Unusual Angiographic Appearance of Scimitar Syndrome Associated With Primitive Hepatic Venous Plexus
An asymptomatic 16-year-old girl presented for a diagnostic cardiac catheterization because of right heart enlargement. On chest radiograph, she had 2 scimitar-shaped shadows in the right lung field. The right lung and airways appeared to be of normal size.
Abnormal pulmonary venous drainage from the right lung was confirmed on the levophase of the right pulmonary artery angiogram, which demonstrated that all venous return from the right lung was directed via 2 anomalous veins to the inferior vena cava (IVC) (Figure 1). The left pulmonary veins (not pictured) connected and drained normally. The inferior vena caval injection (Figure 2) demonstrated an extensive racemose network of venous channels connecting the IVC to the hepatic veins and right atrium. This hepatic venous plexus may represent the precursor of hepatic veins and contributes to the formation of the IVC. Persistence of this primitive venous plexus may also represent a manifestation of the abnormalities of venous development that lead to the development of anomalous pulmonary venous return. This is a rare association with scimitar syndrome, having only been reported a handful of times and usually with relative IVC stenosis, although a normal size IVC maybe present (as in our patient).
The importance of recognizing this abnormality is 2-fold. First, IVC stenosis may be incorrectly diagnosed. There have been reports of attempted surgical enlargement of the IVC when diversion of caval blood via connections to the hepatic plexus was not recognized as the cause of relative IVC underdevelopment. Second, intrahepatic vascular shunts with similar radiographic features are associated with many forms of hepatocellular disease. Recognition of the benign nature of this angiographic appearance may prevent extensive (and expensive) investigation of the hepatobiliary system.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.