MONDAY AFTERNOON, MAY 1, 1972

2:00 P.M. Scientific Session: REGULAR PROGRAM

Los Angeles Ballroom

9. Evaluation and Surgical Management of Acute Evolving Myocardial Infarction

STANTON N. SMULLENS*. LESLIE WIENER*, HRATCH KASPARIAN*,

ALBERT N. BREST*, BENJAMIN BACHARACH*, PAUL H. NOBLE*

and JOHN Y. TEMPLETON, III, Philadelphia, Pa.

This study describes a method of defining the early acute infarction state and the effective management offered by emergency coronary revascularization. Eighteen patients with crescendo angina were deemed candidates for emergency coronary revascularization on the basis of controlled preoperative metabolic and angiographic studies. All patients had chest pain of greater than forty-eight hours duration and electrocardiographs changes suggestive of ischemia. Systemic arterial to coronary sinus venous blood lactate and CPK gradients were measured, and coronary blood flow was determined by constant antipyrme infusion. Myocardial lactate production in sixteen of the eighteen patients, elevation of coronary sinus CPK in all patients and reduction of coronary blood flow in all patients were considered diagnostic of acute evolving myocardial infarction. Emergency cine coronary arteriography and left ventriculography were then performed to precisely define the anatomic lesions. Immediate coronary artery repairs were then made with aorto coronary vein grafts and internal mammary anterior descending anastomoses. An average of 2.5 coronary artery repairs were done per patient. Sixteen of these eighteen high risk patients survived operation. Metabolic studies were repeated in all, two to seven days later. Normal lactate utilization, normal coronary sinus CPK and increased coronary blood flow were observed m every case. All surviving patients have been free of chest pain, arrhythmia or heart-failure for one to seven months following operation.

*By Invitation

10. Aorto-Coronary Bypass for Acute Myocardial Infarction

LAWRENCE H. COHN*, RICHARD GORLIN* and

JOHN J. COLLINS, JR.*, Boston, Massachusetts

Sponsored by Ernest Barsamian

Recent reports have demonstrated the benefits of coronary bypass grafts for pre-infarction angina but the value of such grafts for acute myocardial infarction (MI) is as yet unclear. This report presents the results of immediate operative intervention in five patients who developed acute coronary occlusion during coronary angiography.

The 3 males and 2 females ranged in age from 32 to 55 years, averaging 45. Acute obstruction of the right coronary (RCA), occurred in 4 and the left anterior descending (LAD) in one patient. In all five, because of multiple lesions, coronary bypass was carried out to both the RCA (plus distal endarterectomy in three) and LAD within 3 hours of coronary obstruction documented by angiography.

There were no operative or late deaths nor significant complications. The preoperative clinical symptoms and ECG abnormalities consistent with acute MI were ameliorated in all 5 patients. The average hospital stay was 10 days.

We conclude from this initial experience that immediate coronary bypass for acute MI in this clinical setting is not only feasible but the treatment of choice. It further suggests that earlier diagnosis and treatment may result in improvement in overall mortality from MI.

*By Invitation

11. Endarterectomy as a Supplement to Coronary Saphenous Vein Bypass Surgery

LAURENCE K. GROVES, FLOYD D. LOOP*, and

GARY M. SILVER*, Cleveland, Ohio

In performing vein bypass surgery to the coronary arteries, one on occasion encounters an artery much more diseased than suggested angiographically. Endarterectomy is logical under such circumstances. Early experience with such "fortuitous" endarterectomies led to extension of their use and to surgery on vessels which previously were considered unacceptable. The procedure is most applicable to the right coronary artery, particularly when totally obstructed and associated with a coincidental, more surgically favorable lesion of the left coronary artery. Most endarterectomies have been done without gas and it is not clear that gas improves the ease or extent of endarterectomy. The procedure has always been done through a small coronary artenotomy to which a vein graft from the aorta is then anastomosed. One hundred and two endarterectomies have been performed in ninety-seven patients since July, 1970. There has been one hospital mortality. At the date of this abstract 17 of 19 restudied vessels are patent. At the meeting a much larger followup will be reported.

*By Invitation

12. Secondary Surgical Procedures for Myocardial Revascularization

DUDLEY W. JOHNSON, ROBERT J. FLEMMA*, ALFRED J.

TECTOR*. GEORGE W. BEDDINGFIELD*. JAMES F. HOFFMAN*,

and DERWARD LEPLEY, JR., Milwaukee, Wisconsin

Thirty-six patients having had one to three previous myocardial revascularization attempts have required further revascularization surgery. Recurrent angina which necessitated the secondary surgery was a result of inadequate previous Vineberg procedure (14 patients); late saphenous vein graft closure (11 patients); unsuccessful Beck operation (two patients); and failure of a vein patch graft (one patient). Of special interest is the fact that seven patients in whom further progression of disease in coronary arteries other than those previously successfully revascularized necessitated further surgical intervention.

Angiography is essential to determine whether the recurrent angina is due to new coronary disease or closure of the vein graft. If the problem is "late closure," the initial vein graft flow measurements and condition of the recipient myocardium will help determine feasibility of secondary surgery. Success has been achieved despite previous submtimal fibrosis of the vein.

Technical problems are sometimes considerable in secondary surgery and the various coronary arteries have different degrees of accessibility. This fact has prompted us to bypass lesser degrees of stenosis in the circumflex coronary which is highly inaccessible at reoperation. Technique at initial operation and during secondary procedures which would facilitate and increase safety will be discussed in detail as well as the rationale leading to the original bypass of arteries with lesser degrees of stenosis.

*By Invitation

13. Early Thoracotomy for Empyema

JEAN E. MORIN*, LLOYD D. MACLEAN and

DARRELL D. MUNRO*, Montreal, Quebec, Canada

Thoracotomy was used as primary treatment or in preference to open thoracostomy in 23 patients with empyema over the 11 years, 1960-1971. These patients had not responded to antibiotic therapy, thoracentesis or closed chest drainage. All were severely ill and febrile. At time of operation, a fibropuiulent empyema was found. Concomitant pathology consisted of pneumonia, emphy-sematous bullae, rheumatoid nodule, bronchopleural fistula, and gangrene of the king. Decortication with removal of the fibropurulent exudate was performed in 12 patients. A combination of decortication and pulmonary resection was required in the other 11 patients. Clinical improvement was prompt and the average duration of hospitalization after operation was 14 days. There was no recurrence of empyema in any patient. One death occurred in a 76-year-old patient who had sustained multiple injuries leading to his empyema. Recovery was uneventful in the others. The temperature returned to normal, as an average, on the fourth postoperative day.

The prompt recovery seen in these patients suggests that this treatment can be used earlier and more frequently for thoracic empyema.

14. The High Velocity Pulmonary Injury - Relation to Traumatic Wet Lung Syndrome

HAROLD WANEBO* and JAN VAN DYKE*, New York, New York

Sponsored by Edward J. Beattie, Jr.

In a study of 104 battle casualties who required thoracotomy for penetrating chest injuries, 60 patients required surgical intervention for major pulmonary wounds. Indications for thoracotomy were hemorrhage, extensive chest wall damage, and severely contused and lacerated King, frequently accompanied by hypoxemia. Complicating factors included shock in 67 percent and multiple injuries (extra thoracic) in 80 percent of these patients. The operative procedures performed included pneumonectomy in 7 patients (none survived), lobectomy in 33 patients (17 survived), wedge resection in 8 (7 survived), and oversewing of bleeding pulmonary sites or bronchial repair in 12 patients 10 of which survived. The overall mortality was 43 percent.

Pulmonary insufficiency was the major post-operative complication and occurred in 44 patients. 28 developed traumatic wet lung syndrome, and 17 of these expired. Contributory causes of this syndrome were high velocity chest-lung injury, massive infusion of blood and saline, intra-bronchial hemorrhage and long term respirator care. Suggestions to improve survival include early exploratory thoracotomy and conservative resection of traumatized lung when clinical signs warrant Pneumonectomy is usually contraindicated. Intraoperative use of a Carlens Tube, judicious administration of blood and saline and frequent changing of blood filter sets, careful post-operative use of the volume respirator monitored according to patients arterial gases, and use of appropriate diuretics, steroids, digitalis and antibiotics should improve patient survival in high velocity chest injuries.

15. Acute Respiratory Insufficiency: Treatment Using Prolonged Extracorporeal Circulation

JOHN D. HILL*, MARC DELEVAL*, MOGENS L. BRAMSON*,

ROBERT EBERHART*, ROBERT FALLAT*, JOHN J. OSBORN*

and FRANK GERBODF. San Francisco, California

Twelve patients dying from acute respiratory insufficiency were treated using long-term extracorporeal oxygenation. The diseases treated were: viral pneumonia, 4 cases; pulmonary trauma, 3 cases; respiratory bum, 1 case, pulmonary fat emboli, 2 cases, and 2 cases of aspiration pneumonia. The duration of the bypasses were 12 hours to 9H days. Seven of the twelve patients were taken off extracorporeal circulation with improved and acceptable pulmonary function. Two of these seven cases, having perfusions of 3 and 5 days, were long-term survivors. Five patients died while on extracorporeal circulation.

Two cannulation methods were used. Veno-veno perfusion diverted 48% of the cardiac output through the oxygenator. Venoarterial perfusion oxygenated 65% of the cardiac output and, by reducing the pulmonary artery pressure and the necessary FIO₂ and tidal volume, provided a better environment in which the lung could recover.

Successful reversal of pulmonary pathology related primarily to the tune lapse from pulmonary insult to the beginning of perfusion. Patients rapidly developing acute severe hypoxemia following a pulmonary insult who were placed on extracorporeal circulation early during the inflammatory and exudative stages of their disease, had more rapid reversal of their pulmonary pathology.

*By Invitation

16. Effect of Alterations in Arterial Pressure on Cardiac Performance Early After Open Intracardiac Operations

NICHOLAS T. KOUCHOUKOS*. LOUIS C. SHEPPARD*

and JOHN W. KIRKLIN, Birmingham, Alabama

Since arterial pressure is one of the main determinants of ventricular wall tension during systole (afterload) and has been previously shown to affect ventricular performance in patients with diseased myocardium, this study was undertaken to assess the effects of acute reductions in arterial pressure on cardiac performance early after open intracardiac operations employing Arfonad (tri-methaphan) infusions. Mean left atrial pressure (LAP), mean aortic pressure (MAP) and stroke index (SI) (indicator dilution technique) were measured before and after infusions of Arfonad to produce reductions in MAP while heart rate remained constant In 8 patients with pre-infusion MAP of 109 ± 6 mm Hg, elevated LAP (25 ± 5 mm Hg) and low cardiac index (1.76 ± .32 L/min/M⁷) reductions in MAP (average 19 mm Hg) produced a statistically significant (p < 0.01) fall in LAP (8.2 mm Hg) and an 18% increase in stroke index (p < 0.05). In 5 patients with MAP of 139 ± 10 mm Hg, normal LAP (10 ± 3 mm Hg) and more normal cardiac index (2.78 ± .81 L/min/M²) reductions in MAP (average 31 mm Hg) produced a significant (p < 0.01) fall in LAP (3.6 mm Hg) and a 19% decrease in stroke index (p < 0.05). The data indicate that in patients with normal or elevated MAP, low SI and elevated LAP, SI can be increased significantly by decreasing arterial pressure, and that this may be an effective method of treatment for some patients with impaired cardiac performance following open intracardiac operations.

*By Invitation