Intracardiac Repair of Intermediate Atrioventricular Canal by Nunn's Technique: A Video Presentation

The atrioventricular septal defects encompass a spectrum of lesions in which the common etiology appears to be abnormal development of the superior and inferior endocardial cushions, resulting in a deficiency or absence of the atrioventricular septum [1-6]. This deficiency of the atrioventricular septum results in an ostium primum defect immediately above the atrioventricular valves and a scooped-out area in the inlet (basal) portion of the ventricular septum. Data from the New England Regional Infant Cardiac Program and the Baltimore-Washington infant study defined a prevalence of 0.118 and 0.352 per 1000 live births [7,8]. Approximately, 50-75% of these patients have trisomy 21 [7-9]. When viewed from a reverse perspective, approximately 35-40% of patients with Down’s syndrome have an atrioventricular septal defect [7-9]. Atrioventricular septal defects include a spectrum of malformations. At one end of the spectrum is the partial atrioventricular septal defect characterized by an interatrial communication, but no interventricular communication and a connection of variable width between the left superior and left inferior leaflets. At the other end is the most extreme form with large deficiencies in the atrial and ventricular septa, and a common atrioventricular valvular orifice, known as complete atrioventricular septal defect [1-6].