During pregnancy, the baby exchanges oxygen with the mother through the placenta. Most of the blood bypasses the lungs, necessitating the presence of a patent ductus arteriosus (PDA) to send blood from the lungs to the rest of the body. After birth, under normal conditions, the PDA constricts and closes spontaneously. However, in certain circumstances, such as premature birth, hypoxia, acidosis, or pulmonary hypertension, making mechanism fail and a patent ductus arteriosus then remains open.
Patent ductus arteriosus (PDA) occurs in up to 4 out of every 1,000 newborns, accounting for approximately 10% of all congenital heart defects. The prevalence is significantly higher, reaching up to 65%, in extremely low birth weight premature infants.
If patent ductus arteriosus is large, it can lead to pulmonary edema, requiring increased respiratory support. Some infants may develop intestinal infections, or it can be severe until pulmonary hemorrhage and death occur.
If the patent ductus arteriosus (PDA) is small, babies may not have any symptoms at first, and it is often diagnosed through physical examination by detecting a heart murmur or noticing slower weight gain compared to peers. Currently, it is recommended to close the PDA in all infants, even those without symptoms, to prevent the risk of an infected large blood vessel.
There are several methods to close a patent ductus arteriosus (PDA)
1.The use of medications.
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin or paracetamol can help the PDA to constrict. These medications are effective when initiated in the early neonatal period. However, the use of medication is effective only in premature infants and cannot be used in patients with kidney problems or those who are prone to bleeding.
2.Surgery
Open chest surgery can be performed from the side to tie off and cut the extra cardiac vessel (PDA ligation). The surgery must be carried out by a specialized cardiothoracic surgeon to avoid complications, such as injury to the lymphatic duct or damage to the vocal cord nerves. Additionally, close postoperative monitoring is required in the intensive care unit (ICU).
3.Transcatheter PDA device closure
Transcatheter PDA device closure involves inserting a catheter through a blood vessel in the groin to deliver a disc-like device to close patent ductus arteriosus. The advantages of this method are no surgical scars, faster recovery, and a lower risk of complications. However, it requires an interventional radiology suite and may not be suitable for all types of PDAs
Patent ductus arteriosus (PDA) can be closed, which is often curative. However, not all PDAs should be closed, especially in conditions like Tetralogy of Fallot, where the PDA can actually help to alleviate cyanosis. Therefore, a detailed echocardiogram by a pediatric cardiologist is essential before making any treatment decisions.
Dr.Kantima Pongpichayasiri
Pediatric Cardiologist, Phyathai 2 Hospital