Ventricular septal defect closure in tetralogy of Fallot: the aortic rule.

Ventricular septal defect (VSD) closure is an important part of the surgical repair of tetralogy of Fallot and related anomalies. Visual appreciation of the VSD size (either transinfundibular or transatrial) can be misleading. My colleagues and I describe a simple and precise way to predict the size and shape of the VSD patch before extracorporeal circulation: the patch should be circular with a diameter identical to that of the mid ascending aorta.