Kidney function and mortality post-liver transplant in the Model for End-Stage Liver Disease era

Current aspects of renal dysfunction after liver transplantation

The development of chronic kidney disease (CKD) after liver transplantation (LT) exerts a severe effect on the survival of patients. The widespread adoption of the model for end-stage liver disease score strongly impacted CKD incidence after the procedure, as several patients are transplanted with previously deteriorated renal function. Due to its multifactorial nature, encompassing pre-transplantation conditions, perioperative events, and nephrotoxic immunosuppressor therapies, the accurate identification of patients under risk of renal disease, and the implementation of preventive approaches, are extremely important. Methods for the evaluation of renal function in this setting range from formulas that estimate the glomerular filtration rate, to non-invasive markers, although no option has yet proved efficient in early detection of kidney injury. Considering the nephrotoxicity of calcineurin inhibitors (CNI) as a factor of utmost importance after LT, early nephroprotective strategies are highly recommended. They are based mainly on delaying the application of CNI during the immediate postoperative-period, reducing their dosage, and associating them with other less nephrotoxic drugs, such as mycophenolate mofetil and everolimus. This review provides a critical assessment of the causes of renal dysfunction after LT, the methods of its evaluation, and the interventions aimed at preserving renal function early and belatedly after LT.

Preoperative risk factors for massive transfusion, prolonged ventilation requirements, and mortality in patients undergoing liver transplantation

Background

Despite improvements in techniques and management of liver transplant patients, numerous perioperative complications that contribute to perioperative mortality remain. Models to predict intraoperative massive blood transfusion, prolonged mechanical ventilation, or in-hospital mortality in liver transplant recipients have not been identified. In this study we aim to identify preoperative factors associated with the above mentioned complications.

Methods

A retrospective observational analysis was conducted on data collected from 124 orthotopic liver transplants performed at a single institution between 2014 and 2017. A multivariable logistic regression using backwards elimination was performed for three defined outcomes (massive transfusion ≥ 10 units packed red blood cells (PRBC), prolonged mechanical ventilation > 24 h, and in-hospital mortality) to identify associations with preoperative characteristics.

Results

Statistically significant (P < 0.05) associations with massive transfusion ≥ 10 units PRBC were hepatocellular carcinoma and preoperative transfusion of PRBC. Significant associations with prolonged mechanical ventilation > 24 h were hepatitis C, alcoholic hepatitis, elevated preoperative alanine aminotransferase, and hepatorenal syndrome. Male gender was protective for requiring prolonged mechanical ventilation. End-stage renal disease and hepatitis B were significantly associated with increased in-hospital mortality.

Conclusions

This study identified risk factors associated with common perioperative complications of liver transplantation. These factors may assist practitioners in risk stratification and may form the basis for further investigations of potential interventions to mitigate these risks.

Outcomes of liver transplantation in patients with hepatorenal syndrome

Hepatorenal syndrome (HRS) plays an important role in patients with liver cirrhosis on the wait list for liver transplantation (LT). The 1 and 5-year probability of developing HRS in cirrhotic with ascites is 20% and 40%, respectively. In this article, we reviewed current concepts in HRS pathophysiology, guidelines for HRS diagnosis, effective treatment options presently available, and controversies surrounding liver alone vs simultaneous liver kidney transplant (SLKT) in transplant candidates. Many treatment options including albumin, vasoconstrictors, renal replacement therapy, and eventual LT have remained a mainstay in the treatment of HRS. Unfortunately, even after aggressive measures such as terlipressin use, the rate of recovery is less than 50% of patients. Moreover, current SLKT guidelines include: (1) estimation of glomerular filtration rate of 30 mL/min or less for 4-8 wk; (2) proteinuria > 2 g/d; or (3) biopsy proven interstitial fibrosis or glomerulosclerosis. Even with these updated criteria there is a lack of consistency regarding long-term benefits for SLKT vs LT alone. Finally, in regards to kidney dysfunction in the post-transplant setting, an estimation of glomerular filtration rate < 60 mL/min per 1.73 m² may be associated with an increased risk of patients having long-term end stage renal disease. HRS is common in patients with cirrhosis and those on liver transplant waitlist. Prompt identification and therapy initiation in transplant candidates with HRS may improve post-transplantation outcomes. Future studies identifying optimal vasoconstrictor regimens, alternative therapies, and factors predictive of response to therapy are needed. The appropriate use of SLKT in patients with HRS remains controversial and requires further evidence by the transplant community.