Does liver biopsy accurately measure fibrosis in Fontan-associated liver disease? A comparison of liver biopsy pre-combined heart and liver transplant and liver explant post-transplant.

The accuracy of liver biopsy to stage fibrosis due to Fontan-associated liver disease (FALD) remains unclear. We compared the results of biopsy pre-combined heart and liver transplantation (CHLT) to the results of whole liver explant. Liver biopsy and explants from 15 Fontan patients (ages 16-49, median 28 years) were retrospectively reviewed. Staging was as follows: stage 0: no fibrosis, stage 1: pericellular fibrosis, stage 2: bridging fibrosis, and stage 3: regenerative nodules. There is no stage 4. Clinical characteristics including Model of End-stage Liver Disease eXcluding INR and Varices, Ascites, Splenomegaly, and Thrombocytopenia (VAST) scores were collected, and descriptive statistics and Mann-Whitney U tests were used to analyze the data. All patients had biopsies with at least bridging fibrosis, and all had nodularity on explant; transjugular biopsy never overestimated fibrosis. Explant showed higher-grade fibrosis (stage 3) than pre-CHLT biopsy (stage 2) in 6 of 15 patients and equal grade of fibrosis (stage 3) in 9 of 15 patients. Though clinical characteristics varied significantly, VAST score was ≥2 in all but two patients. Transjugular liver biopsy does not overestimate and can underestimate fibrosis in Fontan patients undergoing CHLT, likely due to the patchy nature of fibrosis in FALD.