Unexpected co-arctation of aorta detected by transesophageal echocardiography during patent ductus arteriosus ligation.

In the presence of a large patent ductus arteriosus (PDA), aortic co-arctation (CoA) cannot be diagnosed clinically because PDA masks the clinical features. This condition impedes the identification of CoA by transthoracic echcocardiography. However, the closure of PDA can result in a severe clinical condition that causes a patient with undiagnosed CoA to suffer from shock and multi-organ failure. In this article, a case of PDA was presented, in which transesophageal echocardiography provided full information that could be used as reference to identify and define CoA during PDA ligation surgery.