Bryan C Good1, William J Weiss1,2, Steven Deutsch1, Keefe B Manning1,2. 1. 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA. 2. 2 Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, USA.
Abstract
BACKGROUND: Both pulsatile and continuous flow ventricular assist devices are being developed for pediatric congenital heart defect patients. Pulsatile devices are often operated asynchronously with the heart in either an "automatic" or a fixed beat rate mode. However, most studies have only investigated synchronized ejection. METHODS: A previously validated viscoelastic blood solver is used to investigate the parameters of pulsatility, power loss, and graft failure in a pediatric aortic anastomosis model. RESULTS: Pulsatility was highest with synchronized flow and lowest at a 90° phase shift. Power loss decreased at 90° and 180° phase shifts but increased at a 270° phase shift. Similar regions of potential intimal hyperplasia and graft failure were seen in all cases but with phase-shifted ejection leading to higher wall shear stress on the anastomotic floor and oscillatory shear index on the anastomotic toe. CONCLUSION: The ranges of pulsatility and hemodynamics that can result clinically using asynchronous pulsatile devices were investigated in a pediatric anastomosis model. These results, along with the different postoperative benefits of pump modulation, can be used to design an optimal weaning protocol.
BACKGROUND: Both pulsatile and continuous flow ventricular assist devices are being developed for pediatric congenital heart defectpatients. Pulsatile devices are often operated asynchronously with the heart in either an "automatic" or a fixed beat rate mode. However, most studies have only investigated synchronized ejection. METHODS: A previously validated viscoelastic blood solver is used to investigate the parameters of pulsatility, power loss, and graft failure in a pediatric aortic anastomosis model. RESULTS: Pulsatility was highest with synchronized flow and lowest at a 90° phase shift. Power loss decreased at 90° and 180° phase shifts but increased at a 270° phase shift. Similar regions of potential intimal hyperplasia and graft failure were seen in all cases but with phase-shifted ejection leading to higher wall shear stress on the anastomotic floor and oscillatory shear index on the anastomotic toe. CONCLUSION: The ranges of pulsatility and hemodynamics that can result clinically using asynchronous pulsatile devices were investigated in a pediatric anastomosis model. These results, along with the different postoperative benefits of pump modulation, can be used to design an optimal weaning protocol.
Authors: Matthew E Oster; Kyung A Lee; Margaret A Honein; Tiffany Riehle-Colarusso; Mikyong Shin; Adolfo Correa Journal: Pediatrics Date: 2013-04-22 Impact factor: 7.124
Authors: Christopher S Almond; David L Morales; Eugene H Blackstone; Mark W Turrentine; Michiaki Imamura; M Patricia Massicotte; Lori C Jordan; Eric J Devaney; Chitra Ravishankar; Kirk R Kanter; William Holman; Robert Kroslowitz; Christine Tjossem; Lucy Thuita; Gordon A Cohen; Holger Buchholz; James D St Louis; Khanh Nguyen; Robert A Niebler; Henry L Walters; Brian Reemtsen; Peter D Wearden; Olaf Reinhartz; Kristine J Guleserian; Max B Mitchell; Mark S Bleiweis; Charles E Canter; Tilman Humpl Journal: Circulation Date: 2013-03-28 Impact factor: 29.690
Authors: Douglas Mah; Tajinder P Singh; Ravi R Thiagarajan; Kimberlee Gauvreau; Gary E Piercey; Elizabeth D Blume; Francis Fynn-Thompson; Christopher S D Almond Journal: J Heart Lung Transplant Date: 2009-09-26 Impact factor: 10.247
Authors: Kevin K Whitehead; Kerem Pekkan; Hiroumi D Kitajima; Stephen M Paridon; Ajit P Yoganathan; Mark A Fogel Journal: Circulation Date: 2007-09-11 Impact factor: 29.690