Noninvasive Evaluations to Estimate Graft Steatosis in Living Donor Liver Transplant for Donor Safety and Successful Outcome

Background: In living donor liver transplant, graft steatosis is very important for donor safety and recipient outcome. The purpose of this study was to evaluate the accuracy of noninvasive methods to estimate graft steatosis and establish preoperative selection criteria based on the results. Methods: From January 2014 to September 2018, a total of 204 patients underwent donor hemihepatectomy (right lobe) in our center. Imaging studies, such as computed tomography (CT) and magnetic resonance spectroscopy (MRS) were routinely performed. Patients were divided into 4 groups by the macrovesicular steatosis based on the pathologic report (group 1: <5%, group 2: ≥5 and <10%, group 3: ≥10 and <20%, group 4: ≥20%). Hepatic and splenic attenuation values were measured on noncontrast CT scans by using circular region-of-interest cursors in the liver and spleen. Results: Of the 204 donors, 112 (55.1%) were in group 1, 59 (28.5%) were in group 2, 21 (10.8%) were in group 3, and 12 (5.6%) were in group 4. There were no statistical differences in age and sex among 4 groups, but, body mass index, aspartate aminotransferase, alanine aminotransferase, and all imaging studies were significantly different among the 4 groups. Body mass image, alanine aminotransferase, and imaging studies showed a linear relationship with pathologic data. As a result of drawing receiving operating characteristic curves, excellent area under the curve value is shown at average of regions of interest in liver and MRS. Conclusions: Preoperative CT and MRS provide and accurate method to estimate graft steatosis. If the 2 modalities are properly combined, they can be helpful for donor selection.