Richard R. Lower

Successful homotransplantation of the canine heart after anoxic preservation for seven hours

Abstract Experiments are described in which successful homotransplantation of the dog heart was carried out after seven hours of cardiac anoxia. During the period of extracorporeal preservation, the arrested heart was maintained at 2 to 4 °C. by immersion in cold saline solution. Two animals recovered after transplantation and lived for seven and eleven days, respectively, at which time death was caused by homograft rejection.

ATRESIA OF THE AORTIC ARCH.

A case report of a 16-year-old white girl is presented with the cardiovascular anomaly consisting of interruption of the aortic arch between the innominate artery and the left common carotid artery and distal to a right ligamentum arteriosum. This case is unique because the interruption of the aortic arch was not associated with intracardiac anomalies, a patent ductus arteriosus was not present, and the patient had minimal symptoms. This is the sixth reported attempt at surgical correction of interruption of the aortic arch and represents the fourth successful one.

Electrocardiograms of Dogs with Heart Homografts

Serial electrocardiograms from 50 dogswhich survived 4 days to 12 months with orthotopic cardiac homografts have been evaluated. Although sinus rhythm is the basic mechanism in all homografted hearts, arrhythmias are frequently encountered early in the post-transplant period and later during episodes of threatened rejection. The decrease in QRS voltage which consistently accompanies impending rejection makes the electrocardiogram indispensable in monitoring the cardiac homograft.

Suppression of Rejection Crises In the Cardiac Homograft

aboratory studies of cardiac transplantation have brought to light several unique problems in operative and postoperative manageA ment which require thorough evaluation before clinical trials are to be considered seriously. Attention in this report is focused on two areas: posttransplantation recovery of the heart, and recognition and treatment of cardiac rejection. Observations have been drawn from 20 control homotransplants living 4 to 21 days and 25 animals treated with immunosuppressants surviving from 6 to 230 days.

SPECIAL PROBLEMS IN TRANSPLANTATION OF THE HEART

For 60 years orthotopic transplantation of the heart was thought to be impossible, on both surgical and physiological grounds. In 1905, Carrel and Guthrie transplanted puppy hearts into the necks of adult animals, and for the next 55 years this preparation, modified by Mann and his associates in 1933,2 was the standard for studies of the heart transplant. By €960, with the use of the heartlung machine, topical hypothermia for protection of the anoxic myocardium, and a method for combining the venous anastomoses, that segment of the achievement which was purely surgical had been attained.3 Because of homograft rejection, physiological studies of the heart transplant were delayed until cardiac autotransplantation supplied the requisite long-term s u ~ i v o r s . ~ Acute cardiac denervation produced surprisingly few untoward effects, and two years later, reinnervation was documented. Profiles of cardiac performance were equal to those found in control animals. The last three years, then, have seen considerable progress in meeting the surgical and physiological objections to heart transplants. Enough has been achieved, in fact, to provoke expression of the concept that only the immunological barrier lies between this day and a radical new era in the treatment of cardiac diseases. Furthermore, with a definite increase in survival of renal homografts, it seems logical to conclude that cardiac homografts are just around the corner. The purpose of this report is to identify some problems which require solution before the golden moment in tissue transplantation is upon us.

Pretransplant transfusions in cardiac allograft recipients.

The role of pretransplant transfusion in cardiac allograft recipients was determined retrospectively in 68 patients. Three groups were studied: group 1 (n=29) received no pretransplant transfusion, group 2 (n=15) received transfusion over one year prior to transplantation, and Group 3 (n=24) received 5 or 10 50–100 ml units of random donor red blood cells or buffy coat 2–4 weeks prior to transplantation. Data were analyzed for survival, number of rejection episodes, and number of infections. Immunosuppression included azathioprine, prednisone, and antithymocyte globulin. Survival in transfused patients (groups 2 and 3) was 68% and 51% at 1 and 5 years, respectively, while in the nontrans-fused population (group 1) it was 35% and 16%. The incidence of rejection episodes per year of survival was similar in the three groups (group 1: 1.3, group 2: 1.1, group 3: 1.3; P<0.05). The number of infections per year of survival were greater in the transfused patients but this did not achieve statistical significance (group 1: 1.0, group 2: 1.2, group 3: 1.7; P<0.05). Thus, we conclude that cardiac transplant recipients who have received blood transfusions prior to transplantation may have enhanced survival over patients who have not received preoperative transfusions.

Isolated tricuspid insufficiency: Report of a case with valve replacement

Abstract We have described a case of isolated tricuspid insufficiency in a 34 year old man with a history of prior chest trauma. Clinical, radiologic and laboratory evaluation firmly established the diagnosis of tricuspid insufficiency which was successfully treated surgically by the implantation of a Starr-Edwards valve.

Homograft Heart Valves

T HE STUDY OF homograft heart valves was greatly stimulated in 1962, when Kerwin et al.1 demonstrated function of a cadaver aortic valve which had been placed, seven years before, in a patients descending thoracic aorta.2 Duran and Gunning3 demonstrated the feasibility of using aortic valve homografts in the normal subcoronary position, and clinical trials have been reported by Ross4 and by Barratt-Boyes,5 with good early functional results. Despite the efforts of these few interested groups, general acceptance of the use of homograft valves has been delayed because their fate is not yet predictable. Characteristics which require assessment include the durability of homograft tissue, resistance to endocarditis and thrombosis, the effects of homograft rejection, the potential of replacement by autologous cells, and the possible ongrowth of fibrous tissue from the base similar to that which produced rigidity of synthetic prosthetic leaflets. The optimum manner of valve preparation and storage needs further appraisal to determine the effect on ultimate durability and the other characteristics mentioned above. Replacement of canine pulmonic, mitral, and aortic valves with homologous valves has been performed in this laboratory over the past six years in an effort to answer some of these questions.

RESULTS OF TOTAL SURGICAL CORRECTION FOR FALLOT'S TETRALOGY.

Forty-four consecutive patients have been operated upon for total correction of Fallots anomaly since the opening of the Stanford Medical Center. There were no hospital or operative deaths. The combination of uniformly reversible cardiac arrest, meticulous placement of sutures for closure of the ventricular septal defect, and a flexible plan for enlarging the outflow tract has markedly reduced the operative risk for total surgical correction of Fallots tetralogy.

Present Status of Cardiac Transplantation

Presented at the Eleventh Annual Meeting of the American College of Angiology, New York Citv. June lf-19. 1965. From The Division of Cardiovascular Surgery, Stanford University School of Medicine, Palo Alto, California. Study supported in part by U. S. P. H. S. Grant No. HE-08696. Orthotopic transplantation of the heart became a useful laboratory preparation in 1960.’ Both homotransplantation and autotransplantation were studied