Perspective

Endoscope Holders in Cranial Neurosurgery. Perspective Statement

The use of endoscopic assistance in retrosigmoid approach for tumors of the cerebellopontine angle brought undoubted technological advantages in skull base surgery.

Nonetheless, the use of the endoscope is not as widespread as it could be.

The aim of the study is to analyze the impressions of neurosurgeons and otologists with different experience in vestibular schwannoma surgery, experiencing the introduction of the endoscope in surgical daily practice.

All patients undergoing vestibular schwannoma surgery were recruited in the period from January 2019 to December 2020. The endoscope-assistance and a minimum follow-up of 12 months were considered inclusion criteria. An eight items questionnaire was administered to the surgeons who used endoscope-assistance during surgery.

A total number of 20 patients were recruited. Five surgeons experienced the use of 0° and 45° optics in the “pre-resection” and “intra-meatal” phases of the procedures. The survey gave positive feedbacks on the introduction of the endoscope in vestibular schwannoma resection. The main drawback was the difficulty to manage the use of angled optics.

Despite the known limitations of the study, the idea of investigating surgeons’ impressions on the use of the endoscope could be another motif to explain why this instrument and its diffusion is limited despite its advantages in vestibular schwannoma surgery.

The ability to hold an endoscope is an important skill for surgeons and assistants performing endoscopic neurosurgery. Motion tracking can provide an objective assessment for surgical skills and may aid in endoscopic neurosurgery. We developed a cost-effective system to study the feasibility of objectively distinguishing performance levels for operating an endoscope.

The study was divided into 2 parts. First, a video motion tracking analysis tool was built based on a printed mark and free software (Kinovea 0.8.15). Second, the tool was used to distinguish the holding endoscope performance of the robotic arm by experts (surgeon, n = 3) and novice users (residents, n = 6) under both 0′ and 30′ endoscopes.

Through the printed mark and free software, we successfully built a system for video motion tracking. The data analysis showed that for both 0′ and 30′ endoscopes, the experts had a shorter total distance and depth, smaller average speed and maximum acceleration, and a fewer number of extreme accelerations than their novice counterparts. Compared with experts and residents, the fixed arm had better results.

The simple low-cost video motion tracking system can provide an objective assessment of an endoscope holding skill, which allows for discrimination between an expert and a novice, and can be used by clinical neurosurgeons to select a qualified assistant.