Flexible and comprehensive patient-specific mitral valve silicone models with chordae tendineae made from 3D-printable molds
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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.
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.
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.
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.
Keywords3D printing Flexible mitral valve Surgical training simulator
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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 was obtained from all individual participants included in the study.
Supplementary material 1 (mp4 42338 KB)
- 1.Engelhardt S, De Simone R, Full PM, Karck M, Wolf I (2018) Improving surgical training phantoms by hyperrealism: deep unpaired image-to-image translation from real surgeries. In: Frangi A, Schnabel J, Davatzikos C, Alberola-López C, Fichtinger G (eds) Medical image computing and computer assisted intervention—MICCAI 2018. MICCAI 2018. Lecture Notes in Computer Science, vol 11070. Springer, Cham. https://doi.org/10.1007/978-3-030-00928-1_84
- 2.Engelhardt S, Lichtenberg N, Al-Maisary S, De Simone R, Rauch H, Roggenbach J, Müller S, Karck M, Meinzer HP, Wolf I (2015) Towards automatic assessment of the mitral valve coaptation zone from 4D ultrasound. In: van Assen H, Bovendeerd P, Delhaas T (eds) Functional imaging and modeling of the heart. FIMH 2015. Lecture Notes in Computer Science, vol 9126. Springer, Cham, pp 137–145. https://doi.org/10.1007/978-3-319-20309-6_16
- 3.Engelhardt S, Sauerzapf S, Al-Maisary S, Karck M, Preim B, Wolf I, De Simone R (2018) Elastic mitral valve silicone replica made from 3D-printable molds offer advanced surgical training. In: Maier A, Deserno T, Handels H, Maier-Hein K, Palm C, Tolxdorff T (eds) Bildverarbeitung für die Medizin 2018. Informatik aktuell. Springer Vieweg, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-56537-7_33
- 4.Engelhardt S, Sauerzapf S, Brcic A, Karck M, Wolf I, De Simone R (2019) Replicated mitral valve models from real patients offer training opportunities for minimally invasive mitral valve repair. Interact CardioVasc Thoracic Surg. https://academic.oup.com/icvts/advance-article/doi/10.1093/icvts/ivz008/5345119
- 8.Ilina A, Lasso A, Jolley MA, Wohler B, Nguyen A, Scanlan A, Baum Z, McGowan F, Fichtinger G (2017) Patient-specific pediatric silicone heart valve models based on 3D ultrasound. In: Proceeding of the SPIE 10135, p 1013516Google Scholar
- 9.Kenngott HG, Wünscher JJ, Wagner M, Preukschas A, Wekerle AL, Neher P, Suwelack S, Speidel S, Nickel F, Oladokun D, Maier-Hein L, Dillmann R, Meinzer HP, Müller-Stich BP (2015) OpenHELP (Heidelberg laparoscopy phantom): development of an open-source surgical evaluation and training tool. Surg Endosc 29(11):3338–3347CrossRefPubMedPubMedCentralGoogle Scholar
- 11.Lee CH, Oomen PJA, Rabbah JP, Yoganathan A, Gorman RC, Gorman JH, Amini R, Sacks MS (2013) A high-fidelity and micro-anatomically accurate 3D finite element model for simulations of functional mitral valve. In: Ourselin S, Rueckert D, Smith N (eds) Functional imaging and modeling of the heart. FIMH 2013. Lecture Notes in Computer Science, vol 7945. Springer, Berlin, HeidelbergGoogle Scholar
- 14.Scanlan AB, Nguyen A, Ilina A, Lasso A, Cripe L, Jegatheeswaran A, Silvestro E, McGowan FX, Mascio CE, Fuller S, Spray TL, Cohen MS, Fichtinger G, Jolley MA (2017) Comparison of 3D echocardiogram-derived 3D printed valve models to molded models for simulated repair of pediatric atrioventricular valves. Pediatr Cardiol 39:1–10Google Scholar