Design and Validation of a Cervical Laminectomy Simulator using 3D Printing and Hydrogel Phantoms

• Published in: Operative neurosurgery (Hagerstown, Md.) Vol. 18; no. 2; pp. 202 - 208
• Main Authors: Weiss, Menachem Y, Melnyk, Rachel, Mix, Doran, Ghazi, Ahmed, Vates, G Edward, Stone, Jonathan J
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01-02-2020; Wolters Kluwer Health, Inc
• Subjects: 3D printing; Adult; Aged; Clinical Competence - standards; Computer Simulation - standards; Female; Humans; Hydrogels; Laminectomy - education; Laminectomy - standards; Male; Middle Aged; Neurosurgeons - education; Neurosurgeons - standards; Neurosurgery; Phantoms, Imaging - standards; Printing, Three-Dimensional - standards; Reproducibility of Results; Surgeons; Validation studies; Validity; Resident education; Laminectomy; Simulation; 3D printing; Cervical spine
• ISSN: 2332-4252; 2332-4260
• DOI: 10.1093/ons/opz129

Abstract
BACKGROUND
The development of technical skills for a cervical laminectomy are traditionally acquired through intraoperative learning and cadaveric courses. These methods provide little objective assessment, involve financial and biohazard considerations, and may not incorporate desired pathology.
OBJECTIVE
To develop an inexpensive cervical spine laminectomy simulator capable of measuring operative performance and to assess its face, content, and construct validity.
METHODS
A virtual model was generated and 3D printed into negative molds. A multilayered surgical phantom was fabricating by filling molds with hydrogels, plaster, and fiberglass. A pressure transducer measured simulated spinal cord manipulation. Participants completed full-procedural laminectomy simulations. Post-simulation surveys assessed face and content validity. Construct validity was assessed by comparing expert and novice procedural metrics.
RESULTS
Twelve surgeons participated. The simulator received median face and content validity ratings of 4/5. Differences between experts and novices were found in mean intrathecal pressure wave count (84 vs 153, P = .023), amplitude (4 vs 12% > 2SD above expert mean, P < .001), area under curve (4 vs 12% > 2SD above expert mean, P < .001), procedure time (35 vs 69 min P = .003), and complication rates (none vs 3 incorrect levels decompressed and 1 dural tear, P = .06). Insignificant differences were found in mean pressure wave slope and blood loss.
CONCLUSION
This inexpensive cervical laminectomy simulator received favorable face and content validity ratings, and distinguished novice from expert participants. Further studies are needed to determine this simulator's role in the training and assessment of novice surgeons.