Pulmonary reimplantation response

Heart-lung transplantation for irreversible pulmonary hypertension

Combined heart and lung transplantation was carried out in 17 patients at Stanford University between March, 1981, and December, 1983. The recipients were between 22 and 45 years old. All patients had end-stage pulmonary hypertension; 10 had Eisenmenger's syndrome and the remaining 7, primary pulmonary hypertension. Five patients died within the first few postoperative weeks. The remainder are well between four weeks and 33 months from operation. The immunosuppressive protocol has consisted of cyclosporine with an initial course of rabbit antithymocyte globulin. Azathioprine also was given for the first two weeks and then was replaced with prednisone. Rejection, as diagnosed by cardiac biopsy, was treated with high doses of methylprednisolone. Modifications of technique that have developed include the removal of the recipient heart and lungs separately, and preservation of the lungs with a modified Collins' solution instead of a cardioplegic solution. Rejection occurred in 6 of the 12 survivors. Infections developed in 9 patients, but only one resulted in a fatal outcome (Legionella). Thus, the results of clinical heart-lung transplantation have been considerably superior to clinical efforts in lung transplantation. It is suggested that the combined operation is preferable for the following reasons: (1) all diseased tissue is removed, thus eliminating recurrent infection and ventilation/perfusion disparity; (2) transplantation of the entire heart-lung block preserves coronary-bronchial vascular anastomoses and makes airway dehiscence less likely; and (3) to date, diagnosis of rejection by cardiac biopsy has appeared to be a satisfactory method of diagnosing and treating pulmonary rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Lung transplantation in the rat: II. lung perfusion scintigraphy in normal and left lung-transplanted rats

Lung perfusion scintigraphy with technetium 99m-labeled microspheres was performed in a series of 14 normal rats. The mean value of left lung perfusion was 36.9 +/- 4.9% of total lung perfusion. Duplicate determinations on three possible error levels were evaluated statistically: (1) separation of the lung fields on the computer scintigram, (2) positioning of the animal under the gamma camera, and (3) measurement after a one-week interval. The determinations resulted in standard deviations of (1) 2.8%, (2) 0, and (3) 1.4%, respectively. These results are comparable with those of lung perfusion studies in dogs. Lung perfusion scintigraphy, chest roentgenography, and postmortem examination were used in the functional evaluation of two groups of left lung-transplanted rats: Group A (n = 12) had short-term follow-up and Group B (n = 11) had long-term follow-up. A common finding in Group A was a subnormally perfused and aerated graft, showing normal lung tissue for the most part at postmortem examination. In Group B, grafts were rarely perfused and aerated. At postmortem examination, they were fibrotic or abscessed, possibly due to chronic rejection. A good correlation was found between perfusion scintigraphy, chest roentgenography, and postmortem findings.

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.

Human lung transplantation

The 38th attempt at allotransplantation of a human lung is described in a patient with injury due to smoke inhalation. The innovative features in the procedure included prolonged support with an extracorporeal membrane oxygenator during and for four days following transplantation, pharmacologic control of platelet function with sulfinpyrazone, continuous monitoring with a fiberoptic ear oximeter, and pretreatment of the transplanted lung with cytotoxic durgs. The patient survived until the 18th postoperative day, with no evidence of tissue rejection, but he died following ischemic disruption of the bronchial anastomosis. We conclude that the major determinant in the future of human lung transplantation is related to the establishment of a bronchial arterial supply to the transplanted bronchus.

Lung preservation techniques

Some of the barriers to successful lung transplantation include the lack of acceptable methods for ischemic protection and the absence of reliable systems for preservation. The lung response to 60 minutes of warm ischemia basically consists of alveolar-capillary edema and disruption, mitochondria swelling, interstitial hemorrhage, significantly depressed pulmonary function, elevation of pulmonary vascular resistance, and considerable drop in levels of glucose, phospholipids, and adenosine triphosphate. The tolerance to warm ischemia increases to several hours with the use of different systems of ventilatory assistance with or without positive end-expiratory pressure. Several methods of preservation have been attempted: hypothermia, hyperbaria, and hypothermic pulsatile or nonpulsatile perfusion. Hypothermic pulsatile perfusion appears to offer longer periods of protection than the other methods. Longer periods of ischemia and extended preservation may be made possible by advances in the use of drug protection during warm ischemia and the utilization of intracellular colloid or noncolloid solutions for hypothermic storage or hypothermic pulsatile perfusion.