The Significance of Congenital Portosystemic Shunts in Congenital Heart Disease and the Bizarre Phenomenon of Alternating Portosystemic and Systemic–Portal Shunting

Abstract

Congenital portosystemic shunts (CPSS) are rare vascular anomalies characterized by abnormal connections between the portal/splanchnic veins and the systemic veins. CPSS often occur as an isolated congenital anomaly, but they can also co-exist with congenital heart disease (CHD). Due to their myriad consequences on multiple organ systems, familiarity with CPSS is of tremendous importance to the care of patients with CHD. In single ventricle CHD with interrupted inferior vena cava with azygos continuation to the superior vena cava, a unique and unusual scenario develops consisting of alternating direction of shunting across the CPSS from portosystemic, to systemic-portal, and back again to portosystemic depending on the stage of palliation of the single ventricle CHD. The rationale and timing for interventions to embolize CPSS in this scenario are discussed. Specific shunt embolization techniques are beyond the scope of this manuscript.