After the first successful treatment of tricuspid atresia with the Fontan procedure was reported by Fontan et al. in 1971, the procedure was widely used to treat a variety of complex precordial diseases with only one functioning ventricle. After several modifications, a series of modified Fontan procedures have been developed, and the indications for the procedure have been gradually expanded and the surgical results have been significantly improved. In 1978, Choussat et al. defined the indications for Fontan surgery as 10 criteria. In 1995, Sharma proposed that the selection criteria for Fontan surgery were: (1) satisfactory pulmonary artery size; (2) repairable local pulmonary artery stenosis with In 1995, Sharma proposed that the selection criteria for the Fontan procedure were (1) satisfactory pulmonary artery size; (2) repairable local pulmonary stenosis with well-developed distal pulmonary arteries; (3) pulmonary artery pressure less than 18 mmHg or less than 20 mmHg in the presence of a left-to-right shunt; (4) satisfactory ventricular function (end-diastolic pressure less than 1.6 kPa or good ventricular function on cardiovascular imaging) without significant ventricular hypertrophy; (5) no left ventricular outflow tract obstruction; and (6) no more than moderate atrioventricular regurgitation. for various complex cardiac malformations that meet the above criteria, such as: tricuspid atresia, single ventricle, transposition of the great arteries, double outlet of the right ventricle, double inlet of the left ventricle, and hypoplastic left heart syndrome. 1. Pulmonary vessel size and pulmonary vascular resistance: In 1986, Mayer et al. considered pulmonary vascular lesions to be particularly important when considering Fontan surgery, and their study also showed that surgery was possible when pulmonary vascular resistance (PARI) was less than 2 U*m2. In 1989, Fontan et al. reported the results of a multivariate factor analysis that the McGoon ratio was less than 1.8 when In 1989, Fontan et al. reported that the risk of Fontan’s operation was significantly increased when the McGoon ratio was less than 1.8, and the early (30 days postoperative) mortality or failure rate could be as high as 55% when performing right atrial pulmonary artery connection; the early mortality or failure rate could be as high as 34% when performing right atrial right ventricular connection. In 1994, Senzaki et al. reported no correlation between PAI and pulmonary vascular resistance (Rp) but a significant correlation with pulmonary vascular compliance (Cp) (r=0.71). Patients with small pulmonary arteries cause poor Fontan surgical outcome, but the authors do not believe that PAI must be greater than 250 mm2/m2. 2. Left ventricular function: In 1985, Mair et al. showed that surgical mortality was significantly increased with left ventricular diastolic pressure >25 mm Hg. Seliem et al. concluded that surgical outcome was poor in those with excessive ventricular muscle hyperplasia. In 1990, Mair et al. proposed a new parameter (ratio of pulmonary vascular resistance plus left ventricular end-diastolic pressure to the sum of body and pulmonary circulation blood flow) as a criterion for patient enrollment, with good results. If this index was less than 4.0 in patients before surgery, their postoperative right atrial pressure would not exceed 2.67 kPa, and their immediate and overall survival rates would be 95% and 89%, respectively. The development of the Fontan surgical procedure 1. Right atrial pulmonary artery connection (APC) Kreutzer: In 1971, Fontan et al. first reported the Fontan surgical procedure with the Glenn procedure, a biological flap sewn into the inferior vena cava and a flap tube to connect the right atrium to the pulmonary artery. In the early 1980s, some scholars improved the Fontan procedure by directly anastomosing the right atrium to the pulmonary artery, which was found to be more effective than the original Fontan procedure and had a higher survival rate after surgery. It is called modified Fontan surgery. In 1978, Bowman et al. reported the use of the right atrium-right ventricular connection (RVCON) in the treatment of tricuspid atresia, and the use of the right ventricle and the addition of the same type of valve tube between the atria and the ventricles produced good postoperative cardiac function, reduced right atrial pressure, and increased left ventricular ejection fraction. In 1989, Ibawi et al. applied animal experiments and clinical studies to show that when the size of the right ventricle is more than 30% of the normal value, the implementation of the right atrioventricular connection can increase the beat volume, reduce the body venous pressure, and increase the left ventricular ejection fraction, and there is a tendency for the right ventricle to grow after the operation. In 1988, de Leval et al. reported a laboratory and clinical study of TCPC, which was considered superior to the classic and other types of modified Fontan procedures and could be used in patients with high-risk factors. In 1996, Vitullo et al. reported nine patients after Fontan surgery who were converted to TCPC because of complications, and after the surgery, all but one patient died due to pseudomonas pneumonia, and the remaining eight patients showed significant improvement in symptoms with good results. In 1996, deLeval et al. reported the application of fluid dynamics to study the competition of blood flow after TCPC. They concluded that after TCPC, the flow of blood from the superior and inferior vena cava into the pulmonary artery caused energy consumption due to the change of geometry and caused unreasonable distribution of pulmonary blood flow. Therefore, the authors improved the procedure: after anastomosis of the distal superior vena cava to the proximal aortic side of the right pulmonary artery, the inferior vena cava was connected to the proximal superior vena cava with an intracardiac baffle, and its opening was enlarged and anastomosed to the proximal hilar side of the right pulmonary artery. To further reduce the postoperative complications of TCPC, especially suture-induced atrial arrhythmias, Laschinger et al. performed a new modification, i.e., a bidirectional superior vena cava-pulmonary artery anastomosis plus an inferior vena cava to the extracardiac conduit of the pulmonary artery, with better near- to mid-term postoperative results and a significant reduction in atrial arrhythmias. 4.Whole cavity pulmonary vein connection with a window in the intra-atrial plate block: Based on TCPC, some scholars proposed to open a window in the intra-atrial plate block with a window size of 4-6 mm (also available to poke 5-6 holes with an 18-gauge needle), which can make the postoperative cardiac index rise, oxygen transport also rise, arterial oxygen saturation mildly drop, mixed venous oxygen saturation not much, and it has good effect on patients with Fontan high-risk The results are good in patients with high risk factors for Fontan. Closure of the open window can be achieved by cardiac catheterization with a sheathed catheter clamp or by self-closing, but the long-term effects of closing the open window remain to be demonstrated. In 1995, Laks et al. performed 18 cases in which the superior vena cava was connected to the left pulmonary artery and the inferior vena cava was connected to the right pulmonary artery to make an adjustable atrial septal defect on the plate barrier of the lateral atrial tunnel with good results. The advantages are: (1) providing mandatory pulmonary blood flow to ensure acceptable arterial oxygen saturation; (2) selectively reducing body venous pressure to reduce fluid leakage while maintaining appropriate cardiac output; and (3) available for patients with risk factors for Fontan. 5. Staged Fontan surgery: For patients with Fontan high-risk factors, staged Fontan surgery is available, which can reduce surgical mortality and complication rates. (1) Bidirectional superior cavopulmonary artery bypass (bidirectional Glenn) surgery: In 1989, Mazzra et al. performed this surgery for 18 patients with risk factors for Fontan surgery without death. It is also believed that after bidirectional Glenn procedure, the left ventricular mechanical function improves due to the reduction of volume load and hypoxia in the ventricle, thus creating favorable conditions for later Fontan surgery. (2) Semi-Fontan procedure: The pathophysiological basis of the semi-Fontan procedure is the same as that of the bidirectional Glenn procedure, except that the surgical approach is different. In 1991, Douville et al. were the first to report 17 hemi-Fontan procedures performed on 16 single ventricle patients with satisfactory results. . Similar results have been reported later. The recent and long-term results of the Fontan procedure have undergone 25 years of development since its introduction. The recent and long-term results of the procedure have improved significantly, and the incidence of postoperative complications has decreased significantly. 1. Recent results of Fontan surgery: In the early years, the mortality rate of Fontan surgery was as high as 17% to 21%. In recent years, due to the application of total cavopulmonary artery connection, bidirectional cavopulmonary artery anastomosis and atrial endplate opening, the mortality rate of Fontan surgery has been significantly reduced to about 5% to 8%. In 1995, Uemura et al. reported 57 patients after Fontan surgery who underwent cardiac catheterization to determine their ventricular function at an average of 15 months after surgery. The results were: poor postoperative cardiac function in those with atrioventricular regurgitation; better ejection fraction in the morphologic left ventricle than in the morphologic right ventricle; better body circulation flow index in patients who underwent TCPC than in those who underwent APC; and better myocardial contractility in those who were younger.Knott-Craig et al. performed an early postoperative mortality or surgical failure in 702 patients after Fontan surgery at the Mayo Clinical Hospital. risk factor analysis. The results of the multivariate analysis were: small patient age, high preoperative pulmonary artery pressure, high postoperative right atrial pressure, early surgery, absence of splenic syndrome, long duration of aortic block and ligation of the pulmonary artery were directly related to early death or surgical failure after surgery. 2. Long-term results of Fontan surgery: In 1987, Girod et al. reported a group of patients after Fontan surgery with a mean follow-up of 8.9 years, and 80% of surviving patients had postoperative cardiac function in grades I to II (NYHA classification). In 1990, Fontan et al. reported the results of 334 patients who underwent Fontan surgery with a follow-up of 1 to 20 years. The survival rates at 1, 5, and 10 years after surgery were: 73%, 69%, and 63%, respectively; cardiac function: 48% of those in class I, 16% in class II, and 2% in class III. In 1992, Driscoll et al. reported the results of 352 patients who underwent Fontan surgery at the Mayo Clinical Hospital, 5 to 15 years after surgery. The survival rates at 1, 5, and 10 years after surgery were 77%, 70%, and 60%, respectively; 103 patients required reoperation; at least 20% of the surviving patients had complications with arrhythmias and required antiarrhythmic drugs or pacemaker implantation, mainly atrial arrhythmias, which may have occurred due to: (1) scarring of the atrial wall at the suture and cannula; (2) elevated right atrial pressure and right atrial dilatation; and (3) sinus node insufficiency. The incidence of hypoproteinemia at 5 and 10 years postoperatively was 10.5% and 14.7%, respectively. The reasons for the development of chronic pleural effusion and hypoproteinemia are not well understood, but may be related to chronic high right atrial and body venous pressures and the resulting gastrointestinal malabsorption and hepatic insufficiency. Cardiac function in surviving patients at 5 years after surgery was better than preoperatively in 122 (34.7%), similar to preoperatively in 58 (16.5%), and worse than preoperatively in 126 (35.8%) or dead. The activity level of surviving patients was similar to that of their peers in 43%, and 3% were unable to engage in physical activity. The cause of PAVF is not well understood, but it is thought to be related to the lack of pulsatile perfusion in the lungs and the absence of hepatic venous inflow.