Persistent truncus arteriosus is characterized by which anatomical feature?

Persistent truncus arteriosus is characterized by which anatomical feature?

• A. Double outlet right ventricle
• B. Single arterial trunk
• C. Normal great arteries
• D. Separate aorta and pulmonary with VSD

Answer: (B)

Persistent truncus arteriosus is defined by a single arterial trunk arising from the heart that gives rise to the systemic, pulmonary, and coronary circulations, instead of the normal separate aorta and pulmonary artery. This trunk often overrides a large ventricular septal defect, so blood from both ventricles mixes in one outflow tract. The underlying embryology involves failure of the truncus arteriosus to septate into distinct aortic and pulmonary channels, frequently due to disturbed neural crest cell migration. Clinically, this leads to increased pulmonary blood flow and potential heart failure early in life, and surgical repair aims to create separate aorta and pulmonary arteries while closing the VSD. Therefore, the defining feature is a single arterial trunk.

Persistent truncus arteriosus is defined by a single arterial trunk arising from the heart that gives rise to the systemic, pulmonary, and coronary circulations, instead of the normal separate aorta and pulmonary artery. This trunk often overrides a large ventricular septal defect, so blood from both ventricles mixes in one outflow tract. The underlying embryology involves failure of the truncus arteriosus to septate into distinct aortic and pulmonary channels, frequently due to disturbed neural crest cell migration. Clinically, this leads to increased pulmonary blood flow and potential heart failure early in life, and surgical repair aims to create separate aorta and pulmonary arteries while closing the VSD. Therefore, the defining feature is a single arterial trunk.