Congenital heart disease (congenital heart disease) is a class of common diseases that seriously endanger the health of children, with an incidence of 0.7% to 0.8%, and 150,000 to 200,000 new cases of congenital heart disease each year in China. In recent years, there has been great progress in the diagnosis and treatment of precardiac disease, and it is possible to make early and accurate diagnosis and surgical treatment of various precardiac diseases. Currently, the treatment of common precocious heart diseases including patent ductus arteriosus (PDA), atrial septal defect (ASD), ventricular septal defect (VSD) and pulmonary stenosis (PS) includes medical treatment, transcatheter intervention and surgical treatment; while the treatment of cyanotic precocious heart disease includes surgical and medical-surgical mosaic treatment. The choice of treatment and timing is based on the condition.
I. Internal treatment
1.General treatment
1.1 Nutritional supplementation Children with precocious heart disease often suffer from malnutrition and growth retardation, so it is important to pay attention to the ratio of protein, fat and carbohydrate, as well as vitamin and water supplementation, and if necessary, intravenous or nasal feeding is also necessary to supplement nutrition [1].
1.2 Prevention and treatment of infections Children with precardiac disease are prone to bronchitis and pneumonia, especially in left-to-right shunt precardiac disease, so special attention should be paid to the prevention and treatment of infections; children with precardiac disease are also prone to combined infective endocarditis, with ventricular septal defect, tetralogy of Fallot, patent ductus arteriosus, and aortic stenosis, often occurring before and after surgery; in recent years, mitral valve prolapse with regurgitation has been recognized as the pediatric infective In recent years, mitral valve prolapse with regurgitation has been recognized as the underlying disease of pediatric infective endocarditis [1].
1.3 Regular follow-up Some precardiac diseases such as ASD, VSD, and PDA have a chance of spontaneous closure; therefore, regular follow-up can detect the results in a timely manner; in addition, regular follow-up can also assess the prognosis of precardiac disease and determine the timing and modality of treatment.
2.Drug treatment
2.1 Closed PDA The incidence of PDA in preterm infants is 25%, of which 80% can be closed spontaneously. Indomethacin can be applied in combination with infection or heart failure, which is usually effective 24-48 hours after the drug is administered, but the side effects are large [1].
2.2 Open PDA The main application is prostaglandin E, which has the effect of dilating the arterial duct, increasing pulmonary blood and improving hypoxemia, and is suitable for neonates with severe cyanotic preconditioning who rely on open arterial ducts to maintain life.
2.3 Treatment of complications Precardiac disease can cause more complications and should be treated promptly. If heart failure is present, it is treated with digitalis, vasodilators and diuretics; if pulmonary hypertension is present, it is treated with pulmonary vasodilators, sodium hypophysis and oxygen and nitric oxide; if hypoxic attack is present, it is treated with oxygen, drugs to relieve spasm of right ventricular outflow tract, correction of acidosis and anemia, etc.
Transcatheter intervention
1.Transcatheter valvuloplasty
1.1 Percutaneous balloon pulmonary valvuloplasty (PBPV) A specially designed balloon catheter is delivered to the valve stenosis to dilate the balloon, thereby relieving the stenosis. Indications are typical PS; partial dysplastic pulmonary valve stenosis; and restenosis after surgery or PBPV. Trans-pulmonary valve pressure step difference ΔP ≥ 35 mmHg. age and weight are not limited, severe PS should be treated in the neonatal period or infancy; for PS in small infants under 1 year of age, the selected balloon size should be 90-100% of the pulmonary valve annulus; for PS patients over 1 year of age, the selected balloon size can be 120-140% of the pulmonary valve annulus.
1.2 Percutaneous balloon aortic valvuloplasty (PBAV) Indications are non-valvular dysplastic aortic stenosis with a thin and mobile valve whose transvalvular pressure step difference ΔP ≥ 50 mm Hg. The diameter of the selected balloon catheter should be ≤ the diameter of the aortic annulus, and the balloon/annular ratio is 0.9~1.0.
2.Laser/RF perforation
It is mainly used in neonatal cases of pulmonary valve atresia/intact septum, and it is performed by laser catheter or radiofrequency current catheter to excite through the atretic pulmonary valve, followed by balloon valvuloplasty.
3.Transcatheter angioplasty
A specially designed stent device is delivered to the stenosis site under the guidance of a balloon catheter, and the stent is unstented by inflating the balloon. It is mainly used for aortic stenosis, pulmonary artery branch stenosis, left and right outflow tract stenosis after complicated precordial disease, and vena cava pulmonary vein stenosis.
4.Transcatheter occlusion
4.1 PDA occlusion The spring ring or mushroom umbrella occluder is sent through the cardiac catheter to the location of the arterial catheter to close the arterial catheter and achieve the purpose of occlusion treatment. The indications are typical PDA, age >6 months, weight >5kg; residual shunt after PDA surgery; PDA <2mm, choose spring ring; PDA >2mm, choose mushroom umbrella blocker; PDA without pulmonary hypertension, choose blocker larger than PDA 2~3mm; PDA combined with pulmonary hypertension, choose blocker larger than PDA 4~6mm, PDA diameter >8mm. If the diameter of PDA is >8mm, the blocker should be 6~8mm larger than PDA.
4.2 ASD blocking The mushroom umbrella blocker is used to open the blocker disc on the left and right side of the defect through the cardiac catheterization technique, and the defect is closed under echocardiographic surveillance. The indications are typical secondary foramen ASD, age >3 years, weight >10 kg; distance between the edge of the defect and the superior and inferior vena cava, right superior pulmonary vein and coronary sinus ≥5 mm, and distance from the atrioventricular valve ≥7 mm; pediatric patients whose maximum septal extension diameter is ≥diameter of the defect orifice +14 mm; those with foramen ovale unclosed, who have had a stroke, or who have had a combined cerebral embolism, or who have a family history of stroke. Blocker selection: defect <10mm, blocker type +1~2mm; defect in 10~20mm, blocker type +3~4mm; defect in 20~30mm, blocker type +4~6mm; defect >30mm, blocker type +6~8mm.
4.3 VSD occlusion The femoral artery-VSD-femoral vein track is established through cardiac catheterization technique, and the mushroom umbrella blocker is opened on the left and right sides of the defect, and the defect is closed under echocardiographic surveillance. The indications are typical myocardial and perimembranous VSDs, age >3 years and weight >10 kg; defect orifice diameter <8 mm in pediatric patients and <12 mm in adults; distance between the edge of the defect and the aortic valve ≥2 mm and distance from the tricuspid valve ≥2 mm; residual defects after VSD surgery, and ventricular septal perforation due to acute heart attack or trauma. Blocker selection: when the defect is 2-7 mm, the blocker model should be 2-3 mm larger; when the defect is >8 mm, the blocker model should be 4-5 mm larger.
4.4 Other rare precordial occlusion such as coronary arteriovenous fistula, pulmonary arteriovenous fistula, body-pulmonary collateral vessels, etc., can choose spring ring, vascular plug and mushroom umbrella occluder for occlusion.
4.5 Balloon atrial septal stoma A catheter with a balloon at the tip is selected and delivered into the left atrium. The filled balloon is used to tear the atrial septum, causing a larger ASD, so that the blood flow between the left and right heart can be fully mixed to improve hypoxia, prolong life and create conditions for further surgery. It is mainly used for neonatal large vessel transposition/intact septum, total pulmonary vein ectopic drainage/unclosed foramen ovale and left ventricular dysplasia syndrome.
Third, surgical treatment
1.Palliative surgery
1.1 Body-pulmonary artery shunt Artificial vessel is implanted between the subclavian artery and the pulmonary artery. The indications are all children with little pulmonary blood and pulmonary artery dysplasia, including newborns and infants. It mainly increases pulmonary blood flow and improves arterial oxygen saturation.
1.2 Right ventricular outflow tract evacuation The right ventricular outflow tract is evacuated under extracorporeal circulation, and the right ventricular outflow tract to the pulmonary artery is enlarged with a patch. The indications are children with pulmonary valve stenosis, severe hypoplasia of the main pulmonary artery and branches in tetralogy of Fallot, and pulmonary valve atresia with intact ventricular septum. It mainly relieves right ventricular outflow tract obstruction and reduces ventricular burden; the main pulmonary artery and bilateral pulmonary arteries are evenly developed; pulmonary blood flow is easier to control.
1.3 Pulmonary artery girdle annuloplasty Systolic girdle annuloplasty of the main pulmonary artery. The indications are multiple VSD less than 6 months old; VSD combined with malnutrition, severe heart failure or uncontrollable infection; VSD combined with other congenital anomalies that cannot be treated in time; large-vessel transposition with VSD, which can be preceded by pulmonary artery girdle annuloplasty to prevent pulmonary hypertension and increase left ventricular pressure; palliative surgery for left heart dysplasia syndrome. The main purpose is to reduce pulmonary blood, reduce the left heart load and prevent the development of pulmonary vascular obstructive lesions.
1.4 Bidirectional Glenn shunt Anastomosis of the superior vena cava with the end of the right pulmonary artery. The indications are pulmonary ischemic complex precordial disease, tricuspid atresia, single ventricle with PS, large vessel transposition with VSD, PS, and tricuspid inferior malformation. The main objectives are to increase pulmonary blood flow and improve arterial oxygen saturation; to improve hypoxia, reduce cardiac load and increase cardiac excretion; and to homogenize bilateral pulmonary blood.
1.5 Blalock-Hanlon procedure i.e. atrial septotomy enlargement. The indications are complete transposition of the great vessels and tricuspid atresia without adequate body-pulmonary circulation traffic. The main purpose is to increase intra-atrial shunt goodness, improve arterial oxygen saturation, and prepare for radical treatment.
2.Radical surgery
The timing and methods of radical surgery vary for different types of precordial disease, but with the improvement of various techniques in preoperative diagnosis, surgery, extracorporeal circulation and perioperative management, the current tendency is to perform surgical treatment in infancy and at the appropriate time to avoid irreversible damage to the myocardium.
2.1 VSD: defects in the perimembranous and myocardial parts can be closely followed up if the symptoms are mild due to the chance of natural closure, and if closure does not occur by the age of 4 to 5 years, surgical treatment can be considered. Large defects with uncontrollable heart failure or pneumonia occurring within 6 months of age should be operated as early as possible; early surgery is advisable at 6 months to 2 years of age when there is a progressive increase in pulmonary artery pressure although heart failure and pneumonia can be controlled. The sub-stem type defect is prone to aortic valve prolapse, so early surgery is recommended.
2.2 SD: Simple ASD can be treated surgically at the age of 3 to 5 years. 2 years of age can be followed closely if the symptoms are mild because of the chance of natural closure, and if closure does not occur by the age of 5 to 6 years, surgery can be considered. Early surgery is advisable in cases of large defects leading to uncontrollable heart failure or pneumonia, or in those with a tendency to progressive increase in pulmonary artery pressure, or with other cardiac malformations.
2.3 PDA; surgical treatment is possible at any age. Infants with large PDA fractional flow, recurrent heart failure and pneumonia, medical treatment is ineffective or difficult to control, surgical ligation should be performed as early as possible. If and infective endocarditis, surgery should be performed 3-6 months after active and effective anti-inflammatory treatment and infection control, but if anti-infective treatment is difficult to be effective, a combination of surgery and anti-inflammatory treatment is required.
2.4 PS: Surgical treatment can be performed at any age. Mild cases with insignificant symptoms can be followed up and observed. Severe stenosis with a pressure difference between the right ventricle and the pulmonary artery ≥80 mmHg requires early treatment. In cases of valve or annular dysplasia, particularly severe stenosis, or concurrent other cardiac malformations, surgery to relieve stenosis under direct vision is recommended. In severe cases, emergency surgery should be performed.
2.5 Tetralogy of Fallot: Surgical correction is the fundamental treatment for Tetralogy of Fallot. At present, radical surgery is advocated at 6 months to 1 year of age. Early surgical intervention is required if the condition is severe with hypoxic seizures, or palliative surgery can be performed first, followed by elective radical treatment 1 to 2 years later.
2.6 Complete transposition of the great arteries: 50% of children with untreated transposition of the great arteries die within 1 month after birth and 90% die within 1 year. Currently, radical treatment is advocated in the neonatal period or within 3 months of age. Because of the risk of arrhythmias and heart failure in palliative care, most believe that early radical treatment is more reasonable. In cases of intact ventricular septum with transposition of the great arteries, Switch surgery is recommended within 1 month after birth, or intra-atrial transposition surgery is recommended from 6 months to 1 year of age. In cases with VSD, Switch surgery is recommended within 3 to 12 months. However, patients who are not suitable for radical surgery still need to consider palliative surgery first to create conditions for radical surgery.
Medical-surgical mosaic treatment
It is a treatment mode combining interventional therapy and cardiac surgical treatment, which can improve the success rate of surgery for complex precardiac disease, avoid the risk of reoperation and trauma, and improve the long-term postoperative outcome.
1.Pre-surgical interventional treatment
There are mainly percutaneous balloon atrial septal stoma and body-pulmonary collateral vascular occlusion, etc.
2.Intraoperative interventions
To avoid cardiac incision and extracorporeal circulation, a blocker is placed through the right ventricle to block the myocardial VSD under the guidance of transesophageal ultrasound after opening the chest.
3.Post-surgical interventions
Open blocking of the lateral circulation after surgery for complex precordial disease; blocking of residual shunts after VSD, ASD, PDA; balloon dilation and stent implantation for re-stenosis after PS and aortic narrowing.