title: In-vitro investigation of cerebral-perfusion effects of a rotary blood pump installed in the descending aorta.
abstract: This study describes use of a cardiovascular simulator to replicate the hemodynamic responses of the cerebrovascular system with a mechanical circulatory support device operating in the descending aorta. To do so, a cerebral autoregulation unit was developed which replicates the dilation and constriction of the native cerebrovascular resistance system and thereby regulates the cerebral flow rate within defined limits. The efficacy of the replicated autoregulation mechanism was investigated by introducing a number of step alterations in mean aortic pressure and monitoring the cerebral flow. The steady responses of the cerebral flow to changes in mean aortic pressure were in good agreement with clinical data. Next, a rotary pump, modeling a mechanical circulatory support device, was installed in the descending aorta and the hemodynamic responses of the cerebral system were investigated over a wide range of pump operating conditions. Insertion of a mechanical circulatory support device in the descending aorta presented an improved cardiac output as a result of afterload reduction. It was observed that the primary drop in cerebral flow, caused by the pump in the descending aorta, was compensated over the course of five seconds due to a gradual decrease in cerebrovascular resistance. The experimental results suggest that the implantation of a mechanical circulatory support device in the descending aorta, a less invasive procedure than typical mechanical circulatory support implantation, will not have an adverse effect on the cognitive function, provided that the cerebral autoregulation is largely unimpaired.
authors.affiliation: School of Engineering and Materials Science, Queen Mary University of London, London, UK.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Rezaienia
authors.affiliation: School of Engineering and Materials Science, Queen Mary University of London, London, UK.
authors.forename: Gordon
authors.initials: G
authors.lastname: Paul
authors.affiliation: School of Engineering and Materials Science, Queen Mary University of London, London, UK.
authors.forename: Eldad
authors.initials: E
authors.lastname: Avital
authors.affiliation: School of Electrical and Electronic Engineering, Shiraz University of Technology, Shiraz, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Rahideh
authors.affiliation: Department of Cardiology, London Chest Hospital, Barts and the London NHS Trust, London, UK.
authors.forename: Martin Terry
authors.initials: MT
authors.lastname: Rothman
authors.affiliation: Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, MO, USA. Electronic address: korakianitis@alum.mit.edu.
authors.forename: Theodosios
authors.initials: T
authors.lastname: Korakianitis
mesh_terms: D001013:Aorta, Thoracic / Q000502:physiology*; D062186:Arterial Pressure; D001243:Assisted Circulation / Q000295:instrumentation / Q000379:methods; D002302:Cardiac Output; D002560:Cerebrovascular Circulation; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D010477:Perfusion
keywords: Cardiovascular simulator VAD; MCS; Minimally invasive