Abstract 15947: In-vitro and Computational Study of the Assisted Bidirectional Glenn Procedure for Initial Palliation of Single Ventricle Physiology
Introduction: For single ventricle hearts, palliation with systemic-to-pulmonary shunt remains unsatisfactory. However, initial bidirectional Glenn anastomosis is discouraged because the neonatal SVC may be unable to provide adequate pulmonary blood flow (PBF). We propose a radical approach, called the Assisted Bidirectional Glenn (ABG), where flow in a Glenn would be augmented by a shunt between the innominate artery and SVC. Motivated by the ejector pump concept in fluids engineering, we attempt to improve PBF without increasing SVC pressure. ABG is proposed as a replacement for the stage-one operation and potentially can be converted to stage-two circulation by blocking the shunt via a catheter.
Methods: A multiscale framework is adopted to model, both numerically and experimentally, the conventional stage-one (BT shunt) and neonatal stage-two surgeries (Glenn), as well as the ABG. Multiscale modeling allows for prediction of global response of the circulatory system to the altered anatomy, as well as detailed hemodynamics. Lumped parameter network is constructed and tuned based on clinical measurement of 23 stage-one patients. A mock circulatory system was built to experimentally simulate the three surgical options and to validate computational results. Two levels of pulmonary vascular resistance (PVR) are considered to simulate neonatal (high PVR) and pre-stage two (normal PVR) conditions.
Results and Conclusions: Our simulation results show that ABG provides (1) 30% higher PBF compared with stage-two; (2) 14% higher systemic oxygen delivery compared to stage-one; (3) 46% lower heart load compared to stage-one and; (4) 5 mmHg higher SVC pressure compared to stage-two (Figure 1-a). Experimental results verify the simulations, confirming the changes in PBF and SVC pressure (Figure 1-b). Future studies will focus on methods to decrease the SVC pressure with enhanced PBF through design optimization.
Author Disclosures: M. Esmaily-Moghadam: None. J. Zhou: None. T. Hsia: None. R. Figliola: None. A. Marsden: None.
- © 2014 by American Heart Association, Inc.