Acute Kidney Injury Patterns Following Transplantation of Steatotic Liver Allografts

Expanding Liver Transplant Opportunities in Older Patients With Nonconventional Grafts

INTRODUCTION

Broader use of donation after circulatory death (DCD) and nonconventional grafts for liver transplant helps reduce disparities in organ availability. Limited data, however, exists on outcomes specific to nonconventional graft utilization in older patients. As such, this study aimed to investigate outcomes specific to conventional and nonconventional graft utilization in recipients > 70 y of age.

METHODS

1-to-3 matching based on recipient sex, Model for End-Stage Liver Disease score, and donor type was performed on patients ≥70 and <70 y of age who underwent liver transplant alone at Mayo Clinic Arizona between 2015 and 2020. Primary outcomes were posttransplant patient and liver allograft survival for recipients greater than or less than 70 y of age. Secondary outcomes included grafts utilization patterns, hospital length of stay, need for reoperation, biliary complications and disposition at time of hospital discharge.

RESULTS

In this cohort, 36.1% of grafts came from DCD donors, 17.4% were postcross clamp offers, and 20.8% were nationally allocated. Median recipient ages were 59 and 71 y (P < 0.01). Recipients had similar Intensive care unit (P = 0.82) and hospital (P = 0.14) lengths of stay, and there were no differences in patient (P = 0.68) or graft (P = 0.38) survival. When comparing donation after brain death and DCD grafts in those >70 y, there were no differences in patient (P = 0.89) or graft (P = 0.71) survival.

CONCLUSIONS

Excellent outcomes can be achieved in older recipients, even with use of nonconventional grafts. Expanded use of nonconventional grafts can help facilitate transplant opportunities in older patients.

Decreasing Significance of Early Allograft Dysfunction with Rising Use of Nonconventional Donors

Background and Objectives: Early allograft dysfunction (EAD) is considered a surrogate marker for adverse post-liver transplant (LT) outcomes. With the increasing use of nonconventional donors, EAD has become a more frequent occurrence. Given this background, we aimed to assess the prevalence and impact of EAD in an updated cohort inclusive of both conventional and nonconventional liver allografts. Materials and Methods: Perioperative and one-year outcomes were assessed for a total of 611 LT recipients with and without EAD from Mayo Clinic Arizona. EAD was defined as the presence of one or more of the following: bilirubin > 10 mg/dL on day 7, INR > 1.6 on day 7, or ALT and/or AST > 2000 IU/L within the first 7 days of LT. Results: Within this cohort, 31.8% of grafts (n = 194) came from donation after circulatory death (DCD) donors, 17.7% (n = 108) were nationally shared, 16.4% (n = 100) were allocated as post-cross clamp, and 8.7% contained moderate steatosis. EAD was observed in 52.2% (n = 321) of grafts in the study cohort (79% in DCD grafts and 40% in DBD grafts). EAD grafts had higher donor risk index (DRI) scores (1.9 vs. 1.6, p < 0.0001), were more likely to come from DCD donors (48% vs. 13.8%, p < 0.0001), were regionally allocated (p = 0.003), and had higher cold ischemia times (median 6.0 vs. 5.5 h, p = 0.001). Primary nonfunction events were rare in both groups (1.3% vs. 0.3%, p = 0.22). Post-LT acute kidney injury occurred at a similar frequency in recipients with and without EAD (43.6% vs. 30.3%, p = 0.41), and there were no differences in ICU (median 2 vs. 1 day, p = 0.60) or hospital (6 vs. 5 days, p = 0.24) length of stay. For DCD grafts, the rate of ischemic cholangiopathy was similar in the two groups (14.9% EAD vs. 17.5% no EAD, p = 0.69). One-year patient survival for grafts with and without EAD was 96.0% and 94.1% (HR 1.2, 95% CI 0.7−1.8; p = 0.54); one-year graft survival was 92.5% and 92.1% (HR 1.0, 95% CI 0.7−1.5; p = 0.88). Conclusions: In this cohort, EAD occurred in 52% of grafts. The occurrence of EAD, however, did not portend inferior outcomes. Compared to those without EAD, recipients with EAD had similar post-operative outcomes, as well as one-year patient and graft survival. EAD should be managed supportively and should not be viewed as a deterrent to utilization of non-ideal grafts.

Acute Kidney Injury After Liver Transplant: Incidence, Risk Factors, and Impact on Patient Outcomes

OBJECTIVES

Acute kidney injury is a frequent complication of liver transplant. Here, we assessed the rate and contributing factors of acute kidney injury and need for renal replacement therapy in patients undergoing liver transplant at a transplant center in Tehran, Iran.

MATERIAL AND METHODS

We identified all patients who underwent liver transplant at the Imam Khomeini Hospital Complex from March 2018 to March 2019 and who were followed for 3 months after transplant. Acute kidney injury was defined based on the Acute Kidney Injury Network criteria. We collected demographic and pretransplant, intraoperative, and posttransplant data. Univariable and multivariable models were applied to explore independent risk factors for acute kidney injury incidence and need for renal replacement therapy.

RESULTS

Our study included 173 deceased donor liver transplant recipients. Rates of incidence of acute kidney injury and need for renal replacement therapy were 68.2% and 14.5%, respectively. The 3-month mortality rate among those with severe and mild or moderate acute kidney injury was 44.0% (14/25) and 9.7% (9/ 93), respectively (P < .001). Multivariable analyses indicated that serum albumin (relative risk of 0.55; 95% confidence interval, 0.34-0.87; P = .021), baseline serum creatinine (relative risk of 2.11; 95% confidence interval, 1.56-2.90; P = .037), and intraoperative mean arterial pressure (relative risk of 0.76; 95% confidence interval, 0.63-0.82; P = .008) were independent factors for predicting posttransplant acute kidney injury. Independent risk factors for requiring renal replacement therapy were pretransplant serum creatinine (relative risk of 1.99; 95% confidence interval, 1.89-4.47; P = .044) and intraoperative vasopressor infusion (relative risk of 1.41; 95% confidence interval, 1.38-2.00; P = .021).

CONCLUSIONS

We found a high incidence of acute kidney injury among liver transplant recipients in our center. There was a significant association between severity of acute kidney injury and 3-month and in-hospital mortality.

Post-Liver Transplant Acute Kidney Injury

Acute kidney injury (AKI) is a common condition following liver transplantation (LT). It negatively impacts patient outcomes by increasing the chances of developing chronic kidney disease and reducing graft and patient survival rates. Multiple definitions of AKI have been proposed and used throughout the years, with the International Club of Ascites definition being the most widely now used for patients with cirrhosis. Multiple factors are associated with the development of post-LT AKI and can be categorized into pre-LT comorbidities, donor and recipient characteristics, operative factors, and post-LT factors. Many of these factors can be optimized in an attempt to minimize the risk of AKI occurring and to improve renal function if AKI is already present. A special consideration during the post-LT phase is needed for immunosuppression as certain immunosuppressive medications can be nephrotoxic. The calcineurin inhibitor tacrolimus (TAC) is the mainstay of immunosuppression but can result in AKI. Several strategies including use of the monoclonoal antibody basilixamab to allow for delayed initiation of tacrolimus therapy and minimization through combination and minimization or elimination of TAC through combination with mycophenolate mofetil or mammalian target of rapamycin inhibitors have been implemented to reverse and avoid AKI in the post-LT setting. Renal replacement therapy may ultimately be required to support patients until recovery of AKI after LT. Overall, by improving renal function in post-LT patients with AKI, outcomes can be improved.

Post-Liver Transplant Early Allograft Dysfunction Modifies the Effect of Pre-Liver Transplant Renal Dysfunction on Post-Liver Transplant Survival

Pre-liver transplantation (LT) renal dysfunction is associated with poor post-LT survival. We studied whether early allograft dysfunction (EAD) modifies this association. Data on 2,856 primary LT recipients who received a transplant between 1998 and 2018 were retrospectively reviewed. Patients who died within the first post-LT week or received multiorgan transplants and previous LT recipients were excluded. EAD was defined as (1) total bilirubin ≥ 10 mg/dL on postoperative day (POD) 7, (2) international normalized ratio ≥1.6 on POD 7, and/or (3) alanine aminotransferase or aspartate aminotransferase ≥2000 IU/mL in the first postoperative week. Pre-LT renal dysfunction was defined as serum creatinine >1.5 mg/dL or on renal replacement therapy at LT. Patients were divided into 4 groups according to pre-LT renal dysfunction and post-LT EAD development. Recipients who had both pre-LT renal dysfunction and post-LT EAD had the worst unadjusted 1-year, 3-year, and 5-year post-LT patient and graft survival, whereas patients who had neither renal dysfunction nor EAD had the best survival (P < 0.001). After adjusting for multiple factors, the risk of death was significantly higher only in those with both pre-LT renal dysfunction and post-LT EAD (adjusted hazard ratio [aHR], 2.19; 95% confidence interval [CI], 1.58-3.03; P < 0.001), whereas those with renal dysfunction and no EAD had a comparable risk of death to those with normal kidney function at LT (aHR, 1.12; 95% CI, 0.86-1.45; P = 0.41). Results remained unchanged when pre-LT renal dysfunction was redefined using different glomerular filtration rate cutoffs. Pre-LT renal dysfunction negatively impacts post-LT survival only in patients who develop EAD. Livers at higher risk of post-LT EAD should be used with caution in recipients with pre-LT renal dysfunction.

Diagnostics, Risk Factors, Treatment and Outcomes of Acute Kidney Injury in a New Paradigm

Acute kidney injury (AKI) is a common clinical condition among patients admitted in the hospitals. The condition is associated with both increased short-term and long-term mortality. With the development of a standardized definition for AKI and the acknowledgment of the impact of AKI on patient outcomes, there has been increased recognition of AKI. Two advances from past decades, the usage of computer decision support and the discovery of AKI biomarkers, have the ability to advance the diagnostic method to and further management of AKI. The increasingly widespread use of electronic health records across hospitals has substantially increased the amount of data available to investigators and has shown promise in advancing AKI research. In addition, progress in the finding and validation of different forms of biomarkers of AKI within diversified clinical environments and has provided information and insight on testing, etiology and further prognosis of AKI, leading to future of precision and personalized approach to AKI management. In this this article, we discussed the changing paradigms in AKI: from mechanisms to diagnostics, risk factors, and management of AKI.

Promises of Big Data and Artificial Intelligence in Nephrology and Transplantation

Kidney diseases form part of the major health burdens experienced all over the world. Kidney diseases are linked to high economic burden, deaths, and morbidity rates. The great importance of collecting a large quantity of health-related data among human cohorts, what scholars refer to as “big data”, has increasingly been identified, with the establishment of a large group of cohorts and the usage of electronic health records (EHRs) in nephrology and transplantation. These data are valuable, and can potentially be utilized by researchers to advance knowledge in the field. Furthermore, progress in big data is stimulating the flourishing of artificial intelligence (AI), which is an excellent tool for handling, and subsequently processing, a great amount of data and may be applied to highlight more information on the effectiveness of medicine in kidney-related complications for the purpose of more precise phenotype and outcome prediction. In this article, we discuss the advances and challenges in big data, the use of EHRs and AI, with great emphasis on the usage of nephrology and transplantation.