Thursday Afternoon, April 23, 1959

2:00 P.M. Scientific Session: REGULAR PROGRAM -Pacific Ballroom.

37. The Relationship of Postoperative Acidosis to Pulmonary and Cardiovascular Function.

George H. A. Clowes, Jr., Andrzej Alichniewicz (by invitation),

Louis del guercio (by invitation), and David Gillespie

(by invitation), Cleveland, Ohio

Alterations in the arterial electrolyte pattern and acid-base balance of 42 patients who underwent thoracic surgical procedures have been correlated with observations of their pulmonary and cardiovascular functions during the first two weeks postoperatively. Metabolic acidosis, evidenced by a mean rise of 260% in lactic acid, which only returned to normal by the end of three to five days, is related to the decrease in blood pressure and cardiac output as measured by dye dilution curves. In addition, it was augmented by the fact that almost all patients, and especially those undergoing lobectomy, had oxygen desaturation of the arterial blood for several days. Normally this metabolic acidosis was compensated by a decrease of pCO₂, and was manifested by an increase of tidal volume in the immediate postoperative period. This took place despite a marked reduction of respiratory reserve which had returned to only a 50% value, on the average, by the end of two weeks.

A moderate depression of the ionized calcium level of the blood took place postoperatively in the majority of patients. This was associated with an elevation of inorganic phosphate which usually disappeared within three to four days as urinary output increased.

Seven patients showed signs indicating failure of the circulation in the presence of marked acidosis. In four, this was corrected by measures which improved pulmonary ventilation.

38. Surgical Treatment of Chronic Pericarditis.

W. S Blakemore, C. K. Kirby, H. F. Zinsser, Jr. (by invitation),

W. B. Whitacre (by invitation), and J. Johnson, Philadelphia, Pa.

The favorable results following pericardiectomy in seven patients with prolonged disability but no pericardial constriction or tamponade at operation have been sufficiently gratifying to report in detail. This type of pericarditis is a smouldering, chronic, disabling disease with recurrent exacerbations of fever, malaise and pericardial or pleuritic pain. Modest exertion apparently reactivated the disease, causing frequent hospitalization, financial loss and discomfort over periods of months. This led to trial of treatment by pericardiectomy. There were no operative deaths. The disease process was apparently terminated and rehabilitation was complete in these patients. Twenty-six additional patients have been treated surgically in the past ten years for constrictive pericarditis, with three operative deaths. The use of diagnostic aids such as angiocardiography and right heart catheterization have not been sufficiently satisfactory to preclude surgical exploration as a diagnostic procedure in the more difficult diagnostic problems. Operative technic and pre- and postoperative management must be individualized. The results have been sufficiently gratifying that a vigorous effort should be made to prove the diagnosis and proceed with operation even in severely ill patients.

39. The Results of Surgical Correction of Atrial Septal Defect Complicated by Pulmonary Hypertension.

Bert W. Meyer, John C. Jones, and Harold V. Liddle

(by invitation), Los Angeles, Calif.

The surgical management of atrial septal defects by both open and closed methods has become an accepted procedure with very low mortality. There remains, however, a limited number of patients with atrial defects who have developed high pulmonary arterial pressures, often in excess of systemic pressure. In this group, operative risk is great and the postoperative morbidity severe. 131 patients have been operated upon for atrial septal defect. Among these there are fourteen whose pulmonary artery pressure was in excess of 50 mm. of mercury. Five patients in this series failed to survive the postoperative period. They are discussed in detail.

Pulmonary hypertension, based upon pulmonary vascular resistance, is the complication which so seriously increases the risk in this group of patients. Hypertension based upon elevated pulmonary flow alone does not present this serious risk. The differentiation of these two causes of pulmonary hypertension is difficult in patients with atrial septal defects. A clinical method which is of possible value in this differentiation is presented. The ultimate fate of these patients, including available postoperative catheterization studies, is discussed.

40. Coarctation of the Aorta in Infants: A Clinical and Experimental Study.

Thomas B. Ferguson, Thomas H. Burford, and David Coloring

(by invitation), St. Louis, Mo.

Preductal coarctation of the aorta, when associated with patency of the ductus arteriosus, is recognized as a grave cardiovascular condition. The majority of infants with this combination go into congestive heart failure very early in life. Response to medical treatment is poor. At St. Louis Children's Hospital about 60 proven cases have been seen since 1940 and only a few have survived beyond infancy on medical therapy alone. Because of this, a policy of operative intervention has been followed since 1950 in these seriously ill babies. Diagnosis is possible soon after birth using the "flush" blood pressure technique. Sixteen such infants have been treated, ranging in age from 9 days to 24 months. Thirteen were under 4 months of age. The first 5 cases in the series all died during or after operation. In the last 5 years there have been 11 cases with only 2 deaths. All the survivors are clinically well, although several are suspected of having septal defects which will require closure later. It is concluded from this experience that early surgical intervention is life-saving for infants with this disease.

Experimental studies were done to determine why this combination is so lethal. Dogs with either a patent ductus or a coarctation alone developed no pulmonary hypertension and lived until sacrificed. Eight animals with a patent ductus and a postductal coarctation developed no pulmonary hypertension, some died in pulmonary edema, while others lived until sacrificed. Seven dogs with preductal coarctation and patent ductus all developed pulmonary hypertension, were quite sick, and all died in congestive failure. The development of pulmonary hypertension in the preductal coarctation group seemed to contribute to the gravity of the condition.

41. Problems in the Surgical Management of Coarctation of the Aorta: Based on Experience with Sixty Consecutive Cases.

L. K. Groves and D. B. Effler, Cleveland, Ohio

Surgery for coarctation of the aorta is now well standardized and carries a relatively low operative risk. However there are several problems of selection, technique, and management which warrant discussion. These include:

1. Coarctation Diagnosed in Early Infancy:

Ten patients under one year of age have been operated upon with three deaths. This disease is a significant cause of lethal congestive heart failure in infancy, and successful operation will be lifesaving. Some of these patients may have surgically incurable problems, however, exploration will result in a gratifying salvage. It has on occasion proven extremely difficult to recognize the precise site of coarctation from the outside of the infantile aorta.

2. Coarctation After Age 45:

Three patients in this age group have been operated upon with two postoperative deaths. In this age group the individual may not tolerate the lowering of blood pressure associated with a successful operation. A paradox arises when the patient's cerebral circulation will not permit a surgical cure.

3. How Large Should An Anastomosis Be:

There is considerable disagreement as to what constitutes a satisfactory anastomotic lumen. A corollary to this problem is the question of when to use a graft. It is suggested that in most instances an anastomotic lumen with a diameter of one centimeter is probably adequate.

4. Residual Hypertension:

An occasional patient with a satisfactory anastomosis and equal blood pressures in the arms and legs will have residual hypertension. This problem is discussed and indications for late aortography are suggested.

5. Postcoarctation Syndrome:

Experience with this puzzling postoperative abdominal complication is presented.

42. An Analysis of Deaths Following Cardiac Surgery.

James L. Harrison (ty invitation), Bart. D. Iaia (by invitation), and

Robert P. Glover, Philadelphia, Pa.

In recent years great emphasis has been placed upon the development of proper criteria for the selection of cardiac surgical cases. For the most part these criteria have been promulgated on the basis of long-existing and time-honored clinical concepts too often impressionistic rather than factual.

In an attempt to crystalize the indications for surgery a "backward" look at what has happened over the years seems fitting. To this end a detailed analysis of all cardiac deaths (72 in number) occurring consecutively over a five year period (December 1952 through December 1957 at Presbyterian Hospital) is presented. Specific surgical principles in the light of clinical history, electro-cardiography, radiology, hemodynamics, anesthesia, technique, anatomy and pathology have become apparent.

This study, therefore, points the way to better surgical judgment and performance, of utmost importance at this stage of indecision and possible transition from closed to open heart surgery.