Use of a compact high-definition two-dimensional exoscope in surgical treatment of large vestibular schwannoma

Posterior Cranial Fossa Surgery with a 3 Dimensional Exoscope: A Single-Center Survey-Based Analysis and a Literature Review

OBJECTIVE

The potential advantages of exoscopy have been discussed theoretically for a long time. Such a concept holds significance, especially in the specific setting of the posterior cranial fossa (PCF), characterized by complex anatomy and long and narrow surgical corridors with relatively extreme working angles. We aimed to: 1) analyze the institutional preliminary case-based data on the use of the Robotic 3D Exoscope AEOS Aesculap in three different PCF approaches: retrosigmoid (RSA), midline suboccipital (MSA), and supracerebellar infratentorial via feedbacks was collected using a 20-point questionnaire, and 2) perform a comprehensive review of the literature concerning the use of EX in PCF surgery.

RESULTS

A total of 38 patients with neurosurgical pathologies underwent a neurosurgical procedure using the EX (Robotic 3D exoscope AEOS Aesculap) at our institution between January and March 2022. 21 surgeons were involved in the abovementioned PCF surgeries and answered the questionnaire. The main perceived advantages were in terms of ergonomics (67%), magnification (52%), and visualization of extreme angles. The main reported disadvantage was color vision (16, 76%), followed by manual mobility (24%). Concerning the review, the search of the literature yielded a total of 177 results. Upon full-text review, 17 articles were included, including 153 patients.

CONCLUSIONS

In conclusion, our study provides a comprehensive evaluation of the advantages and challenges associated with using the exoscope in posterior fossa surgery, setting a precedent as the first to report on a questionnaire-based analysis of exoscope utilization in this specific domain.

The New Era of Spinal Surgery: Exploring the Use of Exoscopes as a Viable Alternative to Operative Microscopes-A Systematic Review and Meta-Analysis

BACKGROUND

The growing interest in exoscopic (EX) technology has prompted a comprehensive evaluation of its clinical, functional, and financial outcomes in neurosurgery. This systematic review and meta-analysis aimed to explore the utilization of EX in spine surgery and assess their safety, efficacy, and impact on surgical outcomes.

METHODS

A thorough literature review was conducted using PubMed, Scopus, and Embase databases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The study focused on articles concerning the application of EXs in spinal surgical procedures. The inclusion criteria encompassed various study designs presenting clinical data and intraoperative experiences related to EX utilization in spine surgery.

RESULTS

The meta-analysis included studies examining various aspects of EX utilization, such as intraoperative complications, video/image quality, surgical field visualization, ease of manipulation, ergonomic characteristics, educational utility, surgical duration, and team involvement. Findings indicated that EXs offered superior video quality and favorable ergonomic features. Comparable outcomes were observed in surgical duration, intraoperative blood loss, time to discharge, and postoperative pain levels between EX and conventional microscope approaches.

CONCLUSIONS

This study provides valuable insights into the utilization of EXs in spine surgery, demonstrating their potential advantages and comparable outcomes with conventional microscopes.

From Microscopic to Exoscopic Microsurgery: Are We Facing a Change of Paradigm?

BACKGROUND

Neurosurgery is a medical branch characterized by small and deep surgical field with the need of manipulation and dissection of anatomical structures. High light and magnification are required in order to avoid injuries to important anatomical structures and to avoid permanent neurological deficits. Introduction of operative microscope made a change of paradigm in neurosurgery allowing to better see what could not be seen with common light. Nowadays, introduction of several technologies have increased the safety and efficacy of neurosurgery. Among new technologies, the 3D exoscope is emerging pretending to shift the paradigm of microneurosurgery. In this work, we aim to show our first experience with the use of the exoscope showing advantages and disadvantages.

MATERIALS AND METHODS

We reviewed our surgical database from the introduction of the exoscope in our department (in November 2020 temporarily; then from November 2021 definitively) searching for all the microsurgery interventions performed in the period.

RESULTS

From the introduction of the exoscope in our department, we operated 244 cases with the OM and 228 with the exoscope. We operated 175 lesions located in the supratentorial compartment, 29 in the infratentorial, and 24 in the spinal column. Regarding the OM, the ratios were as follows: 122 females and 122 males; 235 adults and 9 children; 66 supratentorial lesions, 14 infratentorial lesions, and 164 spine surgeries. Our team showed a progressive switch from the microscope to the exoscope. Only one member of our team preferred to continue to use the standard operative microscope.

CONCLUSIONS

Our experience showed no complications related to the use of the exoscope that proved to be safe and effective both for surgery and teaching.

Neurosurgical application of pineal region tumor resection with 3D 4K exoscopy via infratentorial approach: a retrospective cohort study

BACKGROUND

The pineal region tumors are challenging for neurosurgeons and can lead to secondary hydrocephalus. The introduction of the exoscope has provided clinical interventions with high image quality and an ergonomic system for pineal region tumor operations. In this study, the authors describe the exoscopic approach used to facilitate the surgical resection of pineal region tumors and relieve hydrocephalus.

MATERIALS AND METHODS

In this retrospective cohort study, we consecutively reviewed the clinical and radiological data of 25 patients with pineal region lesions who underwent three-dimensional exoscopic tumor resection at a single center.

RESULTS

The patient cohort consisted of 16 males and 9 females, with an average age of 34.6 years (range, 6-62 years; 8 cases aged ≤18). Pathological examination confirmed eight pineal gland tumors, four gliomas, nine germ cell neoplasms, two ependymomas, and two metastatic tumors. Preoperative hydrocephalus was present in 23 patients. Prior to tumor resection, external ventricular drainage (EVD) with Ommaya reservoir implantation was performed in 17 patients. Two patients received preoperative endoscopic third ventriculostomy (ETV), and five patients received a ventriculoperitoneal (VP) shunt, including one who received both procedures. Gross total resection was achieved in 19 patients (76%) in the 'head-up' park bench position using the exoscope. Eight patients (31.6%) with third ventricle invasion received subtotal resection, mainly in glioma cases, which was higher than those without invasion (0%), but not statistically significant ( P =0.278, Fisher's exact test). No new neurological dysfunction was observed after surgery. Two patients (8%) developed intracranial and pulmonary infections, and two patients (8%) suffered from pneumothorax. Hydrocephalus was significantly relieved in all patients postoperatively, and four patients with relapse hydrocephalus were cured during the long-term follow-up. Postoperative adjuvant management was recommended for indicated patients, and a mean follow-up of 24.8±14.3 months showed a satisfied outcome.

CONCLUSIONS

The exoscope is a useful tool for pineal region tumor resection and hydrocephalus relief, particularly with posterior third ventricle invasion, as total resection could be achieved without obvious complication. The special superiority of the exoscope for the indicated pineal region tumors should be highlighted.

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.

Surgical outcomes in large vestibular schwannomas: should cerebellopontine edema be considered in the grading systems?

PURPOSE

Large (> 3 cm) vestibular schwannomas pose complexity in surgical management because of narrow working corridors and proximity to the cranial nerves, brainstem, and inner ear structures. With current vestibular schwannoma classifications limited in information regarding cerebellopontine edema, our retrospective series examined this radiographic feature relative to clinical outcomes and its possible role in preoperative scoring.

METHODS

Of 230 patients who underwent surgical resection of vestibular schwannoma (2014-2020), we identified 107 patients with Koos grades 3 or 4 tumors for radiographic assessment of edema in the middle cerebellar peduncle (MCP), brainstem, or both. Radiographic images were graded and patients grouped into Koos grades 3 or 4 or our proposed grade 5 with edema. Tumor volumes, radiographic features, clinical presentations, and clinical outcomes were evaluated.

RESULTS

The 107 patients included 22 patients with grade 3 tumors, 39 with grade 4, and 46 with grade 5. No statistical differences were noted among groups for demographic data or complication rates. Unlike grades 3 and 4 patients, grade 5 patients presented with worse hearing (p < 0.001), larger tumors (p < 0.001), lower rates of gross total resection (GTR), longer hospital stays, and higher rates of balance dysfunction.

CONCLUSION

With edema detected in 43% of this cohort, special considerations are warranted for grade 5 vestibular schwannomas given the preoperative findings of worse hearing, lower GTR rates, longer hospital stays, and 96% who pursued postoperative balance therapy. We propose that grade 5 with edema offers a more nuanced interpretation of a radiographic feature that holds relevance to treatment selection and patient outcomes.

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.

Three-Dimensional Exoscopic Versus Microscopic Resection of Vestibular Schwannomas: A Comparative Series

BACKGROUND

Microsurgical resection of vestibular schwannoma (VS) is highly challenging, especially because surgical treatment nowadays is mainly reserved for larger (Koos grade 3 and 4) tumors.

OBJECTIVE

To assess the performance of three-dimensional exoscope use in VS resection in comparison with the operative microscope.

METHODS

Duration of surgery and clinical and radiological results were collected for 13 consecutive exoscopic schwannoma surgeries. Results were compared with 26 preceding microsurgical resections after acknowledging similar surgical complexity between groups by assessment of tumor size (maximum diameter and Koos grade), the presence of meatal extension or cystic components, and preoperative hearing and facial nerve function.

RESULTS

Total duration of surgery was comparable between microscopically and exoscopically operated patients (264 minutes ± 92 vs 231 minutes ± 84, respectively; P = .276). However, operative time gradually decreased in consecutive exoscopic cases and in a multiple regression model predicting duration of surgery, and exoscope use was associated with a reduction of 58.5 minutes (95% CI -106.3 to -10.6; P = .018). Tumor size was identified as the main determinant of duration of surgery (regression coefficient = 5.50, 95% CI 3.20-7.80) along meatal extension and the presence of cystic components. No differences in postoperative hearing preservation and facial nerve function were noted between the exoscope and the microscope.

CONCLUSION

Resection of VS using a foot switch-operated three-dimensional exoscope is safe and leads to comparable clinical and radiological results as resection with the operative microscope.

3D Exoscopes are Noninferior to Operating Microscopes in Aneurysm Surgery: Comparative Single-Surgeon Series of 52 Consecutive Cases

OBJECTIVE

The literature on exoscope use in cerebrovascular neurosurgery is scarce, mainly comprising small case series and focused on visualization quality and ergonomics. As these devices become widely used, direct comparison to the operating microscope regarding efficacy and patient safety is necessary.

METHODS

Fifty-two consecutive clipping procedures, performed by 1 senior vascular neurosurgeon, were analyzed. Either an operating microscope with a mouth switch (25 cases with 27 aneurysms; 13 ruptured) or a three-dimensional exoscope with a foot switch (27 cases with 34 aneurysms; 6 ruptured) were used. Durations of major surgical stages, number of device adjustments, numbers of clip repositionings and clips implanted were extracted from surgical videos. Demographic data, imaging characteristics, clinical course and outcomes were extracted from digital patient records.

RESULTS

Duration of surgery and different stages did not differ between devices, except for final site inspection. The number of device adjustments was higher with the exoscope. With progressive experience in exoscope use, the number of device adjustments increased significantly, whereas surgery duration remained unchanged. Favorable outcome (modified Rankin Scale score 0-2) was observed in 80% and 88% of patients in the microscope and exoscope groups, respectively. Ischemic events were found in 2 patients in each group; no other complications occurred.

CONCLUSIONS

In aneurysm clipping, three-dimensional exoscopes are noninferior to operating microscopes in terms of surgery duration, safety, and outcomes, based on our limited series. Progressive experience enables the surgeon to perform significantly more device adjustments within the same amount of surgical time.

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.

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.