The Annals of Thoracic Surgery, Vol 35, 504-515, Copyright © 1983 by The Society of Thoracic Surgeons
Extracorporeal left ventricular assistance with prostacyclin and heparinized centrifugal pump
GM Palatianos, LH Edmunds Jr, DJ Cohen and LW Stephenson
A temporary left ventricular assist system utilizing an improved left
atrial catheter and centrifugal pump was developed and tried in 22
anesthetized sheep to test the hypothesis that prostacyclin (PGI2) and
ionically bound heparin-coated surfaces could prevent thrombosis in this
perfusion system without inhibiting soluble, circulating coagulation
factors. Sheep were perfused at 53.6 ml/kg/min (standard error, 1.5) from
left atrium to aorta for two hours. The pump maintained flow at left atrial
pressures of 3 to 4 mm Hg. As expected, systemic heparin inhibited
coagulation, mildly activated platelets, and prevented thrombosis in
uncoated perfusion circuits and wounds. Infusion of PGI2 (30 ng/kg)min)
without systemic heparin or heparin- bonded extracorporeal surfaces
prevented platelet activation and did not alter coagulation measurements;
however, bleeding times increased and thrombi formed in every circuit. When
heparin was ionically bound to all extracorporeal surfaces, infusion of
PGI2 completely prevented thrombosis within the circuit, inhibited platelet
activation, and did not alter coagulation measurements. Blood spontaneously
clotted in three of six thoracotomy wounds during perfusion. When PGI2
infusion was stopped, heparin-coated surfaces alone failed to prevent
thrombosis within the system in 3 of 5 animals. The combination of PGI2
infusion and heparin-coated extracorporeal surfaces prevents thrombosis
within the perfusion circuit without inhibiting soluble coagulation
factors. This method, using the assist system, overcomes many of the
implementation and bleeding problems associated with other temporary left
ventricular assist devices.
