JAMES D. HARDY 
325 
tis with or without empyema and, rarely, leak- 
age from the bronchial anastomosis or throm- 
bosis of the plumonary artery. Most deaths 
occur within a week, and dogs that survive the 
first week frequently live until sacrificed months 
or years later. The gross (Figure 3) and his- 
tological appearance and the angiograms of the 
chronically replanted lung are essentially nor- 
mal. 
Function of the Replanted Lung 
The function of the replanted lung^^"^^ is of 
vital concern, for it will identify the maximal 
functional capacity which can be expected 
from an allografted organ. Such information is 
essential to the objective of achieving successful 
lung allotransplantation in man. The replanted 
lung does function promptly but this function is 
rarely normal. In fact, the function of the re- 
planted lung frequently declines to approxi- 
mately one-half or less of that recorded preop- 
eratively, after which the function of the 
replanted lung gradually improves fairly 
rapidly up until the end of the first two weeks, 
and subsequently slowly improves for several 
months. The function of the replanted lung 
rarely returns to the preoperative level com- 
pletely, but a certain number of animals can 
survive on a replanted lung after either im- 
mediate or especially late ligation of the con- 
tralateral pulmonary artery. The success rate 
is greater when the right lung is the one re- 
planted, since it has a greater functional ca- 
pacity than the left lung. 
The precise cause or causes of the reduc- 
tion in function exhibited by the replanted lung 
have been the subject of many studies by dif- 
ferent investigators. The cause most clearly 
identified is the development of pulmonary 
edema in the replanted lung, though the precise 
explanation of this edema seen in roentgeno- 
grams is not certain. It is clear that the lung is 
definitely damaged by periods of ischemia, 
despite the fact that the lung tissue can actually 
