B. K. KUSSEROW 
827 
days did you leave the ring in the longest case? 
Dr. KUSSEROW: In the test system? 
Dr. Akutsu : Yes. 
Dr. Kusserow : We arbitrarily terminate the 
implantation at five days. In some of the con- 
trols in which we performed simple constriction 
with no ring, implants were permitted to go for 
a week. 
Dr. Akutsu: I think this method is a very 
good idea. We have been doing a total artificial 
heart implantation and in many cases surviv- 
ing longer than one week after the experiment, 
we didn't see any thrombus formation in the 
device, but in others we saw the infarct in the 
kidney. 
Questioner (Unidentified) : Did plasma he- 
moglobin play a role here at all, or any of 
the products of red cell lysis? 
Dr. Kusserow: The plasma hemoglobin did 
not appear to change appreciably. We have such 
a small surface area here that we could not de- 
tect alterations in plasma hemoglobin level. 
Your point is very important. I assume you 
refer to the release of factors such as ADP 
from lysed red cells which might, in fact, en- 
hance the thrombotic propensity of the blood 
and tend to cause platelet aggregation or en- 
hance it at the ring surface. We are in fact now 
initiating experiments to study the difference 
between the thrombotic propensity of a given 
test surface exposed to "normal" or non-trauma- 
tized blood and to blood which has been altered 
by hemolysis of traumatic origin. 
