Rebecca Bates

Background: 1 in 100 babies are born with a congenital heart defect (CHD).¹ Complications of these malformations include heart failure, arrhythmias, and sudden cardiac death. ² Many defects require catheterization or open heart surgery repair.³ Prognosis is favorable for those that receive surgical intervention, however many children in low and middle-income countries lack access to surgery and thus have significantly worse outcomes and higher mortality.⁴ One aspect of inaccessibility in this area is the lack of surgeons trained to perform the repair procedures. A potential solution to this problem is using low-cost training models to educate surgeons on the techniques in a controlled, repeatable environment.

Methods: A PubMed database search was performed using the keywords “congenital heart defects”,  “surgical training”, “surgical simulation”, and “heart models” with exclusion criteria of articles that were published 5 or more years ago.

Results: This review identified 4 studies using models of different CHDs and surgical training methods. The first study trained residents on silicone models for low and high-difficulty CHD repair procedures.⁵ The low technical difficulty procedure showed resident performance and timing improvements after the first training session and then stabilized for subsequent sessions.⁵ The high technical difficulty procedure showed continuous improvement after the initial three sessions then stabilized. The second study used 3D-printed molds to create silicone models of a CHD which were refined to be more realistic based on feedback from experienced heart surgeons.⁶ Residents trained on these models and showed similar performance improvement to the first study between multiple sessions.⁶ The third study compared silicone and 3D printed heart models created using a “parting and assembly” method in conjunction with an online training module.⁷ Experienced surgeons using the models reported the silicon was adequate meanwhile the 3D printed model lacked enough detail to be anatomically relevant.⁷ The fourth study evaluated residents on the translation of ventricular septal defect repair on a model to surgical outcomes.⁸ Post-training, the performance of residents approached that of experienced fellows.⁸

Conclusions: The performance improvement in trainees utilizing heart models to learn CHD repairs demonstrates their value as a teaching tool. Multiple manufacturing methods were also established as viable options. Further investigation in the area should seek to optimize the cost and reusability of each model to implement tools such as these in low-resource areas.

Works Cited:

1. Wu W, He J, Shao X. Incidence and mortality trend of congenital heart disease at the global, regional, and national level, 1990–2017. Medicine. 2020;99(23):e20593-e20593. doi:https://doi.org/10.1097/md.0000000000020593
2. ‌Bouma BJ, Mulder BJM. Changing Landscape of Congenital Heart Disease. Circulation Research. 2017;120(6):908-922. doi:https://doi.org/10.1161/circresaha.116.309302
3. Meng X, Song M, Zhang K, et al. Congenital heart disease: types, pathophysiology, diagnosis, and treatment options. MedComm. 2024;5(7). doi:https://doi.org/10.1002/mco2.631
4. ‌Cheng SPS, Heo K, Joos E, Vervoort D, Joharifard S. Barriers to Accessing Congenital Heart Surgery in Low- and Middle-Income Countries: A Systematic Review. World Journal for Pediatric and Congenital Heart Surgery. 2023;15(1):94-103. doi:https://doi.org/10.1177/21501351231204328
5. ‌M. Ponzoni et al., “Longitudinal Evaluation of Congenital Cardiovascular Surgical Performance and Skills Retention Using Silicone-Molded Heart Models,” World Journal for Pediatric and Congenital Heart Surgery, vol. 15, no. 3, pp. 332–339, Apr. 2024, doi: https://doi.org/10.1177/21501351241237785.
6. M. Frei et al., “Three dimensional printed molds to obtain silicone hearts with congenital defects for pediatric Heart-Surgeon training,” European Journal of Cardio-Thoracic Surgery, vol. 65, no. 3, Jan. 2022, doi: https://doi.org/10.1093/ejcts/ezae079.
7. B. Peel, W. Lee, N. Hussein, and S.-J. Yoo, “State-of-the-art silicone molded models for simulation of arterial switch operation: Innovation with parting-and-assembly strategy,” JTCVS Techniques, vol. 12, pp. 132–142, Jan. 2022, doi: https://doi.org/10.1016/j.xjtc.2021.12.009.
8. Q. Li et al., “Clinical translation of surgical simulated closure of a ventricular septum defect,” Interactive Cardiovascular and Thoracic Surgery, vol. 35, no. 3, May 2022, doi: https://doi.org/10.1093/icvts/ivac122.