Single ventricle palliation with the Assisted Bidirectional Glenn (ABG)


October 29, 2016

Dr. Shang
Friday, October 28th
1:30-2:30pm
Location: SEH 2000B 

Abstract
Neonates born with single ventricle physiology typically undergo a three-stage procedure to restore a serial pulmonary and systemic circulation. The first stage, a systemic-pulmonary shunt, has the highest mortality rate of the stages (20-30%), yet historically, the second-stage procedure — the Glenn — has an even higher mortality at an early age. The The Assisted Bidirectional Glenn (ABG) is proposed as an early-stage palliative procedure for single ventricle neonates. The ABG augments the pulmonary flow of the stage-2 Bidirectional Glenn (BDG) with a secondary high-velocity flow through a nozzle-like shunt between the innominate artery and the superior vena cava (SVC). The ABG would provide a superior cavopulmonary connection than the systemic-pulmonary shunt that is typically employed as a stage-I procedure (e.g., a modified Blalock-Taussig shunt) and would address the low pulmonary flow associated with the BDG. Following simulations that show the ABG successfully increased pulmonary flows in idealized models, we utilize clinical data of post-stage-1 patients to implement a BDG and ABG in patient-specific 3D models coupled to a lumped parameter network tuned to clinical values for each patient. We evaluate the performance of each surgical procedure with expected flows, pressures, and  oxygen saturations, and heart loads. The ABG performed similarly across different patients; compared to the BDG, the pulmonary flow increased ~20% with a similar increase in the SVC pressure. We identify shunt parameters that are critical to ABG performance, which will be key for further optimization of the ABG in numerical simulations, which are consistent with in vitro experiments conducted by our collaborators. We also discuss efforts to demonstrate the ABG shunt in animal studies. 


Biography
Jessica Shang is an assistant professor of Mechanical Engineering at the University of Rochester. She received a BA from Harvard University, an MPhil from the University of Cambridge, and a PhD in Mechanical and Aerospace Engineering from Princeton University. Prior to joining UR she did her postdoctoral work in Pediatrics at the Stanford School of Medicine, and received an NIH T32 postdoctoral fellowship with the Stanford Cardiovascular Institute. Her research interests include fluid-structure interactions, biofluids, and vortex dynamics. 


Contact
The George Washington University, Mechanical and Aerospace Engineering
800 22nd St NW, suite 3000
Washington, DC 20052
[email protected]