Quantification of degree of steatosis in extended criteria donor grafts with standardized histologic techniques: implications for graft survival

The gap between the availability of livers from organ donors and the increased demand has led many centers to apply strategies to reduce this deficit. Splitting of cadaveric organs for use in 2 recipients; domino transplantation; and organs from living donors, non-heart-beating donors, and extended-criteria donors (ECDs) are all currently used in orthotopic liver transplantation (OLT). Fatty changes in the donor liver are a risk factor for poor function after OLT; however, the presence of steatosis, frequently present in livers from ECDs, does not exclude the use of these organs. Since January 2000 at our institution, we observed 39 steatotic grafts that were stratified istologically as follows: low steatosis, 5% to 15%; mild steatosis, 16% to 30%; moderate steatosis, 31% to 60%; and severe steatosis (>60%). Histologic techniques can enable identification of the type of fatty change as macrovesicular and microvesicular. These alterations have different effects on primary nonfunction and primary dysfunction. Fifteen grafts, all with severe or moderate, macrovesicular changes were discarded. Twenty-four fatty grafts with low to moderate steatosis were utilized for transplant. Sections from 2 liver biopsies (1 wedge in the left lobe and 1 needle in the right lobe) were stained with hematoxylin-eosin, Masson trichrome, Gomori reticulin, and oil red O. The OLT was performed only in patients with a MELD (Model for End-Stage Liver Disease) score lower than 27. The rate of primary dysfunction was 12.5%, and of primary nonfunction 8.4%. The 6-month graft survival for all fatty livers was 80%. We encourage the careful use of grafts with low to moderate steatosis in recipients without additional risks.