Impact of Graft Steatosis on Post-operative Complications After Liver Transplantation

Introduction Solid organ transplantation has become the standard of care for selected patients with end-stage organ dysfunction. With improved surgical techniques, more effective immunosuppressive therapies, and better anti-infective medications, outcomes after solid organ transplantation have improved over the last several years.

The excellent survival rates reported after orthotopic liver transplantation (OLT) have increased the demand for liver transplants and have enhanced the disparity between the number of available donor organs and the need for such organs.

The lack of available organs for liver transplantation (LT) associated with the increased death rates among patients on most waiting lists for LT has triggered the use of so-called extended criteria donor (ECD) grafts, previously called ''suboptimal grafts''. Among the wide range of these ECD livers, hepatic steatosis is one of the most frequent disorders, which is mostly related to an increasing prevalence of non-alcoholic fatty liver disease (NAFLD).

Non-alcoholic fatty liver disease (NAFLD) is increasingly significant in healthy individuals for its high worldwide prevalence, an association with the metabolic syndrome such as insulin resistance, diabetes, dyslipidemia and obesity, and an association with liver-related morbidity and mortality.

Clinical evaluation and current imaging modalities, and serological and laboratory tests can be strongly suggestive of the presence of hepatic steatosis, but none of these is capable of distinguishing steatohepatitis (SH) from uncomplicated steatosis; likewise, these evaluations can generally detect advanced liver disease (e.g. portal hypertension), but none can truly assess the degree of liver necroinflammatory injury, lesser stages of fibrosis and architectural remodeling. Liver biopsy evaluation, therefore, remains the 'gold standard' to unequivocally diagnose SH and to document the severity of hepatic injury and fibrosis.