332 
SURGERY AND TRANSPLANTATION 
STRUCTURES OF HILUM 
Differential Effects on Function 
loteral view of left hilum 
Figure 7. — The various structures of the pulmonary 
hilum were divided individually to determine effects 
on lung function. Only nerve division appeared to have 
a significant deleterious effect. 
tional capacity. Even so, lungs stored for 24 
hours under hyperbaric oxygenation at 43 °C 
and then replanted were able in some dogs to 
provide a normal P02 and PCO2 in arterial blood 
when the animals were subjected to contralat- 
eral pneumonectomy 6 months later. Never- 
theless, these animals were unable to survive 
more than a few hours on the replanted stored 
lung due apparently to increased pulmonary 
arterial pressure and right failure. Cell viability 
studies with the trypan blue technique indicated 
a significant level of cell survival after even 72 
hours of lung storage under hyperbaric oxy- 
genation at 4°C.35 Yet, it should be noted here 
that disagreement exists regarding the value 
of hyperbaria, and extended lung preservation 
through continuous perfusion of the pulmonary 
artery should be further investigated. 
It was concluded from the above studies and 
those reported in the literature by others that 
a functioning human lung allotransplant could 
be readily achieved if certain conditions were 
observed. First, the blood probably should be 
flushed from the organ by brief perusion of the 
pulmonary artery with saline or a colloid solu- 
tion (Rheomacrodex) containing penicillin and 
heparin, perhaps with added xylocaine. Second, 
the perfusion solution should be cold, to reduce 
the temperature of the lung promptly, in order 
to diminish metabolic requirements for oxygen 
and hopefully to reduce the injury caused by 
ischemia and hypoxia. Third, in certain cir- 
cumstances intermittent ventilation of the 
bronchus with 100% oxygen should be useful 
during operation in achieving some oxygena- 
tion of the lung while the various structures 
were being anastomosed in transplantation. 
It was thus established that a functioning 
lung replant or allotransplant could be readily 
achieved if the period of hypothermic hypoxia 
was not prolonged for more than 2-3 hours. 
Much research has been and is still being con- 
ducted for the development of better methods 
of organ storage in general, and these include 
studies of lung preservation as well.^®-^^ 
Pulmonary Lobe Replants and Lung Replants 
in Other Species 
Adams and his associates have studied 
lobar transplantation extensively in the dog. 
By and large, the information obtained has 
not varied significantly from that achieved 
through replantation of the lung and, from 
a practical point of view, we have not con- 
sidered lobar transplantation to offer a suf- 
ficient advantage to accept as a model, as com- 
pared with replantation of an entire lung. 
While our assignment in this symposium is 
that of lung transplantation in dogs, it should 
be noted here that outstanding work has also 
been carried out with baboons. Haglin and 
associates ^^-^^ found that the baboon could 
readily survive on a single replanted lung, 
whereas dogs were rarely able to do so. How- 
ever, in recent years the impoved operative 
technique and postoperative management em- 
