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Flexible and comprehensive patient-specific mitral valve silicone models with chordae tendineae made from 3D-printable molds

  • Sandy EngelhardtEmail author
  • Simon Sauerzapf
  • Bernhard Preim
  • Matthias Karck
  • Ivo Wolf
  • Raffaele De Simone
Original Article

Abstract

Purpose

Given the multitude of challenges surgeons face during mitral valve repair surgery, they should have a high confidence in handling of instruments and in the application of surgical techniques before they enter the operating room. Unfortunately, opportunities for surgical training of minimally invasive repair are very limited, leading to a situation where most surgeons undergo a steep learning curve while operating the first patients.

Methods

In order to provide a realistic tool for surgical training, a commercial simulator was augmented by flexible patient-specific mitral valve replica. In an elaborated production pipeline, finalized after many optimization cycles, models were segmented from 3D ultrasound and then 3D-printable molds were computed automatically and printed in rigid material, the lower part being water-soluble. After silicone injection, the silicone model was dissolved from the mold and anchored in the simulator.

Results

To our knowledge, our models are the first to comprise the full mitral valve apparatus, i.e., the annulus, leaflets, chordae tendineae and papillary muscles. Nine different valve molds were automatically created according to the proposed workflow (seven prolapsed valves and two valves with functional mitral insufficiency). From these mold geometries, 16 replica were manufactured. A material test revealed that EcoflexTM 00-30 is the most suitable material for leaflet-mimicking tissue out of seven mixtures. Production time was around 36 h per valve. Twelve surgeons performed various surgical techniques, e.g., annuloplasty, neo-chordae implantation, triangular leaflet resection, and assessed the realism of the valves very positively.

Conclusion

The standardized production process guarantees a high anatomical recapitulation of the silicone valves to the segmented models and the ultrasound data. Models are of unprecedented quality and maintain a high realism during haptic interaction with instruments and suture material.

Keywords

3D printing Flexible mitral valve Surgical training simulator 

Notes

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical standards

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Supplementary material

Supplementary material 1 (mp4 42338 KB)

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Copyright information

© CARS 2019

Authors and Affiliations

  1. 1.Faculty of Computer ScienceUniversity of Applied Sciences MannheimMannheimGermany
  2. 2.Department of Cardiac SurgeryUniversity Hospital HeidelbergHeidelbergGermany
  3. 3.Faculty of Computer ScienceMagdeburg UniversityMagdeburgGermany

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