title: Effect of Fontan operation on liver stiffness in children with single ventricle physiology.
abstract: OBJECTIVE
  Assess liver stiffness using ultrasound point shear wave elastography (US P-SWE) in children before and after the Fontan operation.
  
  
  METHODS
  Eighteen children undergoing the Fontan operation were prospectively enrolled. Eight US P-SWE measurements were obtained from the right hepatic lobe before surgery, and at multiple postoperative time points. Temporally related inferior vena cava pressure (IVC) data was collected from medical records, when available. Changes in mean liver shear wave speed (SWS) were assessed using a mixed-effect model with post hoc Tukey correction. Changes in IVC pressure were evaluated using the Wilcoxon signed-rank test. A p value less than 0.05 was considered significant.
  
  
  RESULTS
  Mean age at enrolment was 33.5 ± 10.5 months. Baseline mean liver SWS was normal at 1.18 ± 0.29 m/s, increased to 2.28 ± 0.31 m/s at 2.5 ± 1.2 days (p < 0.0001) and to 2.22 ± 0.38 m/s at 7.5 ± 1.4 days (p < 0.0001). Five subjects returned at a mean of 185 ± 28 days, and mean liver SWS remained elevated at 2.08 ± 0.24 m/s (p < 0.0001). Mean IVC pressure increased from 7.2 ± 2.6 mmHg at baseline to 16.44 ± 3.3 mmHg at 2.2 ± 0.8 days post-surgery (p = 0.004).
  
  
  CONCLUSIONS
  The Fontan operation immediately and chronically increases liver stiffness and IVC pressure. Our study provides further evidence that congestion is a key driver of Fontan-associated liver disease.
  
  
  CONCLUSIONS
  • The Fontan operation triggers immediate hepatic congestion and marked liver stiffening. • Congestion, not fibrosis, drives early increased liver stiffness in Fontan patients. • Hepatic congestion persists chronically for months after the Fontan operation. • Congestion confounds shear wave elastography as a post-Fontan liver fibrosis biomarker.
authors.affiliation: Division of Pediatric Gastroenterology, Department of Pediatrics, C.S. Mott Children's Hospital, University of Michigan Health System, 1500 East Medical Center Drive, Ann Arbor, MI, 48109, USA. dipaolaf@med.umich.edu.
authors.forename: Frank W
authors.initials: FW
authors.lastname: DiPaola
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, C.S. Mott Children's Hospital, University of Michigan Health System, 1500 East Medical Center Drive, Ann Arbor, MI, 48109, USA.
authors.forename: Kurt R
authors.initials: KR
authors.lastname: Schumacher
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, C.S. Mott Children's Hospital, University of Michigan Health System, 1500 East Medical Center Drive, Ann Arbor, MI, 48109, USA.
authors.forename: Caren S
authors.initials: CS
authors.lastname: Goldberg
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA, 98105, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Friedland-Little
authors.affiliation: Michigan Institute for Clinical and Health Research (MICHR), University of Michigan, 2800 Plymouth Road, Building 400, Ann Arbor, MI, 48109, USA.
authors.forename: Aishwarya
authors.initials: A
authors.lastname: Parameswaran
authors.affiliation: Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH, 45229, USA.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Dillman
mesh_terms: D002496:Central Venous Pressure / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D054459:Elasticity Imaging Techniques; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000601:surgery; D006801:Humans; D007223:Infant; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D008107:Liver Diseases / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging / Q000502:physiology
keywords: Congenital heart disease; Congestion; Hepatopathy; Shear wave elastography; Ultrasound