gms | German Medical Science

Objective: Exoscopic surgery promises alleviation of physical strain and improved intraoperative visualization for surgical teams during microneurosurgical interventions. This study investigates the impact of a novel 3D4k hybrid exoscope on surgical performance and team workflow in clinical settings.

Methods: Following a preclinical study, we conducted a randomized controlled trial in supratentorial brain tumor cases (n=20). Setup, procedure, case characteristics, surgical performance and user experience have been documented, recorded and analyzed for both ocular group (OG) and monitor group (MG). Validated tools such as the System Usability Scale (SUS) and the Surgical Task Load Index (SURG-TLX) have been used for specification of qualitative feedback.

Results: Frontal, frontoparietal or temporal approaches have been identified as favorable for introducing exoscopic neurosurgery. Mean monitor distance and angle were 180±20cm and 10±10°. Surgical ergonomics when sitting improved significantly in MG compared to OG. Hand-eye coordination required familiarization in MG with more frequent events of hesitations, repetitions/corrections and slowdowns during the first 10 mins of surgery. There was no significant added surgical time in MG (overall surgical time: MG 220±61 mins vs. OG 236±67 mins; mean resection time MG 45±23 mins vs. OG 34±16 mins). Conversion rate in MG was 50% with case-dependent issues in lateral camera inclination and visual tissue differentiation. SUS showed significant differences in 4 items plus overall score with lower usability in MG. SURG-TLX showed significant differences with increase of overall workload and item 6 ‘distraction’ in MG. Image quality in ocular-based surgery was rated superior to current generation 3D4k monitors.

Conclusion: The 3D4k hybrid exoscope can be integrated into established neurosurgical workflows. Exoscopic interventions proved most suited for cranial tumor surgery with frontal, frontoparietal or temporal approaches in non-deep-seated lesions. Surgical ergonomics improve in monitor mode compared to conventional microsurgery. There is an adjustment period for surgical hand-eye coordination, which can be facilitated by additional training. Differences in usability and task load are mainly related to the introduction of a new device and decrease with experience. Small distance and angle of the external monitor are preferable. Further improvements of exoscopic image quality and hands-free control are required.