Monitor-based exoscopic 3D4k neurosurgical interventions: a two-phase prospective-randomized clinical evaluation of a novel hybrid device

Abstract

Background: Promoting a disruptive innovation in microsurgery, exoscopes promise alleviation of physical strain and improved image quality through digital visualization during microneurosurgical interventions. This study investigates the impact of a novel 3D4k hybrid exoscope (i.e., combining digital and optical visualization) on surgical performance and team workflow in preclinical and clinical neurosurgical settings.

Methods: A pre-clinical workshop setting has been developed to assess usability and implementability through skill-based scenarios (neurosurgical participants n = 12). An intraoperative exploration in head and spine surgery (n = 9) and a randomized clinical study comparing ocular and monitor mode in supratentorial brain tumor cases (n = 20) followed within 12 months. Setup, procedure, case characteristics, surgical performance, and user experience have been analyzed for both ocular group (OG) and monitor group (MG).

Results: Brain tumor cases using frontal, frontoparietal, or temporal approaches have been identified as favorable use cases for introducing exoscopic neurosurgery. Mean monitor distance and angle were 180 cm and 10°. Surgical ergonomics when sitting improved significantly in MG compared with OG (P = .03). Hand-eye coordination required familiarization in MG. Preclinical data showed a positive correlation between lateral camera inclination and impact on hand-eye coordination (r_s = 0.756, P = .01). There was no significant added surgical time in MG. Image quality in current generation 3D4k monitors has been rated inferior to optic visualization yet awaits updates.

Conclusions: The hybrid exoscopic device can be integrated into established neurosurgical workflows. Currently, exoscopic interventions seem most suited for cranial tumor surgery in lesions that are not deep-seated. Ergonomics improve in monitor mode compared to conventional microsurgery.

Keywords: Brain tumor; Digital innovation; Exoscope; Intraoperative visualization; Technology evaluation.

Fig. 1

Preclinical setup: face-to-face scenario in spinal task with two 3D monitors (a); training scenario in cranial task (b); intraoperative setup: ›surgical cockpit‹ with 3D4k monitor and navigation screen, camera positioned perpendicular above surgical site (c)

Fig. 2

Synopsis of effects on hand-eye coordination in cranial task performance compared for frontoparietal (light gray) and pterional (dark gray) approaches (participants n = 9); plotted on the horizontal axis are numbers of hesitations, corrections, and direct sight control plus overtime needed for task completion in minutes

Fig. 3

Dimensions of image quality satisfaction (%) present in digital visualization, compared between preclinical (light gray) and clinical (dark gray) settings

Fig. 4

Intraoperative setup in cranial interventions with surgical assistant (S2), scrub nurse (N1), neuromonitorist (M1), and anesthesiologist (A1) showing effects of monitor-to-site angle on surgical performance

Fig. 5

System Usability Scale (SUS) (a) and Surgery Task Load Index (SURG-TLX) (b) across all cases compared for both groups (OG, MG), showing an overall decreased mean usability and an increased mean workload in MG respectively with single users achieving comparable scores in both operating modes