Radical surgery for tetralogy

More and more units are now claiming that symptomatic quadruple infants, including newborns (70% of the total number of operations), are treated with primary surgery. Early surgery can prevent long-term cyanosis and hypoxia from causing damage to organs such as heart, lung, kidney and central nervous system, avoiding severe cyanosis and generating cardiac arrest, and preventing postoperative ventricular arrhythmia. The duration of elective surgery is 1 to 2 years old. Infants should be operated under shunt within 3 months. 3-6 months of babies, such as obstruction in the outflow tract and valve, the pulmonary artery development is normal, can be radical surgery; if the annulus and pulmonary artery is too small, it is a shunt surgery. Those who have been born for more than 6 months can be treated with radical surgery. Treatment of diseases: tetralogy of Fallot in children with tetralogy of Fallot Indication Fallot tetralogy Contraindications 1. The left ventricle and pulmonary artery are poorly developed. The palliative operation should be performed first, and the corrective operation should be performed in stages. 2. Patients with refractory heart failure and severe cardiac insufficiency who have failed medical treatment. 3. Those with severe liver and kidney dysfunction. Preoperative preparation 1. Prevent or correct infections in the respiratory tract and other areas. 2. Encourage patients to drink more water to prevent dehydration and blood concentration. 3. Correct coagulopathy. 4. Patients with severe purpura can intermittently give oxygen. Surgical procedure 1. Position, incision: supine position, sternal midline incision. 2. Cut happy packets: If you plan to use the autologous pericardium to widen the right ventricular outflow tract, you should remove the required pericardial tablets in advance before cutting the happy packets. Then expand the pericardium, up to the aorta pericardial reflex, and release the diaphragm. 3. Extracardiac exploration: 1 measure the diameter of the aorta and pulmonary artery; 2 check whether there is left superior vena cava; 3 whether other malformations are combined; 4 measure the size of each compartment. 4. Establish extracorporeal circulation. 5. Cut the right ventricular outflow tract: suture two traction lines, and cut the right ventricular outflow tract longitudinally between the traction lines, showing the hypertrophic ventricles, baffles and wall bundles. Remove the hypertrophic muscles of the septum and wall bundle and other muscle bundles that impede the outflow tract. 6. Relieve pulmonary stenosis: If the annulus is not narrow, the stenotic pulmonary valve can be hooked to the right ventricle with a right angle pliers or a nerve pull hook. The scissors are used to completely cut the three junctions of the fusion; for example, the pulmonary valve When the ring is narrow, the incision of the right ventricular outflow tract should be extended toward the pulmonary artery, and the annulus should be cut at the valve junction until the stenosis is completely relieved. If necessary, the pulmonary artery bifurcation can be reached, even to the left and right pulmonary arteries. 7. Repair of ventricular septal defect: the ventricular septal defect of quadruple disease is generally larger, and the leading edge of the ventricular septum is pulled forward with a small hook to make the defect and its surrounding structure unfolded, especially the posterior lower edge can be clearly seen. Repair with a patch equal to or slightly larger than the diameter of the ventricular septum. The danger zone is sutured with sutured sutures with a support pad, the remainder is sutured continuously, or continuous sutures are used entirely. The danger zone can also be used in continuous squatting, and the rest can be sutured in general. 8. Widening the right ventricular outflow tract: For the stenosis of the outflow tract, simply relying on the removal of the blocked meat column, often can not completely solve the blockage, most need to use the patch to widen the outflow tract. You can use your own pericardium or you can use artificial blood vessels to widen. If the annulus is narrow, the patch should extend beyond the pulmonary valve to the pulmonary artery to the distal end of the stenosis. If the trunk of the pulmonary artery is narrow, and the left and right pulmonary arteries are also narrow, the patch can extend beyond the pulmonary bifurcation or the left and right pulmonary arteries. If you need to enlarge the right pulmonary artery located behind the ascending aorta, you can cut off the ascending aorta, widen the right pulmonary artery, and then repair the ascending aorta. The above sutures can be sutured in two consecutive ways. If there is oozing, the outer membranes on both sides of the anastomosis can be sutured and compressed, and more blood can be stopped. 9. End the extracorporeal circulation and close the chest. complication 1. Low cardiac output syndrome: This syndrome occurs after surgery for quadruple syndrome, about 10% to 20%, which is also the main cause of early death. Low cardiac output syndrome is more common in patients with quadriple syndrome with pulmonary artery and left ventricular dysplasia and end-to-end determination of right ventricular/left ventricular systolic pressure ratio >0.75, as well as inadequate perfusion technique and myocardial protection, intracardiac The repair is imperfect, the hemostasis is not complete and the heart is embossed. In the event of this syndrome, the following measures should be taken: 1 prolong the mechanical assisted breathing time, sometimes up to 2 ~ 3d; 2 increase the blood volume to increase the central venous pressure to 15 ~ 16mmHg; 3 end with the intra-aortic balloon counterpulsation or Left ventricular assisted circulation, continue to apply after returning to the intensive care unit, until hemodynamic stability and arterial oxygen saturation saturation are gradually stopped; 4 by echocardiography confirmed severe right ventricular outflow tract obstruction and a large number of indoor left to right Diversion, should be reoperation; 5 postoperative thoracic and abdominal exudate, mostly due to severe cyanosis patients are particularly sensitive to the damage of cardiopulmonary bypass, increased capillary permeability after surgery, resulting in increased fluid in the thoracic cavity, abdominal cavity and interstitial space (capillary Leakage syndrome). Every effort should be made to reduce the exudation of intravascular plasma into the extravascular tissue space to cause blood concentration. Patients with pleural and abdominal effusions should be puncture and drainage in time; 6 patients with cardiac tamponade should seek to stop bleeding within 6 hours after surgery; 7 apply low-dose dopamine [3 ~ 5g / (kg · min)] and (or Dobutamine and sodium nitroprusside for continuous intravenous infusion; 8 use digitalis and diuretics for one month to treat heart failure. 2. Residual ventricular septal defect: the incidence of residual residual ventricular septal defect after operation was 3% to 5%, mostly due to imperfect repair defects and patch tear. Early symptoms of left heart failure should be repaired as soon as possible to repair residual ventricular septal defect. In the advanced stage, right heart failure occurs. When echocardiography proves that there is obvious left-to-right shunt, the residual ventricular septal defect should be closed selectively. 3. Perfusion of the lung quadruple syndrome after the operation of the perfusion lung is common in a membrane oxygenator using pure oxygen to cause mixed venous oxygen saturation saturation up to 90% ~ 95%, cells almost anaerobic uptake; 2 formaldehyde on the lungs The harmful effects; 3 insufficient blood dilution; 4 side of the pulmonary artery absent, postoperative contralateral lung congestion; 5 premature detachment from the ventilator, due to insufficient muscle tone caused by hypoventilation hypoxia; 6 rich collateral circulation. Precautions are: 1 Use a mixed gas when operating the membrane oxygenator. The mixed venous oxygen saturation is controlled at about 70%; 2 without formaldehyde sterilization, using a variety of disposable extracorporeal circulation, ethylene oxide defibrillator and arteriovenous cannula and special equipment; 3 pairs of serious Patients with polycythemia have bloodletting after diversion, blood dilution to achieve a hematocrit of 25%; 4 patients with one pulmonary artery absent, continue to apply positive end-expiratory pressure for 2 to 3 days after surgery, and then gradually decompress; 5 When preparing to leave the ventilator, if the patient's muscle tension is found to be poor, the assisted breathing time should be extended; if the tube has been removed, the tracheal tube should be inserted quickly and then mechanically assisted breathing; 6 large collateral vessels should be sought before the circulatory flow. And ligation. Once the symptoms of perfusion lungs appear, they should be diagnosed and treated immediately. In the light, the positive end-expiratory positive pressure assisted breathing and hormones were used. In severe cases, repeated intravenous injections of scopolamine or anisodamine were used to stop a large amount of oozing and/or spurting in the lungs. According to clinical observation, the symptoms of oozing blood in the lungs are earlier than those in the chest radiograph. After treatment, the symptoms of oozing blood in the lungs disappear first, and the flaky shadows in the lungs continue for a while, so the flaky shadows in the chest radiographs are completely After disappearing, the pressure can be gradually reduced to normal. To reduce the positive end-expiratory pressure too early or too fast, often leads to recurrent perfusion of the lungs, and should be avoided. 4. Arrhythmia (1) supraventricular tachycardia occurs in the early postoperative period, mostly due to myocardial injury or hypoxia, should improve ventilation and the application of digitalis and potassium chloride drugs, can alleviate and disappear. Late recurrent supraventricular tachycardia, mostly due to severe right ventricular hypertension, requires reoperation to make the right ventricular outflow tract patch widened. (2) ventricular premature beats or ventricular tachycardia are rare in the early postoperative period, and can be cured by intravenous injection of lidocaine. Frequent ventricular premature beats or ventricular tachycardia in the late stages can lead to sudden death. Therefore, after the operation of the quadruple syndrome, the ECG should be reviewed regularly to treat the arrhythmia in time. Because the right ventricular incision scar produces reentry rapid ventricular arrhythmia, electrophysiological examination and epicardial mapping can be used to remove the incision scar. (3) The incidence of postoperative cardiac block is 1.5%. Once a heart block occurs, a permanent pacemaker is used.