A palliative procedure performed in univentricle patients the Fontan is associated with impaired pulmonary function and liver fibrosis. Currently these patients are monitored using liver function tests (LFTs) and liver ultrasound (US) scans, however these tests are targeted for viral mediated fibrosis. Acoustic radiation force impulse (ARFI) imaging measures tissue elasticity and may have an important role in assessing liver stiffness. We aimed to assess the efficacy of LFTs, liver US and ARFI imaging in diagnosing liver fibrosis in Fontan patients. We also aimed to assess any relation between cardiopulmonary exercise test (CPET) variables and ARFI scores.

Data was collected retrospectively from the Manchester ACHD Centre. We identified 12 patients. The sensitivity of LFTs and liver US was found to be 6.6% and 86% respectively. ARFI identified liver fibrosis in all patients with 33% at F2, 33% at F3% and 33% at F4. There was found to be a slight reduction in% peak VO2 (62.6 vs 46, p=0.2) and% predicted O2 (101.1 vs 88.9, p=0.6) in F3 patients, with a higher VE/VO2 (32.5 and 42.0, p=0.2).

Conclusion LFTs alone are not a suitable screening test for Fontan associated liver fibrosis and liver US does not accurately quantify the degree of fibrosis. ARFI requires further research in larger study samples to determine a role in routine hepatic monitoring of Fontan patients. Although we found a weak relationship between impaired CPET variables and greater ARFI scores, this requires further investigation as a potential diagnostic test for liver fibrosis.