In Vitro and In Vivo Performance Evaluation of the Second Developmental Version of the PediaFlow Pediatric Ventricular Assist Device
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Ventricular assist devices (VADs) have significantly impacted the treatment of adult cardiac failure, but few options exist for pediatric patients. This has motivated our group to develop an implantable magnetically levitated rotodynamic VAD (PediaFlow®) for 3–20 kg patients. The second prototype design of the PediaFlow (PF2) is 56% smaller than earlier prototypes, and achieves 0.5–1.5 L/min blood flow rates. In vitro hemodynamic performance and hemolysis testing were performed with analog blood and whole ovine blood, respectively. In vivo evaluation was performed in an ovine model to evaluate hemocompatibility and end-organ function. The in vitro normalized index of hemolysis was 0.05–0.14 g/L over the specified operating range. In vivo performance was satisfactory for two of the three implanted animals. A mechanical defect caused early termination at 17 days of the first in vivo study, but two subsequent implants proceeded without complication and electively terminated at 30 and 70 days. Serum chemistries and plasma free hemoglobin were within normal limits. Gross necropsy revealed small, subclinical infarctions in the kidneys of the 30 and 70 day animals (confirmed by histopathology). The results of these experiments, particularly the biocompatibility demonstrated in vivo encourage further development of a miniature magnetically levitated VAD for the pediatric population. Ongoing work including further reduction of size will lead to a design freeze in preparation for of clinical trials.
KeywordsPediatric Mechanical circulatory support Ventricular assist device Pre-clinical study In vivo
Support was provided by NIH (HHSN268200448192C, R41-HL077028, R01-HL089456-01A2), NSF (ECS-0300097), Commonwealth of Pennsylvania, UNCF MERCK Graduate Fellowship (Johnson), Cardiovascular Bioengineering T32 Training Program (Woolley), and The Hartwell Foundation (Maul).
Conflict of interest
Technical expertise and intellectual property were provided by LaunchPoint Technologies, LLC and WorldHeart Corporation. Funding for their participation was provided through the NIH funding (HHSN268200448192C). The authors had full control of the design of the study, methods used, outcome parameters, analysis of data, and production of this manuscript.
- 2.Drummond, A., and J. Antaki. Virtual fit study of pediatric heart assist system. In: Digital Human Modeling: Trends in Human Algorithms, edited by Y. Cai. Berlin: Springer, 2008, pp. 71–79.Google Scholar
- 11.Maul, T. M., E. Kocyildirim, J. D. Marks, S. G. Bengston, S. E. Olia, P. M. Callahan et al. Pre-clinical implants of the levitronix PediVAS® pediatric ventricular assist device: strategy for regulatory approval. Cardiovasc. Eng. Tech. 2011. doi:10.1007/s13239-011-0063-5.
- 12.Maul TM, Wearden PD, Winowich S, Wagner WR, Borovetz HS, editors. Clinical Challenges in Pediatric Cardiovascular Support: Children are not Miniature Adults. International Conference on Mechanics and Medicine in Biology; 2008 June; Pittsburgh, PA.Google Scholar
- 21.Vandenberghe, S., P. Segers, B. Meyns, and P. Verdonck. Hydrodynamic characterisation of ventricular assist devices. Int J Artif Organs 24(7):470–477, 2001.Google Scholar
- 23.Wintrobe, M. M. Clinical Hematology (6th ed.). Philadelphia: Lea and Febiger, pp. 427–433, 1967.Google Scholar