How many mm does patent ductus arteriosus need to be before surgery? What impact does patent ductus arteriosus have on the baby?

Patent ductus arteriosus PDA is one of the common types of congenital heart disease, accounting for 15% of the total number of congenital heart diseases, ranking second among congenital heart diseases. The mother often has a history of rubella virus infection in the first three months of pregnancy. It is more common in women. The ductus arteriosus begins to functionally close 10-15 hours after the birth of the baby. From 2 months to 1 year old, most of them are closed. Those who are still not closed after 1 year old are called patent ductus arteriosus. This disease often occurs alone in normal infants, children and premature infants. Or it may be complicated by other congenital heart diseases such as complete transposition of the great arteries, pulmonary atresia, aortic coarctation, interrupted aortic arch, etc. The thickness of the ductus arteriosus varies. The diameter of the ductus arteriosus in full-term infants is similar to that of the descending aorta, generally 5-20mm in diameter and 6-10mm in length. It can be divided into five types: tubular, funnel, window, dumbbell and aneurysm.

1. Patent ductus arteriosus and symptoms: Patients with a small ductus arteriosus may be clinically asymptomatic, while patients with a large ductus may experience coughing, shortness of breath, feeding difficulties, and delayed growth and development.

2. Signs: There is a continuous "machine"-like murmur above the left edge of the sternum, which occupies the entire systolic and diastolic periods and is loudest at the end of systole. The murmur is transmitted to the left subclavian, neck and back. When pulmonary vascular resistance increases, the diastolic component of the murmur may weaken or disappear. In patients with large shunts, a shorter diastolic murmur may be heard at the anterior cusp due to the relative submitral valve. The second sound in the pulmonary valve area is enhanced. In infants and young children, due to the high pulmonary artery pressure, the pressure difference between the aorta and pulmonary arteries is not significant during diastole, so only systolic murmurs are often heard. When combined with pulmonary hypertension or heart failure, there are usually only systolic murmurs. Due to the decrease in diastolic pressure, the pulse pressure difference widens, and peripheral vascular signs may appear, such as water pulse and nail bed capillary pulsation.

3. When the ductus arteriosus of the newborn is not closed, the peripheral arterial pulsation will be loud, and a systolic murmur may be heard under the clavicle or between the shoulder blades (occasionally a continuous murmur may be heard), the precordial pulsation will be obvious, the liver will be enlarged, the condition will be short of breath, and respiratory failure may occur easily, requiring reliance on mechanical ventilation.

Genetics is the main internal factor

Any factors that affect the development of the heart embryo during the fetal period may cause heart malformations, such as the pregnant mother suffering from rubella, influenza, mumps, Coxsackie virus infection, diabetes, hypercalcemia, etc., the pregnant mother is exposed to radiation; the pregnant mother takes anti-cancer drugs or drugs such as tocopherol.

Embryology and pathogenesis

The fetal ductus arteriosus develops from the back of the sixth aortic branchial arch, forming a physiological channel between the aorta and the pulmonary artery for fetal blood circulation. During the fetal period, all pulmonary alveoli are collapsed, do not contain air, and have no respiratory activity, so the pulmonary vascular resistance is very large, so most of the venous blood discharged from the right ventricle cannot enter the pulmonary circulation for oxygenation. Because the pulmonary artery pressure is higher than that of the aorta, most of the blood entering the pulmonary artery will flow into the aorta through the ductus arteriosus and then reach the placenta through the umbilical artery, undergo metabolic exchange with maternal blood in the embryonic disc, and then be returned to the fetal blood circulation by the umbilical vein.

1. Mothers should avoid catching colds in the early stages of pregnancy, such as keeping warm, going to fewer public places, and especially visiting fewer large shopping malls. According to tests, the air quality in large shopping malls with good sealing is very poor, which is an important measure to prevent congenital heart disease.

2. When the heart is nearly fully developed, which is about 2 months of pregnancy, do a color Doppler ultrasound to check the development of the child's heart. If the conditions are good, you should be able to see the development of the child's heart. If the child has a complex heart malformation, such as left ventricular hypoplasia syndrome and other congenital heart diseases that currently have no good treatment, the mother should consider abandoning the fetus. However, the ultrasound fetal heart development requires a relatively high level of level, which is related to the hospital's equipment and the personal level of the doctor.

3. Some people believe that children's congenital heart disease is related to ultrasound, surrounding radioactive substances, etc., but these claims have not been conclusively proven.

4. The impact of air pollution caused by home decoration on heart development is uncertain, but it is definitely not good. It may not affect the heart development of children, but it may affect other aspects of their development. Some of the special smells and irritations we feel after decoration are caused by toxic gases, which may affect the development of the fetus.

5. Parents’ drinking and smoking will affect the development of the fetus.

6. Some medicines should also be avoided.

7. If the fetus is not well developed or healthy, there will be reactions, such as miscarriages in some mothers. Some of these reasons are due to the maternal discomfort and some are due to the abnormal development of the fetus itself. Some mothers use some drugs to protect the fetus, which will have a certain impact on the development of the fetus.

1. Drug treatment The main role of drug treatment is to prevent and treat infective endocarditis, respiratory tract infection and heart failure. For premature infants with patent ductus arteriosus, some drugs (such as indomethacin, aspirin, etc.) can be used to inhibit the synthesis of prostaglandins, shrinking or closing the ductus.

2. Interventional treatment Interventional treatment is a minimally invasive surgery, the most common of which is patent ductus arteriosus closure. It is currently the most common method for treating patent ductus arteriosus and is suitable for all types of patients with patent ductus arteriosus. The method is roughly to use a special wire to clamp a "special patch" into the heart, reach the patent ductus arteriosus, and use the patch to close the unclosed area. This method has the advantages of small surgical trauma, high safety, simple operation, few complications, and short hospitalization time.

3. Surgical treatment: surgical ligation and cutting and suturing. The ideal age is 4-15 years old. If the disease progresses rapidly or there are repeated respiratory tract infections, heart failure, uncontrolled infective endocarditis, congestive heart failure that is ineffective with medical treatment, and symptomatic patent ductus arteriosus, the diagnosis is clear and contraindications are excluded. In principle, emergency surgical treatment should be performed as soon as possible.

Surgical method:

(1) Duct arterial ligation or clamping: The surgery can be performed by entering the left thoracic cavity through a posterolateral chest incision or video-assisted thoracoscopy.

(2) Ductus arteriosus cutting and suturing: After clamping the ductus arteriosus with two duct clamps, the edges of the aorta and pulmonary artery are continuously sutured while cutting between the two clamps.

(3) Internal suture method: under general anesthesia and low-temperature extracorporeal circulation, the heart blood circulation is blocked, and the ductus arteriosus incision is exposed and directly sutured through the pulmonary artery incision.

(4) Catheter occlusion: using a cardiac catheter to release an appropriate occlusion device to occlude the ductus arteriosus.

1. Eat a high-vitamin diet.

2. Eat fresh fruits and vegetables.

3. A high-protein diet is recommended.

4. A low-fat diet is recommended.

1. Avoid high-salt diet.

2. Avoid sweets.

3. Avoid canned drinks and cold drinks.

4. Avoid blindly taking supplements.