Randomized, Controlled Trial of a Novel Rodent-Based Subarachnoid Hemorrhage Simulation System Using Advanced Biometric Analysis

Introduction: Subarachnoid hemorrhage (SAH) remains a core disease managed by skull base and cerebrovascular surgeons, which requires technical expertise under highly challenging operative conditions. Given the declining incidence of operatively managed cases, a mandate exists for high-fidelity simulation systems. We have previously reported and validated a novel rodent model for simulation of Sylvian fissure dissection and cerebrovascular bypass under SAH conditions. In the present study, we report the preliminary results of a randomized trial assessing the validity of the simulation system using biometric parameters to evaluate the relative difficulty of the experimental condition, as compared with control.

Methods: Ten neurosurgery and ENT residents who have completed an intensive week-long microvascular anastomosis training course were randomized 1:1 to control-first versus experimental-first sessions. Each session included end-to-end arterial and venous anastomoses. Task completion was assessed via bypass patency at the conclusion of each session and at 24 hours. Advanced biometric parameters included forearm and hand EMG to assess fatigue, volar hallux accelerometer to assess tremor, and heart rate (HR) to assess overall subject stress.

Results: On average, experimental sessions lasted longer than control sessions (93 and 71 minutes, respectively), with the vessel isolation portion taking four times longer in the experimental procedure (28 and 7 minutes, respectively). All subjects demonstrated baseline tremor bilaterally, with a statistically significant increase in the median frequencies above 8 Hz during the experimental conditions for the surgeon's dominant hand (right) during the clamp 1 (p < 0.00001) and clamp 2 (p = 0.005) portions of the procedures. Flexor digitorum profundus and extensor carpi radialis did not demonstrate significant differences in muscle fatigue between sessions; dominant hand thenar group muscle demonstrated a significant increase in EMG signs of fatigue in the experimental condition (R ² = 0.87). Mean HR and HR variability were significantly increased under experimental conditions. Among 10 subjects, all individuals completed the session tasks under control conditions, and 1 vessel thrombosed; under experimental conditions, 3 failed to complete the task, and 2 additional anastomoses thrombosed, a difference in graft patency that was significantly lower in the SAH model (5 vs. 40%, p = 0.02).

Conclusion: This interim analysis of a randomized, controlled trial assessing the validity of our novel rodent model simulating Sylvian fissure dissection and cerebrovascular bypass under SAH conditions confirms that the experimental model is significantly more difficult than the control conditions. Increases in tremor, muscle fatigue, and HR were noted, which were also significantly associated with worse task-completion and bypass-patency rates. Consideration should be given to incorporation of this and related models into national and international residency curricula.

Publication History

Article published online:
12 February 2021