Detection of patent ductus arteriosus with intraoperative transesophageal echocardiography in a patient undergoing closure of coronary artery to pulmonary artery fistula

Background Coronary artery to pulmonary artery fistula is an unusual vascular anomaly, and the shunt ratio of this fistula is usually small. Case presentation We report anesthetic management of a 55-year-old female with annuloaortic ectasia, aortic valve regurgitation, and coronary artery to pulmonary artery fistula undergoing radical repair. We calculated the left-to-right shunt ratio after placement of a pulmonary artery catheter and found that the ratio was unexpectedly high. Thus, we explored the presence of another shunt by intraoperative transesophageal echocardiography and found patent ductus arteriosus undiagnosed before operation. Conclusions A combination of a pulmonary artery catheter and transesophageal echocardiography is useful to explore the presence of another shunt, such as patent ductus arteriosus during anesthesia.