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3D printed ascending aortic simulators with physiological fidelity for surgical simulation
  1. Ali Alakhtar1,2,
  2. Alexander Emmott3,4,
  3. Cornelius Hart4,
  4. Rosaire Mongrain5,
  5. Richard L Leask4,
  6. Kevin Lachapelle6
  1. 1 Department of Cardiac Surgery, McGill University, Montreal, Québec, Canada
  2. 2 Dpartment of Surgery, Unaizah College of Medicine and Health Sciences, Qassim University, Qassim, Saudi Arabia
  3. 3 Research Institute, McGill University Health Centre, Montreal, Québec, Canada
  4. 4 Department of Chemical Engineering, McGill University, Montreal, Québec, Canada
  5. 5 Department of Mechanical Engineering, McGill University, Montreal, Québec, Canada
  6. 6 Department of Cardiovascular Surgery, McGill University Health Centre, Montreal, Québec, Canada
  1. Correspondence to Dr Kevin Lachapelle, Cardiovascular Surgery, McGill University Health Centre, Montreal, Québec H4A 3J1, Canada; kevin.lachapelle{at}mcgill.ca

Abstract

Introduction Three-dimensional (3D) printed multimaterial ascending aortic simulators were created to evaluate the ability of polyjet technology to replicate the distensibility of human aortic tissue when perfused at physiological pressures.

Methods Simulators were developed by computer-aided design and 3D printed with a Connex3 Objet500 printer. Two geometries were compared (straight tube and idealised aortic aneurysm) with two different material variants (TangoPlus pure elastic and TangoPlus with VeroWhite embedded fibres). Under physiological pressure, β Stiffness Index was calculated comparing stiffness between our simulators and human ascending aortas. The simulators’ material properties were verified by tensile testing to measure the stiffness and energy loss of the printed geometries and composition.

Results The simulators’ geometry had no effect on measured β Stiffness Index (p>0.05); however, β Stiffness Index increased significantly in both geometries with the addition of embedded fibres (p<0.001). The simulators with rigid embedded fibres were significantly stiffer than average patient values (41.8±17.0, p<0.001); however, exhibited values that overlapped with the top quartile range of human tissue data suggesting embedding fibres can help replicate pathological human aortic tissue. Biaxial tensile testing showed that fiber-embedded models had significantly higher stiffness and energy loss as compared with models with only elastic material for both tubular and aneurysmal geometries (stiffness: p<0.001; energy loss: p<0.001). The geometry of the aortic simulator did not statistically affect the tensile tested stiffness or energy loss (stiffness: p=0.221; energy loss: p=0.713).

Conclusion We developed dynamic ultrasound-compatible aortic simulators capable of reproducing distensibility of real aortas under physiological pressures. Using 3D printed composites, we are able to tune the stiffness of our simulators which allows us to better represent the stiffness variation seen in human tissue. These models are a step towards achieving better simulator fidelity and have the potential to be effective tools for surgical training.

  • high-fidelity simulation
  • quality improvement
  • resident training
  • simulator design
  • surgical simulation

Data availability statement

All data relevant to the study are included in the article or uploaded as supplemental information. Data available from primary author: Dr Ali Alakhtar at ali.alakhtar@mail.mcgill.ca (ORCD ID: 0000-0001-8326-3719).

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Data availability statement

All data relevant to the study are included in the article or uploaded as supplemental information. Data available from primary author: Dr Ali Alakhtar at ali.alakhtar@mail.mcgill.ca (ORCD ID: 0000-0001-8326-3719).

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Footnotes

  • Twitter @alimalakhtar

  • Contributors The corresponding author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive licence (or non-exclusive for government employees) on a worldwide basis to the BMJ Publishing Group to permit this article (if accepted) to be published in BMJ editions and any other BMJPGL products and sublicences such use and exploit all subsidiary rights, as set out in our licence. The lead author (the manuscript’s guarantor) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained. AA designed the experiment, performed the experiment, analysed the data and wrote the manuscript. AE performed the experiment, analysed the data and edited the manuscript. CH performed the experiment and performed 3D printing. RM provided the infrastructure and reviewed the manuscript. RLL supervised the study, provided the infrastructure, designed the experiment, reviewed the data analysis and reviewed the manuscript. KL supervised the study, provided the infrastructure, designed the experiment, reviewed the data analysis and reviewed the manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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