Palliative surgery for tetralogy of Fallot with pulmonary stenosis

The ventricular septal defect of tetralogy of Fallot is located in the membrane of the right ventricular septum. The pulmonary stenosis may be a valve, a right ventricular funnel or a pulmonary artery type, and a right ventricle funnel type. The aortic root is moved to the right and rides over the ventricular septum with defects, so it is directly connected to the left and right ventricles. In 20 to 25% of patients with tetralogy of Fallot, the aortic arch and descending aorta are located on the right side, and the right ventricular wall is obviously hypertrophic. When the pulmonary stenosis is severe and occlusion occurs, the pseudo-arterial trunk is formed forever. Current common palliative procedures have standard or modified subclavian artery and pulmonary shunt, central shunt, and right ventricular outflow tract patch widening. The descending aorta and left pulmonary artery shunt (Potts surgery) and ascending aorta and right pulmonary artery anastomosis (Waterstone surgery) are now clinically deprecated. Treatment of diseases: pulmonary dysplasia, pulmonary stenosis Indication 1. Pulmonary artery small and peripheral pulmonary dysplasia. Patients with a McGoon ratio <1.2 and a pulmonary artery index <150 mm2/m2 may survive postoperatively but have poor hemodynamics and advanced effects. 2. Left ventricular dysplasia, ie left ventricular end-diastolic volume index <30ml/m2. 3. Coronary artery malformation, first palliative shunt, right ventricular pulmonary extracardiac duct after 5 years of age. Contraindications 1. The pulmonary artery is extremely thin and cannot be anastomosed. 2. Have severe liver and kidney dysfunction. Preoperative preparation In addition to preoperative preparation for general quadruple surgery, the following symptoms should be noted: 1. Carefully read the film of cardiovascular angiography. Because of the quadruple disease, there are more cardiovascular malformations, such as the right aortic arch, one side of the pulmonary artery, the aortic branch abnormality and the left superior vena cava. Therefore, the blood vessels that are anastomosed to the pulmonary artery should be selected according to the branching of the brachiocephalic artery of the cardiovascular angiography before surgery. 2. Patients with coronary artery malformation should undergo coronary angiography and decide to undergo primary or staging surgery. 3. Cardiovascular angiography found that bilateral pulmonary artery or peripheral pulmonary dysplasia should be done first. 4. Echocardiography showed left ventricular end-diastolic volume index <30ml/m2, and the left ventricle of the left ventricle was smaller than the right ventricle, and the operation could not be performed. The palliative operation should be used. 5. Prostaglandin E1 is used to prolong the opening time of the arterial catheter. Oral propranolol prevents severe cyanosis. Surgical procedure 1. Standard subclavian artery and pulmonary shunt This type of surgery is also known as the standard Blalock-Taussig operation. It is generally recommended to make a chest incision on the opposite side of the descending aorta. The subclavian artery with the innominate artery is ideally fitted to the pulmonary artery to avoid distortion and angulation of the blood vessel. In the case of the left aortic arch, the right thoracic and posterior incision should be made through the fourth intercostal space into the chest, and the lungs should be pulled forward and downward, and the right subclavian artery should be separated from the mediastinum. The separation extends to the origin of the vertebral artery and the internal mammary artery, and the two vessels are ligated. The non-invasive vascular clamp was used to temporarily clamp the proximal end of the subclavian artery to control bleeding, and was cut at the distal end near the vertebral artery and the internal mammary artery. Lower the subclavian artery and the right pulmonary artery. The clamp and the winding respectively block the proximal and distal branches of the right pulmonary artery, and do all the mouth on the upper edge of the pulmonary artery. The end-to-side anastomosis of the subclavian artery and the right pulmonary artery is performed. The trailing edge is 6-0 or 7-0. The polypropylene thread was sutured continuously and the leading edge was sutured intermittently. If the aortic arch is on the right side, the left chest posterolateral incision is made and the chest is inserted through the fourth intercostal space. The left subclavian artery was anastomosed to the left pulmonary artery. 2. Improved subclavian artery and pulmonary shunt This type of surgery is also known as the modified Blalock-Taussig shunt. 4~6mm diameter PTFE tube is used, the upper end of which is anastomosed to the clamped subclavian artery, and the lower end is anastomosed to the pulmonary artery. This surgical separation is small and is not restricted by the subclavian artery diameter. It is the most widely used one. method. 3. Center shunt This procedure is a shunt of the ascending aorta to the pulmonary trunk. Supine position, chest midline incision, cut happy bag. The expanded polytetrafluoroethylene tube was used in a diameter of 4 to 6 mm, and the ends were cut into slopes, which were respectively anastomosed with the pulmonary trunk and the ascending aorta, and were sutured continuously with a 5-0 to 7-0 polypropylene thread. The result was expanded polytetrafluoroethylene. The vinyl tube is U-shaped on the surface of the heart and on the large blood vessels, allowing the ascending aorta blood to flow forward to the pulmonary artery. In the anastomosis, the pulmonary artery trunk and the ascending aorta should be partially clamped. The hepatic artery should be anastomosed first, then the heparin should be injected into the tube, and then the ascending aorta should be anastomosed. All of them are end-to-side anastomosis. After the aortic anastomosis to the last needle, the open pulmonary artery The row is ligated despite the internal gas. At this time, continuous tremor can be seen on the surface of the pulmonary trunk, and the oxygen saturation of the patient's arteries rises immediately. 4. Right ventricular outflow tract patch In the supine position, the mid-thoracic incision routinely establishes cardiopulmonary bypass. After coronary artery perfusion and blockage of the aorta in cold-blood cardioplegia, the right ventricle-to-pulmonary longitudinal incision is made, part of the hypertrophic funnel muscle is removed, and the pericardium is used as the transvalvular ring. Ventricular outflow tract patch. This procedure is suitable for cases of quadruple disease with small pulmonary arteries on both sides. There is also a widening of the closed right ventricular outflow tract patch without extracorporeal circulation. complication Pulmonary infection: application of antibiotics and nebulization.