Open AccessChronic In Vivo Testing of the Penn State Infant Ventricular Assist Device
Author(s) -
W. Jason Weiss,
Edward Carney,
Joseph B. Clark,
Rebecca Peterson,
Timothy K. Cooper,
Thomas P. Nifong,
Christopher A. Siedlecki,
Dennis L. Hicks,
Bradley Doxtater,
Branka Lukic,
Eric Yeager,
John Reibson,
Joshua Cysyk,
Gerson Rosenberg,
William S. Pierce
Publication year - 2012
Publication title -
asaio journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 66
eISSN - 1538-943X
pISSN - 1058-2916
DOI - 10.1097/mat.0b013e318239feb4
Subject(s) - medicine , partial thromboplastin time , heparin , ventricular assist device , cardiology , preclinical testing , anesthesia , heart failure , coagulation , medical physics
The Penn State Infant Ventricular Assist Device (VAD) is a 12-14 ml stroke volume pneumatically actuated pump, with custom Björk-Shiley monostrut valves, developed under the National Heart, Lung, and Blood Institute Pediatric Circulatory Support program. In this report, we describe the seven most recent chronic animal studies of the Infant VAD in the juvenile ovine model, with a mean body weight of 23.5 ± 4.1 kg. The goal of 4-6 weeks survival was achieved in five of seven studies, with support duration ranging from 5 to 41 days; mean 26.1 days. Anticoagulation was accomplished using unfractionated heparin, and study animals were divided into two protocol groups: the first based on a target activated partial thromboplastin time of 1.5-2 times normal, and a second group using a target thromboelastography R-time of two times normal. The second group required significantly less heparin, which was verified by barely detectable heparin activity (anti-Xa). In both groups, there was no evidence of thromboembolism except in one animal with a chronic infection and fever. Device thrombi were minimal and were further reduced by introduction of the custom valve. These results are consistent with results of adult VAD testing in animals and are encouraging given the extremely low levels of anticoagulation in the second group.