Transvenous lung biopsy in the pig MOHSIN

At present there is no satisfactory technique for repeated lung biopsy in recipients of heart-lung transplants. A new technique for lung biopsy, which might be adopted for this purpose, has been developed. A Teflon sheath is inserted through the jugular vein into the pulmonary artery with the aid of a balloon catheter. A flexible biopsy forceps is then introduced through the sheath into the pulmonary arterial tree and advanced into the periphery of the lung, where biopsy samples are taken. The procedure was attempted in 14 pigs. Initially crocodile jaw (two pigs) and fenestrated cups forceps (five pigs), which are currently in use for transbronchial lung biopsy, were used. Subsequently the biopsy forceps was modified and the jaws were replaced by a cutting needle mechanism (six pigs). Out of the 13 animals in which the procedure was technically possible, lung parenchyma was obtained from nine and pulmonary arterial wall from 11. One animal died shortly after the procedure. The cause of death could not be determined with certainty at postmortem examination. There was, however, a small tear on the surface of the lung, which could have produced a tension pneumothorax. The other 12 animals recovered from the procedure. They were killed 24 hours later and postmortem examination was carried out. One animal in which the crocodile jaw forceps had been used had a haematoma in the lower lobe (3 x 3 x 4cm) and 100 ml of blood in the pleural cavity. In the other 11 animals, in which the fenestrated cups or the cutting needle forceps had been used, the intrapulmonary haematomas were 1-2cm in diameter and the pleural surface was intact.lt is concluded therefore that transvenous lung biopsy is feasible and that this procedure might find an application in monitoring rejection in recipients of heart-lung transplants. Early laboratory and clinical experience in heart-lung transplantation suggested a close correlation of rejection in the two organs.' 2 This concept was central to the management of recipients of heart-lung transplants, and has been the basis for using cardiac biopsy in the diagnosis of rejection in the combined graft. Recent experiments in primate heart-lung transplantation have, however, shown that significant pulmonary rejection leading to respiratory failure can occur in the absence of cardiac rejection.3 This has also occurred in clinical practice.4 Independent surveillance of lung rejection if practicable would therefore be a logical approach to this problem. This prompted us to explore the possibility of developing a simple technique for repeated lung biopsy that could be carried out with the same ease and frequency as Address for reprint requests: Mr M Hakim, Department of Cardiothoracic Surgery, Papworth Hospital, Papworth Everard, Cambridge CB3 8RE. Accepted 13 June 1986 transvenous cardiac biopsy.' We considered that it should be possible to perform lung biopsy through the pulmonary arterial tree, with the bioptome introduced percutaneously through the internal jugular vein into the right ventricle and then into the pulmonary artery. The technical challenge was, however, considerable, and we had to prove that the procedure would be safe and that the specimen obtained would be representative.