Tetralogy of Fallot; surgical treatment.

Since Blalock published his first report on the surgical treat ment of pulmonary stenosis, we became greatly interested in this subject. While performing an necropsy on a ten year old child who had tetralogy we found an abnormal vessel which connected the left subclavian and left pulmonary arteries (Fig. 1); this vessel had a very small lumen and evidently was unable to supply enough oxygenated blood to counteract the cyanosis. Nevertheless, this observation was a vivid proof that Nature, in order to overcome the disabling effects of cyanosis, used the same procedure that Taussig advocated. Last year we started to operate on cases of tetralogy having dealt, up to now, with 17 cases which are summarized in Table 1. We are aware, of course, that with this meager experience no conclusions whatsoever can be drawn, but we wish to stress some practical points which evolved from our work. At the outset we had to decide between the two operations which following Taussig's conception were developed to improve the physiologic status of these cyanotic patients: Blalock's and Potts'. Blalock's technic seemed more advantageous considering the fact that if we had an accident the operation could be interrupted at any stage without any major complication; furthermore, should the follow-up of these patients show the inadequacy of the sur gical ductus arteriosus to solve the abnormal physiologic situation or should well known complications of the congenital patent ductus, such as subacute bacterial endocarditis, arise we could proceed to treat these cases as we do with any patent ductus. That much cannot be said of Potts' operation. To establish a sound comparison, both technics should have been performed in the same number of cases; we have not done so on account of the scarcity of Potts' clamps which were not available until very recently. Although the teralogy of Fallot is described as a fairly standard syndrome, there are all varieties and variations of the conditions of this condition, all of which are not amenable to surgical treat ment. It is obvious therefore that an accurate diagnosis is an essential prerequisite to consider the surgical possibilities of a case of tetralogy.