Abstract 13514: Early Detection and Stratification for the Risk of Liver Fibrosis/Cirrhosis in Patients after Fontan Procedure by Using Sono-Elastography with Acoustic Radiation Force Impulse
Background: Late complication of liver such as liver fibrosis/cirrhosis has gained more attention in patients after Fontan procedure, however the non-invasive imaging method to assess the risk of acquiring disease has not been established. Aim: We aim to clarify the characteristics of the liver in Fontan patients, using sonoelastography by acoustic radiation force impulse (ARFI) to calculate the liver stiffness and to stratify the risk of vulnerability.
Methods The subjects were 37 with Fontan (F-pts) (age: 12.5 +/- 5.6 years) and 109 either with minor cardiac anomalies or after uncomplicated definitive surgeries (age: 12.1 +/- 4.9 years) as a control. The imaging apparatus was ACUSON S-2000 (Siemens AG, USA) with 9L4 and 4C1 probe. The liver stiffness was estimated by measuring the shear wave propagation velocity (m/s) (Vs) at the lesion of interest by Virtual Touch tissue quantification (VTTQTM) using ARFI, which was proportional to the degree of tissue stiffness (Young elastic modulus). The patients were in prone position and Vs at the 2-3cm below the surface of the right lobe of liver was measured at 5 times consecutively and averaged.
Results Vs of F-pts (2.28 +/- 0.56 m/s) was significantly higher even shortly after Fontan operation than those of C-pts ( 1.25 +/- 0.23 m/s) (p<0.001). Vs in F-pts was weakly correlated with time after Fontan procedure, the ratio of mean pulmonary artery and aortic pressure : PA/AO (r2=0.23), the ratio of pulmonary and systemic vascular resistance: Rp/Rs (r2=0.13), Ln (BNP) (r2=0.15), but not with CVP, cardiac index, and other biomarker estimations (r-GTP, platelet, Forns index). Six of 37 with protein-losing enteropathy had significantly higher Vs (2.98 +/- 0.8 m/s) than the others without PLE (2.17 +/- 0.47 m/s), but had no difference of CVP. The liver histology of autopsy from PLE patient with Vs of 3.53 demonstrated typical liver cirrhosis although other imaging and biomarker could not be differentiated. All Fontan patients were lower than those of pediatric patients with end-staged liver cirrhosis ( > 4.0).
Conclusion: The Vs measured by VTTQTM could be a powerful non-invasive imaging tool for early detection of liver fibrosis/cirrhosis and for stratification of the risk of vulnerability in Fontan patients.
- © 2012 by American Heart Association, Inc.