342 
SURGERY AND TRANSPLANTATION 
has been performed 28 times in human beings, 
with 23 of these cases having been reviewed by 
Wildevuur and Benfield/^ In general, it has 
been established that the allotransplanted hu- 
man lung functions well. Bilateral lung allo- 
transplantation in man has shown beyond ques- 
tion that the respiratory requirements of the 
individual can be met by the allografts, provided 
that infection, atelectasis, and other complica- 
tions do not impair the functional capacity of 
the transplanted lungs. The longest survivor of 
allotransplantation was Derom's case in Bel- 
gium. '^^ This young man, whose opposite lung 
was essentially destroyed by silicosis, survived 
in fair condition for approximately 9 months. 
Our patient in 1963 lived 18 days and died from 
multiple problems which had been present and 
acknowledged preoperatively.'^'' The lung func- 
tioned well until the terminal problems de- 
veloped in the last 48 hours, and both gross and 
microscopic examination disclosed no evidence 
of rejection. Our second human lung transplant 
was performed in 1969, and this patient lived 
for approximately one month. ^« He died from 
invasive infection involving both the allotrans- 
plant and the opposite lung. Unfortunately, the 
commonest cause of death in lung transplanta- 
tion has been overwhelming infection. The lungs 
are inevitably exposed to organisms from the 
air, and the essential immunosuppressive drugs 
also reduce the patient's defense against bac- 
terial invasion. It has been clearly demonstrated 
that the human lung allograft can function ef- 
fectively as an organ of respiration. What is 
needed now is better and more selective methods 
of immunosuppression, so that the ever-present 
bacterial organisms will not be given the ca- 
pability of invasive infection which can kill 
the recipient. It is perhaps fair to say that lung 
transplantation and heart transplantation rest 
at approximately the level of progress which 
kidney transplantation enjoyed ten years ago. 
With increasing laboratory experience, it will 
be justifiable gradually to increase the clinical 
experience. Lung transplantation should even- 
tually provide respiratory support comparable 
to renal support provided by the renal allografts 
at the present time. 
SUMMARY I 
1. The dog model has proved highly valuable 
in the study of multiple facets and problems in [ 
lung transplantation. [ 
2. Lung replantation in large numbers of 
dogs has identified the function pattern which 
can be expected of the replanted organ, in the ' 
absence of immunological changes which would ' 
be present with a lung allograft. 
3. The function of a lung temporarily de- f 
clines sharply following its replantation but 
function improves substantially over the next ' 
several weeks as pulmonary edema, pneumonitis i 
and atelectasis subside. ' 
4. Operative technique has now been refined 
to a point at which many dogs survive even f, 
immediate bilateral lung replantation. jj 
5. Bronchial anastomotic complications of i 
leakage or stricture are uncommon but do a 
occur. Leakage has also occurred in several jt 
reported human cases. , !! 
8. Lymphatic communications are recon- e 
stituted across the bronchial anastomosis in 
from 7 to 12 days, and their substantial restitu- {J 
tion parallels the subsidence of post-transplant d 
pulmonary roentgen changes. J 
7. Intrinsic pulmonary nerves exhibit de- f 
generative changes following lung replantation, | 
but anatomical and functional recovery can be 
demonstrated months later in varying degrees i 
in different animals. 
8. Lungs replanted in puppies exhibit both 
anatomical and functional growth. ' 
9. - Lungs can be stored for hours, and pro- ^ 
vide substantial function on replantation. How- fi 
ever, long-term storage success has not yet been p 
achieved. I 
10. Bilateral lung replants, performed at the 
same operation, are now readily performed. 
This model compels the animal to survive com- 
pletely on replanted tissue and, already, it has 
shown that pulmonary nerves are not essential ! 
for respiratory activity. However, the pulmo- , 
nary nerves do contribute to the overall quality ' 
of respiration and lung blood flow. ! 
11. Large numbers of lung allotransplanta- j 
tion experiments have been performed with the I 
dog model. In general, the operation is readily j 
accomplished and the lung functions. However, ^ 
rejection eventually occurs in most animals, J 
i 
