Abstract
An intravascular axial flow blood pump has suitable hydraulic characteristics for use to augment pressure in the cavopulmonary circulation in Fontan patients. This study presents the experimental hydraulic performance testing of six flexible-bladed and one rigid-bladed pump prototypes for mechanical cavopulmonary assist. Unique in design, six of these prototypes were manufactured using varying grades of polyurethane material to reduce blade hardness. The hydraulic performance of these prototypes were measured and quantitatively compared to a rigid-bladed prototype through a regression analysis. To shield the vessel wall from the rotating impeller blades, two novel protective cage designs were also evaluated for additional energy augmentation. The pumps with no protective cage produced pressure rises of 1–12 mmHg for flow rates of 0.5–4 L/min at rotational speeds of 4000–7000 rpm. The flexible-bladed prototypes generated pressure rises within 12% of the rigid-bladed pump design. The most flexible prototype (F-15) was able to generate pressure rises within 4.1% of the rigid-bladed impeller. The partially twisted and fully twisted protective cage designs also functioned as desired by augmenting energy transfer in range of 5–15 mmHg, respectively. This study dispels the assumption that rigid-impeller blades are absolutely necessary to maintain the pressure generation of rotary blood pumps and demonstrates the potential of uniquely shaped cage filaments to augment the energy transfer of an axial flow blood pump for mechanical cavopulmonary assistance. The successful development of this blood pump will provide clinicians with a therapeutic option for mechanically supporting the failing Fontan physiology in adolescent and adult patients.
Similar content being viewed by others
References
Bhavsar, S. S., J. Y. Kapadia, S. G. Chopski, and A. L. Throckmorton. Intravascular mechanical cavopulmonary assistance for patients with failing Fontan physiology. Artif. Org. 33(11):977–987, 2009.
de Leval, M. R., G. Dubini, F. Migiliavacca, et al. Use of computational fluid dynamics in the design of surgical procedures: application to the study of competitive flows in the cavopulmonary connections. J. Thorac. Cardiovasc. Surg. 111:502–511, 1996.
Kapadia, J. Y., K. C. Pierce, A. K. Poupore, and A. L. Throckmorton. Hydraulic testing of intravascular axial flow blood pump designs with a protective cage of filaments for mechanical cavopulmonary assist. ASAIO J. 56:17–23, 2010.
Khairy, P., S. M. Fernandez, J. E. Mayer, J. K. Triedman, E. P. Walsh, et al. Long-term survival, modes of death, and predictors of mortality in patients with Fontan surgery. Circulation 117:85–92, 2008.
Lacour-Gayet, F. G., C. J. Lanning, S. Stoica, et al. An artificial right ventricle for failing Fontan: in vitro and computational study. Ann. Thorac. Surg. 88:170–176, 2009.
Riemer, K., G. Amir, S. H. Reichenbach, and O. Reinhartz. Mechanical support of total cavopulmonary connection with an axial flow pump. J. Thorac. Cardiovasc. Surg. 130:351–354, 2005.
Rodefeld, M., J. H. Boyd, B. J. LaLone, et al. Cavopulmonary assist: circulatory support for the univentricular Fontan circulation. Ann. Thorac. Surg. 76:1911–1916, 2003.
Rodefeld, M. D., B. Coats, T. Fisher, J. Brown, and S. H. Frankel. Cavopulmonary assist using a percutaneous, bi-conical, single impeller pump: a new spin for Fontan circulatory support. In: 89th Annual Meeting of the American Association for Thoracic Surgery, Boston, MA, USA, May 9–13, 2009.
Rossano, J. W., and A. C. Chang. Perioperative management of patients with poorly functioning ventricles in the setting of the functionally univentricular heart. Cardiol. Young. 16:47–54, 2006.
Schmitz-Rode, T., J. Graf, J. G. Pfeffer, F. Buss, et al. An expandable percutaneous catheter pump for left ventricular support: proof of concept. J. Am. Coll. Cardiol. 45:1856–1861, 2005.
Smith, E. J., O. Reitan, T. Keeble, K. Dixon, and M. T. Rothman. A first-in-man study of the Reitan catheter pump for circulatory support in patients undergoing high-risk percutaneous coronary intervention. Catheter. Cardiovasc. Interv. 73(7):859–865, 2009.
Throckmorton, A. L., K. K. Ballman, C. D. Myers, S. H. Frankel, J. W. Brown, and M. D. Rodefeld. Performance of an expandable propeller pump for cavopulmonary assist in a univentricular Fontan circulation. Ann. Thorac. Surg. 86:1343–1347, 2008.
Throckmorton, A. L., and S. G. Chopski. Pediatric circulatory support systems: current strategies and future directions. Biventricular and univentricular mechanical assistance. ASAIO J. 54:491–497, 2008.
Throckmorton, A. L., and R. A. Kishore. Design of a protective cage of filaments for an axial flow blood pump for intravascular cavopulmonary assist. Artif. Org. 33(8):611–621, 2009.
Throckmorton, A. L., A. Untaroiu, P. E. Allaire, H. G. Wood, D. S. Lim, M. A. McCulloch, and D. B. Olsen. Numerical design and experimental hydraulic testing of an axial flow VAD for infants and children. ASAIO J. 53:754–761, 2007.
Acknowledgments
The authors wish to acknowledge the financial support for this work provided by the Thomas F. and Katie Jeffress Memorial Trust, Phase I and Phase II Award (Grant Number: J-874), American Heart Association Beginning Grant-in-Aid (Grant Number: 0865320E), National Science Foundation (Grant Number: EEC-0823383), and 2009 Oak Ridge Associated Universities (ORAU) Ralph E. Powe Junior Faculty Enhancement Award. Additional assistance with regard to this study is credited to Robert Saxman, Aaron Pierce, Jeremy Clarke, Ignacio Landeros, and Colin West. We are thankful for their time and help.
Author information
Authors and Affiliations
Corresponding author
Additional information
Associate Editor Keefe B. Manning oversaw the review of this article.
Rights and permissions
About this article
Cite this article
Throckmorton, A.L., Kapadia, J.Y., Carr, J.P. et al. Flexible Impeller Blades in an Axial Flow Pump for Intravascular Cavopulmonary Assistance of the Fontan Physiology. Cardiovasc Eng Tech 1, 244–255 (2010). https://doi.org/10.1007/s13239-010-0026-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13239-010-0026-2