Mixed reality in neurosurgery: redefining the paradigm for arteriovenous malformation planning and navigation to improve patient outcomes.

OBJECTIVE: Brain arteriovenous malformations (AVMs) present significant challenges in neurosurgery, requiring detailed planning and execution. In this study, the authors aimed to evaluate the efficacy of mixed reality (MxR), a synergistic application of virtual reality (VR) and augmented reality (AR), in the surgical management of AVMs. METHODS: A retrospective review was conducted on 10 patients who underwent AVM resection between 2021 and 2023. Preoperative planning used patient-specific 360° VR models, while intraoperative guidance used AR markers for targeted disconnection of arterial feeders. Data were analyzed for surgical duration, blood loss, and postoperative outcomes, stratified by Spetzler-Martin (SM) and supplemented Spetzler-Martin (Supp-SM) grades. RESULTS: In 10 patients with cerebral AVMs, MxR significantly facilitated the identification of 21 arterial feeders, including challenging deep feeders. MxR-assisted surgeries demonstrated efficient identification and disconnection of arterial feeders, contributing to precise AVM resection. The mean surgical duration was approximately 5 hours 11 minutes, with a mean intraoperative blood loss of 507.5 ml. Statistically significant variations in surgical duration and blood loss were observed based on SM and supplemented Supp-SM grades. Two patients experienced worsened postoperative neurological deficits, underscoring the inherent risks of AVM surgeries. The marked difference in hospital stays between patients with ruptured and those with unruptured AVMs, particularly for SM grade III, highlights the significant impact of rupture status on postoperative recovery. CONCLUSIONS: In this study, the authors delineated a novel paradigm using MxR for the surgical intervention of AVMs. Using 3D VR for preoperative planning and AR for intraoperative guidance, they achieved unparalleled precision and efficiency in targeting deep arterial feeders. While the results are promising, larger studies are needed to further validate this approach.

Extended reality in cranial and spinal neurosurgery - a bibliometric analysis.

PURPOSE: This bibliometric analysis of the top 100 cited articles on extended reality (XR) in neurosurgery aimed to reveal trends in this research field. Gender differences in authorship and global distribution of the most-cited articles were also addressed. METHODS: A Web of Science electronic database search was conducted. The top 100 most-cited articles related to the scope of this review were retrieved and analyzed for trends in publications, journal characteristics, authorship, global distribution, study design, and focus areas. After a brief description of the top 100 publications, a comparative analysis between spinal and cranial publications was performed. RESULTS: From 2005, there was a significant increase in spinal neurosurgery publications with a focus on pedicle screw placement. Most articles were original research studies, with an emphasis on augmented reality (AR). In cranial neurosurgery, there was no notable increase in publications. There was an increase in studies assessing both AR and virtual reality (VR) research, with a notable emphasis on VR compared to AR. Education, surgical skills assessment, and surgical planning were more common themes in cranial studies compared to spinal studies. Female authorship was notably low in both groups, with no significant increase over time. The USA and Canada contributed most of the publications in the research field. CONCLUSIONS: Research regarding the use of XR in neurosurgery increased significantly from 2005. Cranial research focused on VR and resident education while spinal research focused on AR and neuronavigation. Female authorship was underrepresented. North America provides most of the high-impact research in this area.

Minimally Invasive Lateral Transorbital Approach for Clipping of Right Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

The lateral transorbital approach is a minimally invasive approach that was first described for accessing the cavernous sinus.1 Although other minimally invasive approaches have been broadly applied to aneurysm surgery,2 the use of transorbital keyholes for this is still quite rare.3,4 We present a 72-year-old man with an incidentally discovered 5-mm middle cerebral artery aneurysm. Despite a low rupture risk,5 the patient himself opted for treatment, and because of the complex shape of the aneurysm, he chose surgical clipping as the treatment of choice. Two unique aspects of the patient's anatomy brought forth transorbital approach for consideration. He had a wide fissure, which opened to the orbital wall, and a giant frontal sinus made its avoidance difficult with any anterolateral transcranial approach. The lateral transorbital approach was started with a transpalpebral incision.4,6,7 Both wings of the sphenoid bone were drilled until the frontal and temporal dura was exposed. Opening this through the orbit gained direct access to the large Sylvian fissure. Two specific challenges were specific to this opening: the aneurysm dome pointed straight at the surgeon, and the M1 segment, needed for proximal control, was directly behind the aneurysm. Despite these, the aneurysm was successfully eliminated through the transorbital approach with no residual or normal branch compromise. Given the specific anatomical provisions, the lateral transorbital approach was an effective and safety alternative to the pterional approach for middle cerebral artery aneurysms. No Institutional Review Board approval was sought or necessary as the patient provided consent for the procedure, publication of his image, and this submission.

Minimally Invasive Bilateral Duo-Keyhole Approach for Giant Falcine Meningioma: 2 Dimensional Operative Video.

One of the key concepts behind minimally invasive keyhole cranial surgery is that as the operative corridor deepens, it also widens. The corridor should therefore be designed parallel to the long-axis of the tumor to optimize visualization.1 These ideas were applied in a duo-keyhole operation for a falcine meningioma. The patient is a 79-year-old woman diagnosed with a large falcine meningioma compressing both frontal lobes. Her tumor was oriented with the long-axis, perpendicular to the superior sagittal sinus, and has bulbous extensions on both sides of the falx. Incisions on the falx, anterior and posterior to the tumor, in addition to a cut between it and the undersurface of the superior sagittal sinus, would render it practically devascularized and "free-floating.2" One keyhole was insufficient, but one anterior and another posterior to the tumor would make the falcine cuts feasible. The operation was performed with the above scheme and the posterior keyhole to the left and anterior one to the right of midline to facilitate surface vascular detachment on both sides. The patient recovered well and was discharged home after 4 days. This procedure highlights that flexible application of the principles of minimally invasive keyhole. Neurosurgery can tailor-make an operation to precisely fit the unique features of a patient and the tumor. The procedure was performed under the ethical guidelines of our hospital. No Institutional Review Board consent was required or sought because the patient gave specific consent to the procedure and publication of her image.

Feasibility of exoscopic keyhole surgery: case series.

Keyhole approaches, performed with the endoscope, microscope, or exoscope, aim to minimize tissue traumatization while maximizing surgical view. The exoscope can provide better ergonomics than the microscope without restricting the space inside of the keyhole, as when using the endoscope. However, a frequently quoted reason for intraoperative exoscope-to-microscope conversion is the absence of sufficient light. In this video, the authors present 4 patients who underwent posterior fossa keyhole surgery without intraoperative conversion. The surgical objective was achieved in all patients without associated morbidity. After adequate adaptation, the exoscope allows sufficient light in the surgical field to perform safe keyhole surgery. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23116.

A Cadaveric Feasibility Study of the Biportal Endoscopic Transfrontal Sinus Approach: A Minimally Invasive Approach to the Anterior Cranial Fossa.

BACKGROUND AND OBJECTIVES: The trans-sinus transglabellar and bifrontal approaches offer direct access to the anterior cranial fossa. However, these approaches present potential drawbacks. We propose the biportal endoscopic transfrontal sinus (BETS) approach, adapting endoscopic endonasal approach (EEA) techniques for minimally invasive access to the anterior fossa, reducing tissue manipulation, venous sacrifice, and brain retraction. METHODS: Six formalin specimens were used. BETS approach involves 2 incisions over the medial aspect of both eyebrows from the supraorbital notch to the medial end of the eyebrow. A unilateral pedicled pericranial flap is harvested. A craniotomy through the anterior table of the frontal sinus (FS) and a separate craniotomy through the posterior table are performed. Two variants of the approach (preservative vs cranialization) are described for opening and reconstruction of the FS based on the desired pathology to access. Bone flap replacement can be performed with titanium plates and filling of the external table defect with bone cement. RESULTS: Like in EEA, this approach provides access for endoscope and multiple working instruments to be used simultaneously. The approach allows wide access to the anterior cranial fossa, subfrontal, and interhemispheric corridors, all the way up to the suprachiasmatic corridor and through the lamina terminalis to the third ventricle. BETS provides direct access to the anterior fossa, minimizing the level of frontal lobe retraction and providing potentially less tissue disruption and improved cosmesis. Cerebrospinal fluid fistula risk remains one of the major concerns as the narrow corridor limits achieving a watertight closure which can be mitigated with a pedicled flap. Mucocele risk is minimized with full cranialization or reconstruction of the FS. CONCLUSION: The BETS approach is a minimally invasive approach that translates the concepts of EEA to the FS. It allows excellent access to the anterior cranial fossa structures with minimal frontal lobe retraction.