Oscar Creech

Surgical implications of single coronary artery A review and two case reports

S ingle coronary artery is a rare anomaly which usually is of no clinical significance.4 In cardiac operations, however, the recognition of this anomaly may be of crucial importance. The present study describes the anatomic variants of single coronary artery, with emphasis on surgical implications. The literature is summarized since the publication of Smith’s collective review in 19.50, and two case reports are added.

Cancer Chemotherapy by Perfusion

Publisher Summary This chapter focuses on cancer chemotherapy by perfusion. Perfusion has been employed in the treatment of cases that are inoperable because of local extension of the tumor, or when the patient has refused radical and deforming extirpative operations. Techniques of regional perfusion are based on the concept that various anatomic regions can be isolated from the remainder of the circulation, supplied with a separate, extraneous system for pumping and oxygenating the blood, and can be maintained for varying periods of time under abnormal conditions without significant systemic effect. By altering the character and temperature of the perfusing medium, the normal biochemical environment of a tumor may be selectively altered. The techniques of perfusion discussed in the chapter include lower extremity perfusion, upper extremity perfusion, pelvic perfusion, brain perfusion, perfusion of oropharyngeal area, and total body perfusion. The chapter also discusses the escape of agent from the perfusion circuit. A standard technique has been developed for determining the dose of a chemotherapeutic agent to be administered by perfusion. The effect upon normal tissues in a perfused region depends upon the amount of an agent used. The pathologic changes occurring in perfused malignant tissues vary widely. In addition to the problems which may follow any major surgical procedure, perfusion techniques give rise to special problems that call for close attention during the period after treatment. The most common complication of cancer chemotherapy by perfusion is depression of hematopoiesis. Morbidity from cancer chemotherapy by perfusion is greater than what would be expected to occur after similar surgical procedures without chemotherapy.

Pressure-volume diagrams of the left ventricle of man; a preliminary report.

Abstract Pressure-“volume” diagrams of the left ventricle of intact man have been recorded. The “volume” component of the trace was obtained indirectly and, therefore, only approximates the true value. With improvements in the method, determination of this parameter should become more accurate. Developmental studies to permit simultaneous recording of the pressure-“volume” diagram and the time-course of pressure, volume, power, accumulated work, and other functions are in progress.

Evaluation of chemotherapy of cancer by regional perfusion.

At Tulane Department of Surgery 597 patients with cancer have been perfused regionally 690 times—350 patients with melanoma, 164 with carcinoma and 83 with sarcoma. Early objective responses were noted in about 70% of patients with melanoma and in 60% with carcinoma and sarcoma. The duration of response in many instances was short whereas the expenditure of operating time and medical manpower was large. In poor‐risk patients with advanced disease the mortality rate was appreciable. In some patients, however, perfusion offered more than conventional therapy and is a valuable technique. In secondary melanoma—involvement of regional nodes, satellitosis or local recurrence—control has been obtained in 10 of 38 patients five years after perfusion. In primary melanoma confined to a limb the disease has been controlled in 10 of 11 patients five years after perfusion, conservative excision and node dissection. In sarcoma confined to the limbs perfusion and wide excision produced control of disease in 10 of 14 patients at five years. Perfusion as an adjunct to excision in patients with carcinoma adds little. Good palliation has been obtained in patients with a variety of malignant tumors by control of primary disease, even in the presence of systemic metastases.

Regional Perfusion for Melanoma and Sarcoma of the Limbs

Regional perfusion was developed in 1957 to increase the tumoricidal dose of anticarcinogenic drugs without increasing its systemic toxicity. Since separation of perfused from unperfused tissues is most successful when the part can be encircled with a tourniquet, the method lends itself well to treatment of tumors of the limbs. This paper describes the operative techniques and presents the results of perfusion for melanoma and sarcoma of the limbs.

The role of the physician in surgery of the heart

Summary The personal and professional relation between physician and surgeon is important in the surgical treatment of patients with heart disease. In general, the diagnosis and evaluation of the patient rest primarily with the physician, whereas the conduct of the operation is primarily the responsibility of the surgeon. The surgeon has learned a great deal about cardiology through association with the physician. The physician who attends operations, on the other hand, broadens his own understanding of heart disease by observing the living heart and studying its behavior. The care of the patient after operation rests about equally with the physician and the surgeon, but because the patient is observed almost exclusively by the physician after discharge from the hospital, he alone can assess the relief of symptoms and any beneficial change in the natural course of the disease. As a result of developments of the past 25 years, surgery of the heart has reached maturity. Today, operation for congenital heart disease, with exception of teralogy of Fallot and other complicated anomalies, is as safe as any other major surgical procedure, and the risk of valvular replacement for acquired heart disease is being reduced rapidly. In the process, a new variety of physician, the cardiologist, has evolved. Today the cardiologist is almost as familiar with surgical treatment of patients with heart disease as the surgeon . He has explored the heart with catheter and contrast material; he has seen the septal defects and the diseased valves in the living heart; and with the surgeon he has kept watch over the patient during the critical early hours after operation when correct interpretation of minute-to-minute events is crucial. Out of this experience has come the concept of the cardiologic team, of which the surgeon is a member, the physician another, and the anesthesiologist another.

The present status of pump-oxygenators and some problems related to their use

Summary During the past decade the pump-oxygenator has been employed extensively for the support of circulation and respiration during open heart operations. It has proven to be a reliable substitute for the heart and lung within certain limits. There are three pump-oxygenator systems in general use today, namely, the Gibbon-Mayo vertical screen unit with roller pumps, the rotating disc oxygenator with roller pumps, the DeWall bubble oxygenator with Sigmamotor pumps. In each of these units oxygenation is accomplished by the creation of a blood-gas interface and the pumps are internally valved producing unidirectional, essentially non-pulsatile flow. Each system is capable of maintaining normal tensions of oxygen and carbon dioxide in arterial blood returning to the patient at flows approaching basal cardiac output. Trauma to the blood is minimal except for prolonged perfusion. The parameters measured during cardiopulmonary bypass are usually arterial and central venous blood pressure, the electroencephalogram and electrocardiogram. Arterial blood pH and total blood volume are frequently measured at the termination of perfusion. Procurement of blood for priming extracorporeal circuits has been a major problem. A number of studies have been made to determine the feasibility of using preserved blood for this purpose. Among these are the use of edglugate magnesium which permits the utilization of blood up to five days after procurement, glycerolized frozen blood and modification of blood preserved in ACD solution. Although all of these methods have promise, it would appear at the present time that the use of freshly drawn heparinized blood is desirable. The physiologic and pathologic alterations occurring during and after extracorporeal circulation have been extensively investigated. Metabolic acidosis is one of the hazards of cardiopulmonary bypass and most often results from inadequate perfusion. For this reason blood flow rates approaching basal cardiac output should be maintained at normal temperatures and reduced flow rates should only be used in association with general body hypothermia. Severe metabolic acidosis in the presence of inadequate cardiac output should be corrected promptly by administration of sodium bicarbonate and by correction of factors leading to its development. Hemolysis may result from trauma to erythrocytes occurring in the pumping system, the oxygenator or from the intracardiac suction apparatus. The ability of the reticuloendothelial system to remove free hemoglobin reduces the hazard of hemolysis since rarely does the free hemoglobin rise above 150 to 200 mg. per cent. Cellular elements undergo a moderate reduction in numbers during and in the first few days following perfusion. This is due not only to hemolysis during perfusion but to reduction in the survival of erythrocytes following perfusion. The phenomenon of sludging has been demonstrated to occur during and after extracorporeal circulation and is thought to be due to inadequate perfusion of certain vascular beds. The addition of low molecular weight dextran to the priming solution of the extracorporeal circuit appears to minimize its development. The most important recent observation concerning changes occurring in blood as a result of extracorporeal circulation concerns the denaturation of plasma proteins during the passage of blood through oxygenators. This is attributed to intermolecular energy known to exist at the blood-gas interface in the system. The reinfusion of the supernatant of plasma following passage through an oxygenator is capable of producing sludging of blood, a toxic reaction, and death in experimental animals. Furthermore, serological incompatibilities may develop as a result of these changes. Experimental studies have confirmed the clinical observations that potassium citrate arrest of the heart is poorly tolerated, because of certain metabolic changes occurring in the myocardium. Cardiac arrest should be avoided whenever possible but if necessary for the proper conduct for the operation it should be induced by hypothermia. Dilatation of the heart, particularly the left ventricle, during cardiopulmonary bypass with cardiac arrest, is poorly tolerated because of the increase in diastolic length of the myocardial fibers. Under these circumstances resuscitation is difficult. To avoid distention of the left ventricle, it should be vented during bypass whenever arrest is induced or for operations on the aortic and mitral values. Cerebral symptoms have been encountered after extracorporeal circulation and are due largely to hypoxia as a result of inadequate perfusion. In some instances cerebral embolization may be the cause of neurologic manifestations. Treatment consist of the induction of general body hypothermia to minimize cerebral edema. Pulmonary complications are frequent following extracorporeal circulation and are responsible for a large proportion of the morbidity and mortality. Problems may arise as a result of inadequate ventilation and impaired diffusion. The use of tracheostomy and a mechanical respirator are invaluable in the treatment of pulmonary complications. Renal function during extracorporeal circulation is proportional to the flow rates maintained during perfusion. Acute renal failure following operation may be due to excessive hemolysis from inadequate perfusion. The maintenance of flow rates approximating basal cardiac output minimize the development of renal insufficiency. Embolization has often been implicated as the cause of a variety of complications arising following extracorporeal circulation but in most instances the evidence is not conclusive. In conclusion, it should be emphasized that any of several types of pumpoxygenator systems will permit intracardiac operations, but only the most careful surgical technique will insure good results. In fact, too much, perhaps, has been said about the apparatus and to little about the men who use it. Certainly, there is no other surgical field which so completely separates the professional from the amateur.