Monday Morning, March 29, 1965

8:30 A.M. Business Session (Limited to Members)

International Room

8:45 A.M. Scientific Session: REGULAR PROGRAM

International Room

1. Immediate Surgery for Traumatic Heart Disease

Thomas F. Boyd, and John W. Strieder,

Boston, Mass.

Until recently, civilian production of the majority of penetrating cardiac wounds was localized to a few southern United States cities. With changes in immigration and social violence, northern hospitals have been forced to evolve their own methods of treatment. The last twenty-five patients with penetrating cardiac trauma who arrived alive at Boston City Hospital are reported. Twenty-two were taken to the Operating Room to be treated by close observation, blood replacement, and pericardiocentesis. On this regimen, several patients rapidly worsened and were operated upon with excellent results. Others were observed for hours and then had a rapidly downhill course, necessitating late operation. These patients eventually succumbed. Immediate operation again became routine therapy and all but a single patient became long-term survivors. Three patients who were operated upon in the Emergency Room did not survive. Sixteen of the patients who arrived in the Operating Room alive and were operated upon within two hours of injury became long-term survivors, including two with bullet wounds of the heart. Four who were operated upon after two hours did not survive. The difference between these groups is statistically significant. We believe, therefore, that immediate surgery is indicated in every patient with penetrating cardiac trauma.

2. Chest Trauma with Pneumothorax and Hemothorax

John W. V. Cordice*, and Jose Cabezon*

New York, N. Y.

Sponsored by George H. Humphreys II

Study was made of 507 cases of chest trauma seen at the Harlem Hospital Center during a seven year period, 1957-1963 inclusive, in which there was hemothorax, pneumothorax or both as significant clinical findings The great majority were stab wounds (420), but there were twenty-five cases of bullet wounds and sixty-one cases in which blunt trauma (beatings, falls, automobile injuries, etc.) was the cause. A small number of patients presented penetrating trauma of the neck, shoulder or abdomen with the wound of entrance not on the chest primarily. Evaluation of the cases was made as regards incidence, source and degree of pneumothorax and hemothorax, and this data was correlated with the types and locations of wounds and the effectiveness of needle versus tube drainage of the pleura. Indications for open thoracotomy will be discussed. Further detailed study and commentary is made of certain groups of patients as follows: Bilateral chest injuries (48), bullet wounds (25); blunt trauma (61); thoraco-abdominal wounds (49); and cervical thoracic wounds (22). Follow-up has been made on the patients as regards the residual radiologic findings and any symptoms or disability referable to the chest. The forty-nine deaths are analyzed as to cause, preventability and errors in diagnosis and management.

3. The Patho-Physiology of Pulmonary Embolism: Relationships to Accurate Diagnosis and Choice of Therapy

David C. Sabiston, Jr., and Henry N. Wagner, Jr.*,

Durham, N. C.

Pulmonary embolism continues to represent a serious and often fatal complication. Despite its importance, opinion is divided concerning the magnitude of pulmonary arterial occlusion required to produce serious hemodynamic effects and the method of choice in establishing an accurate diagnosis. To gain more objective information a combined clinical and experimental study was undertaken. More than 150 patients were evaluated by pulmonary scintiscanning employing radioactive macro-aggregated albumin, and 100 dogs with experimental embolism were studied for acute and chronic responses including the ultimate fate of emboli in the lungs. The following conclusions have been drawn: (1) serious hemodynamic effects occur after more than half of the pulmonary arterial bed is occluded, (2) the diagnosis can be established rapidly and accurately by scintiscanning, (3) in a small number of patients pulmonary arteriography is required for diagnosis, (4) areas of lung with arterial occlusion may become revascularized with the passage of time as demonstrated by serial scanning, and (5) pre-existing cardiac or pulmonary disease seriously aggravates the response to embolism. Analysis of these factors has led to a useful approach in the choice of a group of patients selected for pulmonary em-bolectomy.

4. Intramural Arterial Dissection During Cardiopulmonary Bypass

Donald Elliott*, and Benson B. Roe,

San Francisco, Calif.

Vascular accidents associated with retrograde perfusion through the femoral artery during extracorporeal circulation are rarely reported. Three published cases and many other unreported cases were apparently due to intimal damage at the time of arterial cannulation and provided evidence of extraluminal dissection early in the perfusion. Two cases of fatal intramural aortic dissection are reported which had an abrupt onset after satisfactory total body perfusion for 40 minutes and 60 minutes, respectively. One dissection developed as the result of an arteriosclerotic plaque in the abdominal aorta which became elevated during retrograde flow. The other dissection occurred in an apparently normal segment of the common iliac artery with total dissection of the major arterial tree which was involved with cystic medial necrosis. In both instances abnormal perfusion was immediately recognized by changes in line pressure, intraarterial pressure, and urinary output. Although both of the patients died, the clinical course in the second case strongly suggests that the dissection, regardless of its source, can be managed successfully by: 1) prompt recognition, 2) immediate cessation of retrograde perfusion, and 3) introduction of the perfusion cannula into the ascending aorta.

5. Treatment of Dissecting Aneurysms of the Aorta Without Surgery

Myron W. Wheat, Jr., Roger F. Palmer*, Thomas D. Hartley*,

and Robert C. Seelman*, Gainesville, Fla.

Acute dissecting aneurysm of the thoracic aorta is a serious therapeutic problem with a surgical mortality of 50 to 100%. Theoretical considerations indicate that depression of the initial ventricular impulse (I.V.I.) should result in a major reduction of forces impinging on the aortic wall. Drugs that reduce the rate of ventricular fiber shortening (DL/Dt) in isolated systems should result in reduction of I.V.I, in intact systems and therefore reduce forces furthering dissection. Reserpine, guanethidine, and trimethaphan but not hexamethonium reduce DL/Dt in isolated rabbit hearts. During the past six years we have treated 12 patients with acute dissecting aneurysm of the thoracic aorta. The six patients treated surgically all died. Since October 1963, six consecutive patients with acute dissecting aneurysms of the thoracic aorta have been treated for two to five days with I.V. trimethaphan and I.M. reserpine followed by maintenance on oral reserpine and guanethidine. Pain when present was relieved immediately with administration of trimethaphan. All six patients are living, four months to one year later without evidence of further dissection.

6. Metabolic Alterations Noted in Cyanotic and Acyanotic Infants During Surgery Under Hyperbaric Conditions

William F. Bernhard, Richard Danis*, and Robert E. Gross,

Boston, Mass.

Palliative or corrective surgery was carried out in 100 infants under hyper-baric conditions (30-44 p.s.i. gauge). 76 cyanotic babies (pulmonary or tricuspid atresia, tetralogy, transposition great vessels) comprised Group I, and 24 acyanotic patients (aortic or pulmonic stenosis, aortic coarctation) formed Group II. Metabolic changes were apparent in both groups; however, the most profound alterations occurred in 45 patients of Group I, less than 6 months of age. Precompression studies indicated: arterial Po₂ of 18-40 mm.Hg; lactate-pyruvate ratios (25-70), inversely related to Po₂; excess lactate (1.5-3.5 mM/L); arterial Pco₂ (35-50 mm.Hg); pH (6.90-7.25). In addition, pulmonary compliance was markedly reduced in 10 infants. Following compression, hypercarbia (45-70 mm.Hg) developed, and was treated by administration of an amine buffer. Lactate-pyruvate ratios decreased by conclusion of operation and decompression. 61 infants survived (80%). Acute metabolic disturbances also occurred in 1/3 of Group II patients. Congestive failure resulted in reduced pulmonary compliance, low pH (7.15-7.30) and hypercarbia. Lactate-pyruvate ratios were not elevated unless ventricular fibrillation ensued. Group II survival rate was 88%. These results will be compared with a separate series of 200 infants operated upon under standard conditions (1956-1962).

7. A New Disposable Membrane Oxygenator With Integral Heat Exchange

M. L. Bramson*, John J. Osborn*, F. Beachley Main*,

San Francisco, Calif., Mark F. O'Brien*, Melbourne, Australia,

John S. Wright*, Sydney, Australia, and

Frank Gerbode, San Francisco, Calif.

The paper reports the development, over a five year period, of a new disposable membrane oxygenator which is believed to eliminate some remaining obstacles to the extensive use of heart-lung machines embodying this type of lung. The design and its rationale are described, and it is shown, inter alia, that: a) a compact 14-cell lung with 5.6 sq.m. of effective membrane area, and flow rates up to 5.0 liters per min., will provide adequate O₂and CO₂ exchange for total perfusion of adults, b) the priming volume of such a lung is less than one liter, c) the hemodynamic resistance of the lung, even at high flow rates, is so low that only one pump is required for the extracorporeal circuit, d) essential constancy of the extracorporeal blood volume is maintained notwithstanding wide variations in flow rates and pressures, e) effective control of blood temperature is obtained at no cost in priming volume or additional surfaces in contact with blood, and f) greatly simplified automatic equalization of arterial inflow with venous outflow is obtained. The results of one series of laboratory, and one series of clinical perfusions are reported.

*By Invitation