282 
SURGERY AND TRANSPLANTATION 
aorta was closed by a continuous suture, and 
the chest was closed in routine fashion. 
INSERTION OF TAH 
Since the mediastinum of both sheep and 
calves is extremely thin, sternal splitting inci- 
sions do not offer a special advantage in keeping 
the pleural cavities closed. Opening the chest 
through the fifth intercostal provides a suffi- 
ciently large operative field. In order to obtain 
sufficient room in the area of the short ascend- 
ing aorta, as in implantation of the S-LHAD, 
the brachiocephalic artery and the aortic arch 
were dissected free to be occluded during im- 
plantation. One arterial cannula was inserted 
into the right internal thoracic artery and the 
other into the descending thoracic aorta. For 
venous drainage, one cannula was inserted into 
the supperior vena cava through the left jugu- 
lar vein, and the other into the inferior vena 
cava through the right atrial appendage (Fig- 
ure 7). Since both venae cavae are dissected in- 
side the pericardial sac, the right chest cavity 
was not opened. This apparently helped keep 
the right lung well-inflated and prevented de- 
creased oxygenation immediately after the arti- 
ficial heart started pumping. 
After occlusion of all blood flow into and out 
of the heart, the heart was removed, starting 
first with dissection of the aorta and the pul- 
monary artery as close to the ventricle as possi- 
ble, then the ventricles. The present TAH in use 
consists of an entirely separate right and left 
aggregate. In preparing the atrial edges for 
separate connection of each atrium, two points 
were kept in mind to facilitate secure and easy 
connection of the atria. ( 1 ) The interatrial sep- 
tum should be split sufficiently, starting from 
the middle of the non-coronary aortic valve 
cusp to give a sufficient length of the atrial edge 
on both sides (Figure 8). (2) The coronary 
sinus should be sufficiently freed close to the 
sinus opening and cut between two ligatures. 
After these procedures, connection of the 
prosthetic heart was done in the following 
order : right atrium, left atrium, aorta and pul- 
monary artery. When the connection was made 
by a single purse-string suture placed around 
the atrial edge over the ring embedded in the 
artificial atrium, bleeding was a problem. A sec- 
ond purse-string suture was absolutely neces- 
sary to catch small vessels arising from the bot- 
tom of the atria and opening into the fat in the 
atrioventricular grooves. When the atria were 
connected by a continuous suture, the suture 
was started from the caudal end of the atrial 
septum and continued around the right atrium 
clockwise, through the septum, and around the 
left atrium counter-clockwise to the cranial end 
of the septum. Immediately after the comple- 
tion of the left atrial connection, the side tube 
attached to the left atrium was connected to the 
suction line to drain the bronchial return into 
the oxygenator. 
After completion of connection, residual air 
was removed. For this purpose each of the four 
Figure 7. — Circuit of extracorporeal circulation during 
implantation of TAH. 
