Chronic in vivo testing of the penn state infant ventricular assist device

William J. Weiss, Elizabeth L. Carney, J. Brian Clark, Rebecca Peterson, Timothy K. Cooper, Thomas P. Nifong, Christopher A. Siedlecki, Dennis Hicks, Bradley Doxtater, Branka Lukic, Eric Yeager, John Reibson, Joshua Cysyk, Gerson Rosenberg, William S. Pierce

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)65-72
Number of pages8
JournalASAIO Journal
Issue number1
StatePublished - Jan 2012

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Bioengineering
  • Biomaterials
  • Biomedical Engineering


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