Developing simulation tools for doctors

Background

Certain skills, especially those involving manipulation of 3D structures, can be challenging to master with few opportunities for practice. We developed a high-fidelity, cost-effective model of the face was created using three-dimensional (3D) printing to simulate flap reconstruction following Mohs surgery. We studied the impact of this model on the comfort and proficiency of surgical trainees in flap design for Mohs reconstruction.

Design

Skin, bone, and cartilage of a model face sculpted digitally. Negatives (molds) were 3D-printed and used to create a silicone cast representing the skin. The cartilage and bone models were combined to create a single 3D-printed base upon which to lay the skin.

Screen Shot 2022-08-11 at 7.07.50 PM.png

skin mesh

Skin model sculpted de novo in Blender®

Screen Shot 2022-08-11 at 7.08.26 PM.png

skull and cartilage meshes

Skull and cartilage models sculpted de novo in Blender®

Screen Shot 2022-08-11 at 7.06.56 PM.png

printable base

Skull and cartilage models incorporated into a base on which to lay the silicone skin

Screen Shot 2022-08-11 at 7.14.30 PM.png

mold to cast skin in silicone

"Negative" of the skin created digitally and printed as a mold

Workshop

Surgical residents practiced designing, raising, and insetting banner and bilobed flaps, on the simulation model. Improvement was assessed using a boards-style pre- and post-test in which flaps were planned on clinical photographs. Medical students were randomized to complete a similar practice session with the model or a reading on the topic, after which they completed the same assessment. Participants completed a questionnaire about the model’s didactic and monetary value. This accessible model was superior to traditional teaching materials for Mohs reconstruction.

Results

Residents showed significant improvement after use of the model (banner flap: p=0.002, bilobed flap: p=0.04). Medical students who used the model scored significantly higher than those assigned to train by reading (p=0.001).

Subjective comfort with flap design and execution increased following practice with the model (p=0.001). Although the materials cost for each model was $2.50, participants reported willingness to pay $24.36 (mean) for this tool.

Discussion & affordability

Simulation is a powerful adjunct to intra-operative opportunities and build surgeon confidence by enabling procedural skills to be finessed at their own leisure. The utility of simulators for surgical skill and thus patient outcomes is supported by a growing body of literature with evidence of improved patient outcomes and reduced operative time. While traditional simulation models have been generic in nature, 3D sculpting and printing have introduced infinite possibility for creating customized, reproducible, and affordable models.

To ensure accessibility to training programs, the design of our model focused on ensuring its affordability. Only free software was utilized and models were sculpted free-hand without assistance of commercially available stock models of human figures or anatomy. Silicone cost $2.50 per model, as compared with a mean cost of $24 participants reported willingness to pay. Of note, silicone models, while not reused in our study can be restored by painting fresh silicone onto cut edges, reapproximating edges, and allowing them to cure. This was not done as previously incised lines could confound results, if visible.

Future directions

Our model and workflow can serve as a proof-of-concept for the creation of new simulators of facial anatomy, involving manipulatable bone and cartilage. We are now developing a novel simulation model to train plastic surgeons in rhinoplasty techniques.