Fontan hepatic fibrosis and pulmonary vascular development

Hepatic fibrosis gender differences in extracardiac Fontan patients

OBJECTIVE

We investigated possible gender differences for hepatic fibrosis in extracardiac-Fontan patients.

METHODS

We identified extracardiac Fontan, performed between 2000 and 2016, who underwent cardiac catheterizations with transvenous hepatic biopsies between April 2012 and June 2022. We divided the patients by gender for analysis.

RESULTS

We identified 116 patients who underwent 145 transvenous biopsies, with 29 patients undergoing 2 biopsies at an average interval of 5 ± 1 years. We divided the 145 biopsies into two groups: 1) 98/145 (68%) males and 2) 47/145 (32%) females. For the 47 female liver biopsy specimens, the median total fibrosis score was 3 (0-8), and for the 98 male liver biopsy specimens, the median total fibrosis score was 2 (0-6), p = .007. The average age at surgery for females was 3 ± 1 years and for males 3 ± 1 years, p = .99. Average Fontan duration at biopsy for females was 11 ± 5 years and for males, 10 ± 4 years, p = .23. No other demographic, anatomic, echocardiographic, laboratory, or hemodynamic findings demonstrated statistically significant gender differences.

CONCLUSIONS

Females had statistically significantly higher median total fibrosis scores than males for the similar average age at extracardiac Fontan and average Fontan duration.

An Observation from Liver Biopsies Two Decades Post-Fontan

This brief report describes an observation from liver biopsy results in nonfailing Fontan patients, currently in their second postoperative decade. In three patients, with either atriopulmonary or atrioventricular connections and functional left ventricles, we found no portal fibrosis. In contrast, we found portal fibrosis in three clinically similar, nonfailing Fontan patients with lateral tunnel connections and functional left ventricles. We recognize the results may be secondary to chance; nevertheless, we speculate about possible relevancy.

Fontan Outcomes and Pulmonary Blood Flow at Birth

We previously noted, in a small group of post-Fontan patients, a possible association between hepatic fibrosis scores and the status of pulmonary blood flow at birth. To further explore this observation, we examined data from all Fontan patients seen in our center from July 2010 to March 2015. We identified 200 patients for analysis. Of the 200 patients, 56 underwent transvenous-hepatic biopsy. Of the 200 patients, 13 (6.5%) had protein-losing enteropathy. We divided both the 56 biopsy patients and the entire cohort of 200 patients into 4 groups: (1) unobstructed pulmonary blood flow at birth with functional left ventricles, (2) unobstructed pulmonary blood flow at birth with functional right ventricles, (3) obstructed pulmonary blood flow at birth with functional left ventricles, and (4) obstructed pulmonary blood flow at birth with functional right ventricles. Analysis of the 56 liver-biopsy patient groups showed median hepatic total-fibrosis scores for the 4 groups of 2 (0-6), 2 (0-8), 3 (2-6), and 4 (1-8), respectively, with statistical significance between groups 4 and 1 (p = 0.031). For the entire cohort of 200 patients, we analyzed the incidence of protein-losing enteropathy for each of the four groups and found protein-losing enteropathy percent occurrences of 0, 2.9, 8.8, and 16.1, respectively, with statistical significance between groups 4 and 2 (p = 0.031) and between groups 4 and 1 (p = 0.025). A history of obstructed pulmonary blood flow at birth, coupled with a functional right ventricle, may predict a poorer long-term Fontan outcome.