Two types of ventricular septal defect in corrected transposition of the great arteries: Reference to surgical approaches

Abstract

Six autopsied cases of corrected transposition of the great arteries with VSD were examined from the surgical exposure. Two anatomic types concerning the relative height of the two semilunar valves and the position of the VSD were recognized. In four cases (Type I), the two semilunar valves are at the same height viewed from the anteroposterior direction, the parietal band is hypoplastic, and the VSD is located immediately below the aortic and pulmonary valves. In the other two cases (Type II), the aortic valvular level is higher than the pulmonary valvular level and the parietal band in these cases is well-developed. The VSD located beneath the pulmonary valve is clearly separated from the aortic valve by a well-developed parietal band. The first type has an excellent exposure viewed from the left-sided ventricle, while the second has an extremely poor exposure. Therefore, right-sided ventriculotomy is recommended in the latter type. Furthermore, these two anatomic types can be recognized and differentiated in angiocardiographic findings by the relative height of the two semilunar valves and the presence of a filling defect formed by the crista supraventricularis.