Increased hepatic stiffness as consequence of high hepatic afterload in the Fontan circulation: a vascular Doppler and elastography study.

UNLABELLED: Hepatic dysfunction is a recognized complication after Fontan palliation of congenital heart disease. We sought to quantitatively measure hepatic stiffness and vascular Doppler indices using ultrasound (US) and shear wave elastography (SWE) in a Fontan cohort. Subjects were prospectively recruited for echocardiography and real-time hepatic duplex US with SWE for hepatic stiffness (kPa). Doppler peak velocities, velocity time integral, resistive, pulsatility, acceleration indices (RI, PI, AI), and flow volume were measured in celiac artery, superior mesenteric artery, and main portal vein (MPV). A subset underwent cardiac catheterizations with liver biopsy. Correlations were explored between SWE, duplex, hemodynamic, and histopathologic data. In all, 106 subjects were studied including 41 patients with Fontan physiology (age 13.8 ± 6 years, weight 45.4 ± 23 kg) and 65 controls (age 15.0 ± 8.4 years, weight 47.9 ± 22 kg). Patients with Fontan physiology had significantly higher hepatic stiffness (15.6 versus 5.5 kPa, P < 0.0001), higher celiac RI (0.78 versus 0.73, P = 0.04) superior mesenteric artery RI (0.89 versus 0.84, P = 0.005), and celiac PI (1.87 versus 1.6, P = 0.034); while MPV flow volume (287 versus 420 mL/min in controls, P = 0.007) and SMA AI (829 versus 1100, P = 0.002) were lower. Significant correlation was seen for stiffness with ventricular end-diastolic pressure (P = 0.001) and pulmonary artery wedge pressure (P = 0.009). Greater stiffness correlated with greater degrees of histopathologic fibrosis. No significant change was seen in stiffness or other duplex indices with age, gender, time since Fontan, or ventricular morphology. CONCLUSION: Elevated hepatic afterload in Fontan, manifested by high ventricular end-diastolic pressures and pulmonary arterial wedge pressures, is associated with remarkably increased hepatic stiffness, abnormal vascular flow patterns, and fibrotic histologic changes. The MPV is dilated and carries decreased flow volume, while the celiac and superior mesenteric arterial RI is increased. SWE is feasible in this population and shows promise as a means for predicting disease severity on liver biopsy.

Increased Hepatic Stiffness in Young Adults After Biventricular Repair of Congenital Heart Disease.

BACKGROUND: This study evaluated hepatic stiffness by shear wave elastography to investigate subclinical hepatic changes in a cohort of patients with congenital biventricular heart disease (BHD). METHODS: The BHD patients and age-matched healthy controls were prospectively recruited for hepatic ultrasonography and shear wave elastography. Real-time B-mode imaging with Doppler was performed for celiac axis, superior mesenteric artery, and main portal vein, and hepatic shear wave elastography was assessed. Vascular Doppler indices included peak velocities; velocity time integral, resistive, pulsatility, and acceleration indices; and portal vein volumetric flow. One-way analysis of variance was used for comparisons between controls, BHD, and a cohort of Glenn and Fontan patients. RESULTS: In all, 66 subjects were included. Thirty-six subjects were in the BHD group (male, 25; female, 11; mean age 27.4 ± 4.6 years; mean weight 76.8 ± 18.5 kg), and 30 were healthy controls (male, 11; female, 23, mean age 27.4 ± 3.8 years; mean weight 70 ± 17.2 kg). Shear wave elastography was increased in BHD (8.11 ± 2.07 kPa) compared with controls (5.44 ± 1.18 kPa; P < .001). Hepatic stiffness in BHD was significantly different from that in the Fontan cohort but not in the infant Glenn cohort. CONCLUSIONS: Increased hepatic stiffness was observed in young adults with repaired BHD. Although cause is not established, possibilities include hepatic congestion early in life or elevated central venous pressures due to right heart burden. Further research is required to determine whether these patients will ultimately have clinically relevant liver disease.

Hepatic stiffness in the bidirectional cavopulmonary circulation: The Liver Adult-Pediatric-Congenital-Heart-Disease Dysfunction Study group.

OBJECTIVES: We hypothesized that hepatic injury in single-ventricle CHD has origins that predate the Fontan operation. We aimed to measure hepatic stiffness using ultrasound and shear wave elastography (SWE) in a bidirectional cavopulmonary connection (BCPC) cohort. METHODS: Subjects were prospectively recruited for real-time, hepatic, ultrasound-SWE for hepatic stiffness (kPa) and echocardiography. Doppler velocities, a velocity-time integral, flow volume, and resistive index, pulsatility index, and acceleration index were measured in celiac and superior mesenteric arteries, and in the main portal vein (MPV). Comparisons were made among subjects who had BCPC, subjects who were healthy, and a cohort of patients who had undergone the Fontan procedure. RESULTS: Forty subjects (20 patients who had BCPC; 20 age- and gender-matched control subjects) were studied. The hepatic stiffness in BCPC was elevated, compared with that in control subjects (7.2 vs 5.7 kPa; P = .039). Patients who had BCPC had significantly higher celiac artery resistive index (0.9 vs 0.8; P = .002); pulsatility index (2.2 vs 1.7; P = .002); and systolic-diastolic flow ratio (10.1 vs 5.9; P = .002), whereas the superior mesenteric artery acceleration index (796 vs 1419 mL/min in control subjects; P = .04) was lower. An elevated resistive index (0.42 vs 0.29; P = .002) and pulsatility index (0.55 vs 0.35; P = .001) were seen in MPV, whereas MPV flow was reduced (137.3 vs 215.7 mL/min in control subjects; P = .036). A significant correlation was found for hepatic stiffness with right atrial pressure obtained at catheterization (P = .002). Comparison with patients who underwent the Fontan procedure showed patients who had BCPC had lower hepatic stiffness (7.2 vs 15.6 kPa; P < .001). CONCLUSIONS: Hepatic stiffness is increased with BCPC physiology, and this finding raises concerns that hepatopathology in palliated, single-ventricle CHD is not exclusively attributable to Fontan physiology. Hepatic stiffness measurements using SWE are feasible in this young population, and the technique shows promise as a means for monitoring disease progression.