A Simple 3D Printed Model for Intracranial Vascular Anastomosis Practice and the Rochester Bypass Training Score.

Background And Objectives: Surgical simulation models in cranial neurosurgery are needed to allow affordable, accessible, and validated practice in resident education. Current bypass anastomosis practice models revolve around basic tube tying or complex animal and 3-dimensional models. This study sought to design and validate a 3-dimensional printed model for intracranial anastomosis training.

Methods: A computer-aided design (CAD) generic skull was uploaded into Meshmixer (v.3.5), and a 55-mm opening was created on the right side, mimicking a standard orbitozygomatic craniotomy. The model was rotated 15° upward and 35° left, before a 10-mm square frame was added 80-mm deep to the right orbit. The CAD model was uploaded to GrabCAD and printed using a J750 PolyJet 3D printer before being paired with a vascular anastomosis kit. The model was validated with standardized assessments of residents and attendings by simulating an "M2 to P2" bypass. The Rochester Bypass Training Score (RBTS) was created to assess bypass patency, back wall suturing, and suture quality. Postsimulation survey data regarding the realism and usefulness of the simulation were collected.

Results: Five junior residents (Postgraduate Year 1-4), 3 senior residents (Postgraduate Year 5-7), and 2 attendings were participated. The mean operative time in minutes was as follows: junior residents 78, senior residents 33, and attendings 50. The RBTS means were as follows: junior residents 2.4, senior residents 4.0, and attendings 5.0. Participants agreed that the model was realistic, useful for improving operative technique, and would increase comfort in bypass procedures. There are a few different printing options, varying in model infill and printing material used. For this experiment, a mix of Vero plastics were used totaling $309.09 per model; however, using the more common printing material polylactic acid brings the cost to $17.27 for a comparable model.

Conclusion: This study presents an affordable, realistic, and educational intracranial vascular anastomosis simulator and introduces the RBTS for assessment.