End organ function with prolonged nonpulsatile circulatory support.
The hypothesis tested in these studies was that long-term circulatory support with a nonpulsatile device is safe and causes no end organ dysfunction. An inexpensive, small centrifugal pump with a 7 L/min capacity was implanted in 6 sheep (15 acute implants have previously been reported). The inlet cannula was placed in the left atrium and the outlet graft anastomosed to the descending aorta. A percutaneous cable supplied DC power and heparinized saline (10 ml/hr) for lubrication. Outputs of pump flow, stator, animal core temperature, pump power consumption, and RPM were monitored throughout the course of each experiment. The sheep moved freely within a large pen using an overhead swivel/tether system that carried all input and output lines. Four sheep survived longer than 4 weeks, and the indices of end organ function were analyzed at 28 days. No animal revealed any neurologic dysfunction. Hemoglobin was 9.075 +/- 0.78 g/dl at 28 days, as opposed to 7.475 +/- 0.68 (p = 0.002) before surgery. The blood urea nitrogen was 9.250 +/- 4.57 versus 14 +/- 5.72 mg/dl (p = 0.041), creatinine was 0.775 +/- .10 versus 0.775 +/- 0.05 mg/dl (p > or = 0.999), total bilirubin was 0.425 +/- 0.2 versus 0.225 +/- 0.05 mg/dl (p = 0.092), serum glutamic oxaloacetic transaminase was 74.75 +/- 24 versus 106.25 +/- 15.84 IU/L (p = 0.015), serum glutamic pyruvic transaminase was 36 +/- 28.7 versus 28.3 +/- 5.7 IU/L (p = 0.25), and total protein was 6.675 +/- 0.49 versus 5.47 +/- 0.15 g/dl (p = 0.025). It is concluded that these animals adapted very well to pulseless circulatory support. The results of these studies support the concept of an inexpensive, implantable, centrifugal pump as a ventricular assist device.
Reddy
R C
RC
Department of Surgery, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA.
Goldstein
A H
AH
Pacella
J J
JJ
Cattivera
G R
GR
Clark
R E
RE
Magovern
G J
GJ
D000818:Animals; D001698:Biomedical Engineering; D002498:Centrifugation / Q000295:instrumentation; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005260:Female; D006353:Heart-Assist Devices / Q000009:adverse effects; D006439:Hemodynamics; D006454:Hemoglobins / Q000378:metabolism; D007668:Kidney / Q000503:physiopathology; D008099:Liver / Q000503:physiopathology; D011673:Pulsatile Flow; D012756:Sheep; D013997:Time Factors
D006454:Hemoglobins