Dynamic changes of hepatic microenvironment related to graft function in donation after cardiac death liver transplantation

Abstract

Purpose: The study aimed to evaluate dynamic changes in the liver microenvironment at 3 weeks, 3 months, and 6 months following donation after cardiac death liver transplantation (DCDLT) using multiparametric MRI, and further explore the correlation between the hepatic microenvironment and liver function after DCDLT.

Methods: Twenty-seven patients after DCDLT (the LT group) at times of 3 weeks (LT-3W), 3 months (LT-3M), and 6 months (LT-6M) and 20 normal volunteers (the N group) underwent intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), and blood oxygen level-dependent (BOLD) MR scanning. One-way repeated-measures ANOVA was used to compare MR parameters and liver volume (LV)/estimated standard liver volume (ESLV) at three follow-up times in the LT group. An independent sample t-test was used to compare MR parameters and LV/ESLV between each time of the LT group and the N group. Pearson and Spearman correlation analyses were employed to assess the correlation between MR parameters and liver blood indicators, LV/ESLV after DCDLT.

Results: After DCDLT, true diffusion coefficient (Dslow), pseudo diffusion coefficient (Dfast), perfusion fraction (PF), and apparent diffusion coefficient (ADC) values were increased, and fractional anisotropy (FA) and R2* values were decreased. Dfast values in the LT-3M and LT-6M were significantly higher than in the LT-3W. Compared to the LT-3W, PF and ADC values were significantly increased and R2* values were significantly decreased in the LT-6M (all P < 0.05). All MR parameters in the LT-3W were significantly different from the N group, and Dfast and ADC values in the LT-6M remained significantly higher than in the N group (all P < 0.05). In the LT group, Dslow, Dfast, PF, and ADC values were correlated with liver blood indicators and LV/ESLV (|r| = 0.364-0.561, all P < 0.05).

Conclusion: After DCDLT, the hepatic microenvironment showed an improving trend, which was correlated to the liver function. Except for the microcirculatory perfusion, the hepatic microenvironment was close to normality at six months.

Keywords: Blood oxygen level dependency; Cardiac arrest; Diffusion magnetic resonance imaging; Liver function; Liver transplantation.