Simplified operative method for heart and lung transplantation

History of Lung Transplantation

Lung transplantation remains the only available therapy for many patients with end-stage lung disease. The number of lung transplants performed has increased significantly, but development of the field was slow compared with other solid-organ transplants. This delayed growth was secondary to the increased complexity of transplanting lungs; the continuous needs for surgical, anesthetics, and critical care improvements; changes in immunosuppression and infection prophylaxis; and donor management and patient selection. The future of lung transplant remains promising: expansion of donor after cardiac death donors, improved outcomes, new immunosuppressants targeted to cellular and antibody-mediated rejection, and use of xenotransplantation or artificial lungs.

Brief Overview of Lung, Heart, and Heart-Lung Transplantation

Lung transplantation, heart transplantation, and heart-lung transplantation are life-saving treatment options for patients with lung and/or cardiac failure. Evolution in these therapies over the past several decades has led to better outcomes with application to more patients. The complexity and severity of illness of patients in the pretransplant phase has steadily increased, making posttransplant intensive care unit management more difficult. Despite these factors and the pervasive complications of immunosuppressive therapy, outcomes continue to improve.

History of lung transplantation

Lung transplantation nowadays is a well-accepted and routine treatment for well selected patients with terminal respiratory disease. However, it took several decades of experimental studies and clinical attempts to reach this success. In this paper, we describe the early experimental activity from the mid-forties until the early sixties. The first clinical attempt in humans was reported by Hardy and Webb in 1963 followed by others with short survival only except for one case by Derom et al. who lived for 10 months. Long-term successes were not reported until after the discovery of cyclosporine as a new immunosuppressive agent. Successful heart-lung transplantation (HLTx) for pulmonary vascular disease was performed by the Stanford group starting in 1981 while the Toronto group described good outcome after single-lung transplantation (SLTx) for pulmonary fibrosis in 1983 and after double-lung transplantation for emphysema in 1986. Further evolution in surgical techniques and in transplant type for the various forms of end-stage lung diseases are reviewed. The evolution in lung transplantation still continues nowadays with the use of pulmonary allografts coming from living-related donors, from donors after circulatory death, or after prior assessment and reconditioning during ex vivo lung perfusion (EVLP) in an attempt to overcome the critical shortage of suitable organs. Early outcome has significantly improved over the last three decades. Better treatment and prevention of chronic lung allograft dysfunction will hopefully result in further improvement of long-term survival after lung transplantation.

Heart-lung versus double-lung transplantation for suppurative lung disease

OBJECTIVE

The purpose of this study was to compare outcomes after heart-lung or double-lung transplantation in patients undergoing transplantation because of end-stage suppurative lung disease.

METHODS

We reviewed our experience in patients with cystic fibrosis or bronchiectasis who had heart-lung or double-lung transplantation between January 1988 and September 1997. Twenty-three patients (14 male, 21 cystic fibrosis) had heart-lung transplantation and 24 patients (8 male, 19 cystic fibrosis) had double-lung transplantation. There were no statistically significant differences between the groups in age, weight, preoperative creatinine level, cytomegalovirus status, maintenance immunosuppression, or donor demographics. Patients received induction therapy with monoclonal (OKT3) or polyclonal (rabbit anti-thymocyte globulin) antibody.

RESULTS

Sixteen of 24 patients had double-lung transplantation after 1994 whereas 13 of 22 patients had heart-lung transplantation before 1991, allowing longer follow-up for the heart-lung group. Mean waiting times for transplantation were 270 +/- 245 days (heart-lung) and 361 +/- 229 days (double-lung; P =.20). The 1-, 3-, and 5-year actuarial survival figures were respectively 86%, 82%, and 65% (heart-lung) and 96%, 75%, and unavailable (double-lung; P = no significant difference). The 1-, 3-, and 5-year rates of freedom from obliterative bronchiolitis were respectively 77%, 61%, and 45% (heart-lung) and 86%, 78%, and unavailable (double-lung; P = no significant difference). Linearized overall infection rates (events/100 patient-days) were 2.05 +/- 0.33 (heart-lung) and 2.34 +/- 0.34 (double-lung; P = NS) at 3 months. Thirty-day survival was 100% (heart-lung) and 96% (double-lung). There were 7 late deaths among heart-lung recipients (3 obliterative bronchiolitis, 2 infection, 0 graft coronary artery disease, 2 other) whereas 2 late deaths related to obliterative bronchiolitis occurred in double-lung recipients. Graft coronary artery disease (all stenoses < 50%) affected 15% of heart-lung survivors, whereas 3 double-lung recipients (12.5%) required either bronchial dilatation or stenting.

CONCLUSION

Heart-lung and double-lung transplantation provide similar palliation for patients with end-stage suppurative lung disease. Therefore double-lung transplantation should be the preferred operation for most patients with end-stage suppurative lung disease.

Heart and Heart-Lung Transplantation: An Update

Heart and heart-lung transplantation have been established as effective treatments for a wide variety of end-stage cardiopulmonary diseases. Recent years have seen refinements in surgical techniques for cardiopulmonary replacement as well as the selection and postoperative care of thoracic transplant recipients. Despite substantial clinical progress, however, significant problems remain, particularly donor organ shortage, graft rejection, opportunistic infection, and limited organ preservation techniques. Basic and clinical research are currently addressing these problems. In this brief review, we provide an update of our experiences with heart and heart-lung transplantation in the West (particularly at Stanford University), an outline of the active issues in the field, and some thoughts about the development of thoracic transplantation in Asia.

Haemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

Haemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in 10 cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 degrees head-down tilt (HDT) followed by 30 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15 and 30 min of HDT, and 5, 15 and 30 min of seated recovery. Blood samples were analysed for haematocrit, plasma osmolality, plasma renin activity (PRA) and ADH. Resting plasma volume (PV) was measured by Evans blue dye and per cent changes in PV during posture changes were calculated from changes in haematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. In the cardiac transplant subjects, mean HR decreased (BP less than 0.05) from 102 b.p.m. pre-HDT to 94 b.p.m. during HDT and returned to 101 b.p.m. in seated recovery while BP was slightly elevated (P less than 0.05). PV was increased by 6.3% (P less than 0.05) by the end of 30 min of HDT but returned to pre-HDT levels following seated recovery. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 +/- 5 ml pre-HDT to 105 +/- 4 ml during HDT and returned to 88 +/- 5 ml in seated recovery. Plasma ADH was reduced by 28% (P less than 0.05) by the end of HDT and returned to pre-HDT levels with seated recovery. PRA was also reduced by 28% (P less than 0.05) with HDT. These responses were similar to those of six normal cardiac-innervated control subjects and one heart-lung recipient. Therefore, cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.

Donor core-cooling provides improved static preservation for heart-lung transplantation

Twenty-three dairy calves underwent heart-lung allotransplantation after donor organs were procured using either donor core-cooling through cardiopulmonary bypass (CPB) or pulmonary artery flush (PAF) to assess which method provides optimal graft preservation. In Groups 1 (control) and 2, donors were cooled to 15 degrees C on CPB and organs were either immediately transplanted (Group 1) or stored in saline solution (4 degrees C) for 4 hours (Group 2) prior to transplantation. In Group 3, donors were pretreated with prostaglandin E1 prior to PAF with modified Euro-Collins solution. Organs were stored in saline solution (4 degrees C) for 4 hours and were then transplanted. Acute cardiopulmonary function following transplantation was assessed by the ratio of end-systolic pressure to end-systolic dimension, extravascular lung water (EVLW), lung compliance, arterial oxygenation, and lung biopsy. Cardiac function after the transplantation procedure was similar in all groups, but EVLW values and lung biopsy scores were worse after PAF. Arterial O2 tension appeared lower after PAF, but not significantly so. Core-cooling provides superior static preservation and thus improved graft function in the acute bovine model.

The effect of hypothermic preservation of the heart and lungs on cardiorespiratory function following canine heart-lung transplantation

The effect of hypothermic preservation of the heart and lungs with a crystalloid solution was evaluated in 12 mongrel dogs receiving heart-lung allografts. Six animals served as controls and received an immediate heart-lung transplant. Six animals were in the experimental group and received a heart-lung transplant after 5 hours of preservation at 4 degrees C following perfusion of both organs with a crystalloid solution. Physiological function of the heart and lungs was studied for 20 hours after transplantation. While cardiac function was minimally depressed following preservation, pulmonary function testing demonstrated significantly greater increases in extravascular lung water in experimental animals, suggesting that an ischemic lung injury occurred with this preservation technique. The model allows for future evaluation of other methods of combined preservation of both the heart and lungs for transplantation.

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.

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.