In spite of bringing together the fruits of research in physiology, medicine and surgery, the correction of many defects in the circulatory system has been palliative in nature. To perform these procedures so as to restore the normal circulation of the patient has remained an unreached goal. The main obstacle has been the lack of a method which would allow surgery within the open heart under direct vision.
The brilliant and imaginative studies of Lillehei, Cohen, Warden, and Varco have clarified many of the problems of surgery within the heart by using a donor, a person whose circulation would supply oxygen and sustain the patient whose heart must be opened. These men showed that the oxygen requirements of the body are significantly less than previously believed. They also showed that the requirements of the heart are dramatically reduced when relieved of its pumping duties.
These discoveries made possible the consideration of simple and practical methods for bypassing the cardiac and pulmonary circulation. Thus, linking the circulatory systems of the patient and donor with the aid of a simple pump assures the patient of a continuous controllable supply of oxygenated and chemically balanced blood.
Already the cross-circulation technique has been successfully employed for the intra-cardiac correction of congenital malformations of the heart in several clinics.
Inevitably, improvements will be made in this method and new techniques will be developed as a result of the stimulus of this important work. It is now possible to envision curative surgery for the vast majority of congenital cardiac defects and improved techniques for the repair of acquired heart lesions.