Background: Neuroendoscopy complements exoscopic visualization by providing angled views of anatomical structures hidden from the direct surgical line of sight. However, its practical indications and intraoperative contribution during exoscope-assisted skull base surgery have not been systematically evaluated. This study aimed to characterize the patterns of neuroendoscopic use and its observed intraoperative contribution during exoscope-assisted skull base surgery. Methods: We retrospectively reviewed 164 consecutive skull base procedures performed between March 2024 and June 2026. After excluding 58 pure endoscopic endonasal procedures, 106 exoscope-assisted procedures were analyzed. Neuroendoscopic assistance was used in 42 procedures, each performed in a different patient. Complete operative video recordings from these 42 procedures were retrospectively reviewed by two neurosurgeons, and the observed contribution of neuroendoscopy was classified as visualization-only, confirmatory, or decision-changing. Results: Neuroendoscopic assistance was used in 42 of 106 exoscope-assisted procedures (39.6%), including 30 aneurysms and 12 tumors. The most common indication was clip and perforator confirmation during aneurysm surgery (30/42, 71.4%). The observed contribution was classified as visualization-only in 8 procedures (19.0%), confirmatory in 20 (47.6%), and decision-changing in 14 (33.3%). Among the 14 decision-changing procedures, neuroendoscopic findings led to clip repositioning in 5 aneurysm procedures and additional tumor removal in 9 tumor procedures. No complications judged attributable to neuroendoscope insertion or manipulation were identified in the 42 procedures. Conclusions: Neuroendoscopic assistance provided additional intraoperative information during exoscope-assisted skull base surgery, with decision-changing findings identified in 14 of 42 assisted procedures. These findings characterize the observed contribution and practical indications of neuroendoscopic assistance; however, the retrospective design, selective use of neuroendoscopy, and limited sample size preclude conclusions regarding comparative efficacy or safety.

Objectives: Exoscopes decouple viewing from eyepieces and may improve surgeon ergonomics. We compared upper-limb and neck posture during microscope- and exoscope-assisted frontal sinus procedures in bifrontal craniotomies. Methods: Five surgical cases involving five surgeons yielded 12 paired microscope–exoscope posture observations. Eight pairs from four cases met image-selection criteria and underwent angular measurement using ImageJ version 1.54g and RULA-inspired partial postural assessment. Results: Upper arm elevation decreased from 67.3 ± 6.9° under the microscope to 53.5 ± 5.2° under the exoscope (mean change [exoscope minus microscope], −13.8°; 95% CI, −18.0 to −9.6°; p = 0.0001). Elbow angle increased from 36.1 ± 16.6° to 64.4 ± 8.0° (mean change, +28.3°; 95% CI, +15.5 to +41.2°; p = 0.0012). Neck angle showed no clear change (12.3 ± 4.0° vs. 12.9 ± 7.2°; mean change, +0.6°; 95% CI, −4.1 to +5.4°; p = 0.7666). The upper-arm-related score, including shoulder-elevation and abduction points, was lower under the exoscope (p = 0.0156), whereas the forearm score was numerically lower (p = 0.1250). Conclusions: In this exploratory study, exoscope use was associated with reduced upper arm elevation and an increased elbow angle, but no clear change in the neck angle. The predominance and consistency of the upper-limb findings raise the hypothesis that exoscopic visualization may lessen cervicoscapular muscular demand through reduced upper arm and shoulder elevation, even without a measurable change in the static two-dimensional neck angle. Larger studies incorporating three-dimensional motion analysis, muscle activity, fatigue assessment, and clinical outcome measures are needed to determine whether these postural differences translate into reduced musculoskeletal load or injury risk.

Background/Objectives: Accurate intraoperative identification of the tumor–brain interface is important in brain metastasis surgery, but visual assessment under white light is subjective. Narrow-band imaging (NBI) enhances hemoglobin-dependent optical contrast without an exogenous agent; whether its intraoperative appearance corresponds to tumor tissue, and whether it measurably increases tumor-to-normal image contrast, has not been established in this setting. Methods: In this retrospective, single-center, exploratory study, we evaluated 25 consecutive patients with brain metastases resected using a 4K three-dimensional exoscope equipped with NBI. In three selected patients, spatially adjacent specimens were separately sampled from grayish-appearing and whitish-appearing regions and assessed histopathologically in a non-blinded, descriptive manner. In all 25 patients, paired white-light and NBI images were retrospectively analyzed in Fiji/ImageJ using regions of interest drawn over tissue visually judged to be tumor or normal brain. Results: In the three patients with paired histology, grayish-appearing specimens contained metastatic tumor cells and whitish-appearing specimens did not; this observation derives from a small, selectively sampled subset and should be regarded as preliminary. Across all 25 patients, absolute tumor-to-normal gray-value contrast was significantly greater under NBI than white light (69.628 ± 45.338 vs. 44.287 ± 29.640; mean paired increase, 25.342; 95% CI, 9.169–41.514; p = 0.0035; Cohen’s dz = 0.647), although this increase was not observed in all patients. Conclusions: In this exploratory, non-blinded, retrospective study, NBI increased objective image contrast between visually identified tumor and normal brain relative to white light, and its grayish appearance corresponded to tumor tissue in a small histologically sampled subset. These findings support NBI as a feasible, agent-free adjunct that warrants prospective, blinded validation before its diagnostic accuracy or clinical benefit can be assessed.