The role of hepatic biopsy to detect macrovacuolar steatosis during liver procurement.

The ability to predict graft function before transplantation has proven to be a difficult task, especially for macrovacuolar steatosis that is considered a major cause of posttransplant dysfunction. It is well known that macrovacuolar steatosis greater than 25% influences the short- and long-term outcomes of liver transplantation. We retrospectively analyzed frozen sections from 43 donor livers comparing preoperative laboratory/clinical values, and liver ultrasound of a cohort of donors without (group A, n=21) versus with steatosis of 25% to 35% (group B, n=22) upon liver biopsy performed during harvesting. We analyzed the possible correlations between preoperative donor data and the degree of macrovacuolar steatosis. None of the biochemical and clinical parameters were related to the degree of hepatic steatosis. The only difference between the two groups was the echographic pattern, with evidence of 27% fatty liver by ultrasound in group B and 5% in group A (p=.04). The specificity of hepatic ultrasound for macrovacuolar steatosis was 95% and the sensitivity was only 27%, while the positive and negative predictive value were 86% and 55%, respectively. In conclusion, liver biopsy during donor harvesting remains the gold standard to identify macrovacuolar steatosis greater than 25%. Hepatic ultrasound has a role to exclude the presence of steatosis in normal livers due to its high specificity, but it is not useful to make the diagnosis of a fatty liver since it has a low sensitivity and negative predictive value. Thereafter a liver ultrasound positive for hepatic steatosis alone should not be considered a valuable tool to discard an organ from transplantation.