Abstract
Total cardiopulmonary by-pass by means of the pump-oxygenator is now a safe, reliable technic and allows surgical correction of many intracardiac lesions. Direct-vision surgical procedures are carried out at normal body temperature, with optimal function of the heart and body. Ventricular septal defect and tetralogy of Fallot are the most commonly encountered lesions and are included in the four case histories presented to illustrate methods of preoperative evaluation and application of technics.