Congenital Heart Disease - Cases

1356209 - Multimodality imaging of Abernethy malformation

Thursday, January 26, 2023

7:00 AM – 7:50 AM

Location: Pacific Jewel

Presenting Author(s)

AE

Ahmed El-Medany, MSc

Cardiology Registrar
North Bristol NHS Trust, United Kingdom

Primary Author(s)

AE

Ahmed El-Medany, MSc

Cardiology Registrar
North Bristol NHS Trust, United Kingdom

Co-Author(s)

GR

Gui Rego, MSc

Cardiac Physiologist
Bristol Heart Institute, United Kingdom
MW

Matthew Williams, PhD

Cardiology Consultant
Bristol Heart Institute, United Kingdom
SL

Stephen Lyen, BSc

Radiology Consultant
Royal United Hospitals NHS Foundation Trust, United Kingdom
MT

Mark Turner, PhD

Cardiology Consultant
Bristol Heart Institute, United Kingdom

Description of Clinical Presentation: A 41-year-old transgender female presented to the cardiology clinic with frequent palpitation and occasional dizziness. Previous echocardiography 2 years prior reported a globular left ventricle and mild left atrial dilatation, although mentioned no other abnormalities.

She had had previous equivocal Lyme disease serology, and therefore a cardiac magnetic image resonance (CMRI) scan was organized to assess for possible myocarditis, revealing a large anomalous porto-sytemic shunt in keeping with Type 1b Abernethy malformation (Figures 1-3).

She was subsequently referred to the adult congenital heart disease team and the Hepatologists for further investigation and consideration of percutaneous shunt occlusion.

Computed tomography (CT) confirmed a large aberrant vessel extending from the portal vein to the right atrium. No significant hepatic lesion was identified. In the absence of symptoms, or obvious clinical benefit, the decision was made to avoid percutaneous shunt occlusion.

Diagnostic Techniques and Their Most Important Findings: CMRI

Axial half Fourier single-shot turbo spin-echo and coronal fast imaging with steady-state precession demonstrated the inferior vena cava and extrahepatic portosystemic shunt (Figure 1).

Short axis steady-state free precession cine stack demonstrated the abnormal portal vein and the inferior vena cava entering the right atrium (Figure 2).

Coronal fast imaging with steady-state free precession, posterior to anterior stack, demonstrated the inferior vena cava (A) and extrahepatic portal vein draining into the right atrium (Figure 3).

Coronal maximum intensity projection contrast-enhanced computed tomography of the upper abdomen in the portal venous phase demonstrated the extrahepatic portosystemic shunt, portal vein, and superior mesenteric vein.

Echocardiography

Subcostal transthoracic echocardiography demonstrated the inferior vena cava, superior vena cava, and extrahepatic portosystemic shunt. Color doppler demonstrated venous flow diversion from the portal vein into the right atrium.

Learning Points from this Case:

Abernethy malformation is a rare anomaly involving the portal venous system. Despite its rarity, it is increasingly being reported, and is therefore important to diagnose given the potential adverse clinical consequences if left untreated.

Abernethy malformation is diagnosed via noninvasive cross-sectional imaging such as transthoracic echocardiography, CT, or MRI, demonstrating the shunt and any intrahepatic portal vein branches[1].

It has a spectrum of presentations, ranging from complete lack of symptoms to causing hepatocellular carcinoma (HCC), HE, severe pulmonary hypertension, and diffuse pulmonary arteriovenous malformation[2].

Shunt closure is considered in symptomatic patients and as prophylactic treatment early in the course of the disease to prevent the development of severe complications. Despite shunt closure, the risk of complications never completely disappears, and thus regular surveillance for HCC is important[2].