440 
SURGERY AND TRANSPLANTATION 
Figure 1. — Photomicrograph of allografted left lung 
53 days after transplantation and right pulmonary ar- 
tery ligation. Minimal round cell infiltration is the 
only abnormality present in this and multiple other 
sections from this lung. (Hematoxylin and eosin, 
xlOO.) 
rectly proportional to the increased blood flow, 
indicating that the vascular resistance of the 
transplanted lung was not fixed and could de- 
crease normally when its blood flow was aug- 
mented. This normal characteristic of vascular 
resistance in the autografted lung persisted 
throughout the period of observation, as indi- 
cated by the constancy of pulmonary artery 
pressure and measurements of left lung vascu- 
lar resistance (Table II) . 
All blood gas values measured two to 44 
months after operation were within the range 
of normal for lightly anesthetized dogs breath- 
ing room air. Detailed values are presented in 
Table II and were not significantly different 
from values determined for these parameters 
preoperatively or in normal dogs in which both 
lungs are functioning normally. 
Pulmonary Angiography 
At all times after operation, up to two 
months in dogs with allografts and up to 24 
months in dogs with autografts, pulmonary an- 
giography in all recipient dogs showed that the 
entire pulmonary blood flow traversed the 
transplant, confirming that it alone provided 
pulmonary function. In one autografted dog, an 
angiogram taken two months after operation 
revealed that the diameters of the main and left 
pulmonary arteries had increased significantly j 
when compared with a preoperative angiogram 
from the same dog (Figure 2). Pulmonary an- ' 
giograms of all other long-term survivors re- i 
vealed the pulmonary arterial, capillary, and ' 
venous circulations to be quantitatively and ! 
qualitatively normal at all times up to two years \ 
except for moderate, 25 to 75 per cent, dilata- 
tion of the first, second, and third order arteries 
(Figures 3 and 4) . Despite this dilatation, no an- 
astomotic defects were identified in any of the 
long-term survivors. 
Microscopic Morphology 
Histologic material from the autografted 
lungs was available from four dogs that died 
during the first postoperative week, three dogs 
that died from one to four weeks after opera- 
tion, and six dogs that died from three to 30 
months after operation. The histologic findings 
Figure 2. — Equivalent views of preoperative and post- 
operative angiograms of one dog. Both angiograms 
are in the right posterior oblique projection. A, The 
preoperative angiogram. B, Angiogram performed 
two months after operation. Ai and Bi, Tracings 
from the original roentgenograms. The numbers on 
the roentgenograms and the tracings represent the di- 
ameters, in millimeters, of the vessels at that site as 
measured on the original films. 
