Lung and heart-lung transplantation

This report is a brief summary on current events related to lung and heart-lung transplantation. Eleven patients have undergone transplantation of the heart and both lungs at Stanford University. The ages ranged from 22-45, the average age being about 36 years, and included were four females and seven males. The diagnosis was primary pulmonary hypertension in three and Eisenmenger syndrome--congenital heart disease with pulmonary hypertension--in eight. Eight patients are living and well, two to more than 24 months after transplantation of the heart and both lungs. All these patients were discharged and are fully rehabilitated, which is an important consideration. There have been three operative deaths, one was secondary to two previous operations that made our operation much too long, another was secondary to the use of intravenous cyclosporine, and the third was related to the poor maintenance of the donor lung. Three of the eleven patients were catheterized following the transplant from six months to a year after transplantation, and the pulmonary artery pressure and pulmonary vascular resistance were absolutely normal in all three of these individuals. Of course the plan is to go ahead with further catheter studies at yearly intervals in all of the patients. The last patient underwent transplantation in January, 1983. I think no matter how effective or how ingenious the medical staff is with artificial organs, it will be a long time before these early results of transplantation of the heart and both lungs can be matched by any types of artificial organ implants.

Physiologic aspects of human heart-lung transplantation. Pulmonary function status of the post-transplanted lung

Pulmonary function measurements were performed before and after heart-lung transplantation in nine patients who had undergone surgery for end-stage pulmonary hypertension. In seven of them, sequential follow-up studies were performed at variable times postoperatively with the longest period 27 months. Pre-transplant studies showed a mild restrictive defect in 33 percent and obstructive disease in 50 percent of the patients, respectively. Arterial hypoxemia was present in all patients. The degree of mechanical changes found did not appear severe enough to account for the marked dyspnea and disability characterizing this group of patients with pulmonary hypertension. Following transplantation, all patients showed striking improvement of symptoms and general physical status. In the early post-transplant period, there was a marked decrease in most lung volumes resulting in a moderately severe restrictive ventilatory defect. Flow parameters that were reduced could be related to decreased volumes and not to intrinsic airway obstruction. Arterial O2 tensions improved dramatically and gas exchange was maintained at essentially normal levels. Lung function tended to improve progressively following transplantation with the passage of time. Heart-lung transplant is consistent with an adequate long-term pulmonary functional state which has the capacity to sustain the normal activities of daily living. From the standpoint of lung function, heart-lung transplantation appears to be acceptable as a form of therapy in selected patients.

Acute physiological changes following heart-lung allotransplantation in dogs

The feasibility of clinical heart-lung transplantation requires a better understanding of the physiological consequences of the operation, heart-lung denervation, and the quality of graft preservation. An acute canine model was used to evaluate heart-lung function during the first 24 hours after transplantation. Measurements of cardiopulmonary dynamics were performed in 5 donor animals and compared sequentially after transplantation in the respective recipients. Orthotopic allotransplantation was performed on cardiopulmonary bypass with moderate hypothermia after perfusion of both the heart and lung with a clinical cardioplegic solution (4 degrees C; potassium chloride, 30 mEq/L; mannitol, 20 gm/L). Postoperatively, the animals were ventilated continuously and anesthetized. Hemodynamic variables were monitored, and measurements were made of arterial and venous oxygen, carbon dioxide, saturation, and pulmonary mechanics. Cardiac output and a derived measurement of lung water were determined. Pulmonary vascular resistance, arteriovenous shunt, resistance, and compliance were calculated. At the termination of the experiment, significant differences were observed between donor and recipient lung-water levels (7.7 +/- 0.9 ml/kg versus 12.0 +/- 3.1 ml/kg, respectively; p less than 0.05); 100% arterial oxygen tension (509 +/- 37 mm/Hg versus 227 +/- 114 mm/Hg, respectively; p less than 0.01); and pulmonary compliance (38 +/- 18 ml/cm H2O versus 11 +/- 4 ml/cm H2O, respectively; p less than 0.05). Arteriovenous shunt increased from 12.2 +/- 4 to 16.5 +/- 5% (p = 0.2). This model evaluates the technique currently employed clinically and will be used in the future to compare methods of heart-lung preservation with the goal of allowing distant heart-lung procurement.

Operative technique for heart-lung transplantation

Combined heart and lung transplantation has now been carried out in 17 patients at Stanford University Hospital. The emphasis on the management of donors is upon thorough tracheobronchial toilet and ensuring an absence of significant cardiopulmonary disease. The most important aspects of the recipient operation are to remove the heart and lungs without injury to the phrenic, vagus, or recurrent laryngeal nerves and to ensure hemostasis. This is best effected if the heart and lungs are removed separately. The operative technique for both the donor and recipient is described.

Heart and lung transplantation for pulmonary hypertension

Seventeen patients received combined heart and lung transplants at Stanford University between March 1981 and December 1983. All recipients were suffering from end-stage pulmonary hypertension. Five patients died within the first few postoperative weeks, but the remainder were well between 2 and 35 months after operation. Immunosuppression consisted of cyclosporine with an initial course of rabbit antithymocyte globulin, and azathioprine was given for the first 2 postoperative weeks. Maintenance immunosuppression was achieved with cyclosporine and prednisone. Rejection, as diagnosed by cardiac biopsy, was treated with intravenous methylprednisolone. The functional status of the survivors has been good, and upon discharge from the hospital, all returned to normal activity. Our preliminary experience indicates that cardiopulmonary transplantation represents a realistic therapeutic approach for patients with end-stage pulmonary disease.

A simple method for extended heart-lung preservation by autoperfusion

A modification of Robicsek's autoperfusing heart-lung preparation preserved normal structure in the canine lung for 8 hrs and in the heart for 12 hrs. Applicable to both heart and heart-lung transplantation, the system would permit a safe extension of preservation time limits.

Role of cardiac volume receptors in the control of ADH release during acute simulated weightlessness in man

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce central blood volume shifts in ten cardiac and one heart-lung transplant recipients to assess the contribution of cardiac volume receptors in the control of ADH release during the initial acute phase of exposure to weightlessness. Each subject underwent 15 min of a sitting-control period (C) followed by 30 min of -6 degrees headdown tilt (T) and 30 min of resumed sitting (S). Venous blood samples and cardiac dimensions were taken at 0 and 15 min of C; 5, 15, and 30 min of T; and, 5, 15, and 30 min of S. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Heart rate (HR) and blood pressure (BP) were recorded every two min. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P < .05) from 90 ml in C to 106 ml in T and returned to 87 ml in S. Plasma ADH was reduced by 20% (P < .05) with T and returned to control levels with S. These responses were similar in six normal cardiac-innervated control subjects. These data may suggest that cardiac volume receptors are not the primary mechanism for the control of ADH release during acute central volume shifts in man.

Clinical heart-lung transplantation

Combined heart and lung transplantation was carried out in thirteen patients at Stanford University between March 1981 and May 1983. The recipients were between 22 and 45 years old. All patients were suffering from end-stage pulmonary hypertension; nine patients had Eisenmenger's syndrome; the remaining four were transplanted for primary pulmonary hypertension. Three patients died within one month of surgery. The remainder are well at between 22 months and three weeks from operation. The duration of stay in the hospital for the surviving patients ranged from 38 to 85 days. The immunosuppressive protocol has been essentially the same for all recipients, and has consisted of cyclosporine with an initial course of rabbit antithymocyte globulin (RATG) with azathioprine given for the first two weeks, and then replaced with prednisone. Rejection, as diagnosed by cardiac biopsy, was treated with pulses of methylprednisolone. Early complications included bleeding that necessitated reexploration (five patients); damage to the vagus, recurrent laryngeal, or phrenic nerves (three patients); and failure of the donor lungs (one patient). Modifications of technique that have developed include removal of the recipient heart and lungs separately, and preservation of the lungs with a modified Collins' solution instead of a cardioplegic solution. The results of this operation are considerably superior to clinical efforts in lung transplantation. The combined operation may be preferable for the following reasons: All diseased tissue is removed, thus eliminating recurrent infection, and also perfusion/ventilation disparity. Transplantation of the entire heart and lung block preserves coronary-tracheal vascular anastomoses and makes airway dehiscence less likely. Diagnosis of rejection by cardiac biopsy seems to be a satisfactory method of diagnosis and treatment of pulmonary rejection.

Revascularization of tracheal anastomosis following heart-lung transplantation

The mechanism by which tracheobronchial arterial supply is reconstituted following heart-lung transplantation was investigated in seven monkeys (3 allografts, 2 autografts, and 2 nontransplanted control monkeys) and three patients. Descending tracheal branches of the thyrocervical arteries provided the major tracheal vascular supply. A collateral branch arising from atrial branches of the left coronary artery supplied tracheobronchial branches in the region of the carina in one allograft. In the three patients studied to date by coronary arteriography, a similar collateral supply to the region of the carina and proximal bronchi was demonstrated from atrial branches of both the left and right coronary circulation.

Combined heart and lung transplantation

Combined heart and lung transplantation was carried out in ten patients at Stanford University Medical Center between March, 1981, and December, 1982. All patients had end-stage pulmonary hypertension. 7 of them had Eisenmenger's syndrome and 3 primary pulmonary hypertension. 3 patients died within a month of operation, but the remaining recipients are well 2 months to 2 years after transplantation. The hospital stay of the survivors ranged from 38 to 85 days. All survivors have returned to normal activity. The results of heart and lung transplantation have thus been considerably superior to those reported previously for lung transplantation. It is suggested that cardiopulmonary replacement is suitable treatment for end-stage pulmonary hypertension with or without associated congenital heart disease and that its application to other forms of advanced pulmonary failure may be warranted.

Diagnosis and treatment of allograft rejection in heart-lung transplant recipients

Six patients received heart-lung transplants between March, 1981, and January, 1982. There were four women and two men between 26 and 45 years of age, three with primary pulmonary hypertension and three with congenital heart disease and pulmonary hypertension (Eisenmenger's syndrome). Immunosuppression was primarily with cyclosporin-A, with additional corticosteroid, azathioprine, and rabbit antihuman thymocyte globulin. Six episodes of allograft rejection in four patients (10, 11, 21, 24, 53, and 86 days after transplantation) were detected by means of transvenous endomyocardial biopsy. All patients experienced pulmonary edema early after transplantation (reimplantation response), and two patients required mechanical ventilatory support for allograft rejection at 10 and 11 days. Treatment of rejection consisted of intravenous methylprednisolone (four episodes) or augmented oral prednisone (two episodes), with resolution. No episode thought to be pulmonary rejection has occurred in the absence of cardiac findings. Four patients are alive from 6 to 15 months after transplantation and are functionally normal. Early experience with heart-lung transplantation suggests (1) that allograft rejection can be detected by cardiac findings and successfully treated by augmented corticosteroids, (2) that lung rejection does not occur in the absence of cardiac findings, (3) that the frequency and severity of rejection episodes are not greater than with standard cardiac transplantation, and (4) that the frequency of rejection episodes is highest within the first 60 days after transplantation.

Heart-lung transplantation: successful therapy for patients with pulmonary vascular disease

We report our initial experience with three patients who received heart-lung transplants. The primary immunosuppressive agent used was cyclosporin A, although conventional drugs were also administered. In the first patient, a 45-year-old woman with primary pulmonary hypertension, acute rejection of the transplant was diagnosed 10 and 25 days after surgery but was treated successfully; this patient still had normal exercise tolerance 10 months late. The second patient, a 30-year-old man, underwent transplantation for Eisenmenger's syndrome due to atrial and ventricular septal defects. His graft was not rejected, and his condition was markedly improved eight months after surgery. The third patient, a 29-year-old woman with transposition of the great vessels and associated defects, died four days postoperatively of renal, hepatic, and pulmonary complications. We attribute our success to experience with heart-lung transplantation in primates, to the use of cyclosporin A, and to the anatomic and physiologic advantages of combined heart-lung replacement. We hope that such transplants may ultimately provide an improved outlook for selected terminally ill patients with pulmonary vascular disease and certain other intractable cardiopulmonary disorders.