Various congenital heart defects (CHDs) are characterized by the existence of a single functional ventricle, which perfuses both the systemic and pulmonary circulation. A three-stage palliation procedure, including the final Fontan completion, is often adopted by surgeons to treat patients with such CHDs. The completion Fontan involves the creation of a total cavopulmonary connection (TCPC), commonly accomplished with an extracardiac conduit. This TCPC results in nonphysiologic flow conditions that can lead to systemic venous hypertension, reduced cardiac output, and ultimately the need for heart transplantation. A modest pressure rise of 5–6 mm Hg could correct the abnormal flow dynamics in these patients. To achieve this, we propose a novel conceptual design of a dual-propeller pump inside a flared TCPC. The TCPC dual-propeller conjunction was examined for hydraulic performance, blood flow pattern, and potential for hemolysis inside the TCPC using computational fluid dynamics (CFD). The effect of axial distance between the two propellers on the blood flow interference and energy loss was studied to determine the optimal separation distance. Both the inferior vena cava (IVC) and superior vena cava (SVC) propellers provided a pressure rise of 1–20 mm Hg at flow rates ranging from 0.4 to 7 lpm while rotating at speeds of 6,000–12,000 rpm. Larger separation distance provided favorable performance in terms of flow interference, energy loss, and blood damage potential. The ability of a dual-propeller micropump to provide the required pressure rise would help to augment the cavopulmonary flow and mimic flows seen in normal biventricular circulation.
From the *Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
†Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
‡Department of Radiology, MedStar Medical Group Radiology, Baltimore, Maryland.
Submitted for consideration October 2017; accepted for publication in revised form September 2018.
Disclosure: The authors have no conflicts of interest to report.
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Presented in part at the ASME 2017 Fluids Engineering Division Summer Meeting, August 3, 2017, Waikoloa, Hawaii.
The Dual-Propeller Cavopulmonary Pump concept is covered by a provisional patent and has a full patent application pending http://vtip.technologypublisher.com/technology/23053.
Correspondence: Jakin N. Jagani, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA. Email: firstname.lastname@example.org.