MOLOKHIA, HUFFMAN, ROBINSON, ASIMACOPOULOS, PONN AND NORMAN 
387 
jor problem encountered in left ventricular 
assist device implantation and in all procedures 
in the calf entailing manipulation of the heart. 
Defibrillation is extremely difficult and has 
been performed successfully in only a few in- 
stances. It is therefore of paramount importance 
to prevent the development of ventricular 
dysrhythmias. 
In the first group of eight animals ventilated 
at pressures of 15-20 cm HoO, no specific anti- 
arrhythmic measures were undertaken, and fi- 
brillation occurred during implantation in all 
animals. In only one case was defibrillation suc- 
cessful with multiple 400 joule DC counter- 
shocks. 
The first animal in the series ventilated at 
pressures of 30-40 cm HoO also received no 
specific antiarrhythmic treatment. Despite the 
facts that the introduction of higher ventilatory 
pressures minimized abnormalities of blood 
gases and acid-base balance and that prompt 
correction of any disturbances was possible, 
fibrillation occurred in this animal as well. Thus 
the elimination of hypoxia and acidosis was not 
sufficient to prevent fibrillation. 
Accordingly, subsequent implantations were 
carried out in conjunction with a vigorous anti- 
arrhythmic regimen. Serum potassium levels 
were determined preoperatively, and any tend- 
ency toward hypokalemia was corrected. Lido- 
caine (Xylocaine® HCl, Astra Pharmaceutical 
Products, Worcester, Massachusetts) 22.23 ^as 
used extensively. An initial loading dose of 80- 
100 mg was given early in the procedure. Thirty 
to forty mg were injected into the left atrium 
prior to intracardiac surgical manipulation. In 
addition, a continuous infusion of lidocaine was 
maintained throughout the procedure deliver- 
ing 1 mg/minute. 100% oxygen was adminis- 
tered during all intracardiac procedures. Re- 
placement transfusion with blood prewarmed 
to 37°C is accomplished via a catheter inserted 
in the left internal mammary vein. All animals 
used for implantation or as blood donors are 
typed and cross-matched. Thus far, all have 
been AB negative. These precautions combined 
with an improved technique of implantation to 
avoid acute blood loss resulted in the avoidance 
of ventricular fibrillation in the 15 procedures 
in which they were employed. 
IMPLANTATION 
Blood loss and coronary air embolism were 
frequent complications of left ventricular as- 
sist device implantation in our early studies. 
These problems were minimized by modifying 
the technique described by Bernhard. The modi- 
fied procedure includes the use of a single bal- 
loon Foley catheter and the flooding of both the 
assist pump itself and the operative field with 
carbon dioxide. 
A Dacron graft 20 mm in diameter is anas- 
tomosed end-to-side to the descending thoracic 
aorta at the level of the ninth rib and is oc- 
cluded by a clamp applied close to the aorta to 
avoid intragraft thrombosis. The pericardium 
is opened widely to expose the entire left atrial 
appendage and the apex of the left ventricle. 
Following pericardiotomy, a Silastic ring is 
secured to the apical myocardium by an at- 
tached sewing cuff. One purse-string suture is 
placed at the base of the left atrium and an- 
other proximal to the Silastic ring (Figure 2). 
The outflow tube of the assist pump is con- 
nected to the aortic Dacron graft. 
In initial procedures, a #24 double-balloon 
Foley catheter (Bardex®, C. R. Bard, Inc., Mur- 
ray Hill, New Jersey) with an internal wire 
obturator was passed through an incision within 
the left atrial purse-string suture and the tip 
wedged into the ventricular apex. After in- 
flation of the distal balloon a circular section of 
apical myocardium was excised with a circular 
coring knife until the intraventricular balloon 
was visualized. The balloon was immediately 
deflated allowing passage of the catheter 
through the apex of the left ventricle into the 
free pleural space. The purse-string suture and 
the proximal balloon were utilized to control 
bleeding. The wire obturator within the cath- 
eter was removed and the distal balloon of the 
catheter was inflated within the inflow tube 
of the left ventricular assist device to occlude 
the lumen. Carbon dioxide was then flushed 
through the catheter for two minutes to evac- 
uate all air from the pump. Finally, the proxi- 
mal balloon was deflated to allow manual in- 
sertion of the inflow tube into the left ventricle, 
with the catheter as a guide. A large silk liga- 
ture was used to secure the inflow tube in posi- 
