Mock circulatory loops (MCLs) are usually developed for assessment of ventricular assist devices and consist of abstracted anatomical structures represented by connecting tubing pipes and controllable actuators which could mimic oscillating flow processes. However, with increasing use of short-term peripheral mechanical support (extracorporeal life support [ECLS]) and the upcoming evidence of even counteracting flow processes between the failing native circulation and ECLS, MCLs incorporating the peripheral vascular system and preserved anatomical structures are becoming more important for systematic assessment of these processes. For reproducible and standardized fluid-mechanical studies using magnetic resonance imaging, Doppler ultrasound, and computational fluid dynamics measurements, we developed a MCL of the human circulation. Silicon-based life-sized dummies of the human aorta and vena cava (vascular module) were driven by paracorporeal pneumatic assist devices. The vascular module is placed in a housing with all arterial branches merging into peripheral resistance and compliances modules, and blood-mimicking fluid returns to the heart module through the venous dummy. Compliance and resistance chambers provide for an adequate simulation of the capillary system. Extracorporeal life support cannulation can be performed in the femoral and subclavian arteries and in the femoral and jugular veins. After adjusting vessel diameters using variable Hoffmann clamps, physiologic flow rates were achieved in the supraaortic branches, the renal and mesenteric arteries, and the limb arteries with physiologic blood pressure and cardiac output (4 L/min). This MCL provides a virtually physiologic platform beyond conventional abstracted MCLs for simulation of flow interactions between the human circulation and external circulation generated by ECLS.
From the *Department of Adult and Pediatric Cardiovascular Surgery, University Hospital Giessen, Giessen, Germany
†Research Center for BioMedical Technology (BMT), University of Applied Sciences and Arts, Dortmund, Germany
‡Department of Diagnostic and Interventional Radiology, University Hospital Giessen, Giessen, Germany
§Division of Life Science Engineering, University of Applied Sciences, Giessen, Germany.
Submitted for consideration October 2017; accepted for publication in revised form August 2018.
Disclosure: The authors have no conflicts of interest to report.
This study was funded by the Von-Behring-Röntgen-Foundation (38.000€). The aortic valve prosthesis used in this study was provided free of cost by Medtronic, Luxembourg. The authors of this manuscript have research support from The German Heart Foundation, the University Hospital Giessen and Marburg Research Fund, and the Von-Behring-Röntgen Foundation (P.G., and A.B.). P.G. received a travel grant (1000€) from Orion Pharma GmbH, Hamburg.
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Contributions of the authors are as follows: Johannes Gehron: project design, leader of the study group, drafting the manuscript, final approval; Julian Zirbes: conception and construction of the model, data analysis and interpretation, critical review, and final approval of the manuscript; Markus Bongert: conception of the model, data analysis and interpretation, critical review, and final approval of the manuscript; Stefan Schäfer: conception of the model, imaging, drafting the manuscript, critical review, and final approval of the manuscript; Martin Fiebich: conception of the model, imaging, drafting the manuscript, critical review, and final approval of the manuscript; Gabriele Krombach: conception of the model, imaging, drafting the manuscript, critical review, and final approval of the manuscript; Andreas Böning: conception of the model, drafting the manuscript, critical review, and final approval of the manuscript; Philippe Grieshaber: project design, leader of the study group, drafting the manuscript, final approval.
Correspondence: Philippe Grieshaber, Department of Adult and Pediatric Cardiovascular Surgery, University Hospital Giessen, Rudolf-Buchheim-Str. 7, DE-35392 Giessen, Germany. Email: Philippe.firstname.lastname@example.org.