Tuesday Afternoon, March 29, 1949

2:00 P.M. Scientific Session.

6. Total Failure of Sternal Fusion With Herniation of Pericardium.

Herbert G. Maier, M.D., New York, N. Y., and

Frank Bortone, M.D., Jersey City, N. J.

A case of complete lack of fusion of the entire length of the sternum with herniation of the pericardium is reported. The congenital defect was successfully corrected by surgery in infancy. The importance of performing the operation very shortly after birth is well illustrated by our case.

The embryological development of the sternum is briefly reviewed. The relationship of cleft sternum and ectopia cordis is discussed.

Due to the lack of rigid thoracic cage at the site of the sternal defect, considerable paradoxical motion may occur with resultant respiratory and cardiocirculatory difficulty. If only a partial cleft sternum or a narrow sternal fissure is present, symptoms may be absent.

7. Angiocardiography and Aortography in the Diagnosis of Congenital Cardiovascular Lesions.

Thomas H. Burford, M.D. and (by invitation)

Merl J. Carson, M.D. and Wendell G. Scott, M.D.,

St. Louis, Mo.

With the development of the tautography by one of our group (W.G.S.), the technique of cardiovascular visualization has become an invaluable and extremely accurate method of diagnosis in congenital lesions of the heart and great vessels. The intravenous injection of diodrast by this technique serves admirably to elucidate the type of deformity present in the heart. Retroarterial injection has proven equally valuable in clarifying anomalies of the aorta and its immediate branches.

The valuable procedure of cardiac catheterization is limited in application. The very young subjects in whom diagnostic difficulties are most commonly encountered have not been suitable subjects for catheterization in our experience. It is in this group that visualization is of the greatest value.

The procedure is of further value in that it affords accurate, pre-operative evidence of operability or inoperability in certain lesions, particularly coarctation of the aorta.

A relatively large experience is reviewed, with a description of the techniques and an appraisal of the results. (Lantern slides and a five-minute colored movie.)

8. Angiocardiography in the Diagnosis of Mediastinal and Paramediastinal Masses.

Osler A. Abbott, M.D., Emory, Ga. and (by invitation)

Ted F. Leigh, M.D. and William A. Hopkins, M.D.

This presentation discusses the role which may be played by the use of diodrast visualization in evaluating mediastinal and paramediastinal tumors. The use of the angiocardiogram constitutes the main point of discussion, but the role of diodrast visualization of the innominate veins and superior vena cava are also discussed. The value of this technique in lesions of vascular origin is easily appreciated. Its value in non-vascular lesions is also stressed.

Unusual cases are presented, which emphasize the need for this method of investigation in the majority of mediastinal lesions. A case of congenital massive aneurysm of the superior vena cava is included in the presentation, and the successful method of operative correction presented. The importance of angiocardiography in different projections is also considered.

9. Anesthesia for Thoracic Surgery, A Study of the Effect of the Open Pleura on the Blood Gases.

Henry K. Beecher, M.D. (by invitation)

Massachusetts General Hospital, Boston, Mass.

Abnormality in the blood gases (too low oxygen, too high carbon dioxide) is a common cause of disaster during thoracic surgery. Procedures in anesthesia must be designed to preserve these gases within normal limits. Our anesthesia practices are given with studies of the arterial blood in some forty patients during trans-pleural thoracic surgery.

10. Blood Volume Changes in Tuberculous Patients Treated by Thoracoplasty.

Frank F. Allbritten, Jr., M.D., John H. Gibbon, Jr., M.D.

and (by invitation) Herbert Lipshutz, M.D. and

Bernard J. Miller, M.D., Philadelphia, Pa.

A rising pulse rate and falling blood pressure has occasionally required the discontinuance of a stage of thoracoplasty in patients with pulmonary tuberculosis. This occurs more commonly in patients with far advanced bilateral disease and in the second and third stages of thoracoplasty. Although blood lost at operation was adequately replaced it occurred to us that an unrecognized diminution in circulating blood volume could account for these symptoms. It was conceivable that these chronically ill patients had a diminished blood volume on admission to the hospital and that there was an additional unrecognized blood loss into the operative wound between stages. The following study was made in order to obtain pertinent data.

Observations were made on ten patients with pulmonary tuberculosis treated by thoracoplasty. All had seven rib thoracoplasties. The plasma volume was determined by the method of Gibson and Evelyn. The blood volume was calculated from this figure and the hema-tocrit. The blood lost during each stage of thoracoplasty was measured by weighing sponges before and after use, and this estimation was compared with the difference in circulating blood volume before and after operation. The blood lost between the stages of thoracoplasty was taken as the difference between the blood volume at the completion of one stage and the blood volume immediately preceding the next stage.

With one exception, all patients in this series had a diminished blood volume prior to thoracoplasty, computing normal volume from surface area by the method of Gibson and Evans.

The operative blood loss during the first stage was found to be almost twice as much as that occurring at the second and third stages; averaging 832 cc. in the first stage, and 480 cc. and 397 cc. in the second and third stages, respectively.

A significant decrease in the circulating blood volume was found to occur in the interval between stages. Between the first and second stages the decrease in blood volume averaged 428 cc. and between the second and third stages it averaged 445 cc. Some of the decrease in blood volume between stages has been attributed to the extravasation of serosanguinous fluid into the large wound space which is created after the upper three to five ribs are resected. With the completion of a seven rib thoracoplasty, the scapula drops in to obliterate this space.

Patients with arrested disease following thoracoplasty regained and maintained a normal circulating blood volume.

These measurements indicate the advisability of restoring a normal circulating blood volume preceding a surgical procedure in patients with pulmonary tuberculosis, as well as adequate replacement of blood during operation and between stages of a thoracoplasty.

11. Pulmonary Circulation and Alveolar Ventilation-Per-fusion Relationships After Pneumonectomy.

A. Cournand, M.D. and (by invitation) R. L. Rilev, M.D.

and A. Himmelstein, M.D., New York, N. Y.

Fourteen patients ranging in age from 14 to 72 years were studied after pneumonectomy. The time since pneumonectomy was less than seven months in six cases and from two to eleven years in the remaining eight cases. The preoperative diagnoses included chronic pulmonary suppuration, tuberculous bronchial stenosis and carcinoma of the bronchus.

The pulmonary blood flow and pulmonary arterial pressure were measured at rest in eight cases and following exercise in four cases, using the technic of cardiac catheterization. The correlation between ventilation and perfusion was studied in all 14 cases by recently developed technics which involved the determination of pCO2 and pO2 in the arterial blood and the calculation of alveolar gas tensions. On the basis of these measurements it is possible to estimate the proportion of mixed venous blood which fails to pass through normally ventilated alveoli and to estimate the proportion of inspired air which fails to reach normally perfused alveoli. In all cases the studies were supplemented by the measurement of lung volumes, maximum breathing capacity, ventilation and gas exchange as previously reported.

Although the dynamics of the pulmonary circulation at rest were but slightly altered even in cases studied several years after pulmonary resection, there was invariably a significant degree of pulmonary arterial hypertension during moderate exercise. This finding is in contrast with observations in normal individuals during much more severe exercise (Am. J. Physiol. 152:372, 1948). Since the blood flow through the remaining lung during moderate exercise exceeded the flow through each lung of normal individuals during severe exercise, it cannot be stated whether the rise in pulmonary arterial pressure was due to pathological changes in the pulmonary vascular system or to the inability of the normal vascular bed of one lung to accommodate an unusually large blood flow. The relationships between alveolar ventilation and alveolar perfusion were normal in six cases. In the remaining eight there was evidence of perfusion of poorly ventilated areas and/or ventilation of poorly perfused areas. There was no consistent correlation between these changes and a) the type of disease prior to pneumonectomy, and b) the presence or absence of a thoracoplasty. In the older age group moderate emphysema invariably developed with evidence of ventilation of poorly perfused areas.