gms | German Medical Science

Objective: To assist the clinical introduction of a novel surgical microscope with hybrid (digital monitor- and analog ocular-based) visualization capability, a preparatory evaluation study has been conducted. Study goals were to assess the impact of exoscopic surgery on neurosurgical task performance, to identify suitable clinical use cases, to define compatible surgical access strategies and to determine required workflow adjustments for 3D4k surgery.

Methods: 12 neurosurgical professionals (6 residents, 6 consultants) performed predefined tasks on a skull/brain and spine phantom in a simulated OR team setting. The tasks (vessel and nerve preparation, end-to-end anastomosis) were completed either solely with 3D4k vision (with 3D glasses) or in comparison with conventional microsurgery on the same system. Setup alterations, working zones, exoscope interaction and control, 3D monitor position, distance and angle, contrast and depth perception were documented, followed by usability surveys with all participants.

Results: In monitor-based task performance, 10 of 12 participants (83,3%) had a higher rate of movement hesitations and corrections compared to ocular-based performance as well as increased alternate viewing directions between monitor and surgical site for direct visual control of action. 3D depth perception has been consistently rated excellent (91,7%) yet in 5 participants (41,7%) inferior to ocular-based surgery. Across different craniotomies in supine position, the frontoparietal and pterional approach proved to be suitable, while retrosigmoidal and suboccipital access routes were less favorable. Preferred monitor positions were next to the OR table in direct sight axis to the surgeon (150 cm distance, 0-44° angle) with the exoscope positioned overhead, allowing for an upright head position, comfortably accessible working space and facilitated instrument handling.

Conclusion: Depending on the surgical access, 3D4k exoscopic surgery can improve intraoperative ergonomy and comfort in cranial interventions. Neurosurgical standard tasks can be performed successfully while hand-eye coordination initially requires adjusted training, especially in off-focus areas. Visual quality and field-of-view resolution in deep lesions require further investigation, as does the monitor integration in more complex image-guided setups involving neuronavigation. This study will be followed by a randomized clinical evaluation under routine intraoperative conditions.