The McGill simulator for endoscopic sinus surgery (MSESS): a validation study

Abstract

Background: Endoscopic sinus surgery (ESS) is a technically challenging procedure, associated with a significant risk of complications. Virtual reality simulation has demonstrated benefit in many disciplines as an important educational tool for surgical training. Within the field of rhinology, there is a lack of ESS simulators with appropriate validity evidence supporting their integration into residency education. The objectives of this study are to evaluate the acceptability, perceived realism and benefit of the McGill Simulator for Endoscopic Sinus Surgery (MSESS) among medical students, otolaryngology residents and faculty, and to present evidence supporting its ability to differentiate users based on their level of training through the performance metrics.

Methods: 10 medical students, 10 junior residents, 10 senior residents and 3 expert sinus surgeons performed anterior ethmoidectomies, posterior ethmoidectomies and wide sphenoidotomies on the MSESS. Performance metrics related to quality (e.g. percentage of tissue removed), efficiency (e.g. time, path length, bimanual dexterity, etc.) and safety (e.g. contact with no-go zones, maximum applied force, etc.) were calculated. All users completed a post-simulation questionnaire related to realism, usefulness and perceived benefits of training on the MSESS.

Results: The MSESS was found to be realistic and useful for training surgical skills with scores of 7.97 ± 0.29 and 8.57 ± 0.69, respectively on a 10-point rating scale. Most students and residents (29/30) believed that it should be incorporated into their curriculum. There were significant differences between novice surgeons (10 medical students and 10 junior residents) and senior surgeons (10 senior residents and 3 sinus surgeons) in performance metrics related to quality (p < 0.05), efficiency (p < 0.01) and safety (p < 0.05).

Conclusion: The MSESS demonstrated initial evidence supporting its use for residency education. This simulator may be a potential resource to help fill the void in endoscopic sinus surgery training.

Figure 1

Hardware of the MSESS. View of the endoscope and the microdebrider handles (above) with VR view seen on the display monitor (below).

Figure 2

VR representation of sinonasal cavity. Views of an ethmoidectomy (left) and sphenoidotomy (right) using the microdebrider.

Figure 3

Percentage of tissue removed during simulation tasks. The graph represents means +/- SD. There was no statistically significant difference (p > 0.05) between all 4 groups for all three surgical tasks. When combining the groups into novices (students and junior residents) and senior surgeons (senior residents and attending faculty), there was a statistically significant difference for the wide sphenoidotomy (p = 0.01).

Figure 4

Time to complete the simulation tasks. The graph represents means +/- SD. Statistically significant difference (p < 0.005) between junior residents and senior residents. No difference between medical students and junior residents, nor between senior residents and attending faculty.

Figure 5

Path length (Distance travelled within nasal cavity). The graph represents means +/- SD. Statistically significant difference between junior residents and senior resident for both the endoscope (p < 0.001) and the microdebrider (p < 0.001). No difference between medical students and junior residents, nor between senior residents and attending faculty.

Figure 6

Distance between tool tips through the simulation tasks. The senior residents and attending faculty demonstrate far less fluctuation than medical students and junior residents.

Figure 7

Percentage of no-go zones removed. The graph represents means. Statistically significant difference between junior residents and senior residents for the percentage of lamina papyracea removed (p < 0.005). No difference between medical students and junior residents, nor between senior residents and attending faculty. No statistical difference for other no-go zones.