PRECONDITIONING, IMPLANTATION AND POSTOPERATIVE 
CARE OF THE ARTIFICIAL HEART RESEARCH CALF 
J. L. Peters, F. M. Donovan, J. Kawai, 
C. S. Kwan-Gett, H. H. J. Zwart and W. J. Kolff 
In the last two years, seventy total heart implanta- 
tion experiments have been performed in the calf. Em- 
phasis has been to develop a preconditioned calf pro- 
gram to provide a standardization calf with a known 
growth and clinical history prior to implantation. Dura- 
bility and short-term mock circulation testing procedures 
are performed on the artificial heart prior to im- 
plantation to assess its durability and functional char- 
acteristics. Implantation procedures have been devel- 
oped to minimize trauma and blood damage and thereby 
more accurately separate the effects of implantation 
from the pumping of the artificial heart. These include 
deep hypothermia with circulatory and respiratory ar- 
rest during implantation of the artificial heart, and 
double bypass in which the natural ventricles are ex- 
cised after the artificial heart is anastomosed and is 
maintaining the circulation. Two types of experimental 
procedures are used to study the artificial heart in vivo. 
One is the hemodynamic evaluation of the artificial heart 
in which multiple pressure recordings are made. An- 
other procedure consists of one or two pressure record- 
ings to reduce disturbances to the animal and allow long 
survival. Postoperative care of the calf with an artificial 
heart includes continuous monitoring of the clinical 
condition and physiological studies of the cardiovas- 
cular, pulmonary and renal systems. Autopsy exami- 
nations are performed on the suspended animal by re- 
moving the lateral rib cages in order to assess the fit 
of the artificial heart, possible vessel kinking and fu- 
ture design criteria. To date a calf has survived 260 
hours with a total artificial heart. This calf supported 
itself, ate and drank, showed interest in its surround- 
ings and required no respiratory support for eight days. 
The use of systematic and standardization procedures 
for preconditioning of calves, implantation of the arti- 
ficial heart and postoperative care have produced long 
survivors and new design criteria for future artificial 
hearts. 
INTRODUCTION** 
In 70 total heart implantations in calves in 
the last two years in the laboratory of W. J. 
* Department of Surgery. Division of Artificial Organs, University 
of Utah, College of Medicine, Salt Lake City, Utah. 
** Supported by: N. H.L.I. (Medical Devices Applications Pro- 
gram), NIH Contract No. NIH 69-2181; and Program Project Grant 
from NIH, N.I.L.I., H.E. 13738-OlAl to the University of Utah, 
Dr. W. J. Kolff, Principal Investigator. 
Kolff, methodologies have been developed to 
improve the use of the calf as a model for arti- 
ficial heart research. The emphasis has been 1) 
to improve the quality of the calf prior to de- 
livery to our facility; 2) to develop better 
methods of surgical implantation in order to 
minimize trauma and thereby more easily 
separate the effects of pumping of the artificial 
heart from those of implantation; and 3) to 
evaluate and develop techniques of postopera- 
tive care and data acquisition. 
CALF PRECONDITIONING 
In order to evaluate the effects of pumping 
by a total artificial heart in the calf, it is neces- 
sary to have a calf with a known clinical and 
developmental history. Since an artificial heart 
experiment is expensive, a calf with pneumonia, 
lung worms, dehydration and other pathological 
conditions (as found in stockyard calves) would 
increase the probability of uncontrolled vari- 
ables and failure of the experiment (particu- 
larly a long survival experiment) from causes 
unrelated to the pumping of the artificial heart. 
In 1970, in conjunction with a local research 
animal supplier (Mr. Tom Imlay, Animals for 
Research, 4996 So. Redwood Rd., Murray, Utah 
84107), we established a preconditioned calf 
program. The environment for these calves was 
quite extensive. Four to five hundred calves 
(98% Holstein and 2% other breeds) were 
raised simultaneously in specially designed 
growing nurseries and pens. The calves were 
obtained at birth from dairies within the Utah 
area. The nursery where the newborn calves 
were housed could hold 300 calves at one time. 
These calves were in individual elevated pens 
with controlled temperatures and humidity and 
fed on a combination of milk and supplemental 
grain — alfalfa pellets fortified with vitamins. 
Music was played at intervals to keep the young 
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