Design and validation of a hemispherectomy simulator for education

OBJECTIVE Early adaptors of surgical simulation have documented a translation to improved intraoperative surgical performance. Similar progress would boost neurosurgical education, especially in highly nuanced epilepsy surgeries. This study introduces a hands-on cerebral hemispheric surgery simulator and evaluates its usefulness in teaching epilepsy surgeries. METHODS Initially, the anatomical realism of the simulator and its perceived effectiveness as a training tool were evaluated by two epilepsy neurosurgeons. The surgeons independently simulated hemispherotomy procedures and provided questionnaire feedback. Both surgeons agreed on the anatomical realism and effectiveness of this training tool. Next, construct validity was evaluated by modeling the proficiency (task-completion time) of 13 participants, who spanned the experience range from novice to expert. RESULTS Poisson regression yielded a significant whole-model fit (chi(2)= 30.11, p < 0.0001). The association between proficiency when using the training tool and the combined effect of prior exposure to hemispherotomy surgery and career span was statistically significant (chi(2)= 7.30, p = 0.007); in isolation, pre-simulation exposure to hemispherotomy surgery (chi(2)= 6.71, p = 0.009) and career length (chi(2)= 14.21, p < 0.001) were also significant. The mean (+/- SD) task -com- pletion time was 25.59 +/- 9.75 minutes. Plotting career length against task-completion time provided insights on learning curves of epilepsy surgery. Prediction formulae estimated that 10 real-life hemispherotomy cases would be needed to approach the proficiency seen in experts. CONCLUSIONS The cerebral hemispheric surgery simulator is a reasonable epilepsy surgery training tool in the quest to increase preoperative practice opportunities for neurosurgical education.