Circulatory Bypass of the Right Side of the Heart. Vi. Shunt between Superior Vena Cava and Distal Right Pulmonary Artery; Report of Clinical Application in Thirty-eight Cases.

IT HAS been more than 10 years since our first successful anastomosis of the side of the superior vena cava to the distal end of the right pulmonary artery in a dog.' The dog is still alive, in fact is robust and leading an active life in a domestic environment. In the 10 years following, several hundred experimental anastomoses have been performed. Results of these have been reported recently.2 From this experimental work it has become evident that partial bypass with the superior vena cava is preferable to that with the inferior vena cava. Total right heart bypass has never resulted in prolonged survival in animals and probably is not practical in man. More than 6 years have elapsed since our first successful superior vena cava-pulmonary artery anastomosis in a patient.3 Since operation , the patient, a 7-year-old boy with transposition of the great vessels and pulmonary stenosis, has been free from complaints, except for a mild cyanosis increasing on vigorous exercise, and has been leading a normal life. The cava-pulmonary artery anastomosis has been used in 3S patients in our clinic. All patients had severe malformation of the right side of the heart for which no established corrective procedure was available. It is the purpose of this present paper to report the postoperative results and show our progress with the clinical application of the procedure, not to offer a definitive evaluation that must Fromi-the await further operative experience and a longer period of follow-up examination. Methods Blood was obtained by arterial puncture while the subjects were at rest and in certain patients also during activity, either voluntary or while struggling and crying. The use of 100 per cent oxygen eliminated any possible unsaturation due to ventilatory factors, an essential consideration in those infants who received thiopental anesthesia to ensure a resting state during sampling. Arterial oxygen was determined directly by a modified Roughton-Scholander technic in the early years of the study, while more recently it has been calculated from arterial P02 utilizing appropriate pH correction factors and oxygen capacity. The shunt calculations require, in addition to arterial oxygen, pulmonary capillary and mixed systemic venous oxygen contents. Pulmonary capillary oxygen has been calculated as the volume expressing the normal percentage of oxygen capacity plus appropriate dissolved oxygen. Mixed venous oxygen content has been arbitrarily assumed to be 4 ml./100 ml. less than arterial. Only data from samples removed during the …