Diaphragmatic subaortic stenosis resection

Congenital diaphragm-type subaortic stenosis refers to an obstruction caused by a localized fibrous or fibromuscular septum under the aortic valve to the left ventricular outflow tract. Such circular fibers or fibromuscular tissue are generally firmly attached to the hypertrophic interventricular septum and to the left, and may be located in any plane between the aortic valve root and the anterior anterior leaflet of the mitral valve. The fibrous ankle adjacent to the aortic valve can adhere to the base of the aortic valve leaflet, but is usually separated from the aortic valve by a few millimeters. Such fiber barriers are typically about 2 to 3 mm thick and are connected to the base of the leaflets in a semilunar or nearly circular shape, with a central opening, or a slit-like opening. In the muscular ventricular septum below the right coronary valve, there are varying degrees of secondary hypertrophy or bulging, which can aggravate the stenosis. The most common cardiac malformation of this type of lesion is ventricular septal defect, and abnormal fibrous or fibromuscular compartments are often located below the interventricular septum. In some cases, it is also possible to merge the right ventricular outflow tract stenosis. In 1956, Brock reported the use of transventricular expansion to treat such primary subvalvular stenosis. In 1960, Spencer et al. further reported that surgery under extracorporeal circulation removed the lesions that caused obstruction and was successful. Treating diseases: heart failure Indication Diaphragm aortic stenosis is suitable for: 1. Infant heart enlargement, heart failure. 2. Frequent dizziness during childhood, A-s hypoxic attack. 3. ECG prompts left ventricular hypertrophy and strain. 4. Cardiac catheterization showed that the pressure gradient of the left ventricular outflow tract was 50 mmHg or more. 5. Two-dimensional echocardiography suggests a combination of other cardiac malformations and a proposed correction. Contraindications Asymptomatic in childhood, left ventricular outflow tract pressure step <50mmHg, normal electrocardiogram, no need for surgery. However, it should be followed up every year. If there is a change in the condition, surgery should be performed in time. Preoperative preparation In addition to general routine procedures for open heart surgery, two-dimensional echocardiography and color Doppler examination should be performed before surgery to understand the pathological anatomy of the aortic valve, the size of the annulus and left ventricle, and whether or not the aortic regurgitation is combined. The extent of this in order to choose the appropriate surgical approach. Attention should be paid to monitoring the circulation, respiration and metabolism of critically ill infants before surgery. In the case of cardiac insufficiency, patients should be treated with diuretic diuresis. If necessary, positive inotropic drugs should be given. Newborn patients with critical illness need emergency treatment. Once the diagnosis is established, the prostaglandin E1 should be administered first through the central vein, the arterial catheter should be opened, and the right-to-left shunt of the transcatheter can be restored, which can reduce pulmonary hypertension and maintain systemic perfusion, so that it can be obtained from systemic low perfusion and acidosis. ease. These infants often need tracheal intubation and mechanical ventilation, and appropriate application of vasoactive drugs such as dopamine can help improve respiratory and circulatory function. Surgical procedure 1. Make a transverse incision under the ascending aorta and extend the lower end to no coronary sinus. 2. Retract the aortic right coronary valve and the non-crown valve, reveal the subvalvular fibrosis, and determine the relationship between the abnormal diaphragm and the surrounding structure, ie, the aortic valve, anterior mitral valve, ventricular septum and His bundle position, and the diaphragm itself. Lesion condition. 3. From the boundary between the right coronary artery and the left coronary valve, the fibrous tendon is clamped with the gums, pulled inward and outward to determine the dead point, and a sharp knife is used to make a mouth from the base of the dead point to the free edge, and then through the above The longitudinal incision was performed in a counterclockwise direction along the free wall of the ventricle to remove the abnormal fibrous septal tissue and directly to the base of the anterior mitral valve. In this part, only the fibrous tendon can be removed, and the mitral-aortic annulus and its connection are retained. 4. Cut the remaining part of the abnormal fiber septum clockwise along the interventricular septum to the membrane section. 5. Aortic subvalvular stenosis often combined with ventricular septal defect, if the ventricular septal defect is large, it is recommended to use the right ventricular outflow tract transverse incision, through the ventricular septal defect exploration and resection of the aortic valve abnormal diaphragm. The two traction wires are sewn on the abnormal diaphragm to help reveal, and then the abnormal diaphragm is completely removed along the bottom of the fiber muscle partition, which is more convenient to operate. complication Common complications after aortic stenosis are arrhythmia, complete atrioventricular block, mitral and aortic valve injury and residual stenosis, which may affect short-term and long-term effects. The incidence of aortic regurgitation caused by subaortic stenosis is about 10%, which is lower and lighter than that caused by aortic stenosis. Incision of the subvalvular stenosis If the mitral valve is often injured, the mitral valve often causes severe regurgitation. A mitral valve replacement is required. The incidence of complete atrioventricular block after aortic stenosis is approximately 2% to 3%, and permanent pacemakers are often required to maintain cardiac function. Most of the above complications occur at an early stage. With the accumulation of cardiovascular surgery experience and technical improvement, there have been few reports recently.