Clinical implications of preoperative and intraoperative liver biopsies for evaluating donor steatosis in living related liver transplantation

Abstract

The role of liver biopsy in selecting optimal donors is an area of continuing controversy in living donor liver transplantation (LDLT). Our aim was to assess the potential implications of preoperative and intraoperative biopsies for evaluating donor liver fat content. Three thousand eight hundred fifty-nine consecutive subjects underwent predonation needle biopsy of the right lobe, and 1766 of these subjects actually donated their livers for LDLT and underwent intraoperative wedge biopsies of paired right and left lobes. The preoperative workup protocol also included abdominal ultrasonography (USG) and computed tomography (CT). Intersample agreement on steatosis grades (<5%, 5% to <15%, 15% to <30%, and ≥30%) was calculated, and clinicometabolic factors related to sampling variability were evaluated. For detecting ≥30% steatosis in the 3859 potential donors, USG and CT had sensitivities of 84.9% and 57.3%, specificities of 76.3% and 92.7%, positive predictive values of 29.6% and 48.0%, and negative predictive values of 97.7% and 94.8%, respectively. Analyses of the 1766 actual donors showed that with respect to the total steatosis grades of intraoperative right and left biopsies versus preoperative biopsy, 36.7% and 36.0% of the pairs, respectively, differed from the weighted κ values of 0.44 and 0.40. Similar agreement levels existed for macrovesicular and microvesicular steatosis subtypes. The per-subject agreement rate for the total steatosis grade between intraoperative right and left biopsies was 83.6%. According to a multivariate analysis, independent factors affecting the variability of the total steatosis results from preoperative and intraoperative biopsies (major features) were higher systolic blood pressure, body mass index, and alanine aminotransferase values and lower high-density lipoprotein cholesterol values. In conclusion, imaging may be insufficiently sensitive for evaluating donor hepatic steatosis. Preoperative and selective intraoperative liver biopsies are mandatory for assessing donor steatosis in LDLT unless preoperative imaging demonstrates no fat.