Postoperative outcomes following glioblastoma resection using a robot-assisted digital surgical exoscope: a case series

Revolutionizing Brain Tumor Care: Emerging Technologies and Strategies

Glioblastoma multiforme (GBM) is one of the most aggressive forms of brain tumor, characterized by a daunting prognosis with a life expectancy hovering around 12-16 months. Despite a century of relentless research, only a select few drugs have received approval for brain tumor treatment, largely due to the formidable barrier posed by the blood-brain barrier. The current standard of care involves a multifaceted approach combining surgery, irradiation, and chemotherapy. However, recurrence often occurs within months despite these interventions. The formidable challenges of drug delivery to the brain and overcoming therapeutic resistance have become focal points in the treatment of brain tumors and are deemed essential to overcoming tumor recurrence. In recent years, a promising wave of advanced treatments has emerged, offering a glimpse of hope to overcome the limitations of existing therapies. This review aims to highlight cutting-edge technologies in the current and ongoing stages of development, providing patients with valuable insights to guide their choices in brain tumor treatment.

Comparative analysis of exoscope-assisted spine surgery versus operating microscope: A systematic review

Background

Limitations in the operative microscope (OM)'s mobility and suboptimal ergonomics created the opportunity for the development of the exoscope. This systematic review aims to evaluate the advantages and disadvantages of exoscopes and OMs in spine surgery.

Methods

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic search was conducted in the major research databases. All studies evaluating the exoscopes and/or OMs in spinal procedures were included.

Results

There were 602 patients included in the 16 studies, with 539 spine surgery patients, 19 vascular cases, 1 neural pathology case, 19 cranial cases, and 24 tumor pathologies. When examining surgical outcomes with the exoscope, results were mixed. Compared to the OM, exoscope usage resulted in longer operative times in 7 studies, comparable times in 3 studies, and shorter operative times in 3 studies. Two studies found similar lengths of stay (LOS) for both tools, two reported longer LOS with exoscopes, and one indicated shorter hospital LOS with exoscopes. One study reported higher exoscope-related blood loss (EBL), but four other studies consistently showed reduced EBL. In terms of image quality, illumination, dynamic range, depth perception, ergonomics and cost-effectiveness, the exoscope was consistently rated superior, while findings across studies were mixed regarding the optical zoom ratio and mean scope adjustment (MSA). The learning curve for exoscope use was consistently reported as shorter in all studies.

Conclusion

Exoscopes present a viable alternative to OMs in spine surgery, offering multiple advantages, which supports their promising role in modern neurosurgical practice.

RoboticScope-Assisted Microanastomosis in a Chicken Leg Model

Background  Many recent studies show that exoscopes are safe and effective alternatives to operating microscopes (OM). Developments of robotics and automation are present in neurosurgery with the appearance of a newer device such as RoboticScope (RS) exoscope with a digital three-dimensional (3D) image and a head-mounted display. The body of the RS is connected to a six-axis robotic arm that contains two video cameras, and serves as stereovision. This robotic arm allows accurate 3D camera motions over the field of view, giving the user a great degree of freedom in viewpoint selection. The surgeons may specify the direction and speed of the robotic arm using simple head movements when the foot pedal is pressed. Since its development in 2020, the RS has occasionally been used in neurosurgery for a multitude of procedures. Methods  This study showcases vessel microanastomosis training on chicken legs using the RS. The aim of this study is to demonstrate the feasibility of the RS without a comparative analysis of the standard OM. The study was conducted in 2023 during a month-long trial period of the device at the Department of Neurosurgery of the Clinical Center of the University of Sarajevo. All procedures including RS-assisted anastomosis were performed by a neurosurgeon in anastomosis training (A.A.) supervised by a senior vascular neurosurgeon (E.B.). For the purpose of the study, we evaluated occlusion time in minutes, bypass patency with iodine, and overall satisfaction of the trainee in terms of light intensity, precision of automatic focus, mobility of the device, ergonomics, and convenience of the helmet. Results  Ten RS-assisted microanastomoses were performed by interrupted suturing technique with 10.0 nylon thread. Bypass training included seven "end-to-side," two "end-to-end," and one "side-to-side" microanastomoses. The smallest vessel diameter was 1 mm. Occlusion time improved by training from 50 to 24 minutes, with contrast patency of the anastomoses in all cases without notable leakage of the contrast, except one case. Complete satisfaction of the trainee was achieved in 7 out of 10 cases. During this period, we also performed different RS-assisted surgeries including a single indirect bypass, convexity brain tumor resection, and microdiscectomies. Conclusion  RS provides a new concept for microanastomosis training as an alternative or adjunct to the standard microscope. We found a full-time hands-on microsuturing without the need for manual readjustment of the device as an advantage as well as instant depth at automatic zooming and precise transposition of the focus via head movements. However, it takes time to adapt and get used to the digital image. With the evolution of the device helmet's shortcomings, the RS could represent a cutting-edge method in vessel microanastomosis in the future. Nevertheless, this article represents one of the first written reports on microanastomosis training on an animal model with the above-mentioned device.

Application of the Robotic-Assisted Digital Exoscope for Resection of Posterior Fossa Tumors in Adults: A Series of 45 Cases

BACKGROUND AND OBJECTIVES

Complete safe resection is the goal when pursuing surgical treatment for posterior fossa (PF) tumors. Efforts have led to the development of the exoscope that delineates tumors from non-neoplastic brain. This investigation aims to assess patient outcomes where PF tumor resection is performed with the exoscope by a retromastoid or suboccipital approach.

METHODS

A retrospective analysis was conducted for patients with PF tumors who underwent exoscope resection from 2017 to 2022. Patient demographics, clinical, operative, and outcome findings were collected. Extent of resection studies were also performed. Associations between perioperative data, discharge disposition, progression-free survival (PFS), and overall survival (OS) were evaluated.

RESULTS

A total of 45 patients (22 male patients) with a median age of 57 years were assessed. Eighteen (40%) and 27 patients (60%) were diagnosed with malignant and benign tumors, respectively. Tumor neurovascular involvement was found in 28 patients (62%). Twenty-four (53%) and 20 (44%) tumors formed in the cerebellum and cerebellopontine angle cistern, respectively. One tumor (2%) was found in the cervicomedullary junction. The mean extent of resection was 96.7% for benign and malignant tumors. The PFS and OS rate at 6 months (PFS6, OS6) was 89.7% and 95.5%, respectively. Neurological complications included sensory loss and motor deficit, with 11 patients reporting no postoperative symptoms. Of the neurological complications, 14 were temporary and 9 were permanent.

CONCLUSION

The exoscope is an effective intraoperative visualization tool for delineating PF tumors. In our series, we achieved low postoperative tumor volumes and a high gross total resection rate.

Intraoperative Imaging and Optical Visualization Techniques for Brain Tumor Resection: A Narrative Review

Advancements in intraoperative visualization and imaging techniques are increasingly central to the success and safety of brain tumor surgery, leading to transformative improvements in patient outcomes. This comprehensive review intricately describes the evolution of conventional and emerging technologies for intraoperative imaging, encompassing the surgical microscope, exoscope, Raman spectroscopy, confocal microscopy, fluorescence-guided surgery, intraoperative ultrasound, magnetic resonance imaging, and computed tomography. We detail how each of these imaging modalities contributes uniquely to the precision, safety, and efficacy of neurosurgical procedures. Despite their substantial benefits, these technologies share common challenges, including difficulties in image interpretation and steep learning curves. Looking forward, innovations in this field are poised to incorporate artificial intelligence, integrated multimodal imaging approaches, and augmented and virtual reality technologies. This rapidly evolving landscape represents fertile ground for future research and technological development, aiming to further elevate surgical precision, safety, and, most critically, patient outcomes in the management of brain tumors.

Exoscopic Microsurgery: A Change of Paradigm in Brain Tumor Surgery? Comparison with Standard Operative Microscope

BACKGROUND

The exoscope is a high-definition telescope recently introduced in neurosurgery. In the past few years, several reports have described the advantages and disadvantages of such technology. No studies have compared results of surgery with standard microscope and exoscope in patients with glioblastoma multiforme (GBM).

METHODS

Our retrospective study encompassed 177 patients operated on for GBM (WHO 2021) between February 2017 and August 2022. A total of 144 patients were operated on with a microscope only and the others with a 3D4K exoscope only. All clinical and radiological data were collected. Progression-free survival (PFS) and overall survival (OS) have been estimated in the two groups and compared by the Cox model adjusting for potential confounders (e.g., sex, age, Karnofsky performance status, gross total resection, MGMT methylated promoter, and operator's experience).

RESULTS

IDH was mutated in 9 (5.2%) patients and MGMT was methylated in 76 (44.4%). Overall, 122 patients received a gross total resection, 14 patients received a subtotal resection, and 41 patients received a partial resection. During follow-up, 139 (73.5%) patients experienced tumor recurrence and 18.7% of them received a second surgery. After truncation to 12 months, the median PFS for patients operated on with the microscope was 8.82 months, while for patients operated on with the exoscope it was >12 months. Instead, the OS was comparable in the two groups. The multivariable Cox model showed that the use of microscope compared to the exoscope was associated with lower progression-free survival (hazard ratio = 3.55, 95%CI = 1.66-7.56, p = 0.001).

CONCLUSIONS

The exoscope has proven efficacy in terms of surgical resection, which was not different to that of the microscope. Furthermore, patients operated on with the exoscope had a longer PFS. A comparable OS was observed between microscope and exoscope, but further prospective studies with longer follow-up are needed.

Neurovascular Microsurgical Experience Through 3-Dimensional Exoscopy: Case Report and Literature Review

BACKGROUND

The microscope is important in neurosurgery, but it is not exempt from limitations. The exoscope has emerged as an alternative because it offers better 3-dimensional (3D) visualization and better ergonomics. We present our initial experience in vascular pathology using 3D exoscopy at the Dos de Mayo National Hospital to show the viability of the 3D exoscope in vascular microsurgery. We also provide a review of the literature.

METHODS

In this work, the Kinevo 900 exoscope was used in 3 patients with cerebral (2) and spinal (1) vascular pathology. We evaluated the image quality, equipment management, ergonomics, educational utility, and 3D glasses and recorded the characteristics of the cases. We reviewed the experience of other authors as well.

RESULTS

Three patients underwent surgery: 1 occipital cavernoma, 1 cerebral dural fistula, and 1 spinal dural fistula. Excellent 3D visualization with Zeiss Kinevo 900 exoscope (Carl Zeiss, Germany), surgical comfort, and educational utility occurred, and there were no complications.

CONCLUSIONS

Our experience and that of other authors suggests that the 3D exoscope shows excellent visualization, better ergonomics, and an innovative educational experience. Vascular microsurgery can be performed safely and effectively.

A Multicenter Study Investigating the Surgeon Experience with a Robotic-Assisted Exoscope as Part of the Neurosurgical Armamentarium

BACKGROUND

Improvement of visualization tools in neurosurgery such as the exoscope has raised the question of how this technology compares to the conventional microscope for surgeon ergonomics, discomfort, and patient outcomes. Exoscopes have the advantage of greater optical zoom, resolution, and illumination at a lower light intensity. Heads-up display for both the primary surgeon and other assistants permits neutral positioning of the surgeons while placing the camera in more angled positions. In a survey sample, this study assesses the surgeon experience utilizing 3D exoscope in general neurosurgery cases.

METHODS

Data weere recorded by 8 surgeons at 5 separate hospitals utilizing a mobile phone application survey. Surgeons recorded information about case type, intraoperative clinical outcomes such as blood loss and extent of resection, whether fluorescence visualization was used, as well as surgeon pain when compared to matched cases using conventional tools.

RESULTS

A total of 155 neurosurgical cases were recorded in this multisite study, including 72% cranial cases and 28% spinal cases. Of the cranial cases, 76% were brain tumor resections (31% of which were brain metastases). Surgeons reported significantly less neck (P < 0.0001) and back (P < 0.0001) pain in cases when using the robotic exoscope compared with the conventional microscope or surgical loupes. Surgeons did not convert to a microscope in any case.

CONCLUSIONS

The exoscope provides excellent delineation of tissue with high resolution. Surgeon pain was markedly reduced with the robotic exoscope when compared with conventional technology, which may reduce work-related injury and fatigue, potentially leading to better patient outcomes.

Novel intraoperative strategies for enhancing tumor control: Future directions

Maximal safe surgical resection plays a key role in the care of patients with gliomas. A range of technologies have been developed to aid surgeons in distinguishing tumor from normal tissue, with the goal of increasing tumor resection and limiting postoperative neurological deficits. Technologies that are currently being investigated to aid in improving tumor control include intraoperative imaging modalities, fluorescent tumor makers, intraoperative cell and molecular profiling of tumors, improved microscopic imaging, intraoperative mapping, augmented and virtual reality, intraoperative drug and radiation delivery, and ablative technologies. In this review, we summarize the aforementioned advancements in neurosurgical oncology and implications for improving patient outcomes.

Use of the 3D exoscope for the supracerebellar infratentorial approach in the concorde position: an effective and ergonomic alternative. Illustrative cases

BACKGROUND

The supracerebellar infratentorial approach provides wide flexibility as a far-reaching corridor to the pineal region, posterior third ventricle, posterior medial temporal lobe, posterolateral mesencephalon, quadrigeminal cistern, and thalamus. Traditionally, the patient is placed in the sitting position, allowing gravity retraction on the cerebellum to widen the supracerebellar operative corridor beneath the tentorium. What this approach gains in anatomical orientation it lacks in surgeon ergonomics, as the sitting position presents technical challenges, forces the surgeon to adopt to an uncomfortable posture while performing the microsurgical dissection/tumor resection under the microscope, and is also associated with an increased risk of venous air embolism.

OBSERVATIONS

In this article, the authors present the use of the three-dimensional (3D) exoscope with a standard prone Concorde position as an alternative for the treatment of lesions requiring a supracerebellar infratentorial approach for lesions in the pineal region, posterior third ventricle, and the superior surface of the cerebellar vermis. The authors present four illustrative cases (one pineal cyst, one ependymoma, and two cerebellar metastases) in which this approach provided excellent intraoperative visualization and resulted in good postoperative results. A step-by-step description of our surgical technique is reviewed in detail.

LESSONS

The use of the 3D exoscope with the patient in the prone Concorde position is an effective and ergonomically favorable alternative to the traditional sitting position for the treatment of lesions requiring a supracerebellar infratentorial approach. This technique allows improved visualization of deep structures, with a possible decreased risk of potential complications.

Exoscope as a Teaching Tool: A Narrative Review of the Literature

Recently, the emergence of the three-dimensional (3D) exoscope has proven to be a viable alternative to the operative microscope (OM) as a novel workhorse of microneurosurgical procedures. Through its current iteration, the 3D exoscope has been demonstrated to be at least equivalent to the operative microscope in terms of surgical outcomes in many settings. With its superior ergonomics and simplicity of use, the 3D exoscope has been shown in multiple studies to be a powerful visualizing tool during surgical procedures. Moreover, the exoscopic systems, through their current iterations and by means of a high-resolution 3D monitor and 3D glasses, have allowed all participants present in the operative room to attain an unprecedented level of intraoperative visualization of anatomical structures and surgical maneuvers which are traditionally available only to the first operator. Although long-term data are still lacking regarding its future as a replacement of the OM, the 3D exoscope has revealed itself as an intense subject of discussion in neurosurgery regarding its implication for surgical education, especially for residents and junior neurosurgeons. This article is a review of the current state of the literature on the role of the exoscope in surgical education, underlining its strength as a learning tool and its potential future implications in terms of surgical education.

Ropivacaine represses the proliferation, invasion, and migration of glioblastoma via modulating the microRNA-21-5p/KAT8 regulatory NSL complex subunit 2 axis

Ropivacaine (Rop) is available to suppress the growth of glioblastoma (GBM), while its mechanism has not been completely elaborated. In this study, we explore the latent mechanism of Rop repressing GBM's growth via mediating the microRNA (miR)-21-5p/KAT8 regulatory NSL complex subunit 2 (KANSL2) axis. MiR-21-5p was declined in GBM, while KANSL2 was elevated. Clinical association studies manifested miR-21-5p was distinctly linked to the tumor size and grade of GBM. Rop constrained GBM cell proliferation, invasion, and migration but boosted apoptosis. Elevated miR-21-5p strengthened Rop's action, while augmented KANSL2 weakened Rop's role. Furthermore, the impact of silencing miR-21-5p on GBM was turned around via declining KANSL2 in Rop-treated GBM cells. KANSL2 was the target gene of miR-21-5p. In short, Rop exerted an anti-tumor impact on GBM via mediating the miR-21-5p/KANSL2 axis, which offered novel viewpoints for the later adoption of Rop as GBM drugs.

The Exoscope in Neurosurgery: An Overview of the Current Literature of Intraoperative Use in Brain and Spine Surgery

BACKGROUND

Exoscopes are a safe and effective alternative or adjunct to the existing binocular surgical microscope for brain tumor, skull base surgery, aneurysm clipping and both cervical and lumbar complex spine surgery that probably will open a new era in the field of new tools and techniques in neurosurgery.

METHODS

A Pubmed and Ovid EMBASE search was performed to identify papers that include surgical experiences with the exoscope in neurosurgery. PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) were followed.

RESULTS

A total of 86 articles and 1711 cases were included and analyzed in this review. Among 86 papers included in this review 74 (86%) were published in the last 5 years. Out of 1711 surgical procedures, 1534 (89.6%) were performed in the operative room, whereas 177 (10.9%) were performed in the laboratory on cadavers. In more detail, 1251 (72.7%) were reported as brain surgeries, whereas 274 (16%) and 9 (0.5%) were reported as spine and peripheral nerve surgeries, respectively. Considering only the clinical series (40 studies and 1328 patients), the overall surgical complication rate was 2.6% during the use of the exoscope. These patients experienced complication profiles similar to those that underwent the same treatments with the OM. The overall switch incidence rate from exoscope to OM during surgery was 5.8%.

CONCLUSIONS

The exoscope seems to be a safe alternative compared to an operative microscope for the most common brain and spinal procedures, with several advantages that have been reached, such as an easier simplicity of use and a better 3D vision and magnification of the surgical field. Moreover, it offers the opportunity of better interaction with other members of the surgical staff. All these points set the first step for subsequent and short-term changes in the field of neurosurgery and offer new educational possibilities for young neurosurgery and medical students.

Robotic-Assisted Digital Exoscope for Resection of Cerebral Metastases: A Case Series

BACKGROUND

Surgical resection is the primary treatment for cerebral metastases with safe complete resection as the goal. The robotically assisted digital surgical exoscope is a novel system with advanced visualization methods with recent applications in neurosurgery.

OBJECTIVE

To evaluate the outcomes for patients with cerebral metastases undergoing resection with the surgical exoscope.

METHODS

Data were retrospectively collected from patients with cerebral metastases where resection was achieved with using the surgical exoscope from 2016 to 2020. Demographics, clinical, imaging, and operative and outcome findings were collected. The relationship between perioperative data and discharge disposition as well as progression-free survival (PFS) and 12 mo overall survival (OS) was assessed.

RESULTS

A total of 31 patients (19 males) with a median patient age 63 yr (range 38-80) were included. Average pre- and postoperative volumes were 18.1 cc and 0.75 cc, respectively. Mean depth of the resected lesions was 0.6 cm (range 0-3.6 cm). Complete resection was achieved in 64.5% of patients. The mean extent of resection was 96.7%, with 71.0% achieving PFS at 6 mo. Overall PFS rate was 58.1% and the OS rate at 12 mo was 83.9%. Neurological complications included motor (35.5%) and sensory (12.9%) deficits, with 12 patients reporting no postoperative symptoms.

CONCLUSION

The surgical exoscope can delineate tumor tissues with high resolution, as shown by a gross total resection achieved for the majority of cases in our series. Postoperative complications and patient outcomes were similar to those reported with use of the operative microscope. Use of the exoscope can provide optimal visualization and delineation of cerebral metastases.

Plasmatic exosome-derived circRNAs panel act as fingerprint for glioblastoma

Circular RNAs (circRNAs) have recently emerged as a new class of RNAs, highly enriched in the brain and very stable within cells, exosomes and body fluids. In this study, we aimed to screen the exosome derived circRNAs in glioblastoma multiforme (GBM) and investigate whether these circRNAs could predict GBM as potential biomarkers. The exosome was extracted from the plasma of GBM patients and healthy volunteers and validated by immunoblotting. The circRNA microarray was employed with three samples in each group to screen the dysregulated circRNAs isolated from the exosome. Five circRNAs were first selected as candidates with the upregulated level in exosome isolated from the plasma of GBM. Further validation found that only hsa_circ_0055202, hsa_circ_0074920 and hsa_circ_0043722 were consistent with training set. The Receiver operating characteristic (ROC) curve also revealed a high diagnostic ability an area under ROC curve value (AUC) for single circRNA and combined. The AUC for hsa_circ_0055202, hsa_circ_0074920, hsa_circ_0043722 and the combined was 0.810, 0.670, 0.938 and 0.988 in training set. For the validation set, the AUC was 0.850, 0.625, 0.750 and 0.925. The three circRNAs were further investigated with stable expression in human plasma samples. In conclusion, the exosome derived hsa_circ_0055202, hsa_circ_0074920 and hsa_circ_0043722 might be the potential biomarker for predicting the GBM.

Human Glioblastoma Visualization: Triple Receptor-Targeting Fluorescent Complex of Dye, SIWV Tetra-Peptide, and Serum Albumin Protein

Fluorescence guided surgery (FGS) has been highlighted in the clinical site for guiding surgical procedures and providing the surgeon with a real-time visualization of the operating field. FGS is a powerful technique for precise surgery, particularly tumor resection; however, clinically approved fluorescent dyes have often shown several limitations during FGS, such as non-tumor-targeting, low in vivo stability, insufficient emission intensity, and low blood-brain barrier penetration. In this study, we disclose a fluorescent dye complex, peptide, and protein for the targeted visualization of human glioblastoma (GBM) cells and tissues. Our noble triple receptor-targeting fluorescent complex (named BSA-OXN-SIWV) consists of (i) dipolar oxazepine dye (OXN), which has high stability, low cytotoxicity, bright fluorescence, and two-photon excitable, (ii) tetra-peptide (SIWV) for the targeting of the caveolin-1 receptor, and (iii) bovine serum-albumin (BSA) protein for the targeting of albondin (gp60) and secreted protein acidic and rich in cysteine receptor. The photophysical properties and binding mode of BSA-OXN-SIWV were analyzed, and the imaging of GBM cell lines and human clinical GBM tissues were successfully demonstrated in this study. Our findings hold great promise for the application of BSA-OXN-SIWV to GBM identification and the surgery at clinical sites, as a new FGS agent.

Pseudoprogression versus true progression in glioblastoma patients: A multiapproach literature review. Part 2 - Radiological features and metric markers

After chemoradiotherapy for glioblastoma, pseudoprogression can occur and must be distinguished from true progression to correctly manage glioblastoma treatment and follow-up. Conventional treatment response assessment is evaluated via conventional MRI (contrast-enhanced T1-weighted and T2/FLAIR), which is unreliable. The emergence of advanced MRI techniques, MR spectroscopy, and PET tracers has improved pseudoprogression diagnostic accuracy. This review presents a literature review of the different imaging techniques and potential imaging biomarkers to differentiate pseudoprogression from true progression.

The Neurosurgeon's Armamentarium for Gliomas: An Update on Intraoperative Technologies to Improve Extent of Resection

Maximal safe resection is the standard of care in the neurosurgical treatment of high-grade gliomas. To aid surgeons in the operating room, adjuvant techniques and technologies centered around improving intraoperative visualization of tumor tissue have been developed. In this review, we will discuss the most advanced technologies, specifically fluorescence-guided surgery, intraoperative imaging, neuromonitoring modalities, and microscopic imaging techniques. The goal of these technologies is to improve detection of tumor tissue beyond what conventional microsurgery has permitted. We describe the various advances, the current state of the literature that have tested the utility of the different adjuvants in clinical practice, and future directions for improving intraoperative technologies.