326 
SURGERY AND TRANSPLANTATION 
Figure 2. — Transplantation of left lung. It is essential 
to avoid constriction of pulmonary veins, pulmonary 
artery or bronchus. 
survive two hours of cross-clamping of the 
entire hilum.^" Therefore, the lung should be 
cooled by perfusing the pulmonary artery with 
cold solution at a low pressure, followed by 
expeditious and very gentle replantation. 
Trauma to the lung or liver during the course of 
replantation can produce damage which will be 
reflected in reduced function. Inevitably some 
degree of atelectasis and pneumonitis develop. 
For a time it was believed that division of the 
pulmonary lymphatics was a cause of the 
edema and diminished function which the re- 
planted lung exhibits, and certainly the late 
postoperative improvement in function of the 
replanted lung parallels the reestablishment of 
lymphatic channels across the bronchial suture 
line. Nevertheless, the fact that the curves 
representing diminished lung function and 
diminished lymphatic flow parallel each other 
does not necessarily prove that the diminished 
lung function is due to lymphatic stasis during 
the period prior to regeneration of the lympha- 
tic channels. Other workers have concluded that 
the division of the hilar elements, especially 
the nerves to the lungs, results in alterations 
in the pulmonary surfactant, but different in- 
vestigative teams have reported widely varying 
results in this regard.^^'^^ ^i Ciliary action and 
the clearing of bronchial secretions is somewhat 
impaired in the replanted lung,^^'^^ but ciliary 
action is not completely abolished by dividing 
all elements of the pulmonary hilum. Still other 
groups have called attention to the fact that 
the bronchial arteries are divided with lung re- 
plantation and that usually no attempt is made 
to restore continuity of these vessels.^^ In the 
late post-replant period the bronchial arteries 
do reestablish anastomotic connections with the 
pulmonary artery and the pulmonary veins, in 
the bronchial mucosal plexuses.^^ 
The capacity to transmit oxygen to the ar- 
terial blood is relatively more impaired in the 
replanted lung than is ventilation. The most 
valid studies are achieved by blocking the op- 
posite pulmonary artery with a ballon-tipped 
catheter or by ligation of this artery. Of 
course, contralateral pneumonectomy absolutely 
establishes the quality of function of the re- 
planted lung. In addition to these and still other 
measurements of lung function, the use of radio- 
active xenon (Xenon-133) will give informa- 
tion regarding both the distribution of lung per- 
fusion and the distribution of lung ventilation, 
depending upon whether the material is injected 
intravenously or is inhaled with the gas mix- 
ture. 
In summary, temporary reduction in the 
function of the replanted lung is usually due to 
a number of factors, some of which have clearly 
not yet been identified. Furthermore, the rela- 
tive importance of individual factors which 
have been identified probably varies from ani- 
mal to animal, and certainly they vary in the 
opinion of diflferent groups of workers from 
different laboratories. However, a meticulous 
transplant technique permits the best possible 
post-transplant function. 
