The Use of the Exoscope in Lateral Skull Base Surgery: Advantages and Limitations.

OBJECTIVE: We describe our experience using the extracorporeal video microscope, the "exoscope" for various applications within the field of lateral skull base surgery.

STUDY DESIGN: A retrospective case series was performed investigating patient demographics, indications for surgery, procedure type, operative time, approach to the skull base, complications, adequacy of visualization, and surgeon comfortability.

PATIENTS: Six cases were performed with a three dimensional surgical exoscope, obviating the use of a traditional binocular microscope.

SETTING: Academic, tertiary referral center.

MAIN OUTCOME MEASURES: Type of surgical approach, operative time, patient demographics, surgical complications, and surgeon comfortability.

RESULTS: The following procedures were performed; four vestibular schwannoma resections via suboccipital craniotomy and two combined transmastoid and transtemporal approaches for temporal lobe encephalocele repairs. The average operative time was 227 and 577 minutes for temporal lobe encephalocele repairs and vestibular schwannoma cases, respectively. No intraoperative complications were encountered during these cases. None of the procedures required abandonment of the exoscope in favor of the microscope during the procedure. Advantages include high-resolution three-dimensional visualization, increased degrees of freedom for exoscope adjustment, and reduced surgeon fatigue in a fixed, unnatural posture. Limitations include decreased depth perception and increased operative time.

CONCLUSION: The exoscope system is a safe and effective alternative or adjunct to the existing binocular operating microscope for lateral skull based procedures. The exoscope provides the surgeon with a comfortable, high-resolution visualization without compromising surgical exposure and patient safety.

LEVEL OF EVIDENCE: 4.