Superficial Temporal Artery - Middle Cerebral Artery Bypass Ex-Vivo Hybrid Simulator: Face, Content, Construct, And Concurrent Validity

Abstract Background Cerebrovascular bypass surgical procedures require highly developed dexterity and refined bimanual technical skills. To attain such level of prowess, neurosurgeons and residents traditionally rely on “flat” models (without depth of field) such as chicken wings, live rats, silicone vessels and other materials that stray far away from the reality of the operating room albeit being more accessible. We explore the use of a hybrid ex-vivo simulator that takes advantage of the availability of placenta vessels while retaining the complexity of surgery being performed on a human skull to create a more realistic method to develop cerebrovascular bypass surgical skills. Methods Twelve ex-vivo simulators were constructed using three human placentas and one synthetic human skull for each. Face, content, construct and concurrent validity were assessed by 12 neurosurgeons (6 trained vascular, 6 general neurosurgeons) and compared to other bypass models. Results Fidelity was ranked “low” (Linkert scale score 1-2), “medium” (3) and “high” (4-5) fidelity grades. Face and content validity of the model showed high fidelity to STA-MCA bypass surgeries. Construct validity showed that cerebrovascular neurosurgeons had better performance, while Concurrent validity highlighted that all surgical steps were present. Conclusion The simulator was found to have strong face and content, construct, and concurrent validity for microsurgical cerebrovascular training. allowing simulation of all surgical steps of the bypass procedure. The hybrid simulator seems to be a promising method of shortening the bypass learning curve, however, more studies are required to evaluate the predictive validity of the model.