JAMES D. HARDY 331 
young would grow both in size and in functional 
capacity with the growth of an animal as a 
whole. 
We investigated the growth of lungs re- 
planted in puppies (Figure 8) . After a consider- 
able number of unsuccessful attempts we 
achieved four living animals.^^ These dogs were 
studied one year following a left lung replanta- 
tion, at which time their body weights had al- 
most doubled since the date of lung replanta- 
tion. Endoscopy disclosed that the bronchus 
was narrowed approximately 20% in three pup- 
pies but was narrowed almost 50 % in the fourth 
puppy. Arteriography demonstrated an absence 
of either arterial or venous stenosis and showed 
a normal lung vascular pattern. In the one dog 
sacrificed for histological studies at that time, 
the replanted lung was grossly and microcopi- 
cally normal. The tidal volume and the minute 
volume of the replanted left lungs varied from 
I 46 to 50% of the total in three puppies which 
did not have bronchial stenosis. 
Thus, it was clear that the lung replanted in 
a puppy did have growth potential with respect 
to both anatomic size and functional capacity. 
These findings have since been confirmed by 
others.^^ 
Lung Storage 
In preparation for possible clinical applica- 
tion of lung allotransplantation, we investigated 
various parameters of lung storage for periods 
of up to 48 hours in 101 dogs.^* The excised 
lung was perfused briefly with cold solution 
and placed in a refrigerator at 4°C. It was 
found that the lung withstood ischemia for 
three hours (2 hours of storage plus 1 hour 
for the replantation procedure) with a func- 
tional impairment that was only slightly 
greater than that which followed immediate 
transplantation of the lung. However, storage 
under these conditions for longer periods 
of time resulted in rapidly decreasing func- 
