Monday Afternoon, May 6, 1957

2:00 P.M. Executive Session. (Limited to Active and Senior Members). Grand Ballroom.

3:00 P.M. Scientific Session: REGULAR PROGRAM-Grand Ballroom.

Address by the President, Cameron Haight, Ann Arbor, Michigan

"Some Observations on Esopbageal Atresias

and Fistulas of Congenital Origin"

29. Intrapericardial Bronchogenic Cysts-Report of Two Cases and Probable Embryological Explanation.

C. Harwell Dabbs (by invitation), E. Converse Peirce, II (by invitation),

Knoxville, Tenn. and Ralph Berg, Jr., Spokane, Wash.

Bronchogenic cyst or "teratoma", as many of these are diagnosed, occurring within an intact pericardium is unusual. To date a review of the literature reveals twelve previously reported cases. The present report details two additional cases, both quite large and both removed successfully in a single stage. The correct diagnosis was made pre-operatively in a twenty year old girl with a 650 gram tumor, after clinical study including angiocardiography.

The case histories are documented with x-rays, angiocardiograms, operative photographs, photomicrographs, and a short film strip showing the removal of one tumor.

Although these tumors have frequently been called "teratomas" in the past, the elements present are respiratory epithelium, muscosal glands, smooth muscle, cartilage and lymphoid follicles, structures usually found in bronchogenic cysts. Since the lung buds are in close proximity to the pericardial coelom for several days during the rapidly developing twenty-eight to thirty-six day period, fusion of the pleuropericardial folds may trap tissue of respiratory tract potential within the pericardium. It appears logical to assume that these tumors lying amidst the great vessels and auricles of the heart, and covered with intact pericardium, represent fetal lung bud rests "trapped" within the pericardium as the pleuropericardial folds close.

30. Primary Repair of Traumatic Rupture of the Thoracic Aorta.

Robert G. Pontius (by invitation), Boston, Mass, and

Oscar Creech, Jr., New Orleans, La.

Traumatic rupture of the thoracic aorta from non-penetrating forces is becoming more widely recognized as a clinical entity. While many patients expire promptly from their injury, those who eventually survive frequently develop an aneurysm which requires surgical therapy. Between these two extremes of the clinical spectrum is a region in which prompt recognition and definitive surgical intervention may remove the threats of death from secondary hemorrhage and the sequelae accompanying aneurysm formation.

Such a case is reported in which the victim of an automobile accident developed secondary hemorrhage from a tear in the thoracic aorta while undergoing abdominal surgery for associated injuries. Hemorrhage from the aorta was controlled and a homo-graft used to restore continuity. However, blood loss, aortic occlusion and massive transfusions of citrated blood including use of the intra-arterial route contributed to repeated episodes of cardiac arrest from which the patient expired.

In the past, clinical attention has usually been directed away from the nuances of this injury by other areas of more obvious trauma. A discussion of the clinical aspects and roentgenologic features of this condition, together with proper selection of established techniques of aortic surgery points to the consideration that this condition may soon be treated successfully by primary surgical intervention.

31. The Electro-Encephalogram in Patients Undergoing open Intracardiac Surgery with the Aid of Extracorporeal Circulation.

Richard A. Theye (by invitation), Robert T. Patrick (by invitation)

and John W. Kirklin, Rochester, Minn.

The electro-encephalogram has been continuously monitored in all patients undergoing open intracardiac surgery with the aid of extracorporeal circulation at the Mayo Clinic. This paper reports the electro-encephalographic changes, other than those associated with alterations in the depth of anesthesia, which occurred in the first 100 patients in whom technically satisfactory electro-encephalograms were obtained.

A normal electro-encephalogram predominated in all patients before, during, and after perfusion. However, in 60 patients a change in the electro-encephalogram occurred which was not associated with an alteration in the depth of anesthesia. In these patients the small, fast waves characteristic of light ether anesthesia were temporarily replaced by large, slow waves or even a flat line. In some patients this change occurred more than once.

These large, slow waves were associated with surgical compression of the superior vena cava on 13 occasions. In each instance a normal pattern reappeared with resumption of blood flow through this vessel.

Similar large, slow waves appeared in the electro-encephalogram during a period of reduced cardiac output in 13 instances. These were not associated with the perfusion except in one case of a technical failure.

A similar transient electro-encephalographic change was observed to occur 45 times with the initiation of perfusion. In all cases the normal pattern spontaneously reappeared within a few minutes.

The electro-encephalogram has proved to be a useful monitoring device during the performance of open intracardiac surgery with the aid of extracorporeal circulation at the Mayo Clinic.

7:00 P.M. Cocktails, Banquet and Dancing, Palmer House-Red Lacquer Room.

Attendance limited to Members of the Association and

their ladies, Invited Speakers and their ladies.

Dinner dress preferred.