Simultaneous liver kidney transplantation:

Hepatorenal Syndrome in Cirrhosis

Hepatorenal syndrome (HRS) is a form of kidney dysfunction that characteristically occurs in liver cirrhosis. It is characterized by a marked impairment of kidney function in response to circulatory and hemodynamic alterations that occur in advanced stages of liver cirrhosis, aggravated by systemic inflammation and bacterial translocation. The classical definitions of the types of HRS have been recently revisited and 2 forms of HRS have been redefined: the acute form, referred to as acute kidney injury (HRS-AKI), and the chronic form, referred to as chronic kidney disease. HRS-AKI is one of the most severe forms of AKI in patients with cirrhosis and it consists of an abrupt impairment of kidney function, frequently triggered by an infection, appearing in the setting of advanced decompensated cirrhosis. Differential diagnosis with other causes of AKI is crucial because HRS-AKI requires a specific treatment. Differential diagnosis with AKI-acute tubular necrosis may be challenging and kidney biomarkers may be useful in this setting. Treatment of HRS-AKI is based on the administration of vasoconstrictor drugs in combination with volume expansion with albumin. Prognosis of HRS-AKI is poor, and the ideal definitive treatment consists of liver transplantation or simultaneous liver-kidney transplantation. HRS-AKI has a big impact on patients' quality of life. Management of HRS-AKI remains challenging in specific situations such as alcohol-associated hepatitis or metabolic-associated steatotic liver disease cirrhosis. Developing preventive measures for HRS-AKI, improving its early identification, discovering new biomarkers for differential diagnosis, and improving the response to therapy are some of the unmet needs in the field of HRS-AKI.

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.

Current State of Multiorgan Transplantation and Implications for Future Practice and Policy

The incidence of kidney dysfunction has increased in liver transplant and heart transplant candidates, reflecting a changing patient population and allocation policies that prioritize the most urgent candidates. A higher burden of pretransplant kidney dysfunction has resulted in a substantial rise in the utilization of multiorgan transplantation (MOT). Owing to a shortage of available deceased donor kidneys, the increased use of MOT has the potential to disadvantage kidney-alone transplant candidates, as current allocation policies generally provide priority for MOT candidates above all kidney-alone transplant candidates. In this review, the implications of kidney disease in liver transplant and heart transplant candidates is reviewed, and current policies used to allocate organs are discussed. Important ethical considerations pertaining to MOT allocation are examined, and future policy modifications that may improve both equity and utility in MOT policy are considered.

The Impact of the 2017 Kidney Allocation Policy Change on Simultaneous Liver-Kidney Utilization and Outcomes

Historically in the United States, kidneys for simultaneous liver-kidney transplantation (SLKT) candidates were allocated with livers, prioritizing SLKT recipients over much of the kidney waiting list. A 2017 change in policy delineated renal function criteria for SLKT and implemented a safety net for kidney-after-liver transplantation. We compared the use and outcomes of SLKT and kidney-after-liver transplant with the 2017 policy. United Network for Organ Sharing Standard Transplant Analysis and Research files were used to identify adults who received liver transplantations (LT) from August 10, 2007 to August 10, 2012; from August 11, 2012 to August 10, 2017; and from August 11, 2017 to June 12, 2019. LT recipients with end-stage renal disease (ESRD) were defined by dialysis requirement or estimated glomerular filtration rate <25. We evaluated outcomes and center-level, regional, and national practice before and after the policy change. Nonparametric cumulative incidence of kidney-after-liver listing and transplant were modeled by era. A total of 6332 patients received SLKTs during the study period; fewer patients with glomerular filtration rate (GFR) ≥50 mL/min underwent SLKT over time (5.8%, 4.8%, 3.0%; P = 0.01 ). There was also less variability in GFR at transplant after policy implementation on center and regional levels. We then evaluated LT-alone (LTA) recipients with ESRD (n = 5408 from 2012-2017; n = 2321 after the policy). Listing for a kidney within a year of LT increased from 2.9% before the policy change to 8.8% after the policy change, and the rate of kidney transplantation within 1 year increased from 0.7% to 4% (P < 0.001). After the policy change, there was no difference in patient survival rates between SLKT and LTA among patients with ESRD. Implementation of the 2017 SLKT policy change resulted in reduced variability in SLKT recipient kidney function and increased access to deceased donor kidney transplantation for LTA recipients with kidney disease without negatively affecting outcomes.

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.

The impact of multi-organ transplant allocation priority on waitlisted kidney transplant candidates

Kidney-alone transplant (KAT) candidates may be disadvantaged by the allocation priority given to multi-organ transplant (MOT) candidates. This study identified potential KAT candidates not receiving a given kidney offer due to its allocation for MOT. Using the Organ Procurement and Transplant Network (OPTN) database, we identified deceased donors from 2002 to 2017 who had one kidney allocated for MOT and the other kidney allocated for KAT or simultaneous pancreas-kidney transplant (SPK) (n = 7,378). Potential transplant recipient data were used to identify the "next-sequential KAT candidate" who would have received a given kidney offer had it not been allocated to a higher prioritized MOT candidate. In this analysis, next-sequential KAT candidates were younger (p < .001), more likely to be racial/ethnic minorities (p < .001), and more highly sensitized than MOT recipients (p < .001). A total of 2,113 (28.6%) next-sequential KAT candidates subsequently either died or were removed from the waiting list without receiving a transplant. In a multivariable model, despite adjacent position on the kidney match-run, mortality risk was significantly higher for next-sequential KAT candidates compared to KAT/SPK recipients (hazard ratio 1.55, 95% confidence interval 1.44, 1.66). These results highlight implications of MOT allocation prioritization, and potential consequences to KAT candidates prioritized below MOT candidates.

Monitoring Renal Function and Therapy of Hepatorenal Syndrome Patients with Cirrhosis

Acute kidney injury (AKI) is a frequent complication in patients with cirrhosis. Patients with cirrhosis can develop AKI due to different causes. Hepatorenal syndrome (HRS) is a unique cause of AKI occurring in patients with advanced cirrhosis and is associated with high short-term mortality. The differential diagnosis between different causes of AKI may be challenging. In this regard, new urine biomarkers may be helpful. Liver transplantation is the definitive treatment of patients with HRS-AKI. Vasoconstrictors and albumin represent the first-line pharmacologic treatment of HRS-AKI. This review summarizes current knowledge for the diagnosis and management of HRS in cirrhosis.

Combined Lung-Liver and Delayed Kidney Transplantation for Cystic Fibrosis Clinical Approach and Outcome: A Case Report

Reports on the long-term outcomes and immunosuppressive regimens of multiorgan transplant patients are limited. Here, we describe a patient with cystic fibrosis complicated by multiorgan failure who was successfully treated with combined liver lung transplant and delayed kidney transplant, resulting in excellent outcomes. Delayed kidney transplant was done to reduce the operative stress of a single procedure, giving time for adequate resuscitation and weaning from vasopressors. Our patient's postoperative course was complicated by post-transplant lymphoproliferative disease, which was successfully treated with rituximab and reduced dosages of immunosuppression.

Ascites and Hepatorenal Syndrome

Ascites occurs in up to 70% of patients during the natural history of cirrhosis. Management of uncomplicated ascites includes sodium restriction and diuretic therapy, whereas that for refractory ascites (RA) is regular large-volume paracentesis with transjugular intrahepatic portosystemic shunt being offered in appropriate patients. Renal impairment occurs in up to 50% of patients with RA with type 1 hepatorenal syndrome (HRS) being most severe. Liver transplant remains the definitive treatment of eligible candidates with HRS, whereas combined liver and kidney transplant should be considered in patients requiring dialysis for more than 4 to 6 weeks or those with underlying chronic kidney disease.

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.

Hepatorenal syndrome

Hepatorenal syndrome (HRS) is a form of kidney function impairment that characteristically occurs in cirrhosis. Recent changes in terminology have led to acute HRS being referred to as acute kidney injury (AKI)-HRS and chronic HRS as chronic kidney disease (CKD)-HRS. AKI-HRS is characterized by a severe impairment of kidney function owing to vasoconstriction of the renal arteries in the absence of substantial abnormalities in kidney histology. Pathogenetic mechanisms involve disturbances in circulatory function due to a marked splanchnic arterial vasodilation, which triggers the activation of vasoconstrictor factors. An intense systemic inflammatory reaction that is characteristic of advanced cirrhosis may also be involved. The main triggering factors of AKI-HRS are bacterial infections, particularly spontaneous bacterial peritonitis. The diagnosis of AKI-HRS is a challenge because of a lack of specific diagnostic tools and mainly involves the differential diagnosis from other forms of AKI, particularly acute tubular necrosis. The prognosis of patients with AKI-HRS is poor, with a median survival of ≤3 months. The ideal treatment for AKI-HRS is liver transplantation in patients without contraindications. Medical therapy consists of vasoconstrictor drugs to counteract splanchnic arterial vasodilation together with volume expansion with albumin. Effective measures to prevent AKI-HRS include early identification and treatment of bacterial infections and the administration of albumin in patients with spontaneous bacterial peritonitis.

Receiving Hypertensive Donor Grafts Is Associated with Inferior Prognosis in Simultaneous Liver-Kidney Transplantation Recipients

Background

The impact of hypertensive (HTN) donor grafts on the prognosis of simultaneous liver-kidney transplantation (SLKT) patient is not known, and an applicable risk scoring system for SLKT patient survival is lacking. This study aimed to evaluate the impact of donor HTN on patient survival of SLKT recipients and to identify independent risk factors.

Material/Methods

Data from 3844 adult SLKT recipients receiving deceased donor grafts from March 2002 to December 2014 in the Scientific Registry of Transplant Recipients (SRTR) database were retrospectively analyzed. Kaplan-Meier analysis was used to compare patient and graft survival. Multivariate Cox proportional hazard models were built to identify independent risk factors associated with patient and graft survival.

Results

SLKT patients receiving HTN donor grafts had significantly shorter 5-year patient survival and kidney graft survival rates than did those receiving non-HTN donor grafts (50.1% vs. 63.2%, p<0.0001 and 45.4% vs. 67.8%, p<0.0001, respectively). Multivariate analysis identified HTN donor, donor age, donation after cardiac death, cold ischemia time, recipient age, recipient condition at transplant, recipient hepatitis C infection, need for life support, and recipient pre-transplant albumin level as independent risk factors associated with inferior patient survival in SLKT recipients. A risk scoring model that predicted excellent stratification of prognostic subgroups was established (AUC, 0.762; 95% CI, 0.739–0.785).

Conclusions

An SLKT patient receiving a graft from an HTN donor has an inferior prognosis. A risk scoring system applicable to patient survival in SLKT recipients was developed.

Outcomes of simultaneous liver-kidney transplantation: implications for patient selection

PURPOSE OF REVIEW

Rates of simultaneous liver kidney (SLK) transplantation have continued to increase despite lack of clear allocation guidelines and outcomes data. The organ procurement and transplantation network (OPTN)/UNOS board approved a new SLK allocation policy to standardize medical eligibility and optimize organ utilization. This review highlights the rationale behind these new selection criteria and posttransplant outcomes in various patient populations.

RECENT FINDINGS

Uniform criteria for SLK transplantation were adopted in August 2017 and state SLK should be reserved for select patients with cirrhosis who have chronic kidney disease for longer than 3 months, sustained acute kidney injury, or particular metabolic diseases. Many patients who previously underwent SLK did not meet these criteria, reducing organ availability for patients awaiting kidney-alone transplantation. The new criteria includes a 'safety net' policy allowing for renal transplant priority for liver-alone recipients who do not meet criteria for SLK but fail to have renal recovery within the first year.

SUMMARY

The new SLK allocation policy was adopted to avoid kidney transplantation in those patients who have a significant chance of recovering renal function post-liver transplant and those with a poor chance of survival in whom SLK is futile.

Excellent outcomes in combined liver-kidney transplantation: Impact of kidney donor profile index and delayed kidney transplantation

The positive impact of delayed kidney transplantation (KT) on patient survival for combined liver-kidney transplantation (CLKT) has already been demonstrated by our group. The purpose of this study is to identify whether the quality of the kidneys (based on kidney donor profile index [KDPI]) or the delayed approach KT contributes to improved patient survival. In total, 130 CLKTs were performed between 2002 and 2015, 69 with simultaneous KT (group S) and 61 with delayed KT (group D) (performed as a second operation with a mean cold ischemia time [CIT] of 50 ± 15 hours). All patients were categorized according to the KDPI score: 1%-33%, 34%-66%, and 67%-99%. Recipient and donor characteristics were comparable within groups S and D. Transplant outcomes were comparable within groups S and D, including liver and kidney CIT, warm ischemia time, and delayed graft function. Lower KDPI kidneys (<34%) were associated with increased patient survival in both groups. The combination of delayed KT and KDPI 1%-33% resulted in 100% patient survival at 3 years. These results support that delayed KT in CLKT improves patient survival. The combination of delayed KT and low KDPI offers excellent patient survival up to 3 years. Improved outcomes in the delayed KT group including high KDPI kidneys supports expansion of the donor pool with the use of more extended criteria donor and donation after circulatory death kidneys. Liver Transplantation 24 222-232 2018 AASLD.

Simultaneous Liver-Kidney Transplantation: Impact on Liver Transplant Patients and the Kidney Transplant Waiting List

Purpose

The number of simultaneous liver-kidney transplants (SLKT) performed in the USA has been rising. The Organ Procurement and Transplantation Network implemented a new policy governing SLKT that specifies eligibility criteria for candidates to receive a kidney with a liver, and creates a kidney waitlist “safety net” for liver recipients with persistent renal failure after transplant. This review explores potential impacts for liver patients and the kidney waitlist.

Recent Findings

Factors that have contributed to the rise in SLKT including Model for End-stage Liver Disease (MELD)-based allocation, regional sharing for high MELD candidates, and the rising incidence of non-alcoholic steatohepatitis will continue to increase the number of liver transplant candidates with concurrent renal insufficiency. The effect of center behavior based on the new policy is harder to predict, given wide historic variability in SLKT practice.

Summary

Continued increase in combined liver/kidney failure is likely, and SLKT and kidney after liver transplant may both increase. Impact of the new policy should be carefully monitored, but influences beyond the policy need to be accounted for.