Transvenous lung biopsy in the pig.

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 4 cm) 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 1-2 cm in diameter and the pleural surface was intact. It 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.