442 
SURGERY AND TRANSPLANTATION 
Figure 5. — Photomicrograph from the transplanted 
lung of a dog that died 14 months after autotrans- 
plantation of the left lung and ligation of the right 
pulmonary artery. No significant abnormalities are 
evident. (Hematoxylin and eosin, x60.) 
the procedure. The ability to accomplish this 
has significance in two regards. First, it sup- 
ports the use of single lung transplantation in 
patients with respiratory insufficiency and vas- 
cular disease in both lungs. Second, it provides 
an experimental model for studying the efficacy 
of immunosuppressive methods and preserva- 
tion techniques intended for use in lung trans- 
plantation. 
Figure 6. — Photomicrograph of the transplanted lung 
of a dog that died of unknown causes 30 months 
after autotransplantation of the left lung and right 
pulmonary artery ligation. Except for minimal 
congestion, this lung is normal. (Hematoxylin and 
eosin, xl60.) 
After our initial descriptions of this 
model,^'^ many groups found it difficult to ob- 
tain survival with comparable preparations. 
Some of these investigators also found it diffi- 
cult to reproduce our gradient measurements at 
the pulmonary arterial anastomosis and ex- 
pressed doubt about the importance we attrib- 
uted to the distensible arterial anastomosis. 
However, the studies by Noirclerc, Daicoff, and 
their colleagues proved that even minor con- 
strictions in the left pulmonary artery can, with 
right pulmonary artery ligation, cause substan- 
tial pressure gradients to be generated in the 
left pulmonary artery.^'^^ And recently, Ali- 
can, Ebert, and their associates were able to 
achieve a high percentage of chronic survivors 
in dogs that had undergone left lung autotrans- 
plantation and immediate contralateral pul- 
monary artery ligation.^i'i^ These authors also 
stressed the importance of meticulous surg- 
ical technique ; and although they did not utilize 
a vein patch or spatulation, they did achieve 
distensible arterial anastomoses and low pul- 
monary artery pressures after operation by tak- 
ing small careful externally placed suture bites 
in the arterial wall. The importance of distensi- 
bility of the arterial anastomoses has now been 
demonstrated conclusively by the generalized 
pulmonary arterial widening without anastomo- 
tic narrowing seen on postoperative angio- 
graphy as shown in Figure 2 and confirmed by 
Alican et al. in dogs " and Joseph and Morton in 
baboons. 
Although we originally used a vein patch an- 
gioplasty to achieve distensible arterial anasto- 
moses, we no longer believe that this technically 
difficult maneuver is essential. We and Alican 
and his colleagues have successfully utilized 
simpler albeit exacting techniques to fashion 
nonconstricting transplant arterial anasto- 
moses."^'^! Whatever technique is employed, we 
continue to believe that maintenance of dis- 
tensibility of the large pulmonary arteries 
including the site of anastomosis is essential to 
permit normal vasodilation and survival after 
lung transplantation with immediate ligation of 
the contralateral pulmonary artery. Compar- 
able technical care is probably not essential to 
success in human lung transplantation because 
of the larger size of the structures, because 
