Reversible Hyperinflation in Emphysema

Reversible ~rlnfiation

Emphysema

in s.

Ma,.,holli. Hem, M .D.;t Hobert Bomer, F.R.C.S.;* Stuart W Jamieson, M.B . F.R.C.S.;* joseph Tashjian, M.D.§ and Robert A HaloorBeR, M .D.§

Pulmonary emphysema results in hyperinflation of the lungs and concomitant changes in the configuration of the

thoracic cavity. We descn"be a patient who underwent bilateral lung transplantation fur emphysema due to alpha, antitrypsin de8cieney. Dramatic changes in chest dimensions and configuration occurred following transplantation, demonstrating the dynamic and reversible nature of the thoracic cavity abnormalities of emphysema. (Cheat 1989; 96:421-22)

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ulmo nary emphysema results in hyperinflation of the lungs and concomitant changes in the configuration of the thoracic cavity.'"" The advent of clinical lung transplantation has given us the opportunity to determine the degree of plasticity of the chest wall changes of emphysema. In this report, we present a patient who underwent bilateral lung transplantation for emphysema due to alpha-antitrypsin de6ciency, and describe the dramatic changes in the thoracic cavity configuration which occurred following transplantation. CASE REPORT

A 43-year-old man was evaluated prior to lung transplantation. A diagnosis of alpha,-antitrypsin deHciency had been made in 1981 when he presented with exertiooal dyspnea. At that time , his FEV, was 0.9 liters and increased by 20 percent with inhaled bronchodilators. He was treated with theophylline, inhaled p-adrenergic agonist!, prednisone, and oxygen. Over the ensuing years, his exercise tolerance gradually decreased and he was forced to take a desk job. In December, 1986 be was referred to the University of *From The University of Minnesota and The Minnesota Heart and Lung Institute, Minneapolis. tDivision of Pulmonary Medicine, Department of Internal Medicine. *Department of Radiology. 'Division of Cardiovascular and Thoracic Surgery, Department of Surgery. Reprint requem: Dr. Hertz, Box 227 MalP Memorial Building, Unioemty ofMinnuotD HorpittJl, MinneapOlU 55455

Minnesota Medical Center for evaluation . The patient had a 15 pack-year cigarette smoking history and quit smoking in 1980. He has a brother with severe emphysema. Physical examination revealed a large-chested man in mild respiratory distress at rest. The chest was hyperresonant to percussion. The breath sounds were markedly diminished and no wheezes, rales or rhonchi were heard. Jugular venous distention, hepatomegaly and edema were absent. The a1pha,-antitrypsin level was 54 mgldl, and the Pi phenotype was Z. Pulmonary function tests revealed an FEV, ofO.5lilers (15 percent of predicted) and an FVC of 2.3 liters (54 percent of predicted). The Dco was 10.9 mVmin/mm Hg (35 percent of predicted). Boom air arterial blood gas analysis showed pH, 7.42; Po" 65; and Pco, 36. The chest film (Fig 1) showed depressed diaphragms, increased retrosternal air space , and decreased pulmonary vascular markings. The patient underwent successful bilateral lung transplantation in January, 1988. A chest x-ray film taken immediately postoperatively revealed a marked change in the configuration of the chest with elevation of the diaphragms as compared with the preoperative HIm.The patient required reoperation on the 6th postoperative day to repair a small pleural air leak and was discharged from the hospital on the 21st postoperative day on cyclosporine A, azathioprine (Imuran) and prednisone. One month after transplantation, he was successfully treated for episodes of cytomegalovirus pneumonia and lung rejection. Since that time his course has been remarkable only for steady improvement in pulmonary function and exercise tolerance. Seven months after transplantation, pulmonary function tests show an FEV, of 3.2 liters (88 percent of predicted), an FVC of 3.5 liters (SO percent of predicted), and a Dco of 16.6 mVmin/mm Hg (54 percent of predicted). Arterial blood gas levels drawn while the patient was breathing room air showed pH, 7.36; Po" 96; and Peo.. 35. In comparing the preoperative and postoperative chest films (Fig 1 and 2), the diaphragms have been elevated two full intercostal spaces, the lung height has been reduced from 28.7 em to 22.6 em, and the retrostemal air space has decreased from 6.5 em to 3.1 em . CT scans (Fig 3) show that the anterior-posterior diameter of the chest has decreased by 2.5 cm and the width of the chest has decreased by 1.5 em . DISCUSSION

This patient suffered from severe emphysema due to

alpha-antitrypsm deficiency. Emphysema has been defined by the American Thoracic Society as " a condition of the lung characterized by abnormal, permanent enlargement of airspaces distal to the terminal bronchiole, accompanied by

FIGURE 1. PAand lateral chest x-ray films prior to lung transplantation CHEST I 96 I 2 I AUGUST, 1989

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FIGllRE 2, PA and lateral chest x-rayfllms following bilateral lung transplantation.

FIGl'RE 3, CT scans of chest before (left) and after (right) transplantation. the destruction of their walls . . ,... The chest x-ray findings in emphysema reflect these processes: pulmonary parenchymal destruction is manifested by decreased vascular and interstitial markings; airspace enlargement is manifested by signs of lung hyperinflation, with depressed diaphragms. increased lung height, increased size of the retrosternal air space; and increased anterior-posterior dimension of the chest. I ·' Typical cr scan findings in emphysema patients include non-peripheral low attenuation areas and vascular pruning due to parenchymal destruction, and increased anterior-posterior and transverse chest wall dimensions reflecting hyperinflation. '-7 Changes in the configuration of the chest wall occur due to the hyperinflation of the lungs. Prior to the advent of clinical lung transplantation, the degree of plasticity of chest wall changes of emphysema was unknown; indeed, some clinicians believed that the overdistended chest cavity would not be able to decrease in size to accommodate the smaller transplanted lungs. However, the chest x-ray films of our patient demonstrate a dramatic change in the appearance of the chest cavity following bilateral lung transplantation with elevation of the diaphragms to attain a normal position, reduction in lung height and decreased width of the retrosternal air space. The cr scans demonstrate decreases in the anterior-posterior and transverse chest wall dimensions. Our findings indicate that the changes in the configuration and size of the thoracic cavity which accompany emphysema do not reflect permanent distortions of the bony structures 422

of the chest wall , but rather are the result of a dynamic interaction of the lungs and chest wall structures which can be altered rapidly. The change in chest wall size and configuration to match that of the transplanted lungs is likely a factor in the progressive improvement in parameters of respiratory mechanics seen in heart-lung transplant patients' and in our bilateral lung transplant patient. REFERENCES 1 Thurlbeck WM, Simon C, Radiographic appearance of the chest

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