Wednesday Morning, July 5, 1939

9:00 a. m. Business Session.

9:30 a. m. Scientific Session.

1. Benign Chondroma of the Chest Wall.

Fred R. Harper, Denver, Colorado.

Abst. The paper includes a review of the literature with particular reference to the tendency of chondromata to undergo sarcomatous degeneration.

The case reported is that of a girl aged seventeen years. The roentgenograms were typical of benign chondroma of the chest wall. The tumor was completely removed through an anterolateral incision which proved to be cosmetically superior to the usual approach directly over the tumor. The patient has been carefully followed for more than a year with no evidence of recurrence.

2. Primary Tumors of the Ribs.

Robert M. Janes, Toronto, Canada.

Abst. If one may judge from experience in this centre primary tumors of ribs are quite rare. This group of 8 cases comprises all that have been operated on over a period of 15 years and is made up of 1 giant-celled tumor, 2 apparently single myelomas, 2 chondromas, 2 osteogenic sarcomas and 1 chondrosarcoma. A method of repair of the defect resulting from removal of an anterior chest wall tumor is described.

3. Pectus Excavatum.

A. Lincoln Brown, San Francisco (by invitation).

Abst. On the basis of our experience with 5 operative cases of tricherbrust, the following conclusions are reached:

1. That in fully developed (adult) conditions, removal of the depressed sternum alone may not effect a permanent relief of symptoms.

2. That since the depression develops gradually over a period of years, simple surgical intervention in infancy may prevent the further development of the anomaly.

Our clinical experience and anatomical studies have shown that, 1. the condition is hereditary, 2. it is brought about by overactivity of the diaphragm, 3. when the sternum is released there still remains a contracted depressed substernal ligament with its attached periosteum, therefore unless this ligament is also freed, the condition and symptoms dependent thereupon, are likely to persist or recur, 4. in the growing child, the further development of the condition may be prevented, by simple section of the anterior attachments of the diaphragm to the gladiolus, and of the substernal ligaments at the level of the junction of the zyphoid and gladiolus thereby releasing a majority of the unusual depressing force.

4. Primary Tumors of the Diaphragm.

Joseph W. Gale and (by invitation)

Stanley R. Edwards, Madison, Wisconsin.

Abst. There have been numerous reports in which the diaphragm has been secondarily invaded by tumors arising in neighboring structures. The occurrence of primary tumor of the diaphragm is extremely rare, however, and only eleven cases have been reported. Seven were malignant and four were benign. Four cases have been operated upon. The signs and symptoms are not typical but certain diagnostic procedures, including the use of x-ray with artificial pneumothorax and pneumoperitoneum, will render invaluable assistance in arriving at a correct diagnosis. These will be discussed along with a report of the successful removal of a primary malignant tumor of the right hemidiaphragm in a patient who has remained free from recurrence for nine months.

5. Removal of Teratoma from Anterior Mediastinum.

(Moving picture demonstration)

Stuart W. Harrington, Rochester, Minnesota.

Wednesday Afternoon, July 5, 1939

2:00 p. m.

6. Address by Dr. Clarence Crafoord, Stockholm, Sweden, on Pulmonary Ventilation and Anesthesia in Major Chest Surgery.

7. Differential Pressure and Reduced Lung Function in Intrathoracic Operations.

W. E. Adams, Chicago, Illinois.

Abst. Methods of administration of anaesthesia as well as anaesthetic agents used in intrathoracic surgery have become increasingly significant concomitant with the development of that branch of surgery. The scope and utility of differential pressures during surgical pneumothorax are enumerated and discussed. Experimental and clinical evidence is presented describing the hazards associated with some methods of obtaining and maintaining differential pressures. Experimental work concerning lowered vital capacity and its importance in dif­ferential pressures during intrathoracic operations is presented and its clinical application is discussed. Our experience with various methods of administration of anaesthesia in surgical pneumothorax is presented.

8. Further Studies on Survival Following the Maintenance of Life During Experimental Occlusion of the Pulmonary Artery.

John H. Gibbon, Jr., Philadelphia, Pennsylvania.

Abst. Attempts to carry out surgical procedures within the cardiac chambers or great vessels at the base of the heart have not been attended as yet with much success. It is obvious that any operative procedure upon the heart could be better performed if that organ were temporarily relieved of its function of pumping blood. If the flow of blood through the heart and lungs could be safely stopped for thirty minutes, then it is conceivable that a new field of cardiac surgery might be developed.

A method is described by which life can be maintained in animals when the flow of blood through the heart and lungs is completely stopped by clamping the pulmonary artery. The method consists of the continuous withdrawal of blood from a peripheral vein, the introduction of oxygen into the blood, and the continuous return of the oxygenated blood to the animal's arterial system through a peripheral artery.

The difference between this method and those used for the perfusion of isolated organs lies in the added technical difficulties entailed in the use of small peripheral vessels for the perfusion. The vessels must be of such small size that their ligation does not result in any impairment of nutrition or function of the tissues supplied by them. The use of such peripheral vessels permits the animal's heart and lungs to again resume their normal functions after removal of the clamp from the pulmonary artery and the cessation of the extra-corporeal circulation.

Thirteen experiments are reported in which this method was employed. In these experiments the pulmonary artery was completely occluded for from 10 to 25 minutes, during which time life was maintained by an extra-corporeal circulation. Five animals lived 24 to 48 hours after the experiment. Four animals lived from 8 to 23 days after the experiment. Finally, four animals lived from one to 11 months after periods of occlusion of the pulmonary artery of from 12 to 20 minutes. These four animals were normal in every respect and exhibited no neurological changes.

Control experiments, performed under identical conditions with the exception that the extra-corporeal circulation was not used, have demonstrated irreparable neurological changes with periods of occlusion of the pulmonary artery of five minutes or longer, and have also shown the impossibility of restoring life after a 10 minute period of occlusion of the pulmonary artery. So far as we are aware, this constitutes the first report of the successful temporary substitution of an entirely mechanical apparatus for the functions of the heart and lungs of an animal, followed by the prolonged survival of the animal. It is hoped that the method may be perfected eventually to such an extent that it may be safely employed on human beings.

9. Hemicardiac Hypertrophy and Enlargement Solely Due to Increased Peripheral Resistance: A Study of Pulmonic and Aortic Stenosis Experimentally Produced.

Emile Holman, San Francisco, California.

Abst. Small puppies ranging in age from ten days to six weeks were operated upon, the aorta and pulmonary artery being partially ligated just beyond the heart. The development of the heart was followed both by x-rays and necropsy studies, comparing the experimental animals and their hearts with litter mates as controls. Some interesting observations have been made on the dilatation and hypertrophy that occurs under these circumstances, compared with the dilatation that occurs in the presence of an arteriovenous fistula.

10. Factors Affecting the Regeneration of the Lung.

Roy Cohn, San Francisco, California (by invitation).

Abst. It has been demonstrated by Addis et al that organ weight is to a large extent a factor of organ work. Studies were made upon the remaining lung tissue following removal of from one to four of the five lobes in the rat. As a control, the lungs of 372 rats of various body weights up to 350 grams were plotted against their respective body weights. The resulting straight line was used as the basis for predicting lung weights from a given body weight in the rat.

It was found that except in the old rats the original weight was restored by the remaining lung tissue within a period of two weeks. The old rats did not equal the preoperative lung weight even in thirty days whereas the young rats had restored the total lung weight to normal in as little as seven days.

The change in weight of the remaining lung tissue depended upon the size of the remaining thoracic cage. If the size of the space which the remaining lung tissue had to fill was decreased, as by phrenic avulsion, thoracoplasty, placing wax in the thorax at the time of operation, then the remaining lung tissue did not approximate the predicted weight. If the size of the thoracic cage was increased by placing the rats in an atmosphere com­parable to a very high altitude, the lung weights were as much as forty per cent higher than the predicted weights.

The heart weights increased in all cases after thirty days, again as much as forty per cent.

When large doses of thyroxin were administered, the usual increase in weights of the heart, liver, and kidneys was noted. An irregular increase in weight in the lungs on the basis of the body weight prediction was found to disappear when the correction was made for loss of body weight from the thyroxin.

Histological material and x-ray studies were made but gave no proof of the cause of the increase in weight of the remaining lung.

An approximate method for counting the alveoli was devised. With this method no increase of the number of alveoli could be demonstrated even in the lobes that had increased as much as three times their original weight.

Further studies including in vivo staining of the lung before pneumonectomy, as well as changes in the hemoglobin of the blood are in process of completion.