The article Treatment Strategies for Ventricular Septal Defects provides a more comprehensive discussion of the treatment strategies for ventricular septal defects from a professional’s perspective and is an important reference for patients and parents. Ventricular septal defect is the most prevalent congenital heart malformation, and how and when it is treated is a matter of lifelong well-being for many patients. The vast majority of ventricular septal defects require surgical treatment, and only myocardial ventricular septal defects can be interventionally occluded. The vast majority of ventricular septal defects can be treated with a small right axillary cosmetic incision.
A ventricular septal defect is a condition in which the ventricular septum is embryologically underdeveloped, forming abnormal traffic and producing a left-to-right shunt at the ventricular level. Ventricular septal defect is the most common type of congenital heart disease. Ventricular septal defects may be present alone or as part of a complex cardiac malformation.
Ventricular septal defects account for approximately 20% of all congenital heart disease and may be present alone or in combination with other malformations. The defects are between 0.1-3 cm, larger in the membranous region and smaller in the muscular region, which is also known as Roger’s disease. If the defect is <0.5 cm, the fractional flow is small and there are no clinical symptoms. In small defects, the right ventricle is predominantly enlarged, while in large defects, the left ventricle is more enlarged than the right ventricle.
Complications of ventricular septal defect
(i) Infective endocarditis
It is rare in infants under 1 year of age, and the highest incidence was seen in a group of patients by Corone et al. between 15 and 29 years of age. Generally speaking, the longer the survival time, the greater the chance of complicating infective endocarditis. According to the literature, the incidence is 25-40%. However, since the widespread use of antibiotics and chemotherapy, the incidence has decreased significantly, from about 5-6% to as low as 2-3.7%. However, its annual patient incidence is still 0.15% to 0.3%.
(B) Aortic valve insufficiency
Nodas reported an incidence of 4.6% and Tatsuno reported 8.2%. There are two reasons for incomplete closure: (1) the defect is located immediately below the aortic annulus and the annulus lacks adequate support. When a high velocity shunt is ejected from left to right, it pulls the aortic valve leaflet downward, first lengthening it and then creating a prolapse, resulting in incomplete closure. If the defect is not repaired in time, the insufficiency of closure will gradually worsen. (ii) Some defect edges thicken, mechanically contract, and even form fibrous bands, pulling the aortic valve and producing closure incompetence.
(C) Conduction block
Secondary fibrosis of the endocardium at the edge of the membranous defect compresses the adjacent conduction bundle, producing complete or incomplete conduction block.
Internal treatment
The main prevention and treatment are infective endocarditis, pulmonary infection and heart failure.
Surgical treatment
Small ventricular septal defects are usually asymptomatic, and the defect shrinks with age, and it is thought that about 25% of them close spontaneously. Large defects present 1 to 2 months after birth with shortness of breath, excessive sweating, slow weight gain, and pallor. The child often has respiratory infections and is prone to pneumonia. A murmur may be heard on auscultation. Diagnosis can be made by cardiac color Doppler ultrasonography.
(A) Indications for surgery, which can be summarized as follows
1.No need for surgery Small defects without symptoms or progressive closed defects with gradual reduction of symptoms are not operated for the time being and are observed.
2, elective surgery The size of the defect, from small to medium, with mild symptoms, no pulmonary hypertension, and pulmonary blood flow: body blood flow at about 2:1. In the follow-up, the heart murmur, electrocardiogram and chest X-ray changes are not significant, you can wait until school age to perform surgery; if during the observation period, the pulmonary artery pressure increases, the heart murmur becomes shorter, and the diastolic murmur in the apical region becomes low or disappears, the surgery should be performed earlier.
3, early surgery in large ventricular septal defect infants and children, heavy symptoms, pulmonary vascular endothelial cell proliferation, structural changes and pulmonary vascular growth obstruction, such as surgery within 8 months to repair the ventricular septal defect, one year after surgery pulmonary vascular changes can be restored, and there are new blood vessels growing. In infants and children who underwent surgery at 9 months of age or later, there was a persistent increase in pulmonary vascular resistance after surgery, suggesting that the hypertrophy and peripheral extension of the pulmonary vascular muscle layer and intimal hyperplasia did not completely degenerate and that there was a limit to the growth of new vessels.
However, some authors have suggested that persistent postoperative increases in pulmonary vascular resistance only occur in children who have undergone surgery after 2 years of age.
Kirklin et al. concluded that even very severe pulmonary hypertension returned to normal or near normal when surgery was performed within 2 years of age, whereas 50% of those operated on above 2 years of age had persistent pulmonary hypertension. In contrast, this was not the case in those operated on within 2 years of age.
Therefore, surgery within 2 years of age can prevent obstructive pulmonary vascular disease. Close observation and repeat cardiac catheterization are needed to control the timing. However, the younger the age, the higher the operative mortality rate. In case of elective surgery, it is generally not done in 3-month-old infants, and the ventricular septal defect is left to close or shrink on its own.
4, emergency surgery large ventricular septal defect of newborn or infant, fractional flow, complicated by life-threatening intractable heart failure and pulmonary insufficiency, positive medical therapy is ineffective, should create conditions for surgery, even within 3 months of birth. Pulmonary artery annuloplasty can be considered to save lives. This procedure is now less frequently performed and tends to be performed more often for repair, but technically one should be prepared to repair other combined malformations at the same time.
According to Kirklin, there are only two types of large septal defects that require pulmonary artery annuloplasty: multiple septal defects scattered in the septal bundle or anterior part of the septum, along with septal defects; the other is a large septal defect, similar to the atrial canal type, in which the tricuspid tendon straddles the septum, the tricuspid annulus rides over both ventricles, and the tricuspid tendon may be attached to the left side of the septum. The right ventricle is often underdeveloped.
(B) Contraindications to surgery
(1) Cyanosis in the medical history, especially at rest, with a reverse shunt, mainly from right to left;
(ii) On physical examination, no tremor can be detected in the precordial region and the systolic murmur is short and soft;
③ Radiographic chest radiograph shows a more prominent pulmonary artery segment, but the lung is not congested; the left ventricle is not large or close to normal;
④Electrocardiogram shows that the electrical axis becomes right-skewed, and the right precordial leads are typical right ventricular hypertrophy with large R waves with tangents, while the Q waves in the left precordial leads disappear, the R wave voltage is lower than normal, and the S waves are deep;
⑤ Right heart catheterization, confirmed that the shunt is right-to-left and pulmonary vascular resistance is greater than 10wood/m2.
The above cases should not be operated, otherwise the patient may not pass the operation, and the life expectancy after the operation is shorter than those who do not do the operation.
Surgical methods.
1.Ventricular septal defect repair.
2. Interventional blocking treatment is limited to myocardial ventricular septal defects.
Surgical incision.
(1)Conventional incision
1 median sternal incision, skin incision is located in the middle of the anterior chest, about 20-25cm long, and split the sternum completely, easy to have postoperative liquefaction or infection of the incision, poor wound healing, easy to leave knife scars and deformities such as chicken chest.
(2)Small incision
Minimally invasive small incision means that the incision length of the surgical approach is 6~10cm, and the incision is located in a relatively concealed part of the chest.