Intraoperative Neuronavigation Research Articles

The use of intraoperative CT-neuronavigation in Wiltse approach. A technical note.

The paraspinal approach was first introduced in 1968 and later refined by Leon Wiltse to gain access to the lateral interevertebral foraminal region. However, challenges can arise due to unfamiliarity with this approach, unique patient anatomy, or in case of revision surgery, potentially elevating the risk of complications and/or poor outcome. Here we report on two cases in which the intraoperative Oarm CT neuronavigation was used during a Wiltse approach. Under general anesthesia, the spinous process near the surgical level is exposed through a midline incision. The patient's reference anchor is then attached to the exposed spinous process. Intraoperative CT is acquired and transferred to the Stealth Station S8 Surgical Navigation System (Medtronic). The Wiltse approach is now performed through a paramedian incision under neuronavigation guidance and perfectly tailored to the patient's unique anatomy. The first case was a patient harboring a left lumbar intraextraforaminal schwannoma and the second one was a patient with an extraforaminal lumbar disc herniation at the adjacent level of a previous lumbar instrumentation. We were able to easily identify and remove both the lesions minimizing the surgical approach with no complication and optimal clinical outcome. Our cases demonstrate the feasibility of application of intraoperative O-arm CT-neuronavigation to the Wiltse approach. In our opinion, this technique helps in minimizing the surgical approach and rapidly identifying the lesion of interest. Further studies are needed to address the effective utility and advantages of intraoperative CT-neuronavigation in this specific surgical scenario.

Complete removal of a cavernous malformation in the dorsal pons, in contact with the expanded transpontine vein: illustrative case.

Craniotomy is required for the removal of brainstem cavernous malformations (CMs) with repeated hemorrhage, and this condition is often complicated by an accompanying developmental venous anomaly (DVA). However, a DVA of the brainstem or cerebellum with drainage penetrating the pons is an exceptional finding. A 57-year-old man presented with double vision. Computed tomography revealed progressive enlargement of the hemorrhage in the dorsal pons. Contrast-enhanced magnetic resonance angiography revealed an expanded transverse vessel penetrating the center of the pons in contact with the CM. Digital subtraction angiography revealed that the DVA, comprising the expanded transpontine vein and some cerebellar medullary veins acting as normal venous drainage, coexisted with the CM. By utilizing the angioarchitecture and intraoperative neuronavigation system data, electrophysiological mapping, and indocyanine green videoangiography, complete removal of the CM was accomplished while preserving the DVA and brain function. This study presents the intraoperative images of an expanded transpontine vein as a DVA, which has never been depicted in a live patient before, accompanied by a CM in the dorsal portion of the pons. https://thejns.org/doi/10.3171/CASE24314.

Posterolateral approaches to the thoracic spine for calcific disc herniation: is wider exposure always better?

To compare the costotransversectomy (CTV) and transpedicular (TP) approaches versus the transfacet (TF) approach for the surgical treatment of calcific thoracic spine herniations (cTDH), in terms of surgical and clinical outcomes. Surgical approaches for cTDH are debated. Anterior approaches are recommended, while posterolateral approaches are preferred for non-calcific, paramedian, and lateral hernias. Currently, there is limited evidence about the superiority of a more invasive surgical approach, such as CTV or TP, over TF, a relatively less invasive approach, in terms of neurological outcome, pain, and surgical complications, for the treatment of cTDH. A retrospective, observational, monocentric study was conducted on patients who underwent posterolateral thoracic approaches for symptomatic cTDH, between 2010 and 2023, at our institute. Three groups were drafted, based on the surgical approach used: TF, TP, and CTV. All procedures were assisted by intraoperative CT scan, spinal neuronavigation, and intraoperative neuromonitoring. Analyzed factors include duration of surgery, amount of bone removal, intraoperative blood loss, CSF leak, need of instrumentation for iatrogenic instability, degree of disc herniation removal, myelopathy recovery. Afterwards, a statistical analysis was performed to investigate the bony resection of the superior posterior edge of the vertebral soma. The primary outcome was the partial or total herniation removal. This study consecutively enrolled 65 patients who underwent posterolateral thoracic surgery for cTDH. The TF approach taking the least, and the CTV the longest time (p < 0.01). No statistical difference was observed between the three mentioned approaches, in terms of intraoperative blood loss, dural leakage, post-resection instrumentation, total herniation removal, or myelopathy recovery. An additional somatic bony resection was successful in achieving total herniation removal (p < 0.01), and the extent of bony resection was directly proportional to the extent of hernia removal (p < 0.01). No statistically significant differences were highlighted between the TP, TF, and CTV regarding the extent of cTDH removal, the postoperative complications, and the neurological improvement. The described somatic bone resection achieved significant total herniation removal and was directly proportional to the preop against postop anteroposterior diameter difference.

Minimally Invasive Approaches in Reoperations after Conventional Craniotomies : Case Series.

Reoperations are part of neurosurgical practice. In these cases, an already formed craniotomy seems the most logical and appropriate. However, reoperations via large approaches can be quite traumatic for the patient. Then minimally invasive approaches, being less traumatic, can be a good alternative. We describe 7 consecutive patients who underwent reoperations using minimally invasive approaches in the areas of conventional craniotomies. Surgical Theater® visualization platform was used for preoperative planning. The study evaluated the size of surgical approach, surgical efficacy, and the presence of complications. The size of a minimally invasive craniotomy was significantly smaller than that of a conventional approach. The preoperative goals were achieved in all described cases. There were no complications in the early postoperative period. Although the anatomy of the operated brain region in reoperations is altered, keyhole approaches can be successfully used with the support of preoperative planning and intraoperative neuronavigation. Given that the goals of reoperations may differ from those of the primary surgery, and a large approach is more traumatic for the patient, minimally invasive craniotomy can be considered as a good alternative. The successful use of minimally invasive approaches in areas of conventional craniotomies reinforces the philosophy of keyhole neurosurgery. In cases where goals can be achieved using small approaches, it makes no sense to use large conventional ones. Minimally invasive approaches can be successfully used during reoperations in patients after conventional craniotomies.

297 Impact of Navigated Intraoperative Ultrasound on Brain Shift and Gross Tumor Resection

INTRODUCTION: Intraoperative imaging and neuronavigation aid in achieving maximum tumor resection. However, tissue removal during surgery can cause brain shift, which alters the relative anatomy and “de-calibrates” the standard approaches. While intraoperative MRI (iMRI) is the gold-standard to correct for brain shift, it is expensive, time-consuming, and logistically difficult. As an alternative, we investigated an approach which combines intraoperative ultrasound (ioUS) technology with preoperative imaging to allow for real-time compensation of brain shift and assessment of extent of resection (EOR). METHODS: We prospectively enrolled patients undergoing neurosurgical tumor resection at Massachusetts General Hospital beginning April 2023. Patients were registered with Brainlab Ultrasound Navigation prior to surgery. ioUS sweeps were acquired before cortex incision, mid-resection, and post-resection with bkActiv and fused to preoperative MRIs. Four points around the tumor were longitudinally tracked to assess brain shift. Data included sweep duration, image processing speed, extent of brain shift as determined by intraoperative markers, and EOR assessed from the ioUS compared with postoperative MRIs. RESULTS: Seven patients were enrolled (average age 62 ± 15, 75% male) with frontal (n = 5), temporal (n = 1), and occipital (n = 1) gliomas (n = 4) and metastases (n = 3). All patients exhibiting total resection as determined by ioUS also demonstrated total resection on post-operative MRI, evaluated independently by a neuroradiologist. The average time of scan and image processing (n = 19) was 5.7 ± 1.9 and 27.8 ± 6.5 seconds respectively. CONCLUSIONS: Navigated ioUS offers accurate and efficient assessment of EOR during surgery for tumor resections. Furthermore, when brain shift is detected, navigated ioUS can allow for compensation and continued utilization of navigation via the acquisition of a brand new, navigable, intraoperatively acquired dataset.

Intraoperative mixed-reality spinal neuronavigation system: a novel navigation technique for spinal intradural pathologies.

The objective of this study was to assess the intraoperative accuracy and feasibility of 3D-printed marker-based mixed-reality neurosurgical navigation for spinal intradural pathologies. The authors produced 3D segmentations of spinal intradural tumors with neighboring structures by using combined CT and MRI, and preoperative registration of pathology and markers was successfully performed. A patient-specific, surgeon-facilitated application for mobile devices was built, and a mixed-reality light detection and ranging (LIDAR) camera on a mobile device was employed for cost-effective, high-accuracy spinal neuronavigation. Mobile device LIDAR cameras can successfully overlay images of virtual tumor segmentations according to the position of a 3D-printed marker. The surgeon can visualize and manipulate 3D segmentations of the pathology intraoperatively in 3D. A 3D-printed marker-based mixed-reality spinal neuronavigation technique was performed in spinal intradural pathology procedures and has potential to be clinically feasible and easy to use for surgeons, as well as being time saving, cost-effective, and highly precise for spinal surgical procedures.

Craniovertebral Junction Surgical Approaches: State of Art.

Surgical approaches directed toward craniovertebral junction (CVJ) can be addressed to the ventral, dorsal, and lateral aspects through a variety of 360° surgical corridors Herein, we report features, advantages, and limits of the updated technical support in CVJ surgery in clinical setting and dissection laboratories enriched by our preliminary surgical results of the simultaneous application of O-arm intraoperative neuronavigation and imaging system along with the 3D-4K EX in TOA for the treatment of CVJ pathologies.In the past 4years, eight patients harboring CVJ compressive pathologies underwent one-step combined anterior neurosurgical decompression and posterior instrumentation and fusion technique with the aid of exoscope and O-arm. In our equipped Cranio-Vertebral Junction Laboratory, we use fresh cadavers (and injected "head and neck" specimens) whose policy, protocols, and logistics have already been elucidated in previous works. Five fresh-frozen adult specimens were dissected adopting an FLA. In these specimens, a TOA was also performed, as well as a neuronavigation-assisted comparison between transoral and transnasal explorable distances.A complete decompression along with stable instrumentation and fusion of the CVJ was accomplished in all the cases at the maximum follow-up (mean: 25.3months). In two cases, the O-arm navigation allowed the identification of residual compression that was not clearly visible using the microscope alone. In four cases, it was not possible to navigate C1 lateral masses and C2 isthmi due to the angled projection unfitting with the neuronavigation optical system, so misleading the surgeon and strongly suggesting changing surgical strategy intraoperatively. In another case (case 4), it was possible to navigate and perform both C1 lateral masses and C2 isthmi screwing, but the screw placement was suboptimal at the immediate postoperative radiological assessment. In this case, the hardware displacement occurred 2months later requiring reoperation.

Fixation Technique with Pedicle Screws Assisted with Intraoperative TC and Neuronavigation: A Systematic Review

Fixation Technique with Pedicle Screws Assisted with Intraoperative TC and Neuronavigation: A Systematic Review

Endoscopic transsphenoidal resection of a non-functioning ectopic pituitary adenoma located in the clivus: a case report and literature review

We successfully removed a rare ectopic pituitary adenoma from a 64-year-old female patient initially misdiagnosed with a chordoma. The tumor was located in the slope region and posed a challenge due to its rarity and location. Using neuro-navigation and neuro-endoscopic techniques, we performed a transnasal transsphenoidal resection and confirmed postoperatively that the tumor was a non-functional pituitary adenoma. Although the patient experienced temporary cortisol deficiency after surgery, she recovered well. To accurately diagnose ectopic pituitary adenomas of clivus, doctors must carefully evaluate the patient's imaging results and hormone levels. If necessary, nuclear medicine scans can also aid in diagnosis. Endoscopic transnasal-transsphenoidal surgery is the preferred treatment method, and preoperative multimodal imaging evaluation and intraoperative neuro-navigation technology are essential for a successful surgery.

Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging-Tractography in Resective Brain Surgery: Lesion Coverage Strategies and Patient Outcomes.

Diffusion tensor imaging (DTI)-tractography and functional magnetic resonance imaging (fMRI) have dynamically entered the presurgical evaluation context of brain surgery during the past decades, providing novel perspectives in surgical planning and lesion access approaches. However, their application in the presurgical setting requires significant time and effort and increased costs, thereby raising questions regarding efficiency and best use. In this work, we set out to evaluate DTI-tractography and combined fMRI/DTI-tractography during intra-operative neuronavigation in resective brain surgery using lesion-related preoperative neurological deficit (PND) outcomes as metrics. We retrospectively reviewed medical records of 252 consecutive patients admitted for brain surgery. Standard anatomical neuroimaging protocols were performed in 127 patients, 69 patients had additional DTI-tractography, and 56 had combined DTI-tractography/fMRI. fMRI procedures involved language, motor, somatic sensory, sensorimotor and visual mapping. DTI-tractography involved fiber tracking of the motor, sensory, language and visual pathways. At 1 month postoperatively, DTI-tractography patients were more likely to present either improvement or preservation of PNDs (p = 0.004 and p = 0.007, respectively). At 6 months, combined DTI-tractography/fMRI patients were more likely to experience complete PND resolution (p < 0.001). Low-grade lesion patients (N = 102) with combined DTI-tractography/fMRI were more likely to experience complete resolution of PNDs at 1 and 6 months (p = 0.001 and p < 0.001, respectively). High-grade lesion patients (N = 140) with combined DTI-tractography/fMRI were more likely to have PNDs resolved at 6 months (p = 0.005). Patients with motor symptoms (N = 80) were more likely to experience complete remission of PNDs at 6 months with DTI-tractography or combined DTI-tractography/fMRI (p = 0.008 and p = 0.004, respectively), without significant difference between the two imaging protocols (p = 1). Patients with sensory symptoms (N = 44) were more likely to experience complete PND remission at 6 months with combined DTI-tractography/fMRI (p = 0.004). The intraoperative neuroimaging modality did not have a significant effect in patients with preoperative seizures (N = 47). Lack of PND worsening was observed at 6 month follow-up in patients with combined DTI-tractography/fMRI. Our results strongly support the combined use of DTI-tractography and fMRI in patients undergoing resective brain surgery for improving their postoperative clinical profile.

Fully endoscopic posterior fossa decompression for Chiari malformation type I: illustrative case.

Surgery for symptomatic Arnold-Chiari malformation type I involves posterior fossa decompression. There are various approaches, including endoscope-assisted ones. New possibilities and fields of application of fully endoscopic techniques are currently being developed since new and advanced endoscopic equipment and instrumentation are available. The authors describe the case of a fully endoscopic microsurgical procedure in a 30-year-old female patient with progressive vertigo who was diagnosed with Chiari malformation type I. Neuronavigation and neuromonitoring were used during the surgery. Fully endoscopic surgery can be successfully performed in patients with Chiari malformation I. Intraoperative neuromonitoring and neuronavigation increase safety during this procedure.

Computed tomography-guided intraoperative navigation in children with congenital scoliosis versus freehand/fluoroscopy methods

BACKGROUND: The choice of techniques for the treatment of children with congenital spinal deformities remains one of the most significant problems of spinal surgery. This topic is relevant given the peculiarities of the disease course, severity and rigidity of deformities, their steady and rapid progression, formation of compensatory curvature, and a significant decrease in the quality and life expectancy of patients.&#x0D; AIM: To compare screw misposition, adverse outcomes, intraoperative blood loss, and time required for pedicle screw placement with further deformity correction under computed tomography (CT) guidance with intraoperative navigation versus fluoroscopy.&#x0D; MATERIALS AND METHODS: This single-center, prospective comparative study was conducted from 2019 to 2022 at the National Scientific Center of Traumatology and Orthopedics named after academician N.D. Batpenov. Patient demographics and surgical outcomes were obtained from the medical records. All patients underwent a comprehensive clinical and radiological examination before surgery, after surgery, and at the stages of dynamic observation. Data of patients with congenital malformations of the spine were analyzed. The study involved 42 patients aged 318 years with congenital kyphoscoliosis of the thoracic and/or lumbar spine. The patients were divided into two groups according to the method of surgical correction used: the O-arm navigation group and the C-arm group.&#x0D; RESULTS: Data of patients who underwent surgery for congenital scoliosis of the spine were analyzed. The patients were divided into the O-arm navigation group, which included patients who underwent surgery using the O-arm mobile intraoperative CT with the seventh-generation Stealth Station navigation system in combination with intraoperative neuromonitoring, and the C-arm group, which included patients who underwent surgery under the control of the intraoperative C-arm. In both groups, 364 screws were placed, of which 189 screws were placed under neuronavigation, and 175 screws were placed using the C-arm. The effectiveness of the intraoperative neuronavigation system in combination with neuromonitoring showed 97.11% correct placement (grades A and B) of pedicle screws. The use of an intraoperative C-arm showed 89.63% (grades A and B) correctness. The proportion of misplaced screws corresponding to GertzbeinRobbins classes CE was higher in the C-arm group (10.37%) than in the navigation group (1.49%) (p 0.005). No severe neurological disorders, postoperative infection, or adverse clinical outcomes were observed in both groups.&#x0D; CONCLUSIONS: The installation of pedicle screws using CT-guided navigation (O-arm) did not prolong the operation time, did not increase blood loss, and reduced the risk of screw mispositioning compared with freehand and fluoroscopy pedicle screw placement.

Intraoperative glioma characterization using time-resolved fluorescence spectroscopy.

2072 Background: Extent of surgical resection significantly improves progression-free and overall survival in glioma patients. Due to the infiltrative nature of gliomas, tumor margin detection is often difficult, and current intraoperative visualization methods are limited. Time-resolved fluorescence spectroscopy (TRFS) has the potential of differentiating glioma from normal brain tissue, thereby maximizing extent and safety of resection. Methods: Twenty-seven preoperative patients diagnosed with glioma met inclusion criteria for an IRB-approved study aimed to assess the accuracy of TRFS relative to tissue histopathology for differentiating glioma from normal cortex (NC), normal white matter (NWM), and white matter with edema (WME). A multi-channel TRFS system was developed for in vivo brain tissue and tumor characterization during glioma surgery. A custom-designed fiber optic probe was used to deliver ultrafast laser pulses to tissue regions of interest and collect fluorescence signals, with simultaneous registration to intraoperative neuronavigation. The fluorescence light was collected using a photomultiplier tube and digitized across six wavelength bands. Biopsies were taken at each measurement site for evaluation by a blinded neuropathologist to determine the accuracy of TRFS, which was calculated using parameters derived from the recorded fluorescence pulse and used to characterize tissue signatures. Results: During surgical resection of 27 patients, 162TRFS measurements were collected in vivo followed by biopsy of the same tissue. Samples from brain tumors (39 low grade gliomas (LGG, WHO grade I to III), 35 high grade gliomas (HGG, WHO grade IV)) were compared with 47 samples of normal brain tissue (NC and NWM). The time-resolved system was able to differentiate LGG from normal tissue with 97% sensitivity and 93% specificity (93% PPV and 98% NPV). When all tumor grades were tested, the sensitivity dropped to 91% (96% PPV and 86% NPV), which we believe reflects the heterogeneity of HGG. HGG alone showed a sensitivity of 83% and specificity of 93% (91% PPV and 88% NPV). Normal cortex had the fastest decays across all wavelength bands among different tissue types, WME had longer decays compared to other tissue types at all wavelengths, and HGG had a variable but predictably different fluorescence decay pattern. Conclusions: TRFS is an intraoperative tool that can distinguish glioma from normal brain tissue and has the potential to maximize safe surgical resection.

Minimally Invasive Hematoma Evacuation Using the MindsEye Expandable Tubular Retractor: A Technical Note

Recent advances in intraoperative neuronavigation and cranial access devices have facilitated an increasing interest in the use of minimally invasive techniques (minimally invasive surgery) to safely treat subcortical lesions via a parafascicular approach. Newly developed expandable retractors, such as the MindsEye system further optimize such approaches. In this technical report, we describe the nuances in minimally invasive surgery parenchymal hematoma evacuation using the MindsEye device. After placement of the device, the inner stylet and inner obturator are removed, and the expandable sheath is left in place and secured into place with a Greenberg refractor. The sheath easily dilates to the surgeonss preference with a dial, and the walls of the sheath are composed of a thin, clear, membrane to allow easy visualization of the lesion. We additionally retrospectively reviewed clinical characteristics and outcomes across three patients treated at our facility with spontaneous multicompartment intracranial hematoma using the MindsEye system. We provide a video case demonstrating the use of the MindsEye retractor in a transfrontal parenchymal hematoma evacuation. Successful evacuation with achieved in less than 90 minutes with near total clot removal and resolution of mass effect for all reviewed cases with no patients experiencing procedure-related postoperative decline. Minimally invasive catheter-based and parafascicular approaches using tubular retractors are increasingly recognized as a viable option in the treatment of subcortical lesions. The MindsEye is the first expandable brain access port designed for removal of deep intracranial lesions. We believe it represents a recent addition in the armament of cranial surgeons.

A Review of Innovated Treatment for Gliomas

Brain tumors are difficult to be totally cured , and also associated with high rates of mortality and morbidty, therefore the therapy is always a hot issue.This review introduces glioma treatment techniques through literature summarization and qualitative analysis. According to the data, technologies that can improve median survival and potentially substitute contemporary techniques during the treatment, including photon therapy, and hyperthermia. Moreover, some techniques can improve the accuracy and safety of surgical, such as Intraoperative Neuromonitoring and Neuronavigation During Resection. Other treatment methods, such as gene therapy and immunotherapy, are feasible based on their principles. However, their current effects have not reached expectations, so they are not widely used at this stage, and further innovation and experimental proof are needed.

Magnetic Resonance Tractography and Intraoperative Direct Electrical Stimulation in Eloquent Area Glioma Surgery for 102 Cases: A Tertiary Care Center Experience From Northwest India.

Surgery of eloquent area gliomas is challenging and requires monitoring of the nearby white fiber tracts. In the present study, we analyzed 102 patients with eloquent region gliomas and discussed the concept of intraoperative dynamic white fiber tract navigation and monitoring. A total of 102 patients with an eloquent area glioma (52 insular, 29 motor area, 21 temporoparietal) were evaluated. The position of the white fiber tracts (corticospinal tract [or motor fiber; CST], inferior fronto-occipital fasciculus [ventral language fiber; IFOF], superior longitudinal fasciculus [SLF], and arcuate fasciculus [dorsal language fiber; AF) was recorded. Awake mapping of the cortical and subcortical eloquent structures was performed for all 102 patients. The suction stimulator was coregistered and used as a dynamic stimulator navigator. Of the 102 patients, 60 were men and 42 were women, with an average age of 39.8 years. Most of the white fiber tracts were normal (CST, 31.3%; IFOF, 39.2%; SLF/AF, 40.19%) or displaced (CST, 59.8%; IFOF, 47.05%; AF/SLF, 44.11%). A few were disrupted (CST, 8.8%; IFOF, 13.7%; SLF/AF, 15.7%). The extent of tumor resection was 82.8%, 86.5%, and 94% for those with insular glioma, motor area glioma, and temporoparietal glioma, respectively. Of the 102 patients, 18 had developed transient speech and language disturbances with improvement, and 14 had developed motor deficits, of whom, all except for 2, had shown gradual improvement. When the dynamic suction stimulator navigator was used, the extent of resection was 96.5%, without any added deficits. The use of intraoperative neuronavigation and neurophysiological assessment can help achieve maximal tumor resection of eloquent area gliomas. Use of the integrated suction stimulator navigator provided dynamic navigation and mapping of the peritumoral eloquent fibers.

Evaluation of the Efficiency of Neuronavigation in Patients with Glioblastoma

Objective: To investigate the effect of neuronavigation use on mortality in patients with glioblastoma. Methods: For each of the 26 patients that underwent neuronavigation-assisted supratotal resection for glioblastoma between 2018 and 2020, one patient that underwent supratotal resection without navigation was selected. Results: Radiographic radicality was observed in 35% of the cases in the neuronavigation-assisted surgery group and 29% of those in the conventional surgery group. Absolute and relative residual tumor volumes were significantly lower in the neuronavigation-assisted surgery group. Radical tumor resection was associated with a very significant increase in survival. There was no significant difference in the survival rates between the patients that underwent surgery with and without neuronavigation. This was attributed to the small number of participants and supratotal resection being performed in all statistically determined patients The low median survival period of glioblastoma may have also contributed to this finding. Conclusions: Surgery plays an important role in the treatment of glioblastoma. A combination of techniques including intraoperative magnetic resonance imaging, neuronavigation, ultrasound, and fluorescence guidance allows for safe and maximum surgical resection, leading to better outcomes in terms of survival and postoperative functional recovery. However, despite maximal surgical resection and adjuvant chemotherapy-radiotherapy, most cases develop tumor recurrence within 10 months, which is considered to be due to established cancer stem cells. Therefore, there is an urgent need to develop more effective treatment strategies for glioblastoma.

Use of Mixed Reality in Neuro-Oncology: A Single Centre Experience

(1) Background: Intra-operative neuronavigation is currently an essential component to most neurosurgical operations. Recent progress in mixed reality (MR) technology has attempted to overcome the disadvantages of the neuronavigation systems. We present our experience using the HoloLens 2 in neuro-oncology for both intra- and extra-axial tumours. (2) Results: We describe our experience with three patients who underwent tumour resection. We evaluated surgeon experience, accuracy of superimposed 3D image in tumour localisation with standard neuronavigation both pre- and intra-operatively. Surgeon training and usage for HoloLens 2 was short and easy. The process of image overlay was relatively straightforward for the three cases. Registration in prone position with a conventional neuronavigation system is often difficult, which was easily overcome during use of HoloLens 2. (3) Conclusion: Although certain limitations were identified, the authors feel that this system is a feasible alternative device for intra-operative visualization of neurosurgical pathology. Further studies are being planned to assess its accuracy and suitability across various surgical disciplines.

Robotics and computer-assisted procedures in cranial neurosurgery

The medical technical innovations over the last decade have made operations in the highly sensitive regions of the brain much safer. Presentation of how far computer assistance and robotics have become incorporated into clinical neurosurgery. Evaluation of the scientific literature and analysis of the certification status of the corresponding medical devices. The rapid development of computer technology and the switch to digital imaging has led to the widespread introduction of neurosurgical planning software and intraoperative neuronavigation. In the field of robotics, the penetration into clinical neurosurgery is currently still largely limited to the automatic setting of trajectories. The digitalization of imaging has fundamentally transformed neurosurgery. In the field of cranial neurosurgery, computer-assisted procedures can now be distinguished from noncomputer-assisted procedures only in ahandful of cases. In the coming years important innovations for the clinical implementation can be expected in the field of robotics.

Combined Transoral Exoscope and OARM-Assisted Approach for Craniovertebral Junction Surgery. New Trends in an Old-Fashioned Approach.

The introduction of recent innovations in the field of intraoperative imaging and neuronavigation, such as the O-arm StealthStation, allows for obtaining crucial intraoperative data by performing safer and controlled surgical procedures. As part of the improvement of surgical visual magnification and wide expansion of surgical corridors, the 3D 4 K exoscope (EX) has nowadays become an interesting and useful tool. The transoral approach (TOA) is the historical gold-standard direct microsurgical route to ventral craniovertebral junction (CVJ). We herein report our experience, consisting of ten cases via TOA concerning the simultaneous application of an O-arm with a StealthStation navigation system (Medtronic, Memphis, TN) and an imaging system, along with the 3D 4 K exoscopes in the TOA, for the treatment of CVJ pathologies. No intraoperative neurophysiological changes or postoperative infections occurred, but neurological improvement was evident in all the patients. A complete decompression and a stable instrumentation and fusion of the CVJ were accomplished in all cases at the maximum follow-up time. With EX, the role of the surgeon becomes self-sufficient with better individual surgical freedom compared to endoscopic surgery and excellent 3D vision and magnification. O-arms offer absolutely reliable intraoperative support for more-effective CVJ decompression. Nevertheless, with O-arm-assisted neuronavigation, it can be difficult to navigate C1 lateral masses and C2 isthmi, and converting 3D into 2D real-time navigation can be quite complicated. Finally, the combination of an EX with an O-arm appears more time-consuming compared to the old-fashion one.