Background/Objectives: 5-aminulevulinic acid (5-ALA)-guided surgery for high-grade gliomas remains a challenge in neuro-oncological surgery. Inconsistent fluorescence visualisation, subjective quantification and false negatives due to blood, haemostatic agents or optical impediments from the external light source are some of the limitations of the present technology. Methods: The preliminary results from this single-centre retrospective study are presented from the first 35 patients operated upon with the novel Nico Myriad Spectra System©. The microdebrider (Myriad) with an additional in situ light system (Spectra) can alternately provide white and blue light (405 nm) to within 15 mm of the tissue surface to enhance the morphology of the anatomical structures and the fluorescence of the pathological tissues. Results: A total of 35 patients were operated upon with this new technology. Eight patients (22.85%) underwent tubular retractor-assisted minimally invasive parafascicular surgery (tr-MIPS). The majority had high-grade gliomas (68.57%). Fluorescence was identified in 30 cases (85.71%), with residual fluorescence in 11 (36.66%). The main applications were better white–blue light alternation and visualisation during tr-MIPS, increase in the extent of resection at the border of the cavity, identification of satellite lesions in multifocal pathology, the differentiation between radionecrosis and tumour recurrence in redo surgery and the demarcation between normal ependyma versus pathological ependyma in tumours infiltrating the subventricular zone. Conclusions: This proof-of-concept study confirms that the novel in situ light-source delivery technology integrated with the usual intraoperative armamentarium provides a spatially, functionally and oncologically informed framework for glioblastoma surgery. It allows for the enhancement of the morphology of anatomical structures and the fluorescence of pathological tissues, increasing the extent of resection and, possibly, the prognosis for patients with high-grade gliomas.

Trans-sulcal minimally invasive parafascicular surgery is an emerging technique to approach deep lesions with minimal brain retraction. Localization of the tubular retractor during surgery is critical, and intraoperative magnetic resonance imaging and neuronavigation present limitations. We describe the intraoperative use of O-Arm® coupled with pre-operative tractography to precisely localize the tubular retractor. With air acting as contrast, the tubular retractor was localized in three dimensions, without any additional disruption to white matter tracts or nearby vascular structures. We conclude that visualization of tubular retractor using an intraoperative computerized tomography scan is a safe and feasible adjunct in resection of deep lesions via a minimally invasive approach.

Background: The tubular retractor-assisted minimally invasive parafascicular approach (trMIPS) is a transsulcal approach to deep-seated brain tumours. It is a safe surgical approach but its impact on the microvascular dynamics of the retracted cortex and its clinical implications are unknown. Methods: This was a single-centre prospective study including patients with deep-seated brain tumours operated on with a trMIPS (BrainPath Nico System^©). All patients underwent pre- and post-cannulation indocyanine green study using a FLOW 800 module in a KINEVO Zeiss^© microscope. Speed, delay, time-to-peak (TtP) rise-in-time and cerebral blood flow index (CBFI) metrics were assessed. Results: Thirty-five patients were included, with 144 regions-of-interest (ROIs) selected. The majority of patients were diagnosed with glioblastoma (51.43%), and 37.14% of patients had a preoperative focal neurological deficit (FND) at presentation. A ROI-based analysis concluded that an increase in speed and CBFI was related with a worse neurological outcome when comparing the pre- and post-brain cannulation assessments (speed: deterioration = 43.12 ± 80.60% versus stable = −14.51 ± 57.80% versus improvement = 6.93 ± 31.33%, p < 0.0001; CBFI: deterioration = 50.40 ± 88.17% versus stable = −2.70 ± 67.54% versus improvement = −38.98 ± 26.17%, p = 0.0005). These findings were reproducible in a combined-ROI per patient analysis and confirmed after adjustment for confounding. Conclusion: Microvascular flow dynamics impact trMIPS outcomes as an increase in the speed and CBFI after decannulation was related with worse neurological outcome.

Intracranial dermoid cysts are benign lesions that may be diagnosed incidentally or present symptomatically due to mass effect—focal neurological deficits, seizures and/or hydrocephalus—or chemical meningitis secondary to spontaneous rupture. The use of tubular retractors in minimally invasive parafascicular surgery (tsMIPS) has been described extensively as a technique to preserve neurological function whilst safely maximizing the extent of resection. The authors present the first use of the tsMIPS approach for removal of a dermoid cyst in a 68-year-old female who presented with abulia and seizures due to a large Sylvian fissure dermoid cyst. This approach minimized trauma to surrounding cortical–subcortical structures, as supported by connectome analyses, without sacrificing visualization of the operative field. Additionally, itavoided manipulation of the lenticulostriate arteries attached to the walls of the dermoid cyst. The use of an endoscope ensured complete drainage of the cyst components and therefore the effectiveness of the procedure.

Background/Objectives: Navigated intraoperative ultrasound (N-ioUS) compensates for brain shift, but its place within a multimodal workflow alongside neuronavigation, 5-aminolevulinic acid (5-ALA) fluorescence and neurophysiological monitoring is not well defined. We describe functional and surgical outcomes in a single-centre series of functional-eloquent tumours resected with N-ioUS within such a workflow. Methods: Retrospective descriptive cohort study, reported per STROBE, of 104 consecutive patients who underwent N-ioUS-assisted resection of functionally eloquent intracranial tumours between 2011 and 2023. N-ioUS was an inclusion criterion, so no comparison group was available; the same-institution 5-ALA cohorts are cited as context only. Results: The cohort comprised WHO grade 4 gliomas (n = 42), WHO grade 2–3 gliomas (n = 33), metastases (n = 21) and other tumours (n = 8); 5-ALA was used in 74.0% and neurophysiological monitoring in 94.2%. No residual tumour was described in 22.5% of grade 4 gliomas, 53.3% of grade 2–3 gliomas and 73.7% of metastases with a documented extent of resection. Among patients at risk with documented postoperative status, a new motor deficit occurred in 4/16 (25.0%) grade 4, 4/21 (19.0%) grade 2–3 and 1/7 (14.3%) metastases patients. Median overall survival was 12.7 months for grade 4 gliomas and 22.2 months for metastases and was not reached for grade 2–3 gliomas; within grade 4 gliomas, no difference by extent of resection was detected in an underpowered exploratory comparison (log-rank p = 0.593). Conclusions: In this single-arm series the resection endpoint in eloquent tumours was set by functional rather than anatomical boundaries, and rates of complete resection and new deficit were in keeping with that constraint. The design permits no inference about the independent effect of N-ioUS, whose contribution may be greatest where the endpoint is anatomical, as in metastases, and requires prospective controlled evaluation.