ABSTRACTS

Fourteenth Annu a1 Southern Thoracic

Meeting of the . . Surgical Association

November 9-1 1, 1967, Sheraton-Dallas Hotel, Dallas, Tex.

1. P R O G N O S T I C F A C T O R S I N M A L I G N A N T T U M O R S OF T H E L U N G Harry A . Wellons, Jr., M.D. (by invitation), George Johnson, Jr., M.D., Dewey Pate, M.D. (by invitation), Walter A . Benson, M.D. (by invitation), and Richard M . Peters, M.D., Chapel Hill, N.C.

T h e overall prognosis for patients with malignant tumors of the lung con- tinues to be poor. I n order to evaluate the experience at North Carolina Memo- rial Hospital, 582 patients with 100% follow-up have been reviewed with emphasis on prognostic factors and the results of different modes of therapy.

Five-year survival rates were determined by a life table analysis. For the entire group, the survival rate was 7.4%. Males accounted for approximately 80% of the series; 75% were unresectable when first seen. In nonresected patients x-ray or combined therapy resulted in a 1-year survival of 22% compared to 14% survival of those receiving chemotherapy or no treatment.

Pulmonary resection was performed in 146 patients with a 5-year survival rate of 27%. T h e survival rate for pneumonectomy was almost identical to that of more limited resections, although the operative mortality was twice as high. Conservative pneumonectomies carried a better prognosis than more radical pro- cedures with 5-year survival rates of 34% and 18%. Differentiated squamous tumors, the most common type, had a 5-year survival rate of 43% compared to 5% for adenocarcinoma, 20% for pleomorphic tumors, 10% for alveolar cell, and 0% for undifferentiated large cell tumors. Survival was reduced to 7% if the tumor size was greater than 5 cm. and to approximately 20% when there was vascular invasion. Although local extension into lymph nodes was not associated with any change in survival rate, survival in those with lymph node metastasis was reduced to 15%.

While this study reconfirms the poor overall prognosis for patients with malignant tumors of the lung, it illustrates that resection can improve survival and that vascular invasion and lymph node metastasis do not preclude long-term survival.

2. C E R V I C O M E D I A S T I N A L L Y M P H N O D E BIOPSY F O R DIAGNOSIS OF I N T R A T H O R A C I C LESIONS H . H . Shah, M.D. (by invitation), C. Lamber, M.D. (by invitation), D. L. Paulson, M.D., J . J . McNamara, M.D. (by invitation), and H . C . Urschel, Jr., M.D., Dallas, Tex.

Cervicomediastinal lymph node biopsy (CME) is employed in the evaluation

VOL. 4, NO. 5, NOV., 1967 483

Abstracts

of intrathoracic lesions to avoid exploratory thoracotomy for diagnosis and to assist in determining the operability of malignant pulmonary lesions.

CME was planned in 212 cases between 1959 and 1966. Twenty-three patients had positive supraclavicular nodes and required no mediastinal exploration. In the remaining 189 patients, CME was positive in 89, 17 were benign, and the rest were malignant lesions. Even though the chest x-ray and laminagrams did not reveal mediastinal fullness, 60% had diagnostic mediastinal biopsies.

Of the 100 patients with negative lymph nodes, 48% were not explored be- cause of other contraindications; of the 52% explored, 90% were resectable. Only 2 of these had positive mediastinal nodes with the CME being negative (false negative).

The complication rate was 1.6%, and there was no mortality. CME is a safe procedure with minimal complications which should be employed in the diag- nostic work-up of all intrathoracic lesions. I t reduces the frequency of unneces- sary exploratory tlioracotomy and increases resectability rate at the time of sur- gery.

3. T H E EFFECT OF PROLONGED CARDIOPULMONARY BYPASS (2-4 H O U R S ) UPON L U N G F U N C T I O N A N D R E S P I R A T O R Y W O R K W . H . Lee, Jr., M.D., N . Cooper, M.D. (by invitation), Y . M . Matsuzira, M.D. (by invitation), and A . Najib, M.D. (by invitation), Charleston, S.C.

The frequency of serious pulmonary complications following prolonged pump oxygenator perfusions for cardiac operations is a well-recognized problem. The etiology of “post-perfusion lung” remains unsolved, although previous in- vestigations have suggested several possible causative factors. This report com- prises a detailed analysis of respiratory function and pulmonary surfactant activity before and after operation in 25 mongrel dogs divided into groups of 5 as follows: I, control thoracotomy, open chest for two hours; 11, control thoracotomy, open chest for four hours; 111, thoracotomy with “partial” perfusion for two hours; IV, tlioracotomy with “total” perfusion for two hours; V, thoracotomy with “total” perfusion for four hours. All perfusions were performed by standard cannulation techniques, employing a Kay-Cross disc oxygenator.

Results, two-hour perfusion: The perfusion groups exhibited changes of only borderline statistical variance from thoracotomy controls, with an increase in ventilation and VeO,, decrease in 0, consumption (10-30%), and decrease in respiratory work efficiency. There was no significant variance from the controls in pulmonary surfactant activity.

Four-hour perfusion: The perfusion group displayed highly significant aber- rations from the control thoracotomy group, with an increase in work, ventila- tion, VeO,, and a striking reduction in efficiency of work of respiration and of pulmonary surfactant activity.

4 . ,Joseph S. McLaughlin, M.D. (by invitation), Robert T . Singleton, M,D. (by invita- tion), Safuh Attar, M.D., Leonard Scherlis, M.D. (by invitation), and R Adams Cowley, M.D., Baltimore, Md.

From March, 1965, to March, 1967, permanent catheter pacers of the Char- &&-Greatbatch type were inserted in 25 patients ranging in age from 53 to 85 (average age 7 1). The basic diagnosis in all patients was arteriosclerotic cardio- vascular disease. Twenty patients, including 2 patients without complete A-V block, had had Stokes-Adams attacks. Definite evidence of previous or acute myocardial infarction was present in the electrocardiograms of 4. Temporary pacing catheters were inserted via an anticubital vein in 9 patients one to nine days prior to permanent pacemaker insertion.

Complications of significant magnitude to prolong hospitalization were few. A staphylococcus bacteremia originating in a temporary pacer insertion site OC-

P E R M A N E N T T R A N S V E N O US PACING

484 THE ANNALS 01; THORACIC SURGERY

Abstracts

curred in 1 patient. With antibiotic coverage the temporary catheter was removed and a permanent catheter inserted, with a successful outcome. Ventricular per- foration occurred twice, in 1 instance producing a fatal result. Battery failure has occurred once, 14 months following insertion.

Four patients died, all within one month of operation. Three of these patients had electrocardiographic evidence of previous or acute myocardial infarction. Death was sudden and unexpected and presumably occurred on the basis of acute arrhythmia.

Twenty-one of 25 patients are alive 3 to 27 months following operation and are demonstrating good cardiac function without evidence of heart failure or Stokes-Adams attacks.

5. COROhTARY A N G I O G R A P H Y : IhTDICATIOhTS, TECHNIQUE>Y, A N D CO MPLI C A T I ONS T. Takaro, M.D., C . H . Dal-t, Jr,, M.D. (by invztation), S . M . Scott, A f . L I . , and R . G. Fzyh, M.D. (by invitation), Oteen, N.C.

Coronary angiography as a diagnostic procedure is being used with increas- ing frequency throughout the United States and Canada. It is possible to begin to evaluate the usefulness of the test, the varieties of techniques available, and the risks; it also seems worthwhile to do so.

In experience at this hospital with over 400 such studies, the indications h v e solidified into 5 major categories: (1) for the evaluation of patients with angina, as a prelude to consideration for myocardial revascularization procedures; (‘2) in the differential diagnosis of atypical chest pains and nonspecific cardiomyopathies; (3) in the preoperative evaluation of patients with other significant cardiovascular conditions, such as aortic and mitral valvular diseases and abdominal aortic aneurysms; (4) combined with internal thoracic arteriography, in the postoper- ative assessment of patients following myocardial implantation procedures; and (5) in assessment of the coronary arteries of patients with complete heart block requiring treatment with pacemakers.

While the standard technique introduced by Sones was used in most of the cases, a number of other techniques were also found to be necessary, including transfemoral approaches by way of the Seldinger technique and approaches via the left brachial artery. Specially shaped catheters and special equipment were most helpful in facilitating these procedures, and these are described.

Complications can be divided into the following categories: vascular, per- taining to the peripheral vessel catheterized; and cardiac, including disturbances of rhythm and function. While no lives or limbs were lost in this series, cardiac arrest, serious arrhythmias, documented myocardial infarction, and significant vascular problems occurred sufficiently frequently (in at least 25 patients) to keep one mindful that constant vigilance and attention to detail are necessary to min- imize the risks.

6. James J . Yashar, M.D. (by invitation), Daniel E. Jenkins, M.D. (by invitation), Thomas C . Black, M.D. (by invitation), David Bahar, 111.0. (by invitation), How- ard T . Barkley, M.D., and Michael E. De Bakey, M.D. (by invitation), Houston, Tex.

Failure of medical treatment to accomplish conversion of sputum and closure of cavities in pulmonary tuberculosis within a reasonable period of time presents an indication for surgical intervention. This report concerns 660 patients with pulmonary tuberculosis, 78 of whom were patients with pulmonary disease causetl by atypical mycobacteria and 10 of whom were patients having disease caused by mixed organisms. These patients were operated on during a 12-year period be- cause of failure of medical treatment. The average duration of medical treatment prior to surgery was 16 months. A positive sputum culture was obtained within

S U R G I C A L T R E A T M E N T OF P U L M O N A R Y TUBERCULOSIS

VOL. 4, NO. 5, NOV., 1967 485

Abstracts

90 days preceding operation in 66% of those patients with atypical and 31% of those with typical mycobacteria. Streptomycin, para-aminosalicylic acid, and isoniazid were the major antibiotics employed in the medical treatment, except in patients with drug-resistant organisms. Of the 754 operations performed, 85% were excisional procedures and 15% were collapse procedures. The operative mortality was 1.8%. Good results were obtained in 95.8%. Marked contrast in the number of reactivations was noted between the patients with atypical myco- bacteria (27.2% reactivations) when compared to those with typical mycobacteria (2.9% reactivations).

This presentation includes a discussion of complications, reactivations, and long-term results over a 12-year period.

7. T H E SURGICAL T R E A T M E N T OF BULLOUS EMPHYSEMA Dona1 M . Billig, M.D. (by invitation), S. F. Boushy, M.D. (by invitation), and R. Kohen, M.D. (by invitation), Houston, Tex.

We have studied 63 patients with bullous emphysema, 26 of whom have had resection of bullous lesions. Twelve of these patients were followed for three to eleven years after surgery; they were interviewed and had pulmonary function tests, consisting of forced vital capacity (FVC) and its subdivisions and maximal voluntary ventilation (MVV). Fourteen patients were operated upon within the last two years. All of these, as well as the 37 nonsurgical patients, had extensive pulmonary function studies. Bronchospirometry was performed in most patients. Some patients had pulmonary angiograms, bronchograms, and laminagrams as well. In the patients followed for three to eleven years after surgery, there was no recurrence of a resected bullous lesion. In the patients operated upon within the past two years, there was one death from a massive pulmonary embolus. Minor space problems constituted the only other complications. These were all treated conservatively with good results.

There was a marked tendency to increasing airway obstruction with increas- ing age of the patients. Patients with severe airway obstruction required intensive tracheal toilet, and in one patient who was severely incapacitated, a tracheostomy was performed at the completion of the operation. Intermittent positive-pressure breathing and inhalation of mucolytic agents was of great help in clearing secre- tions in these patients. In contrast, patients having lesser degrees of obstruction posed no difficulties in postoperative management. Patients with minimal or no dyspnea sustained no change of symptoms following surgery. Patients with mod- erate to severe dyspnea showed marked improvement in exercise tolerance after surgery. This clinical improvement was not well reflected in postoperative pulmo- nary function tests. The reasons for this disparity are apparent and are discussed.

The natural course of this disease is progressive enlargement of the bullae, increased severity of airway obstruction, and-with time-emphysema. Because of these facts, and in view of the difficulty in postoperative care imposed by severe degrees of airway obstruction and also the absence of recurrence after resection, early surgical treatment of these lesions seems advisable. Cases illustrating this course of events are presented.

8. T H E V A L U E A N D APPLICABILITY OF P R O L O N G E D E N D O T R A - C H E A L I N T U B A T I O N Charles R. Hatcher, Jr., M.D., John R. Calvert, M.D. (by invitation), Will iam D. Logan, Jr., M.D., Panagiotis Syrnbas, M.D., and Osler A . Abbott , M.D., Atlanta, Ga.

In recent years, endotracheal and nasotracheal tubes have been inserted and allowed to remain in place for an extended period of time in order to avoid or delay tracheostomy. Our group has been favorably impressed with this approach to airway management in the following clinical situations: ( 1 ) open-heart surgery

486 THE ANNALS OF THORACIC SURGERY

Abstracts

-especially if median sternotomy has been performed; (2) acute laryngotracheal bronchitis or other acute inflammatory conditions producing airway obstruction in children; (3) myasthenia gravis-in crisis or following thymectomy; and (4) central nervous system depression secondary to trauma, disease, or following cardiorespiratory arrest and resuscitation.

This report discusses the psychological preparation desirable when possible, tube selection and technique of insertion, and postoperative management. T h e use of a short double-ballooned nasotracheal tube to simplify mechanical con- nections and to avoid pressure necrosis without risk of aspiration is illustrated and emphasized.

Improvement in equipment and nursing care available in intensive care units permit safe usage of endotracheal intubation for extended periods of time to avoid certain problems inherent in tracheostomy.

9. I M M E D I A T E A N D LONG-TERM E V A L U A T I O N OF OPERATIVE T R E A T M E N T FOR COMBINED C O A R C T A T I O N OF T H E A O R T A A N D P A T E N T DUCTUS ARTERIOSUS J . Alex Haller, Jr., M.D., Mary Jane Luke, M.D. (by invitation), and James S. Donahoo, M.D. (by invitation), Baltimore, Md.

Because of a well-documented mortality in young children with combined ductus and coarctation who are treated nonoperatively, an earlier surgical attack has been advocated. The immediate mortality and potential problems in growth and development which may accompany this approach have dampened enthusi- asm for wider use of early correction of both lesions. We have, therefore, reviewed our experience at Johns Hopkins with 25 consecutive children with this comhina- tion of defects.

Nine of these children were under 1 year of age at resection. Sixteen had other significant cardiac defects, of which the commonest were ventricular septal defect (12) and atrial septal defect (4). Four patients died before operation; 21 were operated upon with 6 deaths. Three of the 4 infants under the age of 1 year survived surgical correction. The long-term follow-up of surviving children has revealed an encouragingly healthy group of patients despite many residual cardiac anomalies. Operative and postoperative principles in management which have evolved during this experience are discussed.

10. MECHANICAL V E N T R I C U L A R ASSISTANCE I N H U M A N BEINGS David B . Skinner, Capt, USAF, MC (by invitation), Richard H . Hood, Jr., Col, USAF, MC; Eliot Schechter, Maj, USAF, MC (by invitation), Thomas F . Camp, Jr., Maj, USAF, MC (by invitation), and George L. Anstadt, Maj, USAF, VC (by invitation), Lackland AFB, Tex.

Mechanical ventricular assistance is a simple and effective method to give total circulatory support without the need for vascular cannulations or extra- vascular circulation. Previously reported dog experiments have demonstrated that hemodynamic, metabolic, and hematologic changes occurring during assis- tance are compatible with survival of an animal whose circulation is completely supported by assistance for 24 hours. Other dog experiments have shown that survival following left circumflex coronary artery division is improved signifi- cantly when ventricular fibrillation is induced and assistance is given for 5 hours following myocardial infarction. Assistance has been given to dogs for 3 hours following insertion of prosthetic heart valves without dislodgment of the valves.

T o adapt this method for human use, a larger and modified apparatus has been developed and tested in calves. Modifications and results obtained will be described. Experience with a protocol for the selection and treatment of patients by ventricular assistance will be presented. Two groups of patients have been

VOL. 4, NO. 5, NOV., 1967 487

A bstracts

chosen for initial applications of this method: (1) patients undergoing open-heart surgery whose hearts are unable to maintain the circulation after bypass has been discontinued; (2) hypotensive patients suffering from myocardial infarction who do not respond to all standard forms of treatment.

11. M E C H A N I C A L C I R C U L A T O R Y SUPPORT I N A C U T E M Y O C A R - D I A L SHOCK Dennis Rosenberg, M.D., D. Winkler, M.D. (by invitation), R. Levy, M.D. (by invitation), and J . Kaplan (by invitation), New Orleans, La.

Methods of assisting the failing heart or circulation are receiving a great deal of attention. Permanently implantable ventricular assist devices or temporary circulatory assist devices that do not require thoracotomy are being used increas- ingly. Both aim at reduction of peripheral resistance during systole, reduction of left ventricular pressure and cardiac work, and augmentation of diastolic aortic pressure with improvement of coronary flow.

A modified, synchronized myocardial augmentation apparatus was tested in the animal lab. Basically, three major techniques were evaluated in 60 dogs.

1. Synchronized arterio-arterial pumping 2. Synchronized veno-arterial pumping with oxygenation of blood 3. Synchronized aorto-femoral pumping

Cardiogenic shock was induced in the animals by ligation of the left circum- flex coronary artery with production of ventricular fibrillation. Circulation was assisted for 1% to 2 hours, after which defibrillation and resuscitation were attempted. Cardiac output, coronary flow rates, aortic pressures and flow rates, arterial and venous oxygenation, and kidney function were monitored.

It was shown that circulatory support for 2 hours or longer will reduce the mortality following left circumflex coronary artery ligation. I t will frequently prevent the onset of ventricular fibrillation and will allow easy reversal of fibrilla- tion when present. Support is most successful with synchronized veno-arterial bypass and with synchronized aorto-femoral pumping.

This study is encouraging. I t has shown that myocardial workload can be reduced, coronary flow is improved, and coronary collateral circulation is in- creased with minimal trauma to the blood by the use of this apparatus. The system is simply and quickly placed in operation and might have clinical applica- tion for hours or possibly days in patients who continue to deteriorate following myocardial infarct or cardiac arrest. A resume of current methods of circulatory assistance is also presented.

12. V A L V E REPLACEMENT I N C H I L D R E N Fred H . Taylor, M.D., and Hugh M . Foster, Jr, M.D. (by invitation), Charlotte, N.C.

The biological aspects of inserting metal, plastics, and fabrics within the heart chambers leave much to be desired. In view of this, most surgeons are very reluctant to insert artificial valves in children. An occasional child, however, has such severe hemodynamic changes from badly damaged heart valves that a pros- thetic replacement is the only solution to the problem.

Four children, ages 9, 12, 15, and 15, have had single heart valve replace- ments. Two of these replacements were aortic and two were mitral. The preopera- tive findings, reasons for surgery, and the clinical results in this small series are presented along with a review of the literature. It would appear that heart valves are replaced in children in isolated instances in many centers, and an accumula- tion of this data is brought forward to stimulate discussion of the subject.

488 THE ANNALS OF THORACIC SURGERY

Abstracts

13. T . D . Bartley, M.D., L. E. Crevasse, M.D. (by invitation), J . R . Green, M.D. (by invitation), J , W . Linhait , M.D. (by invitation), W . J . Taylor, M.D. (by invitation), and M . W . Wheat, Jr., M.D., Gainesville, Fla.

Since the advent of the Starr-Edwards mitral prosthesis, 119 operations limited to the mitral valve have been performed at the University of Florida Medical Center. Eighty-two patients underwent prosthetic replacement of the valve, 38 had open valvuloplasty, and there was 1 closed commissurotomy.

Fifty-six patients are long-term survivors in the group that underwent prosthetic replacement; there were 19 operative and 7 late deaths. The peripheral embolization rate was 21%. Of the last 50 patients undergoing prosthetic replace- ment of the mitral valve, 9 died at surgery and 1 died later; there was 1 case of suspected peripheral embolization. In 15 of the long-term survivors who under- went postoperative cardiac catheterization, hemodynamic improvement was ob- served in all save 1, who subsequently underwent successful reoperation for leaks around the prosthesis.

No mortality has been observed in the 37 patients undergoing valvuloplastic procedures. One has undergone successful replacement for mitral insufficiency.

T h e absence of mortality in those undergoing open valvuloplasty and the steady decrease in mortality and morbidity in those undergoing valve replacement have encouraged us to suggest open operation for all who need mitral valve surgery, regardless of their physical condition. If adequate valvuloplasty is impos- sible, the valve is replaced.

P R O S T H E T I C R E P L A C E M E N T OF T H E M I T R A L V A L V E

14. CARDIAC SURGERY D U R I N G PREGhTANCY Harold A . Collins, M.D., Rollin A . Daniel, Jr., M.D., and H . Wzlliam Scott, JT. , M.D. (by invitation), Nashville, Tenn.

The physiological stress of pregnancy in a patient with cardiac disease may produce cardiac decompensation. Most such patients can be managed satisfactorily with medical therapy. Congestive cardiac failure, unresponsive to medical treat- ment, or unusual circumstances related to a specific cardiac lesion may necessitate operative therapy during pregnancy. We have encountered eight patients in whom cardiac surgery was performed during pregnancy without maternal or fetal mortality.

Three patients with severe mitral stenosis and congestive cardiac failure had a mitral commissurotomy in either the first or second trimester. All were signifi- cantly improved and proceeded through uneventful pregnancies and deliveries. The special problems associated with coarctation during pregnancy dictated surgical therapy in three patients. One patient had a therapeutic abortion prior to operation; the other two had normal pregnancies and deliveries following resection of the coarctation. An atrial septa1 defect was closed with the aid of temporary cardiopulmonary bypass during the first trimester in one patient. In another patient a patent ductus was divided during the second trimester because of subacute bacterial endarteritis. Both patients proceeded through uneventful pregnancies.

It is our impression that cardiac surgery during pregnancy is well tolerated and may be advantageous for selected patients under special circumstances.

15. EXPERIENCE W I T H M E T A L S T R U T S F O R CHEST W A L L S T A B I L I - Z A T I O N Paul C , Adkins, M.D., Diller B . Groff, I I I , M.D. (by invitation), and Brian Blades, M.D. (by invitation), Washington, D.C.

In the past decade, various types of metal struts have been utilized to achieve stabilization of segments of the sternum. Controversy still exists regarding the necessity for a prosthesis in repair of a funnel chest deformity, but our experience

VOL. 4, NO. 5, NOV., 1967 489

A bstracts

indicates that a prosthesis is important and adds considerably to the long-term cosmetic result. A 5-year follow-up on those cases in which a simple, substernal strut was used points out certain technical aspects concerning insertion and removal of the struts which are worthy of emphasis. Principally, these are selec- tion of the appropriate siLe strut, slight over-correction of the deformity, and continued internal fixation for 3 to 6 months. The relative merits of the various metal prostheses which are currently available will be discussed and the potential application of these struts in situations other than pectus excavatum deformities will be outlined.

16. REVASCULARIZATION OF T H E P O S T E R I O R W A L L OF T H E H E A R T BY R I G H T I N T E R N A L M A M M A R Y A R T E R Y I M P L A N T A T I O N : A Q U A N T I T A T I V E STUDY A.M. AlShamma, M.D. (by invitation), R. L. Criollos, M.D. (by invitation), and B. B . Roe, M.D. (by invitation), San Francisco, Calif.

The anterior wall of the left ventricle has been revascularized by implanta- tion of left internal mammary artery. New collateral channels have been clocu- mented by angiography, metabolic studies, and direct-flow measurements (from our laboratory). The posterior (diaphragmatic) aspect of the left ventricle is less readily revascularized, and several approaches to it have been suggested. This report presents the flow studies of right internal mammary artery implantation into the posterior wall of the left ventricle.

Terminal studies of collateral flow were conducted on 21 mongrel dogs six months after revascularization surgery. Five control dogs had no operation. Eight dogs had posterior implantation of the totally mobilized right internal mammary artery with simultaneous application of ameroid constrictors to the left circum- flex and right coronary arteries. Eight dogs had identical mammary artery implantation but did not have ischemia induced with constrictors. The induced collateral coronary blood flow was directly measured by collecting the effluent from the isolated right heart supported by extracorporeal circulation. Occlusion of the aortic root obliterated normal coronary flow so that residual flow rep- resented collateral flow.

Collateral flow in control animals was zero. In those with right internal mammary artery implant and ischemia, average collateral blood flow was 30 ml. per minute. In animals without ischemia, the flow was only 5 ml. per minute. Significant arteriovenous differences in oxygen and carbon dioxide tensions indi- cate that the new collateral channels perfuse the myocardium. Collateral flow valves were correlated with Schlesinger mass injection and histological studies of intimal thickening.

17. SERUM ENZYME A N D ELECTROCARDIOGRAPHIC CHANGES FOL- L O W I N G M Y O C A R D I A L REVASCULARIZATION Edward B. Diethrich, M.D. (by invitation), John E. Liddicoat, M.D. (by invita- tion), Samuel A . Kinard, M.D. (by invitation), H . Edward Garrett, M.D. (by in- vitation), and Michael E. De Bakey, 111.0. (by invitation), Houston, Tex.

Myocardial revascularization procedures alter the postoperative serum en- zyme levels and electrocardiographic patterns. These alterations may create diffi- culty in diagnosing either myocardial ischemia or myocardial infarction in the postoperative patient.

Serial electrocardiograms and serum glutamic oxylacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and lactic dehydrogenase (LDH) studies have been analyzed in 40 patients undergoing simultaneous right and left internal mammary artery implantation for myocardial revascularization.

Several enzymatic and electrocardiographic patterns following revasculariza- tion were observed. None of the patients had a completely normal electrocardio-

490 THE ANNALS OF THORACIC SURGERY

Abstracts

gram postoperatively. T h e most common abnormalities were nonspecific ST-T wave changes and sinus tachycardia. Similarly, there were no patients with a normal LDH level postoperatively. The SGOT and SGPT determinations varied considerably from normal levels to ranges consistent with moderate myocardial damage.

The enzymatic and electrocardiographic findings in these 40 patients will be presented along with the diagnosti; crjteria used for establishing the presence of postoperative myocardial ischemia and infarction. The management of the patient following myocardial revascularization in view of these studies will be discussed.

18. A O R T I C A R C H ANOMALIES Eugene Linberg, M.D., Safuh Attay, M.D., R Adams Cowley, M.D., and Joseph McLaughlin, M.D. (by invitation), Baltimore, Md.

True vaxular rings or similar vascular lesions which behave like true rings are an important cause of tracheal and esophageal obstruction in infants. An extensive and somewhat confusing literature has evolved concerning them. This presentation is based on experience with over 10 patients with vascular rings. Aberrant subclavian vessels are not considered to produce a true vascular ring and are not included in this discussion. Main points of consideration will be (1) diagnosis on the basis of the appearance of x-rays of the barium-filled esoph- agus, (2) operative approach, (3) technical considerations, and (4) postoperative care.

19. EMPYEMA: A DIFFERENT APPROACH T O T R E A T M E N T John W . Polk, M.D., and Alan H . Bailey, M.D., Mt. Vernon, Mo.

Even with modern antibiotic therapy, empyema still occurs in rare instances. The standard treatment-drainage and thoracoplasty-is being replaced by other methods which are easier and certainly less painful to the patient. Claggett has reported his method of treating empyema using antibiotics and irrigations as a basis for cleaning u p the pleural space.

In 1960, we had embarked on the treatment of two cases of empyema without thoracoplasty. These infections occurred in two late postpneumonectomy patients. One was treated with Staphcillin and the other with Coly-Mycin. Since that time, six other cases have been treated in a similar manner. In six of the eight cases, only an empyema was present. In the other two, the empyema was complicated by a bronchopleural fistula. Case reports and follow-up on these will be presented.

20. M A N A G E M E N T OF T H O R A C I C EMPYEMA Lester R. Bryant, M.D. (by invitation), James M . Chicklo, M.D. (by invitation), Richard R. Crutcher, M.D., Gordon K. Danielson, M.D. (by invitation), J . Kent Trinkle, M.D. (by invitation), and William Mallette, M.D. (by invitation), Lex- ington, Ky.

Fifty-seven consecutive cases of nontuberculous thoracic empyema have been reviewed to compare the efficacy of open and closed methods of management. Positive bacteriological cultures were obtained in 13 of 18 children and in 25 of 39 adults. Forty cases were associated with primary pulmonary infection, 11 were postoperative empyemas, and 6 followed thoracic trauma.

Closed tube thoracostomy was the initial method of treatment in 33 patients, but 16 required further therapy. The average hospitalization was 14 days. Open drainage, either primary or following closed tube thoracostomy, was performed in 21 patients. This method was successful in 12 patients, with an average hospitalizz- tion of 15 days. Seven patients had primary decortication, with 1 failure. An

VOL. 4, NO. 5, NOV., 1967 491

A bstracts

average interval of 18 days occurred in 10 patients who required secondary decortication following an initial drainage procedure. Hospitalization averaged 28 days in this group.

The occurrence of fibrothorax or trapped lung after empyema has been overemphasized. Primary decortication is indicated only when there is associated major pulmonary collapse or multiple loculations. The need for secondary decortication should be recognized, however, within 2 to 4 days after tube thoracostomy is initiated. Open tube thoracostomy remains an excellent method of management in selected cases of empyema.

21. S U R V I V A L A F T E R SUSPENSION OF PERFUSION D U R I N G ASAN- GUINEOUS CARDIOPULMONARY BYPASS Will iam A . Neely, M.D., and Joseph L. Haining, Ph.D. (by invitation), Jackson, Miss.

We have previously reported survival of dogs following 20 minutes of com- pletely asanguineous anoxic perfusion with a buffered electrolyte-dextran solu- tion. We now report the efficacy of suspending perfusion.

Adult mongrel dogs were perfused with a bloodless solution via femoral arteries, the blood and fluid being returned later from a catheter in the right atrium. Perfusion rate, vascular pressures, temperatures, and ECG were recorded. Group I was perfused with N,/CO, (90110) saturated solution to zero hematocrit (i.e., 5 minutes). The pump and respirator were then stopped for 15 minutes, after which perfusion was resumed for 2 to 5 minutes and samples of effluent taken serially for lactic acid analysis. Blood was then returned and respiration recom- menced. In Group 11, perfusate saturated with 100% CO, was substituted for NJCO, solution for the last 2 minutes of the initial washout in an attempt to prevent lactic acidosis during suspension. In Group 111, the dogs were perfused as in Group I except very cold fluid was used and the total washout period was 6 minutes followed by approximately 55 minutes of no perfusion. Four of the 5 dogs in Group I survived the procedure, 2 without ill effects. ECG was manifest during the period of stasis. In contrast, 4 of the 5 dogs in Group I1 fibrillated, and only 1 survived. Lactic acid in the stagnant vascular pool of Group I1 dogs was one-third to one-half that in Group I. In Group 111, 7 dogs have been perfused and 4 are long-term survivors; there were no ill effects. The nonsurvivors could be accounted for by technical errors. These experiments demonstrate that under proper conditions tissues can tolerate anoxia without blood for long periods of time-long enough to be clinically useful. The disadvantages of perfusion with blood are obviated.

22. CEREBROVASCULAR INSUFFICIENCY A F T E R BLALOCK-TAUSSIG S H U N T S John S. Vasko, M.D. (by invitation), Richard I . Tapper, M.D. (by invitation), and James W . Kilman, M.D. (by invitation), Nashville, Tenn.

A significant number of patients who have had Blalock-Taussig shunts for congenital cyanotic heart disease have developed symptoms compatible with cerebrovascular insufficiency, but little attention has been given these often-vague complaints. The effects of subclavian-pulmonary artery shunts on cerebral blood flow and cardiac output were determined in 12 anesthetized dogs. Subclavian- pulmonary artery anastomoses were constructed retaining the ipsilateral vertebral and distal subclavian arteries in communication. Blood flow was measured in the carotid and vertebral arteries, the shunt, and the ascending aorta with an electro- magnetic flowmeter. Shunting increased cardiac output an average of 28% and decreased average carotid and vertebral flow by 82% and 25%, respectively; the retrograde flow in the ipsilateral vertebral artery approximated 50% of the flow in the contralateral vertebral artery. Shunt occlusion increased carotid and retro-

492 THE ANNALS OF THORACIC SURGERY

A bst racts

grade vertebral flow substantially, although cardiac output decreased. A selective flow of systemic arterial blood into the low resistance pulmonary circulation during the entire cardiac cycle permitted substantial regurgitant flow in the carotid artery during cardiac diastole and was responsible for the reduced carotid flow in the presence of an increased cardiac output. Occlusion of the ipsilateral vertebral artery eliminated the “subclavian steal” and reduced carotid and contra- lateral vertebral flow.

These studies indicate that subclavian-pulmonary artery shunts decrease cerebral blood flow substantially and that if the ipsilateral vertebral and distal subclavian arteries communicate, a significant “subclavian steal” can occur which may result in cerebrovascular insufficiency.

23. N E U R O V A S C U L A R COMPRESSION A T T H E SUPERIOR T H O R A C I C A P E R T U R E : S U R G I C A L M A N A G E M E N T Thomas B . Ferguson, M.D., and Thomas H . Burford, M.D. (by invitation), St. Louis, Mo.

Since 1927, when Adson advocated section of the anterior scalene muscle for relief of symptoms associated with cervical rib, it has been recognized that com- pression of the neurovascular bundle can occur at seven different anatomical points. T h e tendency in the past has been to regard each type as a distinct disease entity (“syndrome”), and corrective surgical procedures designed to relieve con- striction at a given anatomical area can be found in the thoracic, vascular, neuro- surgical, and even orthopedic literature. The recent routine use of arteriography and venography in the work-up of these patients has demonstrated the fallacy of attempting to pinpoint the area of constriction by history and physical findings and has shown that many patients have more than one point of compression, factors which undoubtedly are in part responsible for the variability in reported surgical results.

All disorders of the thoracic outlet have one feature in common: the first rib contributes directly or indirectly to the compression in every case. Complete removal of the first rib can therefore be curative in every patient, and we believe this operation should be established as the only surgical procedure for these dis- orders. A series of twelve successfully treated cases, many showing unusual features, will be presented in support of this thesis.

24. Yale H . Zimberg, M.D., and Cornelius G. Lynch, M.D. (by invitation), Richmond, Va.

C O N T R O L L E D A T E L E C T A S I S I N T H O R A C I C SURGERY

Endobronchial catheterization in pulmonary surgery has been effective in preventing bronchial cross-contamination during thoracotomy and has allowed safe anesthesia in traumatic injuries of a lung and in intrinsic, profuse bleeding from one lung.

T o determine the effect of variations in technique of produced atelectasis, adult mongrel dogs, mechanically ventilated (pressure and volume controlled), had monitoring of blood gases and venous and arterial pressures during thora- cotomy. Following clamping of the right or left main bronchus, mild hyperventi- lation with a high oxygen mixture and rapid complete atelectasis allowed blood pH, pC02, and p 0 2 to remain within normal limits. Slow or incomplete atelectasis due to various control causes and compression atelectasis of one lung resulted in derangements of blood gases.

In the past eight years endobronchial Catheterization using the Carlens, White, or Bryce-Smith tube has been used in well over 1,000 patients undergoing thoracic surgery. In a number of patients, blood gases and pressures have been monitored throughout the procedure. There have been no complications at- tributable to the tubes. Using 1% fluothane vaporized with 100% oxygen and

VOL. 4, NO. 5, NOV., 1967 493

Abstracts

rapid complete atelectasis of the operated lung, patients with poor lung function have had periods of complete atelectasis in excess of two hours without deleterious changes and without demonstrable postoperative sequelae in the hyperventilated or atelectatic lung. This technique has safely broadened the operability in pa- tients with significant intrinsic generalized pulmonary pathology. The procedure, because of its safety in comparison with compression atelectasis, has been used with great facility in extrapulmonary thoracic procedures such as esophagectomy and aneurysmectomy. In such cases, the increased effective ventilation, decreased lung trauma, and decreased mediastinal compression with the maintenance of more normal blood gases and pressures has significantly decreased morbidity and mortality while allowing a more rapid, thorough technical procedure. The present technique and the limitations and indications of controlled atelectasis in man are described, and selected studies under various conditions of controlled atelectasis in dogs and man are shown.

25. T H E M A N A G E M E N T OF G U N S H O T W O U N D S OF T H E CHEST Sobrab Gerami, M.D. (by invitation), James E. Cousar, III, M.D., James M . Davis, M.D., and Thad M . Moseley, M.D. (by invitation), Jacksonville, Fla.

In spite of extensive experience with gunshot wounds of the chest in World War I1 and the Korean War, as well as in civilian practice in the past decade, there is an apparent lack of uniformity of opinion regarding the management of these injuries. Some have suggested that a more aggressive surgical approach be followed, while others are of the opinion that thoracotomy should be used only for specific indications and for those patients not responding to conservative measures.

In view of this divergence of opinion we felt that it would be worthwhile to review our experience in the treatment of 103 patients with gunshot wounds of the chest treated at the Duval Medical Center from 1959 through 1965. Seventy- three of these patients had wounds confined to the chest, while the remainder had multiple injuries. The mortality rate was 4% in the former group and 9.4% for the entire series. This compares favorably with other reports, and we have concluded on the basis of this study that most patients with gunshot wounds of the chest can best be managed with conservative measures.

494 THE ANNALS OF THORACIC SURGERY