T. AKUTSU, H. TAKAGI AND H. TAKANO 
283 
R. ATRIUM 
PURSESTRING SUTURE 
Figure 8. — Showing anatomy and surgical procedure in 
calf after the natural heart has been completely re- 
moved. Hemiazygos vein directly drains in the coro- 
nary sinus. Lower drawing shows that the interatrial 
septum has been split providing a sufficient edge for 
connection of both artificial atria. 
chambers and the two artificial vessels has a 
side-tube at its highest point when the animal is 
on its back and the chest is open. These tubes 
were later used for pressure recording. Re- 
moval of air was begun from the right side. 
After the right atrium had been filled with sa- 
line through its side tube, the side tube was 
clamped and the vena cavae released. Air was 
sucked out of the ventricle with a syringe con- 
nected to its side-tube, thereby permitting sa- 
line and blood to flow into the ventricle and fill 
it. The pulmonary artery was undamped, and 
the air was sucked from it. Then the ventricle 
was checked again to make sure that no air was 
inside. 
On the left side, the procedure was almost the 
same. The left atrium was first filled with blood 
coming from the lung, and then the left ventri- 
cle and the aorta were filled. Later these side 
tubes were used for pressure monitoring as well 
as for blood sampling. Immediately after the 
extracorporeal circulation was stopped, the 
prosthetic heart was activated. During the first 
20 beats, only the descending aorta was opened, 
and the brachiocephalic artery was kept closed 
to prevent the brain from getting air which 
might have been left in the left ventricle. After 
checking for bleeding or leaks, the apex of both 
ventricles were fixed to the sternum in order to 
hold the device in place. Two chest tubes were 
inserted into the left chest cavity on the ventral 
side (for blood) and on the dorsal side (for 
air). Air tubes, side-tubes, and the lead of a 
flow-meter probe which was placed around the 
aorta or the pulmonary artery were lead out 
through the fourth intercostal space. As soon as 
the chest was closed in routine fashion the ani- 
mal was placed in a cage in a normal position. 
The cannula inserted initially in the left fe- 
moral vein for monitoring of venous pressure 
and the cannula in a branch of the left femoral 
artery for arterial pressure were transferred 
each to the right atrial line and to the internal 
thoracic artery which was used for perfusion of 
the upper part of the body during extracorpo- 
real circulation. Since the level of the anesthesia 
was maintained as light as possible, animals 
awoke quickly. 
AFTERCARE 
When we were using sheep, they were sus- 
pended by two wide canvas bands which were 
placed beneath the chest and the forelegs, and the 
abdomen and the hind legs. Both edges were 
hooked to several springs attached to a sturdy 
frame so that the sheep's body was always 
maintained about 15 cm above the floor and the 
feet were touching the floor (Figure 9) . A stan- 
chion consisting of two metal bars was fixed 
around the neck. Thus, the sheep was able to sit 
and stand, or turn its head, but could not go for- 
ward or backward. When the sheep was awake 
and strong enough to hold its body weight on its 
legs, the system worked perfectly. However, 
when the sheep was weak and its whole body 
weight was supported by the canvas bands, the 
chest was compressed interfering with respira- 
tion. After we changed from the sheep to the 
calf, hanging of the canvas bands with springs 
was abandoned. The bands were affixed when 
the calf was placed in a cage from the operative 
