Tricuspid atresia (TA) is a condition in which the tricuspid valve leaflet is completely undeveloped and absent, with no direct communication between the right atrium and the left ventricle. The incidence is 0.039‰-0.1‰ of live births, accounting for about 1.2% of congenital heart disease, and is a relatively rare congenital heart malformation. It is the 3rd most common cyanotic heart malformation, after tetralogy of Fallot and complete transposition of the great arteries. Overview In 1817, Kreysig first clearly described the anatomic features of tricuspid atresia of the heart, namely the lack of direct communication between the right ventricle and the right atrium. in 1861, Schuberg first applied the term tricuspid atresia to describe this malformation. Although several cases were reported in the English literature in the 19th century, it was not until 1917 that Hess formally adopted the term tricuspid atresia in the literature. in 1906, Kuhen reported that the aorta could be normal or transposed in patients with tricuspid atresia. It is generally accepted that under normal development of the embryo, the endocardial cushions fuse to divide the atrioventricular canal evenly between the right and left orifices and participate in the formation of the membranous ventricular septum and closure of the foramen 1 of the atrial septum. During this process, the tricuspid valve develops abnormally, with degeneration of the leaflets, lack of leaflet tissue, and closure of the foramen by fibrous tissue, leading to tricuspid valve atresia. The prognosis for children with tricuspid atresia without postnatal surgery is extremely poor, with clinical manifestations and survival rates related to the anatomic type of tricuspid atresia and the combined malformations, with a 1-year postnatal natural history survival rate of only 10%. In 1945, Blalock and later Potts and Waterston performed body-pulmonary shunts in patients with tricuspid atresia with low pulmonary blood flow to increase pulmonary blood flow and improve cyanosis. Blalock and Halon performed atrial septal defect enlargement in 1950 and Rashkind applied catheter balloon atrial septostomy in 1966, both of which reduced symptoms in critically ill patients. 1959 Glenn first reported the use of superior vena cava with right pulmonary artery shunt, and in 1985 Hopkins et al. created a bidirectional cavopulmonary shunt based on the classic Glenn procedure. In 1971 Fontan placed a homogeneous valved aorta between the right atrium and pulmonary artery and implanted an aortic valve in the inferior vena cava port at the same time as the Glenn procedure. A complete right heart bypass procedure, known as the Fontan procedure, was completed. Later, it was continuously improved by Kreutzer, Bjork and Fontan and became modified Fontan procedure. After more than 20 years of development, the application of extracardiac conduit total cavopulmonary artery bypass was successful. Clinical manifestations 1. Symptoms The length of survival of patients with tricuspid atresia is closely related to pulmonary blood flow. Keith et al. reported that 50% of patients with tricuspid atresia survived to 6 months, 33% survived to 1 year, and only 10% survived to 10 years. Cases with small atrial septal access present clinically with venous congestion in the body circulation, jugular venous anger, hepatomegaly and peripheral-type edema. Due to the low pulmonary blood flow, most cases present with cyanosis from the neonatal period, shortness of breath after exertion, squatting position or hypoxic syncope. pestle-like fingers (toes) are often seen in patients over 2 years of age. In cases of increased pulmonary blood flow, cyanosis is reduced, but there is often shortness of breath and rapid breathing, and pulmonary infection is likely to occur, and congestive heart failure is often present. 2. Signs The systolic blowing murmur produced by pulmonary valve stenosis or ventricular septal defect can often be heard at the left edge of the sternum, and a continuous machine-like murmur can be heard in those with combined ductus arteriosus. A mid-diastolic roller murmur may be heard in cases of increased pulmonary blood flow. There may also be signs of hepatomegaly, edema, jugular venous anger, and pulmonary edema.