The permanent arterial trunk is a rare congenital cardiac malformation with only a single arterial trunk originating from the heart and supplying the coronary, pulmonary, and corporal arterial circulations. The vast majority of cases are combined with VSD and have a single semilunar valve. The conical septum is in fact completely absent, and the single semilunar valve may have 2, 3, 4 or more leaflets. It is very rare to find a case without a combined VSD in which the aortic and pulmonary semilunar valves appear to be formally separated but are actually fused. There are also very rare cases in which the coaptation valve may span completely over the right ventricle; in such patients, the left ventricle and mitral valve may be extremely hypoplastic if not combined with VSD. In TA, developmental variants of the 4th to 6th primitive aortic arch may result in hypoplasia or dissection of the aortic arch. In such cases, a large ductus arteriosus arch is present between the common arterial trunk and the thoracic descending aorta. In contrast, when the aortic arch is well developed, arteriovenous ducts are rarely seen. Anomalies in the origin and distribution of the coronary arteries are more common in patients with TA. As with TOF, coronary variants associated with surgery include a right coronary origin from the left anterior descending branch. Frequently, the left trunk is found to emanate high on the common arterial trunk, which may interfere with surgery due to the close proximity of the left trunk to the pulmonary artery opening, or the narrowing of the opening. Two classic approaches to TA staging have evolved. the Collett and Edwards staging is named based on the location of the origin of the pulmonary artery. In type I, the main pulmonary septum is partially formed and therefore the main pulmonary artery trunk is present. In type II, the left and right pulmonary artery branches originate from the back of the adjacent common arterial trunk. In type III, the openings of the left and right pulmonary artery branches on the common arterial trunk are far apart, on the right and left posterior sides of the common arterial trunk, respectively. Type IV is also included in the Collett and Edward subtype, in which the true pulmonary artery branches are absent and pulmonary blood flow is supplied by main-pulmonary collateral branches (often referred to as “pseudo-truncus”, which is now considered by most not to be a TA, but rather a subtype of PA-VSD). (one of the subtypes of VSD). The other major typing system for TA was developed by Van Praagh. In this typology, type 1 is characterized by the partial presence of the main pulmonary septum and the presence of the main pulmonary artery trunk. type 2 is defined by the absence of the main pulmonary septum and the absence of the main pulmonary artery trunk; the left and right pulmonary artery branches originate from the common arterial trunk, respectively, and both are close to each other without specialization. type 3 refers to the unilateral “absence” of the pulmonary artery emanating from the common arterial trunk, so that In type 4, the aortic arch is hypoplastic or disconnected and a large unclosed ductus arteriosus is present. van Praagh typing also details the presence (type A) and absence (type B) of VSD. Therefore, the diagnostic designation for each TA patient includes a letter and a number. For example, TA with combined aortic arch dissection would be typed as type A4 if combined with VSD. In general, the surgical procedure for TA with fused or nearly fused pulmonary arteries (large aortic coarctation) includes the freeing of the right and left pulmonary branches from the arterial trunk, the association of the pulmonary branches with the right ventricle (this usually requires, but does not always require, some kind of conduit), and the closure of the ventricular septal defect. The surgical procedure for TA combined with aortic arch dissection or narrowing (large pulmonary artery coarctation) includes freeing the right and left pulmonary branches from the trunk, connecting the pulmonary branches to the right ventricle, connecting the descending aorta to the trunk and ascending aorta, and closing the septal defect. Most studies, but not all, have demonstrated that long-term survival is more challenging in the latter patients. Permanent arterial trunk (TA) staging Modified Van Praagh staging – Van Praagh staging – Collett / Edwards staging TA combined with fused or near-fused pulmonary arteries (large aortic type) — Type A1, A2 — Type I, II, III TA combined with loss of one pulmonary artery (large aorta type combined with loss of one pulmonary artery) — Type A3 TA combined with Aortic arch dissection or narrowing (large pulmonary artery type) – Type A4 How to elaborate the definition and guidelines of “significant modification?” The definition and guidelines are very difficult. Co-stem regurgitation is best assessed by echocardiography, and an experienced clinician will always make a tendentious assessment; the same is true for describing the degree of co-stem stenosis, as cardiac catheterization is rarely performed in such patients. Left or right ventricular dysplasia may also be a predisposing diagnosis, thereby influencing the surgeon’s choice of whether to perform biventricular or univentricular repair. The idea that this diagnostic terminology allows patients with slightly smaller but “acceptable” ventricular volumes to be treated equally for biventricular correction may suggest a more comprehensive assessment in the long-term risk assessment. Coronary artery anomalies should be combined in the database regardless of their presence or absence, and TA combined with coronary anomalies can be coded using the standard nomenclature system in Coronary Artery Anomalies and entered into the complex database as an additional or secondary diagnosis under the first diagnosis of TA. “TA with IVS” can be used in all TA patients without VSD. Since the vast majority of patients have a combined VSD, the characteristics of the VSD can be described as an additional or secondary diagnosis using standard nomenclature, just like other VSDs. Although most VSDs are associated with the arterial trunk (type 1 VSD; subarterial; supratentorial; conal septal defect; funnel) in approximately 80% of cases, some VSDs are type 2 VSDs (paramembranous; perimembranous; outflow tract; conal ventricular in approximately 20% of cases. type 2 VSDs may extend into the outflow tract portion of the septum, and this type of type 2 VSD is surgically More care should be taken to avoid causing conduction block during repair. The patient’s size (weight and body surface area) and gestational age are considered potential surgical risk factors. As with other cardiac malformations with multiple pulmonary hemorrhages, preoperative risk factors include congestive heart failure, pulmonary hypertension, dysplasia, multiorgan malfunction, mechanical ventilation dependence, and vasoactive drug dependence. Other possible risk predictor variables include common trunk valve regurgitation and/or stenosis, right or left ventricular dysplasia, aortic arch obstruction or dissection, and DiGeorge syndrome. Intraoperative risk factors, as with other complex cardiac malformations, include the establishment of extracorporeal circulation, the presence or absence of ischemic myocardial arrest, and the presence or absence of deep hypothermic arrest of the circulation.