Wednesday Morning, April 29, 1964

8:30 A.M. Scientific Session: THORACIC SURGERY FORUM

Grand Ballroom

31. Blood Loss Associated with Administration of Low Molecular Dextran

Antonio A. Garzon*, Gerald W. Shaftan*,

and Karl E. Karlson, Brooklyn, N.Y.

Five groups of dogs were bled a volume equivalent to the test infusion. According to group, they were immediately infused with either 30 ml./kg. L.M.D. in saline, 20 ml./kg. L.M.D. plus 10 ml./kg. saline, 10 ml./kg. L.M.D. plus 20 ml./kg. saline, 30 ml./kg. saline or 30 ml /kg. auto-logous blood. One group was neither bled nor infused and only repeat sets of incisions were made. Before bleeding five incisions down to fascia were made on one flank of each dog. After bleeding and infusion of the test solution, five similar incisions were made in the other flank. The duration of bleeding and amount of blood loss per unit time was determined for each set of incisions. The following coagulation tests were performed before infusion and 15 minutes, 60 minutes, and 4 hours after infusion: clotting time, clot retraction, whole blood clot lysis, euglobulin clot lysis, prothrombin consumption, prothrombin activity, fibrinogen, and platelet count. There was no significant change in any of these tests attributable to L.M.D. Only animals receiving L.M.D. had increased bleeding. Duration of bleeding increased an average of 15% after 10 ml./kg. L.M.D., 462% after 20 ml./kg., and 407% after 30 ml./kg. L.M.D. Weighed blood loss increased 1.8-fold after 10 ml./kg. L.M.D., 4 6-fold after 20 ml./kg, and 42-fold after 30 ml./kg. L.M.D.

32. Extracorporeal Circulation, Pulmonary Compliance, and Pulmonary Surfactant

Isidore Mandelbaum*, and Samuel T. Giammona*,

Indianapolis, Ind.

Sponsored by Harris B Shumacker, Jr.

Respiratory insufficiency may be a serious problem following extracorporeal circulation. This experiment was carried out to study the effects of extra-corporeal circulation upon the pressure-gas volume relationship and surface active agent content of a dog's lung. Since cardiopulmonary bypass is associated with decreased pulmonary arterial blood flow, the left pulmonary artery was occluded initially in 7 dogs for 3 hours There was no alteration in the pressure-volume curves or surfactant content (modified Wilhelmy and Du-Nuoy methods). In 7 animals, the left pulmonary artery was ligated for two weeks. The surfactant content of the left lung decreased considerably and pulmonary compliance fell 50 per cent In 9 dogs, cardiopulmonary bypass with extracorporeal circulation was performed and hourly determinations of pulmonary pressure-volume relationship and surfactant content carried out for 5 hours. There was a progressive decrease in compliance. Surfactant content remained normal until the fourth hour when significant decreases occurred. No surfactant inhibitor was detected in the pump-oxygenator blood. Therefore, temporary pulmonary ischemia for 3 hours has no demonstrable effect upon pulmonary compliance or surfactant content of the lungs. Prolonged ischemia for two weeks alters both factors appreciably. During extra-corporeal circulation, compliance is decreased progressively and significant decreases of surfactant occur after 4 hours

33. Cooling Gradients and Brain Damage with Deep Hypothermia

Carl almond*, John C. Jones, Bert W. Meyer, and

H. Martin Snyder*, Los Angeles, Calif.

During our own experience with deep hypothermia, patients were cooled rapidly and a portion of them suffered brain damage. Drew found mental changes in the first four cases operated upon with a more efficient heat exchanger with rapid cooling. Bjork reported brain damage in five children operated upon utilizing deep hypothermia. In this experiment, dogs were cooled with wide and narrow cooling gradients to determine the effect upon the brain. Brain cell death was seen in the cerebellum, hippocampus, cerebral cortex and basal ganglia in animals cooled rapidly with wide gradients of 15 degrees to 25 degrees Centigrade to temperatures below 10 degrees C. and arrested for thirty minutes. Animals cooled slowly with 5 degrees C. gradients showed only microscopic brain edema. These findings are consistent with the pathological findings reported by Bjork. Clinical evidence has suggested, and this experimental evidence tends to verify the fact that the rate of cooling is important as a cause of brain damage utilizing deep hypothermia.

34. Hemodynamic Studies Before and After Cardioversion

Donald R. Kahn*, William Weber*, William S. Wilson*,

and Herbert Sloan, Ann Arbor, Mich.

Fifteen patients from one week to eight months after successful mitral valve surgery were studied during atrial fibrillation. The electrocardiogram, central aortic pulse and the cardiac output were measured at rest and after three minutes of exercise (710 foot lbs. per min.). Atrial fibrillation was converted to normal sinus rhythm by DC shock, and the above variables were measured six to twelve hours later. During normal sinus rhythm the mean resting cardiac output was 22% higher and the mean cardiac output during exercise was 34% higher than during atrial fibrillation. The increase in cardiac output with exercise during atrial fibrillation was associated with a large rate increase and a small decrease in stroke volume. During normal sinus rhythm the increase in output during exercise was greater and was associated with an increase in both rate plus stroke volume. Patients having a mitral Starr-Edwards valve prosthesis differed qualitatively in that the increase in output after exercise during normal sinus rhythm was not associated with an increase in stroke volume. These studies indicate that atrial contraction significantly augments ventricular performance and suggest that patients with the Starr-Edwards prosthesis cannot increase their stroke volume.

35. Evaluation of Factors Involved in Gastroesophageal Reflux

Harold Stern, Daniel H. Winship*, Lewis M. Karas*,

Walter R. Thayer*, Gilbert S. Melnick*, Elton R. Poindexter*,

and Howard M. Spiro*, New Haven, Conn.

The esophagus of the Macaca mulatta (Rhesus) resembles that of the human anatomically and physiologically. For this reason, it is ideally suited for studies to evaluate factors affecting esophago-gastric reflux. We have studied esophageal function in unanesthetized but restrained monkeys by means of manometric motility techniques, pH determinations, using inlying electrodes, and cineradiographic studies. After the normal sphincteric mechanism was evaluated, various surgical procedures which might effect reflux at the gastroesophageal junction were performed. These included production of fixed or sliding hiatus hernias, unilateral and bilateral phrenic nerve crush, removal of the diaphragmatic sling mechanism, and resection of the gastroesophageal junction as well as alteration of the angle of entry at the junction. Postoperative studies have helped to assess the relative importance of intrinsic and extrinsic sphincteric mechanisms in the prevention of esophageal reflux and will be documented by demonstration of appropriate cineradiographic and esophageal motility studies.

36. Replacement of the Left Hemidiaphragm by an Abdominal Muscular Flap

Jens G Rosenkrantz*, and Ernest K. Cotton*,

Denver, Colo.

Sponsored by William R. Waddell

A simple technique for replacement of the left hemidiaphragm and its application in an infant with agenesis of the left hemidiaphragm are reported. A muscular flap was fashioned from the left upper abdominal wall which, already attached along the costal margin, was swung down and sutured medially and posteriorly to replace the left hemidiaphragm. The details of the procedure will be described. In order to evaluate the function of this innervated muscular flap, two groups of puppies were subjected to trans-abdominal excision of the left hemidiaphragm; in one group the left hemidiaphragm was replaced by the muscular flap; and in the second group by Marlex mesh. Survivors were sacrificed and studied at various times post-operatively (up to one year) and compared with a group of normal dogs of similar ages The following were observed: diaphragmatic excursion under the fluoroscope, integrity at autopsy of the diaphragmatic replacement; and pressure-volume curves on the excised, degassed lungs. The results will be discussed in detail. From these studies it is concluded that this is a simple method for replacement of the left hemidiaphragm and offers certain advantages over previously described procedures

37. Diaphragmatic Thoracoplasty

William D. Logan, Jr.*, Nicholas D. Exarhos*,

and Osler A. Abbott, Atlanta, Ga.

The control of intrathoracic space following lobectomy has been managed .by various methods. Primarily these consist of disfiguring procedures on "the chest wall or the insertion of foreign material into the pleural space. Incising the diaphragm at the periphery and re-implantation at several rib spaces higher will effectively decrease the intrathoracic space following lobectomy in animals. Twelve dogs were operated upon and the diaphragm transplanted following upper or lower lobectomy. Preoperative and postoperative pulmonary function studies and postoperative pulmonary angiograms were done on four animals. All of the animals survived, and their studies were normal. The diaphragm seemed to retain most of its motion and function. This study would indicate that this procedure is surgically feasible and has the advantage of no deformity of the chest wall, no foreign material placed inside the chest, and good postoperative lung function.

38. Definitive Anatomic Repair of Ebstein's Malformation: A New Surgical Technique

Kenneth L. Hardy*, Ivan A. May*,

Charles A. Webster*, and Kent G. Kimball*,

Oakland, Calif.

Sponsored by Paul C. Samson

The complex of deformities included under the heading of Ebstein's Malformation has become more clearly understood in the past few years with the use of more refined diagnostic techniques. Heretofore the surgical therapy of this condition has been limited to a palliative procedure which included some form of right heart by-pass, such as caval-pulmonary artery anastomosis or systemic pulmonary artery shunting. A concept of the physiologic abberations in this condition, together with a surgical technique to correct the altered cardiodynamics, will be defined. A case with preoperative and six months postoperative follow-up, with electrode catheter data, will be presented in which successful anatomic correction of the deformity was carried out, illustrating the validity of the concept.

39. Evaluation of Cardiac Drugs in the Presence of an Implanted Pacemaker: Experimental Study

Pierre Grondin*, Gilles Lepage*, Jean Guicnard*,

and Aydin Karamehmet*, Montreal, Canada

Sponsored by Edouard D. Gagnon

An ever increasing number of cardiac patients have benefited from an implantable pacemaker. These patients occasionally will require some form of treatment for associated cardiac conditions. An effort is made to elucidate problems that have arisen in the postoperative and long-term management of these patients. In the presence of myocardial insufficiency should the treatment be different? A number of authors have frowned upon the use of digitalis. Isoproterenol has been blamed for the occurrence of sudden ventricular fibrillation induced by the electrical stimuli as reported in such conditions. Using two groups of dogs the individual effects of digitalis, quinidine, procaine amide and isoproterenol have been studied. Group A consists of animals with an implantable pacemaker in which a complete A-V block was surgically created. In group B a pacemaker was implanted but the normal sinus rhythm was preserved. These groups fairly well represent the clinical conditions of patients first with a permanent block and second with an intermittent A-V dissociation. The conclusion of these studies are demonstrated.

40. The Surgical Management of Transposition of the Great Vessels

W. T. Mustard, J. D. Keith*, G. A. Trusler*, R. Fowler*,

and L. Kidd*, Toronto, Canada

Mortality from this condition is extremely high in the first few months of life. Total correction under six months will probably remain a surgical feat with a high mortality. A palliative procedure in the neonatal period which would allow subsequent total correction appears to us to be a satisfactory goal. Our results, and those of others, of creating an atrial septal defect in the first few months are encouraging; 75% of these infants can be improved. The second stage, total correction, should be performed before the child deteriorates or develops irreversible pulmonary vascular changes. The operation should be as simple as possible and allow for growth of the heart. Preliminary studies in the laboratory demonstrated that autogenous pericardium will grow when sutured into the atrial wall in piglets. An operation was devised in which a pericardial baffle transposed pulmonary venous return to the right ventricle and systemic venous return to the left ventricle. This procedure has been clinically successful and will be described in detail.

41. Evaluation of Cardiac Function by Suprasternal Puncture

V. L. Willman*, C. R. Hanlon, P. N. Symbas*,

J. J. Kelly*, and J. G. Mudd*, St. Louis, Mo

Measurement of pressure and wave forms in the left atrium and pulmonary artery is useful in evaluation of patients with disease of the mitral valve. The transbronchial, paravertebral percutaneous and transseptal approaches to the left atrium are undesirable because of complexity, discomfort or significant complications. The percutaneous suprasternal puncture of the great vessels and left atrium is simple and safe. It may be performed under local anesthesia without fluoroscopy in less than thirty minutes. Despite its limitations as an investigative tool, it provides information valuable in making clinical decisions. We shall present our experience with the technique including complications and comparison with other methods in a total of 280 patients.

42. Carbodissection of Perivascular Tissue

Russell M. Nelson, and Brent C. Sanders*,

Salt Lake City, Utah

The feasibility of dissecting blood vessels from surrounding investiture by carbon dioxide gas under pressure has been evaluated experimentally and clinically. An apparatus has been developed to accomplish this. Experimental studies were performed in 16 dogs to assess the limits of safety in the event of inadvertent arterial or venous administration of the gas. Safe limits were found to be up to 15 ml/kg. A transient rise in pCO₂ was found, but no effect was observed on survival, pH or pO₂ values. Clinically, this technique has been employed most helpfully in aortic and pulmonary surgery and in secondary cardiac operations in separating pericardial adhesions. No complications have been observed. The assistance rendered to the process of dissection has been gratifying, as will be illustrated by motion pictures. In the dense planes surrounding certain difficult aortic aneurysms, this technique has its limitations, however. The apparatus for sterilizing and delivery of 100% CO₂ gas for dissection will be illustrated.

43. In Vitro Preservation of the Heart with Hypothermia and Hyperbaric Oxygen

Jack H. Block*, William G. Manax*, and

Richard C. Lillehei*, Minneapolis, Minn.

Sponsored by Richard L. Varco

There is a great need for a simple method to preserve hearts in vitro for transplantation. Previously, others have frozen dog hearts with a variety of preservative solutions. Inevitably upon thawing and re-establishing coronary circulation to such hearts in the necks of host dogs, these hearts have shown severe tissue damage and have beat only briefly, if at all. In contrast are the results when dog hearts are held in vitro for 24 hours in a small, pressure-cooker sized hyperbaric chamber at 0 to -4°C and 3 atmospheres of oxygen. When these hearts are placed in the neck of host dogs and coronary circulation restored, the hearts promptly resume beating for prolonged periods without evidence of tissue damage. Neither hypothermia alone nor hyperbaric oxygen alone gives the same results as the combination of the two. Further studies are in progress to find if dog hearts preserved for 24 hours with hypothermia and hyperbaric oxygen will support the circulation when replaced as functioning homografts. If so, such a procedure may be of value in preserving cadaver hearts for transplantation.

*By Invitation