Acute Kidney Injury Before and After Liver Transplant

Post Liver Transplant Renal Dysfunction-Evaluation, Management and Immunosuppressive Practice

Liver transplantation (LT) is an effective and lifesaving treatment for patients with end-stage liver disease and hepatocellular carcinoma. Significant improvement in intermediate and long-term survival has been possible due to advancements in immunosuppressive therapy, perioperative care, and surgical techniques. Despite these advances, metabolic complications, including diabetes mellitus, cardiovascular diseases, malignancies, and renal dysfunction, are challenging issues after LT. Acute kidney injury (AKI) and chronic kidney disease (CKD) after LT are common and result in significant morbidity and mortality. Early diagnosis of kidney injury after LT is challenging, and no technique has yet proven effective in prediction of renal dysfunction. The methods for assessing renal function range from formulas that predict glomerular filtration rate to non-invasive biomarkers. The universal adoption of the model for end-stage liver disease has a direct impact on the incidence of peri-transplant AKI and development of CKD in the long-term. Post-LT renal dysfunction is multifactorial and is usually a result of pre-transplantation comorbidities, occurrence of renal dysfunction on the waiting list, perioperative events, and post-transplant nephrotoxic immunosuppressive medication use. Early identification of patients at risk for renal dysfunction and adoption of preventive measures are crucial in the pre-transplant period. No data are currently available to suggest a surgical technique that reliably demonstrates renal protection. Nephroprotective strategies during LT follow accepted surgical practice guidelines, such as maintenance of intravascular volume and mean arterial pressure. The management of kidney disease following LT is challenging, as by the time the serum creatinine is significantly elevated, few interventions impact the course of progression. Early nephroprotective measures are strongly advised and they mostly center on delaying the administration of calcineurin inhibitors (CNIs) during the initial postoperative period, lowering CNI dosage and combining CNI with mycophenolate mofetil and everolimus. The reasons for renal failure following LT, the techniques used to diagnose it, and the therapies designed to preserve renal function both immediately and late after LT are all critically evaluated in this review.

Meaning and Management of Perioperative Oliguria

Perioperative oliguria is an alarm signal. The initial assessment includes closer patient monitoring, evaluation of volemic status, risk-benefit of fluid challenge or furosemide stress test, and investigation of possible perioperative complications.

Liver Transplantation for Porto-sinusoidal Vascular Liver Disorder: Long-term Outcome

BACKGROUND

Porto-sinusoidal vascular liver disorder (PSVD) is a rare disease that occasionally requires liver transplantation (LT), despite usually presenting preserved liver function. There remains a paucity of data pertaining to LT in PSVD. The aim was to identify features associated with post-LT outcomes in PSVD.

METHODS

Retrospective multicentre study of 79 patients who received LT for PSVD.

RESULTS

Median post-LT follow-up was 37 (range 1-261) mo. Refractory ascites 24 (30%), hepatic encephalopathy 16 (20%), and hepatopulmonary syndrome 13 (16.3%) were the most frequent indications for LT. Hepatocellular carcinoma was the indication in only 2 patients. Twenty-four patients died, 7 due to liver and 17 to non-liver related causes. Post-LT survival was 82.2%, 80.7%, and 68.6% at 1, 2, and 5 y, respectively. Post-LT survival was significantly better in patients without (n = 58) than in those with a persistent severe PSVD-associated condition (n = 21). Pre-LT hyperbilirubinemia levels and creatinine >100 µmol/L were also independently associated with poor survival. Six patients (7.6%) required a second LT. Recurrence of PSVD was confirmed by liver biopsy in only 1 patient and in 3 further patients it was likely.

CONCLUSIONS

LT in PSVD is associated with an acceptable outcome in the absence of associated severe conditions. However, persistence of a severe associated condition, pre-LT high bilirubin levels, or creatinine >100 µmol/L impact outcome, and these are features that should be considered when evaluating PSVD patients for LT. PSVD recurrence is possible after LT and needs to be explored, at least, in cases of posttransplant portal hypertension.

A Novel Online Calculator Predicting Acute Kidney Injury After Liver Transplantation: A Retrospective Study

Acute kidney injury (AKI) after liver transplantation (LT) is a common complication, and its development is thought to be multifactorial. We aimed to investigate potential risk factors and build a model to identify high-risk patients. A total of 199 LT patients were enrolled and each patient data was collected from the electronic medical records. Our primary outcome was postoperative AKI as diagnosed and classified by the KDIGO criteria. A least absolute shrinkage and selection operating algorithm and multivariate logistic regression were utilized to select factors and construct the model. Discrimination and calibration were used to estimate the model performance. Decision curve analysis (DCA) was applied to assess the clinical application value. Five variables were identified as independent predictors for post-LT AKI, including whole blood serum lymphocyte count, RBC count, serum sodium, insulin dosage and anhepatic phase urine volume. The nomogram model showed excellent discrimination with an AUC of 0.817 (95% CI: 0.758-0.876) in the training set. The DCA showed that at a threshold probability between 1% and 70%, using this model clinically may add more benefit. In conclusion, we developed an easy-to-use tool to calculate the risk of post-LT AKI. This model may help clinicians identify high-risk patients.

Association Between Different Versions of the Model for End-Stage Liver Disease Score and Contrast-Associated Acute Kidney Injury in Patients Undergoing Elective Percutaneous Coronary Intervention

BACKGROUND

Pre-procedure liver dysfunction was associated with acute kidney injury after percutaneous coronary intervention (PCI). The aim of this study is to assess and compare the predictive value of different liver function scoring systems for contrast-associated acute kidney injury (CA-AKI) in patients undergoing elective PCI.Methods and Results:A total of 5,569 patients were retrospectively enrolled. The model for end-stage liver disease (MELD) including albumin (MELD-Albumin) score (AUC=0.661) had the strongest predictive value in comparison to the MELD score (AUC=0.627), the MELD excluding the international normalized ratio (MELD-XI) score (AUC=0.560), and the MELD including sodium (MELD-Na) score (AUC=0.652). In the fully adjusted logistic regression model, the MELD-Albumin score and the MELD-Na score were independently associated with CA-AKI regardless of whether they were treated as continuous or categorical variables; however, this was not the case for the MELD score and the MELD-XI score. Furthermore, the addition of the MELD-Albumin score significantly improved the reclassification beyond the fully adjusted logistic regression model. The study further explored the association between different versions of the MELD score and CA-AKI using restricted cubic splines and found a linear relationship between the MELD-Albumin score and the risk of CA-AKI.

CONCLUSIONS

The MELD-Albumin score had the highest predictive value for CA-AKI in patients undergoing elective PCI. The addition of the MELD-Albumin score to the existing risk prediction model significantly improved the reclassification for CA-AKI.

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.

Acute kidney injury and hepatorenal syndrome in cirrhosis

Acute kidney injury (AKI) in cirrhosis, including hepatorenal syndrome (HRS), is a common and serious complication in cirrhotic patients, leading to significant morbidity and mortality. AKI is separated into two categories, non-HRS AKI and HRS-AKI. The most recent definition and diagnostic criteria of AKI in cirrhosis and HRS have helped diagnose and prognosticate the disease. The pathophysiology behind non-HRS-AKI and HRS is more complicated than once theorized and involves more processes than just splanchnic vasodilation. The common biomarkers clinicians use to assess kidney injury have significant limitations in cirrhosis patients; novel biomarkers being studied have shown promise but require further studies in clinical settings and animal models. The overall management of non-HRS AKI and HRS-AKI requires a systematic approach. Although pharmacological treatments have shown mortality benefit, the ideal HRS treatment option is liver transplantation with or without simultaneous kidney transplantation. Further research is required to optimize pharmacologic and nonpharmacologic approaches to treatment. This article reviews the current guidelines and recommendations of AKI in cirrhosis.