Hypothermia as a Means of Performing Intracardiac Surgery Under Direct Vision

¹ The Experimental Surgical Laboratory of the Division of Surgery, Department of Thoracic Surgery, Hahnemann Medical College and Hospital, Philadelphia, Pennsylvania.

1) By the use of hypothermia, metabolism and oxygen requirements of the body may be decreased. With such a method, the period of circulatory arrest can be increased to such an extent that direct intracardiac surgery for definitive repair of valves and septa may be possible.

2) We have presented our technic for an efficient and safe method of producing hypothermia in the experimental animal.

3) By the use of caval occlusion, a relatively bloodless heart can be obtained. Such a method has allowed us to perform cardiotomy on the right auricle and right ventricle for varying periods of time (12 to 30 minutes). This much time would obviously be sufficient for definitive surgery upon the valves and septa.

4) We have presented a preliminary report concerning the technic of hypothermia and cardiotomy. The procedure was performed on 32 dogs, with survival in 80 per cent of the animals with caval occlusion for 12 minutes, and 40 per cent survival in those having caval occlusion for 30 minutes.

5) It is our feeling that such a method will be useful in the surgical management of various disorders of the circulatory system —in particular, defects of the auricular and ventricular septa.