maze surgery

Atrial fibrillation is defined as complete loss of coordinated atrial contraction. The characteristic of atrial fibrillation ECG is that there is no constant P wave in the QRS complex wavefront, but a fast-oscilating "f" wave substitution of size, shape and time, often accompanied by irregular ventricular rate. Atrial fibrillation is the most common arrhythmia, with an incidence of 0.4% to 2.0% in the general population. The incidence rate increases with age, and 5% to 10% for those over 60 years old. The incidence of atrial fibrillation is significantly higher in people with organic heart disease, with 30% of primary cardiomyopathy and up to 60% in patients requiring mitral valve surgery. Atrial fibrillation can also be associated with atrial septal defect and Ebstein cardiac malformation in congenital heart disease. The incidence is >40% in patients aged 25 to 40 years old and greater than 60% in patients over 60 years old. In 1980, Scheinman applied atrioventricular catheter ablation for atrial fibrillation and a pacemaker was installed after surgery. In 1980, Williams and Cox proposed and applied left atrial isolation for atrial fibrillation. The principle of operation was to isolate atrial fibrillation in the left atrium, part of the heart was sinus rhythm, and the right atrium and ventricle coordinated contraction and relaxation, increasing cardiac output, but There is still vibration in the left atrium that can cause thromboembolism. Then in 1985, Guirandon applied the corridor procedure, which was based on the principle of creating a myocardial tissue channel containing the sinus node and the atrioventricular node, and was isolated from the right and left atrial myocardial tissue, so that atrial fibrillation did not affect the conduction of sinus rhythm. And keep the physiological ventricle driven. However, corridor surgery loses the atrial and ventricular synchronous agitation and atrial transmission function, which can not restore normal hemodynamics, and there is a risk of thromboembolism. Since Cox reported that type I maze surgery in 1991 for atrial fibrillation, surgical treatment of atrial fibrillation has progressed greatly, with surgical procedures ranging from type I and type II to type III, as well as current proposed and initiated radiological incision surgery ( Radial incision approach): The treatment ranged from solitary atrial fibrillation to chronic atrial fibrillation secondary to organic heart disease. In 1996, Harada and Sueda found that atrial fibrillation caused by simple mitral valve disease originated in the left atrium, and the application of left maze surgery was proposed. In patients with congenital heart disease such as adult atrial septal defect and Ebstein cardiac malformation with chronic atrial fibrillation, atrial fibrillation originates from the right atrium, and the right maze surgery and the above-mentioned congenital heart malformation are repaired to obtain a satisfactory therapeutic effect. Atrial fibrillation is clinically divided into paroxysmal atrial fibrillation, persistent atrial fibrillation, and permanent atrial fibrillation. Paroxysmal atrial fibrillation, also known as temporary atrial fibrillation, mostly for acute episodes lasting for a few seconds to several days, can automatically restore sinus rhythm, the disease is due to heavy drinking, acute myocardial infarction, acute pulmonary embolism, acute pericarditis. Paroxysmal atrial fibrillation can also be a complication of heart and thoracic surgery. Persistent atrial fibrillation does not interfere with atrial fibrillation and does not automatically switch to sinus rhythm, which can form chronic atrial fibrillation. Permanent atrial fibrillation is chronic atrial fibrillation. The application of drugs or electric shock defibrillation can not be cardioversion. This atrial fibrillation is a lifetime atrial fibrillation. Isolated atrial fibrillation refers to atrial fibrillation without any cause, including no structural heart disease, hyperthyroidism, chronic obstructive pulmonary disease, sinus node dysfunction, and pre-excitation syndrome. Atrial fibrillation can also be associated with various arrhythmias such as atrioventricular reentry tachycardia, atrioventricular junction reentry tachycardia, and autonomous or reentry atrial tachycardia. In some cases, atrial fibrillation is triggered by the arrhythmia mentioned above. If the reentry tachycardia is cured at the side or atrioventricular junction, the atrial fibrillation disappears. The study of the mechanism of atrial fibrillation has lasted for more than 40 years. It is divided into two theories. One is the acceleration of one or more ectopic excitatory episodes, and the other is multiple wavelet reentry rings. An experimental model of atrial fibrillation induced by aconitine and atrial fibrillation induced by aconitine, which supports atrial fibrillation. Recently, at least one specific case has been found, and rapid activation of the excitatory foci can produce atrial fibrillation, and the atrial fibrillation is cured after radiofrequency ablation of the lesion. Recent studies support multiple reentry wavelets such as Moe, suggesting that atrial fibrillation may contain multiple numbers of foldback loops. Allessie believes that there are 5 or more wavelets in the atria, and atrial fibrillation occurs. The more the wavelets, the finer the atrial fibrillation, and the less the number of wavelets, the thicker the atrial fibrillation. The larger the atrial area, the more the number of wavelets can be accommodated. Therefore, the large atrium is mostly atrial fibrillation, and the atrial area is so small that it cannot accommodate 5 wavelet reentry rings, and it can not produce atrial fibrillation. Atrial fibrillation has three physiological hazards: 1 abnormally irregular heartbeat, its rapid heart rate is difficult to control, and the patient has discomfort and anxiety. 2 Loss of coordinated atrioventricular conduction function can reduce the stroke volume by 20%; sustained tachycardia can cause ultrastructural changes in cardiac insufficiency, which can affect cardiac contraction and hemodynamics and produce different degrees of heart failure. 3 Atrial stagnation of blood flow increases the complications of thromboembolism. Treating diseases: atrial fibrillation Indication 1. Persistent or paroxysmal atrial fibrillation is ineffective by medical treatment, including medications that control heart rate and are unable to tolerate arrhythmia symptoms or are unable to tolerate the required medication. 2. Chronic atrial fibrillation or paroxysmal atrial fibrillation patients have at least 1 history of thromboembolism. 3. Atrial fibrillation combined with other heart diseases, such as rheumatic mitral valve disease, coronary artery stenosis, congenital heart disease atrial septal defect or Ebstein cardiac malformation, etc., need to perform intracardiac repair, valve replacement, coronary artery bypass graft surgery Or corrective surgery. The main purpose of mammary surgery for patients with chronic atrial fibrillation complicated with mitral valve disease is to improve the quality of life and labor intensity of patients, so the surgical indications should be strictly controlled: 1 age <60 years old. 2 The history of atrial fibrillation is more than one year. 3 There are serious symptoms and drug treatment is invalid. 4 has a history of thromboembolism. 5 left atrial capacity <300ml. 6 left ventricular function is normal or near normal. Contraindications 1. There is obvious left ventricular dysfunction, not caused by arrhythmia itself. 2. Combined with heart disease or other diseases, the operation endangers the patient's life. 3. Combined with severe hypertrophic cardiomyopathy, the risk is extremely high due to the simultaneous operation of the two procedures. Preoperative preparation In addition to the general routine preparation for cardiopulmonary bypass surgery, the following points are also noted. 1. Echocardiography confirmed the presence or absence of congenital heart malformation or acquired valvular heart disease, measuring the size of the left atrium, with or without atrial thrombosis, especially the left ventricular function indicators in good condition. In patients with coronary artery disease and stenosis, selective coronary angiography and left ventricular angiography should be performed before surgery. 2. Strengthen medical treatment, preoperative application of digitalis and diuretics and energy mixture to improve systemic and cardiac function. 3. The researcher who performed the mechanism of atrial fibrillation, preoperative preparation of the two-atrial epicardial mapping instrument and the detection electrode network. Surgical procedure Maze type III surgery The design principle of labyrinth surgery: Although the Cox epicardial mapping system limits the understanding of the mechanism of atrial fibrillation at that time, it is found that the reentry excitatory pattern and the location change are endless, and it is fleeting and cannot be based on the results of the mapping. Guide the surgery. Therefore, it is proposed that the distance between the surgical incisions of the maze surgery must be smaller than the wavelength of the large reentrant ring, so that it cannot form a foldback in the void region between the incisions, which is the only effective method for preventing the formation of the atrial fibrillation reentry ring. In addition, surgery should also preserve sinus agitation and atrial synchronous transmission, in order to eliminate the risk of thromboembolism. Labyrinth III surgery has been improved on the basis of maze type I and type II: 1 no mammal type I right atrial top incision to avoid damage to the sinus node and its arteries and right atrial sinus impulse. 2 Make a cup-shaped incision around the 4 pulmonary vein openings to minimize the extent of the labyrinth of type I and type II isolation, thus maintaining the function of the left atrium. The midline of the chest is incision, the sternum is opened in the longitudinal direction, the thymus is free, and the happy bag is suspended. The aortic adventitia free aorta was dissected between the aorta and the pulmonary artery and a band was placed. After the aortic band was pulled to the left side, the pericardium of the superior vena cava and the right pulmonary artery were resected, and the pericardium of the superior vena cava and the right pulmonary artery were resected, and the proximal end of the superior vena cava was separated by 2 to 3 cm. Set of belts. In the inferior vena cava, the suture was suspended with a 10-0 thick line and sutured to the chest incision, so that the inferior vena cava was lifted. Separate the pericardial reflexes and mediastinal tissue around the inferior vena cava until the lower part of the right atrium is covered with a band. The aorta and superior vena cava were pulled to the sides respectively, and the pericardium was resected between the right pulmonary artery and the posterior wall of the left atrium, and the top of the left atrium was released. The oblique sinus pericardium is folded back between the pulmonary veins on both sides. The above separation facilitates the exposure, incision and suture of the left atrium. After systemic heparinization, the aortic perfusion tube was inserted close to the innominate artery, and the angled catheter was directly inserted into the superior vena cava at 2 cm on the right atrium, and the inferior vena cava tube with right angle was inserted in front of the lower atrium of the inferior vena cava. Insert the left heart decompression tube into the superior vein. Cut the entire length of the chamber and separate 1 cm from the inside. After the cardiac arrest, the left atrium, the atrial septum and the left atrium were divided into three parts. (1) Right atrial incision: 5 incisions were made in the right atrium and two were frozen near the tricuspid annulus. 1 The right atrial appendage was excised 2 cm distal to the distal end of the centrifuged ear and the right inner blood was aspirated. 2 Make a oblique incision from the right atrial incision to the lateral wall of the right atrium, 2 to 3 cm long. 3Retract the incision and expose the final sputum. Use a long curved forceps to push the right atrium wall to the outside 1 cm after the final sac, and make a 2 cm longitudinal incision on the outside, from which the incision parallels the upper and lower parts to the upper cavity and Proximal vena cava proximal end. Under the condition that the superior and inferior vena cava are completely free, it is easier to make this longitudinal incision, and it can protect the sinus node and its artery. 4 A transverse incision was made in the 2 cm vertical right atrial longitudinal incision above the inferior vena cava cannula to the outside of the right interventricular septum. The longitudinal incision in the lower part of the incision was sutured to prevent tearing of the incision and extension of the incision into the inferior vena cava. Traction of the upper part of the right atrial longitudinal incision, showing a right atrial transverse incision to the tricuspid annulus still 2 to 3 cm distance. To attract the blood of the coronary sinus, cut the endometrium and muscle from the inside of the incision to the tricuspid annulus. At this time, it must be confirmed that the incision has no myocardial fibers, and the fat pad is cut and separated, and the right coronary artery is prevented from being damaged. Freeze at adjacent tricuspid annulus (-60 ° C, 2 min). After washing with warm saline, a 5-0 polypropylene thread was sutured from the medial side of the tricuspid annulus to the right atrial transverse incision adjacent to the interventricular septum. 5 The right atrial anterior incision was made to the opposite side of the right interventricular septum to the opposite side of the initial part of the oblique incision of the right atrial appendage. Retracting the right atrial longitudinal incision, the right atrial anterior incision is approximately 3 cm from the tricuspid annulus. Cut the inner membrane and atrial muscles from the inside of the atrium to expose the fat pad to the tricuspid annulus, and be careful not to injure the right coronary artery. The right atrial anterior incision adjacent to the tricuspid annulus was frozen (-60 ° C, 2 min), washed with warm saline, and the anterior incision was sutured from the inside of the atrium and the posterolateral side with a 5-0 polypropylene thread. At this point, the right atrial anterior incision is sutured. (2) The atrial septal incision and the left atrial incision have a downward oblique incision in the interatrial septum, with 4 incisions in the left atrium and 2 frozen in the left atrium. 1 The left atrium longitudinal incision is made through the chamber ditch. 2 Traction of the right atrium longitudinal incision can be seen in the fossa ovalis and atrial septum. The oval fossa is obliquely cut from the left atrial incision of the atrial septum until the upper edge of the Tadaro ligament, and the adjacent left and right atrial stumps are cut. 3 retraction of the interatrial septum, can reveal the left pulmonary vein opening, mitral valve and its annulus. From the left atrial longitudinal incision of the left ventricle, the left and left pulmonary veins were opened around the 4 open edges of the right atrium, and the posterior wall of the left atrium was cut into a circular incision. The left upper and lower veins were not cut at the edge of the opening, leaving 1 cm of atrial tissue. To prevent misalignment of the incision during suturing, it is advantageous to suture the edge of the incision. 4 Cut the inverted left atrial appendage from the root. The left atrial appendage incision and a circular incision surrounding the bilateral pulmonary vein openings were frozen at the junction of the left upper and lower venous opening edges (-60 ° C, 2 min). The left atrial appendage root incision was sutured with a 4-0 polypropylene thread. 5 The incision between the bilateral inferior pulmonary vein openings is perpendicular to the posterior mitral valve annulus to the left atrial left lower longitudinal incision, the endometrium is cut, the coronary vein is isolated, the atrial muscle is separated and cut, and the coronary sinus is not injured. Left circumflex coronary artery. The former can be repaired, and the latter can be cut to produce a myocardial infarction. The 3 mm cryoprobe was used to freeze the coronary vein (-60 ° C, 3 min). Note that freezing should penetrate the coronary vein to prevent a small amount of myocardial fibers from being left around to cause recurrence of atrial fibrillation. A metal clip is placed in the freezer. If the postoperative atrial fibrillation recurs, the radiofrequency ablation can be performed here. The incision is sutured with a 4-0 polypropylene thread. At this point, mitral valve repair or replacement and/or aortic valve replacement can be performed. The left heart decompression tube can be pulled back from the left superior vein to the left ventricle. A 3-0 polypropylene thread was used to suture up and down from the left inferior and inferior venous incision edge incision, and the edge incision around the left superior pulmonary vein and the left lower pulmonary vein opening was sutured continuously to the right superior venous opening edge and Through the vertical mitral annulus, the left atrial left lower longitudinal incision end and the right lower pulmonary vein opening edge. The 4-0 polypropylene suture was used to suture the interatrial incision and continue to suture the marginal incision surrounding the bilateral pulmonary vein openings. The right atrium stump incision and the left atrial longitudinal incision at the sulcus were sutured. A transverse incision in the lower right atrium was sutured with a 4-0 polypropylene thread. The upper part of the right atrial longitudinal incision was sutured and sutured to the lower part of the atrial longitudinal incision. Finally, sutures of the right atrial oblique incision and the right atrial appendage incision were performed. The maze type III surgical incision was completed. The anterograde and retrograde warm blood perfusion and drainage of the gas in the heart chamber open the aorta. Rewarming and cardiac repulsation, assisted extracorporeal circulation time is about 1/3 or 1/2 of the aortic occlusion time. After the myocardial contraction is strong and the blood pressure is stable, the cardiac pacing lead is placed, and the heart rate is slow for heart pacing. Gradually stop the extracorporeal circulation. 2. Right side maze surgery This procedure is suitable for adult Ebstein cardiac malformation, congenital tricuspid regurgitation and atrial septal defect with chronic atrial fibrillation. The surgical outcome is satisfactory. Extracorporeal circulation in the systemic low temperature (25 ~ 26 ° C). Application of cold blood cardioplegic intermittent coronary artery perfusion and around the heart with ice mud to protect the heart muscle. The midline of the chest is incision, the thymus is separated, and the happy bag is suspended. Separate the upper and lower vena cava sets. The aortic perfusion tube was inserted from the innominate artery, and the right angle tube was directly inserted into the superior and inferior vena cava tubes, and the left heart decompression tube was inserted through the right superior pulmonary vein. Five labyrinths of the right atrium of the labyrinth III and two frozen, and atrial septal oblique incision, and then the repair of atrial septal defect or Ebstein cardiac malformation of the ventricular ventricular folding or tricuspid valve replacement, suture right atrial incision Discharge the gas inside the heart and open the aorta. 3. Left maze surgery In 1995, Harada and Sueda used two-atrial epicardial mapping in patients with atrial fibrillation complicated with mitral valve disease to find regular and recurrent reentry agonism in the left atrium and the shortest perimeter region in the left atrial appendage and left pulmonary vein. It is believed that the majority of atrial fibrillation in the above patients originated from the left atrium, and the left maze surgery was proposed. Anesthesia, postural, extracorporeal circulation and myocardial protection were the same as maze type III surgery. Do the left atrial longitudinal incision in the sulcus, as well as the oblique incision of the fossa ovalis and the circular incision around the edge of the pulmonary vein opening, resection of the left atrial appendage and left atrial left lower longitudinal incision, and mitral valve repair and replacement and labyrinth III incision The 4 incisions in the left atrium and the 2 incisions were the same, and the left atrium and the interatrial incision were sutured later. See Labyrinth III surgery for details. Simultaneous mitral valve repair or replacement. In 1995 and 1997, Sueda reported the results of a modified left maze procedure. The surgical method did not perform a left lower longitudinal incision to perform multiple freezing in the area. 4. Radioactive incision surgery Design Principle: In 1999, Nitta reported that in order to avoid the use of maze surgery, four open circular incisions around the pulmonary vein and the left atrial posterior wall isolation zone affect left atrial activation sequence and systolic function, according to sinus rhythm atrial activation sequence and atrial coronary artery The distributed design of the radiological incision surgery achieves a more atrial agitation than the labyrinth III type surgery and maintains the atrial circulation function of the atrium as the atrium and its peripheral atrioventricular annulus. The small circle is the sinus node and the dark area is the left atrial isolation zone. The arrow indicates the excitatory front from the sinus node to the annulus. Note that radiation incision surgery retains a more physiological atrial activation sequence and most of the atrial blood supply, while maze surgery does not significantly match the atrial activation sequence and destroys part of the atrial coronary artery anesthesia, endotracheal intubation to maintain breathing, supine position. Extracorporeal circulation and myocardial protection, chest median incision, aortic and vena cava intubation, and left ventricular decompression through the right superior venous catheter were the same as maze type III surgery. Radiological incision surgery is simpler than maze type III surgery. The main difference is that the former does not remove the right atrial appendage and discards a circular incision around the four openings of the pulmonary vein. Specific surgical practices: (1) There are 4 incisions in the right atrium and 2 frozen. Right atrial oblique incision and anterior incision were made from the right atrial appendage. The right atrial longitudinal incision and transverse incision were performed as in the labyrinth III type, and frozen in the right atrial anterior incision and transverse incision near the tricuspid annulus (-60 ° C, 2min). (2) The interatrial septum incision is to cut the fossa ovalis from the lower end of the longitudinal incision of the left atrium of the chamber. (3) The difference between the left atrial incision and the maze type III is 4 incisions and more frozen parts. A left atrial longitudinal incision was made in the chamber ditch, and the interatrial septal incision was made to reveal the left atrial appendage and the pulmonary veins with four openings and the mitral valve and its annulus. At the lower end of the left atrial longitudinal incision, the posterior wall of the left atrium was cut along the margin of the right lower pulmonary vein around the left subpulmonary vein until the mitral annulus of the mitral valve was frozen (-60 ° C, 2 min). Remove the left atrial appendage. The top of the left atrium was cut from the upper part of the superior venous opening on both sides until the middle of the lower part of the auricle incision. A 3 mm probe was frozen at the periphery of the pulmonary vein opening, and a 1.5 mm probe was used between the upper and lower pulmonary vein openings (-60 ° C, 2 min). The left atrial appendage was sutured and the left atrium top and bottom incisions were sutured, respectively. Suture the interatrial septum incision. Finally, the right atrial longitudinal incision, transverse incision, anterior incision and oblique incision were sutured in turn. Discharge the gas in the heart chamber and open the aorta. The extracorporeal circulation assisted circulation time is about 1/2 or 1/3 of the aortic occlusion time. When the heart beats vigorously, the nasopharynx temperature is 37 °C, the anus temperature is 35 °C, and the extracorporeal circulation is stopped. complication 1. Bleeding: fine suturing during surgery and strict hemostasis after surgery are the main measures to prevent postoperative bleeding. If there is more postoperative bleeding, it should be immediately sent back to the operating room to open the chest to stop bleeding. When there is bleeding in the posterior wall of the left atrium. The extracorporeal circulation should be applied again, the heart suture should be gently turned over to stop bleeding, and calcium and hemostatic drugs should be added. In a very small number of cases, there is still a small amount of oozing after hemostasis. The left atrium posterior wall incision can be pressed with a sterile long gauze strip. After 3 to 4 days after surgery, a piece of gauze left from the wound is slowly rotated out. This is a measure that must be carried out, but the effect is very significant. 2. Arrhythmia: Postoperative general bradycardia requires a pacemaker. However, there are also 1/5 to 1/3 of atrial rhythm, atrial flutter or atrial fibrillation, which is due to the shortening of the refractory period, and a small reentry loop between the labyrinth of the maze type III surgery. This arrhythmia often disappears with the application of prolonged refractory antiarrhythmic drugs. Most patients use procainamide or diisopropylpyramine in the first 3 months after surgery until atrial flutter or tremor disappear. 3. Low cardiac output syndrome: generally, the cardiac output decreased slightly after surgery, and returned to normal on the 5th to 7th day after surgery. However, patients with mitral and aortic valve surgery may have a relatively high cardiac output syndrome. In addition to drugs that strengthen the strength of myocardial contraction, it is sometimes necessary to add intra-aortic balloon counterpulsation. 4. Sick sinus syndrome: In the past, the incidence of postoperative sick sinus syndrome was higher. Some patients had sick sinus syndrome before surgery. Recently, surgical methods have been improved to prevent damage to the sinus node and its arteries and to prevent the occurrence of this syndrome. Patients with sick sinus syndrome were treated with atrial and ventricular sequential pacing. 5. Complete heart block: Although the incidence of this complication is low, there are very few patients with complete heart block after surgery. A permanent pacemaker is placed in this case. 6. Postoperative pleural effusion, a small number of patients with postoperative delayed pericardial tamponade. Immediate detection of closed chest drainage or pericardial puncture and pericardial drainage should be performed immediately. 7. Simultaneous mitral and/or aortic valve replacement may cause thromboembolic complications after surgery. Intermittent time of prothrombin should be checked intermittently, and warfarin dose should be adjusted in time.