1108 Inferior Vena Cava Diversion into the Left Atrium after Surgical Repair of Atrial Septal Defect: a Rare Case of Chronic Hypoxemia

Abnormal inferior vena cava (IVC) drainage into the left atrium (LA) is an infrequent complication after surgical closure of an atrial septal defect (ASD). We present the case of a 45-year-old woman, with surgical closure of an ASD 8 years before, who consulted for exertional dyspnea and cyanosis. Transthoracic and transesophageal echocardiography showed no residual shunt after contrast administration in both arms, and thoracic CT scan and pulmonary ventilation / perfusion gammagraphy were normal. In the presence of signs strongly suggesting a right-to-left shunt, we decided to complete the study with a CMR,which revealed an anomalous systemic drainage with IVC draining into the LA with right-to-left shunt. Surgical repair of the abnormal IVC drainage was successfully performed. During the intervention cardiac surgeons found a repaired ASD located in the lower portion of the interatrial septum, a large Eustachian valve, which are anatomical features which can sometimes lead to an erroneous suture causing the drainage of the IVC towards the LA. In conclusion, it is essential to carry out an extensive search for possible residual anatomical shunts in patients who undergo surgery and develop hypoxia. The reported case underlines the importance of being aware of this possible complication of the closure of an ASD and highlights that the absence of passage of agitated saline contrast to left chambers with conventional injection by the arms does not rule out any residual shunt, recommending its administration by the lower limbs, as well as the CMR for the definitive diagnosis. Abstract 1108 Figure. CMR imaging 3D reconstruction