The Implementation of an Adjustable Afterload Module for Ex Situ Heart Perfusion

  • Bryan Gellner
  • Liming Xin
  • Roberto Vanin Pinto Ribeiro
  • Ved Bissoondath
  • Pengzhou Lu
  • Mitchell B. Adamson
  • Frank Yu
  • Emanuela Paradiso
  • Jean Zu
  • Craig A. SimmonsEmail author
  • Mitesh V. Badiwala
Original Article



Windkessel impedance analysis has proven to be an effective technique for instituting artificial afterload on ex situ hearts. Traditional fixed parameter afterload modules, however, are unable to handle the changing contractile conditions associated with prolonged ex situ heart perfusion. In this paper, an adjustable afterload module is described comprising of three fully adjustable sub-components: a systemic resistor, a proximal resistor and a compliance chamber.


Using a centrifugal pump, the systemic resistor and compliance chamber were subjected to testing across their operating ranges, whereby the predictability of resistance and compliance values was evaluated. The components were then assembled, and the full module tested on three separate porcine hearts perfused for 6 h with success defined by the ability to maintain physiological systolic and diastolic aortic pressures across flow rate variability.


For both the systemic resistor and compliance chamber, experimental measurements agreed with their theoretical equivalents, with coefficients of determination of 0.99 and 0.97 for the systemic resistor and compliance chamber, respectively. During ex situ perfusion, overall 95% confidence intervals demonstrate that physiological systolic (95–96.21 mmHg) and diastolic (26.8–28.8 mmHg) pressures were successfully maintained, despite large variability in aortic flow. Left ventricular contractile parameters, were found to be in line with those in previous studies, suggesting the afterload module has no detrimental impact on functional preservation.


We conclude that due to the demonstrable control of our afterload module, we can maintain physiological aortic pressures in a passive afterload working mode across prolonged perfusion periods, enabling effective perfusion regardless of contractile performance.


Heart preservation Ex Vivo heart perfusion Ex situ heart perfusion Afterload Heart transplantation Perfusion 



This project was supported by the University of Toronto EMHSeed program, the Translational Biology and Engineering Program in the Ted Rogers Centre for Heart Research, and Toronto General and Western Hospital Foundation.

Supplementary material

13239_2019_447_MOESM1_ESM.pdf (248 kb)
Electronic supplementary material 1 (PDF 248 kb)


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Copyright information

© Biomedical Engineering Society 2019

Authors and Affiliations

  • Bryan Gellner
    • 1
    • 2
  • Liming Xin
    • 1
    • 3
    • 8
  • Roberto Vanin Pinto Ribeiro
    • 3
    • 5
  • Ved Bissoondath
    • 3
  • Pengzhou Lu
    • 1
    • 3
  • Mitchell B. Adamson
    • 3
    • 5
  • Frank Yu
    • 3
  • Emanuela Paradiso
    • 6
  • Jean Zu
    • 1
  • Craig A. Simmons
    • 1
    • 2
    • 7
    Email author
  • Mitesh V. Badiwala
    • 3
    • 4
  1. 1.Department of Mechanical & Industrial EngineeringUniversity of TorontoTorontoCanada
  2. 2.Translational Biology & Engineering ProgramTed Rogers Centre for Heart ResearchTorontoCanada
  3. 3.Division of Cardiovascular Surgery, Toronto General HospitalUniversity Health NetworkTorontoCanada
  4. 4.Department of SurgeryUniversity of TorontoTorontoCanada
  5. 5.Institute of Medical ScienceUniversity of TorontoTorontoCanada
  6. 6.Department of Anesthesia and Pain Management, Toronto General HospitalUniversity Health NetworkTorontoCanada
  7. 7.Institute of Biomaterials & Biomedical EngineeringUniversity of TorontoTorontoCanada
  8. 8.State Key Laboratory of Mechanical TransmissionsChongqing UniversityChongqingChina

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