COMMON ARTERIAL TRUNK Nguyễn Thị Thu Trang CK1-K25 Terminology • Common arterial trunk (CAT) • truncus arteriosus • truncus arteriosus communis • aorticopulmonary trunk Introduction Common arterial trunk (CAT) is characterised by a single great artery arising from the base of the heart, which supplies the systemic, coronary, and pulmonary blood fow A large ventricular septal defect (VSD) is almost always present in this anomaly, resulting from the nearly absence of the infun dibular septum It accounts for up to 2% of congenital cardiac anomalies Embryology • CAT results from failure of the truncus swellings, which normally divide the truncus arteriosus into the aorta and pulmonary arteries during embryogenesis, to fuse, resulting in a persistent common trunk CLASSIFICATION CLASSIFICATION: Collett and Edwards CAT is classified into four types by Collett and Edwards, based on the anatomic origin of the pulmonary arteries - Type 1: a short pulmonary trunk arises from the CAT and divides into right and left pulmonary arteries - Types and 3, both pulmonary arteries arise separately, as individual branches, from the CAT and they are either close anatomically (type 2) or at some distance from one another (type 3) -Type 4: the pulmonary arteries arise from the aortic arch or the descending aorta, now reclassified as pulmonary atresia with VSD rather than CAT CLASSIFICATION: Van Praagh • type A1 is similar to type of Collett and Edwards’s classification • type A2 combines types and • type A3: origin of one branch pulmonary artery (usually the right) from the common trunk, with other lung supplied either by collaterals or a pulmonary artery arising from the aortic arch • type A4 refers to abnormalities of the aortic arch, including complete interruption Imaging • The root of the CAT is large and has a biventricular origin in most cases (overrides the septal defect) • The CAT valve has three leafets (tricuspid) in about 69% of cases, four leafets (quadricuspid) in 22% of cases, two leafets (bicuspid) in 9% of cases The valve leafets are thickened (dysplastic) • detecting a malaligned VSD with an overriding large vessel on the five-chamber view • absence of a separate pulmonary artery and valve arising from the right ventricle • Confirming the diagnosis is usually made by identifying the pulmonary trunk (or arteries) arising directly from the overriding large vessel In the five-chamber view • The four-chamber view appears often normal in CAT Associated Anomalies Variations in coronary artery anatomy can add significant complexity and risk to repair and are relatively common Coronary ostia can originate in various positions Anomalous origin of the left coronary artery from the right coronary will cross the RV outflow tract (RVOT) Structural abnormalities of the truncal valve: three cusps, four cusps and two cusps VSD DiGeorge syndrome: Chromosome 22q11 Deletion The aorta and main pulmonary artery share a common trunk, which bestrides a high ventricular septal defect Findings are compatible with truncus arteriosus (Collett & Edwards type I or Van Praagh type A1) Color Doppler • Color Doppler may be helpful but is not necessary for the diagnosis of CAT • demonstration of the shunt across the VSD • dysplastic truncal valve is a common finding in this anomaly, truncal valve regurgitation in diastole is often demonstrated in color Doppler • In CAT types and 3, color Doppler helps to identify the origin and course of the right and left pulmonary arteries. Figure 26.11: Gray scale (A) and color with spectral Doppler (B) of the five-chamber view in a fetus with common arterial trunk (CAT) with dysplastic valves (same fetus as in Fig 26.4). A shows thickening of the valve leafets (arrow). B demonstrates severe holodiastolic valve regurgitation on color (red) and spectral Doppler in diastole. DiGeorge syndrome • characteristic features of Di George syndrome were present: hypocalcaemia, T cell abnormalities, and overt thymic hypoplasia DiGeorge syndrome OUTCOME https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1767971/ Thank you! ...Terminology • Common arterial trunk (CAT) • truncus arteriosus • truncus arteriosus communis • aorticopulmonary trunk Introduction Common arterial trunk (CAT) is characterised... scale (A) and color with spectral Doppler (B) of the five-chamber view in a fetus with common arterial trunk (CAT) with dysplastic valves (same fetus as in Fig 26.4). A shows thickening of the... combines types and • type A3: origin of one branch pulmonary artery (usually the right) from the common trunk, with other lung supplied either by collaterals or a pulmonary artery arising from the