LIVER STAR Liver Stiffness of Teens, Adults, and Fontan Patients, Affected by Respiration

Background: Fontan-associated liver disease and fibrosis is a well-known long-term consequence in patients with Fontan circulation. It carries an increased risk of liver cirrhosis and thus hepatocellular carcinoma over time. For suitable diagnostics, the liver elastography is a noninvasive, safe, and feasible method to determine liver stiffness and the stage of liver fibrosis. Usually, this examination has to be performed in inspiratory hold to optimize the results. The effect of respiration on these results in Fontan patients is, however, unclear. To optimize the implementation for this examination, the effects of breathing maneuvers and food intake on liver stiffness in patients with Fontan circulation were investigated.

Method: For this prospective study, 25 Fontan patients (group 1) and 51 healthy volunteers in the control group 2 were examined. The control group was additionally divided into two age categories (group 2a: 15–20 years and group 2b: 20–25 years). Liver stiffness was measured by liver elastography once before food intake (= T0, with 6 hours of fasting), followed by ingestion of a standardized chocolate drink (500 mL) with nutritional distribution corresponding to a standardized meal (600 ckal). Following the meal intake, liver stiffness was determined after 15, 30, 45, 60, 90, 120, 150, and 180 minutes, each time in maximal inspiration and expiration. The study was reviewed and approved by the responsible ethics committee.

Results: In the Fontan group (group 1), the only significant difference between respiratory phases was detected 180 minutes postprandially (insp = 12.81 kPA vs. exsp = 14.50 kPA, 11.6%, p = 0.0015). The respiratory maneuvers in the healthy subjects (group 2) did differ significantly only before food intake (T0) (group 2a: insp = 4.13 kPA vs. exsp = 4.64 kPA = 11.09%; group 2b: insp = 3.80 kPA vs. exsp = 4.27, kPA = 11.07%).

Conclusion: We could demonstrate that the breathing maneuvers during the examination have only minimal clinical impact on the results of liver elastography in patients with Fontan circulation. Consequently, liver elastography is reliable independently of food intake and can also be performed on younger patients, who are unable to follow breathing commands, without any impairment of the results.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
28 January 2023