Patent Ductus Arteriosus

The ductus arteriosus is a blood vessel that connects the two main arteries of the body — the aorta and the pulmonary artery. This blood vessel is normal in the fetus, but at birth, the vessel should close. When the ductus arteriosus is persistently open (patent) after birth, extra blood flows into the blood vessels of the lungs and blood is recirculated to the heart causing cardiac enlargement. This is termed a patent ductus arteriosus (PDA).

Treatment consists of specialized catheterization techniques or an operation that is done as soon as possible after diagnosis. Either procedure requires general anesthesia. The catheterization procedures are done using blood vessels in the hind limbs and the surgery is done via an incision in the chest (thoracic surgery). For the catheterization procedure, the PDA is located and occluded with either an occluder device or thromboembolic coil. For the surgical procedure, the PDA is located and closed with a surgical suture.

The prognosis is very good if surgery or catheterization is performed early. With prompt recognition and repair, there is a 90 to 95% success rate. However, only 60% of dogs with mitral regurgitation and congestive heart failure will survive surgical closure of the PDA. Following successful closure of the PDA, most dogs live a normal life. Unless there are complications from other heart defects, or heart failure has already developed, there is rarely a need for any future medicine or exercise limitations.