Patent ductus arteriosus (PDA)
Summary/Definition
Patent ductus arteriosus (PDA) is a relatively common pathological condition, accounting for about 5-10% of all congenital heart defects. This anomaly occurs when the blood vessel connecting the pulmonary artery and the aorta (Ductus Botalli), which should be open before birth and close immediately after birth, remains open. When the arterial vessel is narrowed, the disease remains asymptomatic in most patients and is most often discovered incidentally. However, in the presence of a wide open arterial duct, symptoms of heart failure such as breathing difficulties and other manifestations occur. This occurs because of the increased workload on the heart and lungs due to the outflow of blood from the aorta into the pulmonary artery. The arterial hollow canal, which normally closes after birth, provides oxygen and nutrients to the embryo. Botallus ductus incompletion is a condition in which this arterial canal remains open even though functional closure should occur 12-15 hours after birth and physiological closure should occur 2-4 weeks later. The exact causes of this anomaly are still not fully known. It is thought that it may result from exposure of the embryo to rubella virus in early pregnancy, genetic disorders or changes in the structure of individual chromosomes
Symptoms
The symptoms and the period of symptom onset in cases of Botal duct obstruction are quite diverse. This is mainly due to hemodynamic features that depend on the characteristics of the Botal duct itself. Individuals with an ungrown Botal duct often have no characteristic symptoms and the development of children is normal. The condition is often detected in patients during chest radiological examination or by chance, for example, by listening to noises. Nevertheless, a wide open ductus arteriosus produces symptoms such as increased sweating during breastfeeding, difficulty eating, silent crying and poor weight gain. This condition may also be accompanied by frequent respiratory tract infections. These symptoms indicate the presence of heart failure caused by increased blood flow to the pulmonary artery through the arterial vena cava.
Diagnostics
During clinical examination, auscultation is performed to detect characteristic continuous murmurs associated with blood circulation in the child’s heart. In addition, electrocardiography is performed to record the electrical activity of the heart and echocardiography is performed to assess the functional and structural status of the heart and to detect the presence of an unenlarged Botal duct. Other methods such as chest X-ray defectoscopy, cardiac catheterization, angiography, etc. may be used for diagnosis.
Treatment and course of the disease
Patent ductus arteriosus (PDA) obstruction in full-term infants is different from PDA in preterm infants. This pathology, caused by structural changes in the vessel, is a rare event that can lead to vessel occlusion and problems, even in newborns who are only one week old. When there is an abundant flow of blood from the aorta into the pulmonary artery due to the dilated vessel, breathing problems, growth retardation and other symptoms of heart failure can occur, putting pressure on the lungs and heart. In the long term, this can lead to Eisenmenger syndrome. As you age, the artery can widen and become more vulnerable to rupture, which can be life-threatening. In rare cases, complications such as hardening of the artery wall, embolism, and endarteritis can occur etc. In the case of PDA with small artery size, there may be no symptoms, or symptoms may be associated with audible heart murmurs. Anyway, regardless of the size of the artery, mandatory treatment is necessary because of the possible development of endarteritis. Vascular prostheses can be used for treatment, especially in patients with minor open arterial duct obstruction. This method of treatment is generally used in children over two years of age with a body weight of 10kg or more. The procedure involves closing the duct by inserting special devices, such as plugs or spirals, through a catheter. On the other hand, surgical intervention may be used if the size of the artery is large and there are pronounced clinical symptoms.
Complications
A complication of Patent ductus arteriosus (PDA) can be Eisenmenger syndrome. This syndrome is characterized by the closure of some pulmonary arteries due to increased blood pressure in the pulmonary arteries, resulting in impaired oxygen supply and lividity even at rest (cyanosis). Treatment of Eisenmenger syndrome is aimed at eliminating the symptoms of diseases such as heart failure, hypoxia and hypervolaemia, as in this case it is impossible to correct the causative vascular changes, which are already irreversible.
