the SLK population and its impact of utility considerations. Supplemental digital content is available in the text.

Kidney Injury in Liver Disease

Acute kidney injury (AKI) occurs frequently in patients with liver disease and increases morbidity and mortality. Hepatorenal syndrome is a common cause of AKI in patients with decompensated cirrhosis and is due to alterations in systemic and renal hemodynamics. Serum creatinine-based estimation of kidney function is a key component of the Model for End-stage Liver Disease score in liver transplant candidates. Continuous renal replacement therapy is used in critically ill patients with liver failure and AKI. Simultaneous liver-kidney transplantation (SLK) may be required in patients with liver failure and prolonged AKI. Identification of appropriate candidates for SLK remains controversial.

Avoiding Futility in Simultaneous Liver-kidney Transplantation: Analysis of 331 Consecutive Patients Listed for Dual Organ Replacement

OBJECTIVE

We sought to evaluate outcomes and predictors of renal allograft futility (RAF-patient death or need for renal replacement therapy at 3 months) after simultaneous liver-kidney transplantation (SLKT).

BACKGROUND

Model for End-Stage Liver Disease (MELD) prioritization of liver recipients with renal dysfunction has significantly increased utilization of SLKT. Data on renal outcomes after SLKT in the highest MELD recipients are scarce, as are accurate predictors of recovery of native kidney function. Without well-established listing guidelines, SLKT potentially wastes renal allografts in both high-acuity liver recipients at risk for early mortality and recipients who may regain native kidney function.

METHODS

A retrospective single-center multivariate regression analysis was performed for adult patients undergoing SLKT (January 2004 to August 2014) to identify predictors of RAF.

RESULTS

Of 331 patients dual-listed for SLKT, 171 (52%) expired awaiting transplant, 145 (44%) underwent SLKT, and 15 (5%) underwent liver transplantation alone. After SLKT, 39% experienced delayed graft function and 20.7% had RAF. Compared with patients without RAF, RAF recipients had greater MELD scores, length of hospitalization, intraoperative base deficit, incidence of female donors, kidney and liver donor risk indices, kidney cold ischemia, and inferior overall survival. Multivariate predictors of RAF included pretransplant dialysis duration, kidney cold ischemia, kidney donor risk index, and recipient hyperlipidemia.

CONCLUSIONS

With 20% short-term loss of transplanted kidneys after SLKT, our data strongly suggest that renal transplantation should be deferred in liver recipients at high risk for RAF. Consideration for a kidney allocation variance to allow for delayed renal transplantation after liver transplantation may prevent loss of scarce renal allografts.

NASH Cirrhosis - the New Burden in Liver Transplantation: How Should It Be Managed?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a continuously increasing cause of chronic liver disease and a health burden in all populations affected by the obesity and metabolic syndrome pandemic. Cirrhotic alterations or hepatocellular carcinoma developing from NAFLD may require liver transplantation (LTx).

METHODS

Current literature was screened for data on LTx in the setting of NAFLD.

RESULTS

NAFLD-associated LTx is expected to increase in number and relevance during the next decade. NAFLD is part of the metabolic syndrome and thus connected to various metabolic alterations and comorbidities such as diabetes or hyperlipidemia. Moreover, NAFLD comprises an independent risk factor for cardiovascular and chronic kidney disease, which again are important risk factors for outcome of surgical interventions. Postoperative immunosuppression, possible steatosis of the liver graft, and a continued presence of metabolic alterations may lead to early recurrence of steatosis or even non-alcoholic steatohepatitis. Currently, no data are available on combined approaches of weight loss and LTx for NAFLD.

CONCLUSION

Specific guidelines on how to manage NAFLD-associated LTx are lacking. This particular situation requires close monitoring of metabolic syndrome-associated comorbidities. NAFLD represents a novel challenge to established LTx procedures.

Multiorgan transplantation

Kidney transplantation has proven to be the gold standard therapy for severe chronic kidney disease (CKD) due to multiple etiologies in individuals deemed eligible from a surgical standpoint. While kidney transplantation is traditionally considered in conditions of native kidney disease such as diabetes and immunological or inherited causes of kidney disease, an increasing indication for kidney transplantation is kidney dysfunction in the setting of other severe organ dysfunction that requires transplant, such as severe liver or heart disease. In these settings, multiorgan transplantation is now commonly performed, with controversy regarding the appropriate utilization of kidneys transplanted both from a physiological perspective (distinguishing those who require a kidney transplant) and also from an ethical perspective (allocation of a scarce resource to a more morbid population). These issues persist in the setting of simultaneous pancreas-kidney transplant (SPK), in which utilization for patients with type 1 diabetes has been historically accepted. Questions of physiological benefit persist, and utilization is waning despite broader allocation policies that encourage SPK, including consideration for patients with type 2 diabetes. The purpose of this review will be to summarize the physiological data regarding multiorgan transplantation and place these into context while reviewing current allocation policy in the United States.

Results of Simultaneous Liver and Kidney Transplantation: A Single-Center Review

BACKGROUND

The decision for a simultaneous liver and kidney transplantation (SLKT) is fraught with controversy. The aim of this study was to compare SLKT with liver transplantation alone (LTA) in patients with pretransplantation renal failure.

STUDY DESIGN

A retrospective review comparing patients undergoing SLKT and LTA (with renal failure) between January 2000 and December 2014 was performed.

RESULTS

Of 1,129 liver transplantations, 132 had renal failure pretransplantation; 52 had SLKT and 80 recipients had LTA. Model for End-Stage Liver Disease score and BMI were lower in the SLKT group (p = 0.001). Simultaneous liver and kidney transplantation patients had better overall survival rates at 1 and 5 years compared with LTA (92.3% and 81.6% vs 73.3% and 64.3% respectively; p < 0.01). Graft survival was also superior in patients undergoing SLKT vs LTA. Six of 52 (11.5%) SLKT patients had final positive cross match, but only 1 of 52 (1.9%) kidney grafts was lost to rejection. In the SLKT group, 9 of 52 (17.3%) patients required dialysis post transplantation, but only 2 remained on dialysis beyond 30 days. All patients in the LTA group were on dialysis pretransplantation and significantly more patients (52 of 80 [65%]) required dialysis post LTA (p ≤ 0.0001); 31 of 80 (38.8%) were dialysis dependent for more than 30 days or died on dialysis within 30 days. Two LTA recipients were subsequently listed for kidney transplant.

CONCLUSIONS

Patients with end-stage liver disease on dialysis who undergo liver transplantation have significantly better survival when SLKT is performed. In selected patients, SLKT is an appropriate use of a scarce resource, but better prognostic indicators for selection of patients are still needed.

Acute Kidney Injury in Patients with Cirrhosis

Acute kidney injury (AKI) occurs commonly in patients with advanced cirrhosis and negatively impacts pre- and post-transplant outcomes. Physiologic changes that occur in patients with decompensated cirrhosis with ascites, place these patients at high risk of AKI. The most common causes of AKI in cirrhosis include prerenal injury, acute tubular necrosis (ATN), and the hepatorenal syndrome (HRS), accounting for more than 80% of AKI in this population. Distinguishing between these causes is particularly important for prognostication and treatment. Treatment of Type 1 HRS with vasoconstrictors and albumin improves short term survival and renal function in some patients while awaiting liver transplantation. Patients with HRS who fail to respond to medical therapy or those with severe renal failure of other etiology may require renal replacement therapy. Simultaneous liver kidney transplant (SLK) is needed in many of these patients to improve their post-transplant outcomes. However, the criteria to select patients who would benefit from SLK transplantation are based on consensus and lack strong evidence to support them. In this regard, novel serum and/or urinary biomarkers such as neutrophil gelatinase-associated lipocalin, interleukins-6 and 18, kidney injury molecule-1, fatty acid binding protein, and endothelin-1 are emerging with a potential for accurately differentiating common causes of AKI. Prospective studies are needed on the use of these biomarkers to predict accurately renal function recovery after liver transplantation alone in order to optimize personalized use of SLK.