What Is PDA Heart Surgery?

Ductus arteriosus is a normal connection or opening in a fetus between the descending thoracic aorta and the pulmonary artery. In normal development, the ductus arteriosus closes after birth. Patent ductus arteriosus (PDA) closure surgery is a procedure to close this connection if it persists (remains patent) after birth.

The procedure may be performed as

• Open surgery: the surgeon accesses the thoracic cavity through a large incision in the chest (thoracotomy) and uses standard surgical instruments to perform the procedure.
• Video-assisted thoracoscopic surgery (VATS): the surgeon makes tiny incisions and performs the procedure with tiny surgical instruments inserted through a flexible tube that has a lighted camera (thoracoscope).
• Catheter closure: A plug or coil-like metal device is inserted to block the PDA. The device is advanced through the femoral vein in the groin, into the heart and the PDA, using a flexible tube (catheter).

In an unborn baby, the mother supplies oxygen and the lungs are deflated and nonfunctional. The lungs receive only 5% to 8% of the blood that enters the pulmonary artery. Most of the blood is diverted back through the ductus arteriosus, into the descending aorta for circulation in the body.

The ductus arteriosus closes normally within three days after birth in full-term and normal-birth-weight babies, beginning as soon as the lungs expand and start functioning. When the ductus arteriosus fails to close after birth, the condition is known as patent ductus arteriosus. PDA is mostly diagnosed soon after birth or in childhood but can sometimes go undetected until adulthood.

PDA causes extra blood to be pumped into the pulmonary artery. This forces the heart and lungs to work harder to pump the blood out. If the PDA is untreated, it can lead to 

• high pressure in the pulmonary artery (pulmonary hypertension),
• pulmonary obstructive disease,
• lung congestion, and
• congestive heart failure.

People with PDA are at high risk for bacterial infection of the heart’s inner layer (bacterial endocarditis). A small PDA may cause no symptoms other than a heart murmur, but a large PDA can result in conditions such as

• Rapid breathing
• Difficulty breathing
• Respiratory infections
• Fatigue
• Poor growth in children

PDA may take longer to close in preterm and low-birth-weight babies. In a premature baby, the doctor may elect to wait and monitor the PDA if there are no symptoms of congestive heart failure. The doctor often administers nonsteroidal anti-inflammatory drugs (NSAIDs) to induce PDA closure.

PDA closure surgery is performed when medications do not help in closing the PDA in premature infants, and they develop symptoms of congestive heart failure. Catheter closure is not suitable for premature babies as their blood vessels are too small.

In asymptomatic children and adults, the PDA surgery may be delayed if the PDA is small and does not cause any health issues. All PDA will, however, eventually require intervention since they can be potentially fatal.

PDA closure is not undertaken in the presence of certain vascular or heart abnormalities because survival may depend on the blood pumped through the PDA. The abnormalities include:

• Reversed position (transposition) of the aorta and pulmonary artery
• Severely narrowed aorta (coarctation of aorta)
• Underdeveloped or blocked heart valves (heart valve atresia)
• Underdeveloped lungs (pulmonary hypoplasia)
• Underdeveloped pulmonary artery (pulmonary artery hypoplasia)
• Underdevelopment of the left ventricle (hypoplastic left ventricle)