Extracorporeal Liver Support: An Updated Review of Mechanisms and Current Literature.

Introduction: Acute liver failure is a cause of major mortality in the United States. Although the liver possesses regenerative capabilities, liver transplantation is the mainstay of treating acute liver failure. This modality is associated with many financial and logistic challenges. In this regard, Extracorporeal Liver Support (ECLS) might help in reducing mortality as well as bridge a patient to liver transplant. In some cases, the sequelae of liver failure such as hepatic encephalopathy and multi-organ failure can be postponed long enough for the native liver to self-recover function. With this rationale, we sought to describe the mechanism of various ECLS modalities, provide an overview of the current evidence regarding its use and to highlight future advancements that could overcome hindrances in its use. Methods: A scoping review was performed using PubMed and other databases from 1990 to 2020 with the keywords: 'extracorporeal liver support', 'acute liver failure', 'acute on chronic liver failure', 'albumin dialysis', 'artificial' and 'bioartificial'. Results and conclusions: ECLS has shown significant improvements in bilirubin and urea levels. Various forms of ECLS might also reduce mortality due to liver failure. However, many complications, such as hypotension, anemia, bleeding issues, sepsis, can be anticipated. There are a few barriers to mainstream use of ECLS, such as specific design requirements and high cost that reduce the overall utility of this modality in a small group of liver transplant candidates. Furthermore, a multidisciplinary team approach is required to supervise ECLS, a luxury only available at major academic hospitals. Some advancements for overcoming these barriers include investigation of new scaffolding systems. In order to expand the usage of ECLS, clinical trials focusing on a comparison of different modalities of ECLS with renal replacement therapy in patients with liver failure should be promoted.