The Eustachian Valve as a Pitfall in Persistent Foramen Ovale and Atrial Septum Defect Closure

a A b a n t i c r e b T s t r a A b c w THE EUSTACHIAN VALVE plays an important role during fetal life by directing oxygen-rich blood from the inferior vena cava (IVC) through the foramen ovale into the left atrium (LA) and the systemic circulation. After birth, the eustachian valve disappears or is reduced to a thin, nonfunctional ridge. Occasionally, it remains as an elongated and prominent structure within the right atrium (RA). If the eustachian valve is very prominent with undulating motion, it is called a giant eustachian valve.1 Otherwise, if t is very thin and small, it is called a Chiari network.2 Occasionally, it can be elongated and appears prominent with an undulating motion in echocardiography.1 It is best visualized by transesophageal echocardiography (TEE) in the midesophageal bicaval view, where it can be seen to originate from the junction of the RA and the IVC.2 A patent eustachian valve is not only a possible pitfall in echocardiography but also for the cardiac surgeon closing an atrial septum defect (ASD). There are several reports of the eustachian valve being mistaken for the lower rim of the ASD, thus causing inadvertent diversion of the IVC blood flow into the left atrium.3 Moreover, inflow obstruction of the IVC is reported to cause Budd-Chiari–like symptoms.4 TEE is superior to transthoracic echocardiography for the identification and characterization of ASDs in adults.5 Consequently, the authors resent 2 patients showing intraoperative TEE evidence of nintentional sewing of the eustachian valve into a surgical SD/PFO closure.