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

Congenital portosystemic shunts (CPSSs) are rare vascular anomalies characterized by abnormal connections between the portal/splanchnic veins and the systemic veins. CPSSs often occur as an isolated congenital anomaly, but they can also coexist with congenital heart disease (CHD). Owing to their myriad consequences on multiple organ systems, familiarity with CPSS is of tremendous importance to the care of patients with 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 article.