Mathematical Analysis and Physical Profile of Blalock-Taussig Shunt and Sano Modification Procedure in Hypoplastic Left Heart Syndrome: Review of the Literature and Implications for the Anesthesiologist

2017 ◽  
Vol 21 (2) ◽  
pp. 152-164
Author(s):  
Efrain Riveros Perez ◽  
Ricardo Riveros

The first stage of surgical treatment for hypoplastic left heart syndrome (HLHS) includes the creation of artificial systemic-to-pulmonary connections to provide pulmonary blood flow. The modified Blalock-Taussig (mBT) shunt has been the technique of choice for this procedure; however, a right ventricle–pulmonary artery (RV-PA) shunt has been introduced into clinical practice with encouraging but still conflicting outcomes when compared with the mBT shunt. The aim of this study is to explore mathematical modeling as a tool for describing physical profiles that could assist the surgical team in predicting complications related to stenosis and malfunction of grafts in an attempt to find correlations with clinical outcomes from clinical studies that compared both surgical techniques and to assist the anesthesiologist in making decisions to manage patients with this complex cardiac anatomy. Mathematical modeling to display the physical characteristics of the chosen surgical shunt is a valuable tool to predict flow patterns, shear stress, and rate distribution as well as energetic performance at the graft level and relative to ventricular efficiency. Such predictions will enable the surgical team to refine the technique so that hemodynamic complications be anticipated and prevented, and are also important for perioperative management by the anesthesia team.

Author(s):  
M. Navaratnam ◽  
C. Ramamoorthy

Approximately 960 babies are born per year in the United States with hypoplastic left heart syndrome. Over the last 20 years, advances in surgical techniques, perioperative care, cardiopulmonary bypass, and intensive care unit management have converted this previously fatal condition to one with a neonatal survival rate of 90% to 92% for standard risk patients. Understanding the factors affecting the balance of pulmonary blood flow and systemic blood flow and ensuring adequate cardiac output and end-organ perfusion is critical to successful outcomes. Extracorporeal membrane oxygenation remains an important support modality following stage I palliation. This chapter discusses this syndrome and describes treatment options.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ali Jalali ◽  
Gerard F. Jones ◽  
Daniel J. Licht ◽  
C. Nataraj

This paper is concerned with the mathematical modeling of a severe and common congenital defect called hypoplastic left heart syndrome (HLHS). Surgical approaches are utilized for palliating this heart condition; however, a brain white matter injury called periventricular leukomalacia (PVL) occurs with high prevalence at or around the time of surgery, the exact cause of which is not known presently. Our main goal in this paper is to study the hemodynamic conditions under which HLHS physiology may lead to the occurrence of PVL. A lumped parameter model of the HLHS circulation has been developed integrating diffusion modeling of oxygen and carbon dioxide concentrations in order to study hemodynamic variables such as pressure, flow, and blood gas concentration. Results presented include calculations of blood pressures and flow rates in different parts of the circulation. Simulations also show changes in the ratio of pulmonary to systemic blood flow rates when the sizes of the patent ductus arteriosus and atrial septal defect are varied. These changes lead to unbalanced blood circulations and, when combined with low oxygen and carbon dioxide concentrations in arteries, result in poor oxygen delivery to the brain. We stipulate that PVL occurs as a consequence.


2020 ◽  
Vol 32 (3) ◽  
pp. 531-538
Author(s):  
Elizabeth H. Stephens ◽  
Dipankar Gupta ◽  
Mark Bleiweis ◽  
Carl L. Backer ◽  
Robert H. Anderson ◽  
...  

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