To Pulmonary Venous Atrium Collateral Resulting in Severe Systemic Hypoxemia Post Fontan
Howard S. Weber, MD, FSCAI; Farrah Munir, MD; Bryan P. Stefek, MD; Frank C. Lynch, MD
Introduction
The development of decompressing veno-venous collaterals is common following the bidirectional Glenn shunt and Fontan operations which can result in varying degrees of systemic desaturation. This phenomenon is thought to be a biologic reaction to the increased systemic venous pressure changes associated with this type of circulation. Often, these vessels are of supradiaphragmatic origin such as the brachiocephalic veins which communicate with the inferior cardinal vein, pulmonary venous atrium or coronary sinus. Other potential locations include the azygous and hemiazygous venous systems. The portal venous system is rarely discussed as a potential for veno-venous collateralization, however, it is certainly a vascular territory at risk for dysfunction in the presence of Fontan physiology. We describe an unusual cause of significant systemic hypoxemia many years post extracardiac non-fenestrated Fontan completion secondary to the development of a large portal veno-venous communication with the pulmonary venous atrium that was successfully embolized utilizing an Amplatzer Septal Occluder device.
FIGURE 1 Anterior-Posterior (AP) View IVC injection with opacification of hepatic veins (HV) and Fontan pathway (F). A hepatic vein-to-portal vein shunt (asterisks) is identified on late filling which communicates with a venous structure that ascends above the diaphragm and into the pulmonary venous atrium. (R: patient right; L: patient left; double carrot: sizing catheter in descending aorta)
Case Presentation
The patient is a 17-year-old male with complex single ventricule physiology (dextrocardia with situs ambiguous, asplenia, complete atrioventricular canal, pulmonary valve atresia, right-sided IVC and left-sided SVC with infradiaphragmatic total anomalous pulmonary venous return). He underwent a modified left BT shunt and TAPVR repair soon after birth, followed by a bidirectional Glenn shunt at six months of age and extracardiac non-fenestrated lateral tunnel Fontan completion at four years of age. At five years of age, he underwent a routine post Fontan cardiac catheterization utilizing intravenous conscious sedation which demonstrated acceptable hemodynamics with a mean central venous pressure of 13mmHg and transpulmonary gradient of 4mmHg.
To read the full article, please go to the January 2020 Issue of CCT.