Vibration Controlled Transient Elastography to Evaluate Steatosis in Candidate Living Donors for Liver Transplantation

Abstract

Background. The ability of vibration controlled transient elastography (VCTE) to reliably exclude significant steatosis in living donor candidates could obviate the need for invasive liver biopsies, expedite the donor approval process, and reduce recipient wait time. We therefore aimed to determine whether VCTE controlled attenuation parameter (CAP) could be used to detect steatosis in potential living donors. Methods. Living donor candidates who presented for evaluation between 2016 and 2019 underwent standard donor workup, VCTE, and liver biopsy if indicated. CAP scores were compared with MRI-Fat Fraction and, when available, histologic fat fraction from liver biopsy. Receiver operating characteristic curves were used to identify cutoffs with appropriate sensitivity and specificity for screening. Statistical analysis was conducted using R (version 3.6.0). Results. Seventy-nine candidate living donors presented during the study period, of whom 71 were included in the final analysis and of whom 20 underwent liver biopsy. There was a positive correlation between MRI-Fat Fraction and CAP scores with an observed Spearman correlation coefficient of 0.424 (P < 0.01). A CAP score of 271.5 dB/m or less was determined to have 89.8% sensitivity and 75% specificity for detecting <5% steatosis on MRI. The correlation between CAP and steatosis of available histologic samples had a Pearson correlation coefficient of 0.603 (P = 0.005). A CAP cutoff of 276.0 dB/m demonstrated 66.7% sensitivity and 85.7% specificity for detecting <15% histopathologic steatosis and positive and negative predictive values of 71.5% and 82.7%, respectively. Conclusions. VCTE can be integrated into living donor evaluation to accurately screen for hepatic steatosis.