Surgical correction for sinus venosus atrial septal defect with partial anomalous pulmonary venous connection in a dog.

A 5-year-old male toy poodle was referred for corrective surgery of an atrial septal defect. A sinus venosus-type atrial septal defect (ASD) with partial anomalous venous connection, suspected pulmonary hypertension, and pulmonary edema was confirmed by radiography, echocardiography, and cardiac computed tomography. Thoracic radiographs showed right heart enlargement. Echocardiography revealed right atrial and ventricular dilatation with mild flattening of the interventricular septum. Left-to-right shunt flow through the ASD was observed on color Doppler examination. Surgical correction of the sinus venosus ASD with a partial anomalous pulmonary venous connection was performed under cardiopulmonary bypass. A follow-up evaluation at 1 year after surgery showed resolution of the right-sided volume overload and no evidence of recurrence of ASD. Complications were not observed. Our findings indicate that surgical correction under cardiopulmonary bypass is a valid treatment option for an ASD with a partial anomalous pulmonary venous connection.