Anatomic types of ventricular septal defect with aortic insufficiency: Diagnostic and surgical considerations

Abstract

A series of 11 postmortem cases of ventricular septal defect (VSD) with aortic insufficiency (AI) was presented, and an anatomic classification of VSD with AI was proposed. There are two principal anatomic types: VSD beneath the crista supraventricularis (Type I), and VSD beneath the pulmonary valve (Type II). With a subcristal VSD (Type I), there are two subtypes: without pulmonary infundibular stenosis (Type Ia), and with pulmonary infundibular stenosis (Type Ib). Subcristal VSD with AI (Type I) occurred in seven cases. In six of these, the development of AI appeared basically to be related to the underdevelopment of one aortic commissure, usually the right coronary-noncoronary (4:6 cases). A functionally bicuspid aortic valve resulted in five cases. No pulmonary infundibular stenosis (Type Ia) was found in three cases, while four displayed mild to moderate pulmonary infundibular stenosis (Type Ib). The clinical and laboratory picture without pulmonary stenosis was that of AI with a maladie de Roger type of VSD, while the picture with stenosis was that of AI with acyanotic (atypical) tetralogy of Fallot. Subpulmonary VSD with AI (Type II) occurred in four cases. The subpulmonary VSD is a conal septal defect, the conal septal portion of the crista supraventricularis being absent or defective. All four cases had normal aortic commissures. AI resulted from herniation of the right coronary aortic leaflet through the large subpulmonary VSD into the right ventricular outflow tract, resulting in a mild to moderate pulmonary outflow tract gradient in all. Subcristal VSD with AI, with or without pulmonary stenosis, usually was an aortic commissural deficiency problem (in 6:7 cases). Subpulmonary VSD with AI always was a hernia of a basically normal aortic valve into the right ventricular outflow tract (in 4:4 cases). Since the surgical management of the two principal types of VSD with AI is different, their differential diagnosis is of practical clinical importance.