Embracing Exoscope in the Arsenal of Spine Surgeons in the Low- and Middle-Income Countries

BACKGROUND

Exoscope (EX) is a device that combines the convenience of an endoscope with the image clarity of an operating microscope (OM) to fill the void between the two. This study aims to compare the 2-dimensional EX with OM in spine surgeries and to explore its utility and feasibility in small and peripheral hospitals of low- and middle-income countries.

METHODS

Eighty-two patients with intradural spinal tumors (extramedullary and intramedullary) aged more than 18 years were included between August 2021 and August 2023. Patients with other spinal pathologies were excluded. After each exoscopic surgery, the operating surgeon and assistant had to answer a questionnaire. Postoperatively, outcomes were measured as the length of hospital stay, cerebrospinal fluid leak, and number of reoperations.

RESULTS

Thirty-seven patients were included in the OM group and 45 patients were included in the EX group. In 62%-67% of cases, the overall image quality of the EX was comparable to OM and in 29%-38% of cases, it was superior to the OM. The preparation and installation of the EX were much easier and better than the OM in 93%-100% of the cases. Maneuvering surgical instruments and workflow in the operating theater was much more convenient in the EX group (95%-100% of the cases). Ergonomics was far better in the EX group than in the OM group.

CONCLUSIONS

Spine surgeons can embrace the benefits of EX and increase their range of surgeries to be performed at the small operation theater setup in low-middle income developing countries.

Exoscope Use in Spine Surgery: A Systematic Review of Applications, Benefits, and Limitations

BACKGROUND

Exoscopes were recently developed as an alternative to the operative microscope (OM) and endoscope for intraoperative visualization during neurosurgery. Prior reviews studying mixed cranial and spinal surgical cohorts reported advantages with exoscope use, including improved ergonomics and teaching. In recent years, there has been an increase in exoscope research, with no updated systematic review focused exclusively on the benefits and limitations of exoscope use in spine surgery. Thus, we sought to systematically synthesize the literature related to exoscope-assisted spine surgery.

METHODS

A literature search was conducted using the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to identify relevant studies reported between 2010 and September 2023. Data, such as the exoscope model used, procedure types performed, and user observations, were then collected.

RESULTS

A total of 31 studies met our inclusion criteria, including 481 patients with spine pathologies who underwent a surgical procedure using 1 of 9 exoscope models. The lumbar region was the most frequently operated area (n = 234; 48.6%), and discectomies comprised the most overall procedures (n = 273; 56.8%). All patients benefited clinically. The reported advantages of exoscopes compared with OMs or endoscopes were improved focal distance, surgeon posture, trainee education, compactness, and assistant participation. Other aspects such as stereopsis, illumination, and cost had various observations.

CONCLUSIONS

Exoscopes have advantages compared with OMs or endoscopes during spine surgery. The user learning curve is minimal, and no negative patient outcomes have been reported. However, some aspects of exoscope use necessitate longer term prospective research before exoscopes can be considered a standard tool in the armamentarium of intraoperative visualization strategies.

Implementation of Robotic Exoscope in Minimally Invasive Corpectomy at Thoracolumbar Junction for the Treatment of Traumatic Spinal Cord Compression

The development and diffusion of minimally invasive (MI) approaches have coincided with improvements in magnification systems. The exoscope will probably open a new era in new technologies in spinal surgery. This study reports a retrospective series of 19 thoracolumbar (T11-L2) burst fractures with anterior column failure and cord compression, treated with MI corpectomy and spinal decompression assisted by a three-dimensional high-definition exoscope (Video 1). Exclusion criteria were pathologic or osteoporotic fractures, multilevel fractures, and previous surgery at the site of the fracture. Three key indicators were recorded: surgical time, blood loss, and intraoperative complications. A questionnaire was administered to assess the users' exoscope experience with ergonomics, preparation, magnification, image definition, illumination, and user-friendliness, compared with the operative microscope. To the best of our knowledge, this is the first study reporting on exoscope-assisted MI corpectomy. This procedure permitted low blood loss and less surgical time without intraoperative complications. The exoscope offers clear advantages in terms of ergonomics, definition, and user-friendliness. Moreover, it is a suitable instrument for training and education, providing an opportunity for better interaction with other members of the surgical staff.

Preliminary Experience with 3-Dimensional-Exoscopic Untethering of a Type II Diastematomyelia: Technical Note and Review of the Literature

OBJECTIVE

To describe the use of a high-definition 3-dimensional (3D) exoscope (VITOM 3D exoscope; KARL STORZ GmbH) for the neurosurgical treatment of a rare pediatric disease, type II diastematomyelia with associated tethered cord.

METHODS

A 13-year-old girl who presented with diastematomyelia type II with a tethered cord was surgically treated with the aid of a high-definition 3D exoscope, with a third operator moving and pivoting its arm. Intraoperative monitoring and mapping were arranged. The surgery required a bilateral access to address both the split cord malformation and the tethering of the filum terminale. The filum terminale was identified and cut, and the connective fibrovascular tissue separating the 2 medullary halves was unraveled. These steps were performed with no changes of intraoperative monitoring. Pertinent literature was addressed carefully.

RESULTS

The surgery was successful, and the patient was discharged home on the eleventh postoperative day without any complications. The 3-month postoperative magnetic resonance imaging scan demonstrated regular surgical outcomes; no dynamic motor disturbances were reported. To our knowledge, this is the first spinal congenital malformation treated with the use of a 3D exoscope.

CONCLUSIONS

The use of 3D exoscope is advancing in spinal surgery, as it provides magnification, stereopsis, lighting, and definition comparable with the operating microscope; the addition of a third operator simplified the operations of moving around the arm, releasing these burdens for the surgeons. Our preliminary experience proved that the use of a 3D exoscope is feasible and safe for the surgical management of a type II diastematomyelia with tethered cord.

Even short-term training improves the skills of novice exoscope users: a prospective laboratory experiment

BACKGROUND

The surgical 3D exoscopes have recently been introduced as an alternative to the surgical microscopes in microneurosurgery. Since the exoscope availability is still limited, it is relevant to know whether even a short-term exoscope training develops the skills needed for performing exoscope-assisted surgeries.

METHODS

Ten participants (six consultants, four residents) performed two laboratory bypass test tasks with a 3D exoscope (Aesculap Aeos®). Six training sessions (6 h) were performed in between (interval of 2-5 weeks) on artificial models. The participants were divided into two groups: test group (n = 6) trained with the exoscope and control group (n = 4) with a surgical microscope. The test task was an artificial end-to-side microsurgical anastomosis model, using 12 interrupted 9-0 sutures and recorded on video. We compared the individual as well as group performance among the test subjects based on suturing time, anastomosis quality, and manual dexterity.

RESULTS

Altogether, 20 bypass tasks were performed (baseline n = 10, follow-up n = 10). The median duration decreased by 28 min and 44% in the exoscope training group. The decrease was steeper (29 min, 45%) among the participants with less than 6 years of microneurosurgery experience compared to the more experienced participants (13 min, 24%). After training, the participants with at least 1-year experience of using the exoscope did not improve their task duration. The training with the exoscope led to a greater time reduction than the training with the microscope (44% vs 17%).

CONCLUSIONS

Even short-term training with the exoscope led to marked improvements in exoscope-assisted bypass suturing among novice microneurosurgeons. For the more experienced participants, a plateau in the initial learning curve was reached quickly. A much longer-term effort might be needed to witness further improvement in this user group.

Exoscope Efficacy and Feasibility in Pediatric Spinal Neurosurgery: A Single-Institution Cohort Case Series

BACKGROUND

The exoscope has emerged as an efficacious microscope in adult spinal neurosurgery providing improved operative field visibility and surgeon ergonomics. However, outcome data and feasibility are underrepresented in the pediatric literature. We present the largest case series aimed at assessing operative and clinical outcomes in pediatric patients undergoing various exoscope-assisted spinal surgeries.

METHODS

A retrospective review was conducted on all consecutive pediatric (age <18 years) spinal surgeries performed with the use of an exoscope by 3 senior surgeons at a single institution from 2020-2023. Demographics and clinical and operative outcomes were reviewed and analyzed.

RESULTS

Ninety-six exoscope-assisted pediatric spine surgeries were performed on 89 unique patients, 41 (42.7%) of which were male. The mean age at surgery was 12 (±5.3) years. Spinal cord detethering (55.8%) was the most common procedure performed. The overall mean operative time for all procedures was 155 (±86) minutes, and the mean estimated blood loss was 18 (±41) mL. The mean length of stay was 5.4 (±6.5) days. There were 14 (14.6%) patients with complications in this cohort. At final follow-up, 64 (83.1%) of symptomatic patients reported neurologic symptom improvement.

CONCLUSIONS

Using the exoscope in a variety of pediatric spinal surgeries resulted in an acceptable average operative time, estimated blood loss, length of stay, and rate of neurologic symptom improvement. The exoscope appears to be an efficacious option for pediatric neurosurgical spinal procedures.

Exo- and endoscopic lateral orbital wall approach for the medial temporal lobe glioma: how I do it

BACKGROUND

The endoscopic transorbital approach provides a direct access to the medial temporal lobe (MTL). However, when excising a highly vascular tumour, a wider access route that enables the concurrent use of standard neurosurgical instruments with both hands is preferable.

METHOD

We described the concept and technique of the lateral orbital wall approach (LOWA), which comprises orbitotomy and mini-craniotomy to treat MTL lesions using an exoscope and endoscope.

CONCLUSION

The LOWA provides a safe and natural surgical corridor to the MTL and enables 2- or 3-hand surgery. Hence, LOWA can potentially improve safety and efficiency to treat MTL lesions.

Exoscopic-assisted posterior approach for the removal of thoracic dumbbell schwannoma: Three-dimensional operative video

"Dumbbell" tumors are described as benign neoplasms presenting both intraspinal and extraspinal extensions, connected through the intervertebral foramen (McCormick, 1996) [1]. About 90 % of such tumors are histologically classified as schwannomas that most frequently arise in the thoracic region (Takamura and et al., 1997) [2]. Diagnosis is usually achieved as soon as the dimensional increase of the intracanal portion results in nerve or spinal cord compression (Ishikawa and et al., 2002) [3]. How to obtain a complete surgical resection of tumors with large or ventrally located extraforaminal components with a minimally invasive approach is still debated (Payer and et al., 2006) [4]. The single-stage posterior removal of the tumor is the most performed approach for lesions presenting with a small extra-foraminal component (Payer and et al., 2006) [4]. However, due to the reduced visual surgical field and poor control of the surrounding structures that could be obtained with an operative microscopic (OM) view, the application of this approach still appears to be limited to lesions with a large extraspinal component. An alternative surgical approach is the lateral transthoracic transpleural approach, which, however, carries greater risks of complications and often requires assistance from a thoracic surgeon. During the last decade, the exoscope was developed as a hybrid optical instrument, standing between the OM and the endoscope, merging the pros and cons of both visualization technologies, providing a wide viewing angle, high-resolution images, and non-monoaxial view. In this work we present a case of a 60-years old male patient with a 6-month history of dorsal pain and mild left limb paresthesia resistant to conservative treatment in which for the first time a single stage exoscopic-assisted (Olympus ORBEYE 4K-3D exoscope) posterior approach was used to remove entirely a thoracic dumbbell schwannoma with large extraspinal involvement.

Intraoperative Performance with the Exoscope in Spine Surgery: An Institutional Experience

BACKGROUND

Exoscope use in spinal neurosurgery has become a promising surgical option providing enhanced operative field visibility and ergonomics. However, data on its use in spine surgery are underreported in the literature. We aimed to assess the intraoperative outcomes in exoscope-assisted spine surgery compared with similar procedures performed using the operative microscope.

METHODS

A retrospective review was performed of all spinal surgeries performed using an exoscope and, subsequently, an equal number of operative microscope cases performed by 2 senior surgeons at a single institution from 2016 to 2023. The variables included demographics, clinical presentation, surgical treatment, and operative outcomes.

RESULTS

A total of 123 exoscope spinal surgeries were performed on 116 unique patients with a mean age of 67 ± 14 years, of whom 60 (52%) were women. The microscope group included 126 surgeries on 120 unique patients with a mean age of 62 ± 14 years, of whom 53 (45%) were women. The mean blood loss (28 mL vs. 132 mL; P = 0.0009), operative time (83 minutes vs. 103 minutes; P = 0.006), and length of stay (1.04 days vs. 1.73 days; P = 0.02) were significantly less for the exoscope group than for the microscope group.

CONCLUSIONS

The use of the exoscope resulted in a shorter operative time, less blood loss, a shorter length of stay, and favorable clinical outcomes compared with the use of the operative microscope. Neurosurgeons should consider this seemingly efficacious and ergonomically favorable visual technology for spinal surgeries.

Exoscopic microneurosurgery in pediatric brain tumors: an ideal tool for complex and peculiar anatomo-topographic scenarios?

PURPOSE

Since its introduction in the 1950s, the microsurgical paradigm has revolutionized neurosurgery. New technologies have been introduced over the years trying to overcome limits of the classical operating microscope. The recently developed 3D exoscopes represent a potential new paradigm for micro-neurosurgery. We analyzed our own experience with a 4 K-3D exoscope in a series of pediatric brain tumors to verify its advantages and limitations in comparison to the operating microscope and in light of the literature.

METHODS

Twenty-five pediatric patients with brain tumors underwent surgery at our Institute; the population has been analyzed and described. A score to evaluate the exoscopes and compare it to the operating microscope was considered and postoperatively applied to each single case.

RESULTS

The exoscope appears to be at least comparable to the operating microscope (OM) in all analyzed aspects. In the case of deep-seated or fourth ventricle tumors, the exoscope seems to be superior to the microscope. A surgeon-dependent learning curve is necessary for neurosurgeons to be confident with the exoscope.

CONCLUSION

Exoscopes appear to be as safe and effective as operating microscopes in pediatric neuro-oncological surgery. They have some advantages that make them superior to microscopes, particularly regarding surgeon ergonomics and fatigue, visual field qualities, and higher choice of intraoperative viewing angles.

Defining the Learning Curve of the Exoscope in Spine Surgery

INTRODUCTION

In recent years, introduction of the exoscope system has been responsible for a new era of optics in surgery. Such a system has started to be widely used in neurosurgery. More recently, the exoscope has also been increasingly used for spinal procedures. Thus, we aimed to explore the potential for exoscope-assisted spinal procedures and define the advantages and drawbacks of implementing the system into our daily routine.

METHODS

To achieve the aim of the study, we retrospectively reviewed the case series of patients treated by a senior surgeon and analyzed the results, complications, and operative time. The operating times were compared between the exoscope-assisted procedures and microscope-assisted procedures.

RESULTS

A total of 24 spinal procedure were performed with the exoscope in a 2-month period. In this first patient series performed by a single surgeon without experience with the exoscope, the learning curve seemed to be relatively low, with mastery of the instrument achieved after the performance of only a few cases. Comparing the cases after the plateau of the learning curve had been reached with those performed during the still active phase of the learning curve, a significant difference was found in the operative times. No statistically significant difference was detected in terms of blood loss or intraoperative complications.

CONCLUSIONS

Based on our first experience, use of the exoscope shows promising potential for opening up new frontiers in spinal microsurgery. In addition, it has a low learning curve for experienced surgeons.

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.

Cadaveric study of ergonomics and performance using a robotic exoscope with a head-mounted display in spine surgery

The conventional microscope has the disadvantage of a potentially unergonomic posture for the surgeon, which can affect performance. Monitor-based exoscopes could provide a more ergonomic posture, as already shown in pre-clinical studies. The aim of this study was to test the usability and comfort of a novel head-mounted display (HMD)-based exoscope on spinal surgical approaches in a simulated OR setting. A total of 21 neurosurgeons naïve to the device were participated in this prospective trial. After a standardized training session with the device, participants were asked to perform a single-level thoracolumbar decompression surgery on human cadavers using the exoscope. Subsequently, all participants completed a comfort and safety questionnaire. For the objective evaluation of the performance, all interventions were videotaped and analyzed. Twelve men and nine women with a mean age of 34 (range: 24-57) were participating in the study. Average time for decompression was 15 min (IqR 9.6; 24.2); three participants (14%) terminated the procedure prematurely. In these dropouts, a significantly higher incidence of back/neck pain (p = 0.002 for back, p = 0.046 for neck pain) as well as an increased frequency of HMD readjustments (p = 0.045) and decreased depth perception (p = 0.03) were documented. Overall, the surgeons' satisfaction with the exoscope was 84% (IqR 75; 100). Using a standardized, pre-interventional training, it is possible for exoscope-naïve surgeons to perform sufficient spinal decompression using the HMD-based exoscope with a high satisfaction. However, inaccurate HMD setup prior to the start of the procedure may lead to discomfort and unsatisfactory results.

What is the Marginal Intraoperative Cost of Using an Exoscope or Operative Microscope for Anterior Cervical Discectomy and Fusion? A Time-Driven Activity-Based Cost Analysis

OBJECTIVE

Our primary objective was to compare the intraoperative costs of 3 different surgical visualization techniques for anterior cervical discectomy and fusion (ACDF). Specifically, we used time-driven activity-based costing (TDABC) methodology to compare costs between ACDFs performed with operative microscopes (OM-ACDF), exoscopes (EX-ACDF), and loupes (loupes-ACDF).

METHODS

Total cost was divided into direct and indirect costs. Individual costs were obtained by direct observation, electronic medical records, and through querying multiple departments (business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented. We identified all instances of loupes-ACDF (n = 882), EX-ACDF (n = 26), and OM-ACDF (n = 52) performed at our institution. We performed multivariable linear regression analyses to compare costs between these modalities, accounting for patient-specific factors as well as number of levels fused, surgeon, and hospital site.

RESULTS

The average total intraoperative costs per loupes-ACDF, EX-ACDF, and OM-ACDF cases were $7081 +/- $2,942, $7951 +/- $3,488, and $6557 +/- $954, respectively. Regression analysis revealed no difference in intraoperative cost between loupes-ACDF and EX-ACDF (P = 0.717), loupes-ACDF and OM-ACDF (0.954), or OM-ACDF and EX-ACDF (0.217). On a more granular level, however, EX-ACDF was associated with increased cost of consumables, including drapes, compared to both OM-ACDF (β-coefficient: $369 +/- $121, P = 0.002) and loupes-ACDF (β-coefficient: $284 +/- $86, P = 0.001).

CONCLUSIONS

Although hospitals may be aware of the purchasing fees associated with microscopes and exoscopes, there is no clear documentation of how these technologies affect intraoperative cost. We demonstrate a novel use of TDABC for this purpose.

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 4 years, 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: 25.3 months). 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 2 months later requiring reoperation.

Surgical Posture with Microscopic Versus Exoscopic Visualization in Anterior Cervical Procedures

BACKGROUND

Surgeons sustain deviated postures during procedures even with the use of loupes or an operative microscope. The surgical exoscope is a new intraoperative visualization technology designed to improve surgical ergonomics; however, no objective data exist to say that surgeon posture is significantly improved. This study aimed to quantify the difference in posture during standard anterior cervical spine procedures performed with the aid of an operative microscope versus an exoscope.

METHODS

This was a prospective cohort study utilizing a posture-sensing device at the surgeon's cervicothoracic junction. The primary outcome was the proportion of time under scope spent in a deviated posture, defined as greater than 10 degrees of deviation from neutral in the x- and y-axes (flexion/extension and lateral bending) of the surgeon's upper torso. Average deviation from baseline for the x-, y-, and z-axes (flexion/extension, lateral bending, and axial rotation, respectively), as well as the percentage of operative time spent with the visualization aid was also analyzed.

RESULTS

Overall, 37 anterior cervical procedures were recorded: 18 were performed with an exoscope and 19 with a microscope. Surgeons spent significantly more time in the deviated posture with the operative microscope than with the exoscope (32% vs. 8% with x-axis >10 deg, P <0.005; 20% vs. 6% with y-axis >10 deg, P <0.05). This is also reflected by the significant differences in the average deviation in the x- and y-axes, while under scope.

CONCLUSIONS

Utilizing the exoscope for anterior cervical spine procedures allows surgeons to spend less time in a deviated posture.

3D4K exoscope in epilepsy surgery: a seminal experience

BACKGROUND AND OBJECTIVES

To report the progressive introduction of the exoscope (EX) from surface lesionectomy to antero-mesial temporal lobectomy (AMTL) in an epilepsy surgery practice.

METHODS

We describe a population of ten consecutive patients undergoing EX surgery, with a minimum follow-up of 6 months, that was compared to a similar population of patients referred to operative microscopic surgery (OM).

RESULTS

All surgeries were performed with the use of EX or OM alone. Transient neurological complications for surgery in eloquent regions were recorded in one patient for each population. Nine and seven patients undergoing, respectively, EX and OM surgery resulted in Engel class Ia (90% vs. 70%). The mean duration of EX and OM surgery resulted in 265.5 and 237.9 min, respectively, with a mean of 308.3 and 253.3 min for AMTL cases, respectively.

CONCLUSIONS

This preliminary study revealed that ORBEYE EX can be safe and effective in different types of epilepsy surgeries. The transition from OM to EX is fast, even though it is slower for the more challenging mesial temporal structure removal. Ergonomic and operative team interaction is improved by the use of EX. Our data need to be confirmed by larger studies.

Functionality and Usability of the Exoscope in Microvascular Decompression for Hemifacial Spasm and Trigeminal Neuralgia

BACKGROUND

Studies on the functionality and usability of the exoscope in neurosurgical procedures against surgical microscopes (SMs) are limited. This study aimed to examine the functionality and usability of the exoscope during microvascular decompression (MVD) surgery.

METHODS

Seven neurosurgeons evaluated the usefulness of a 4 K, 3-dimension digital exoscope in MVD by answering a questionnaire. The questionnaire inquired about the functionality and usability of the exoscope by utilizing a visual analog scale (VAS; 1-10). A score of 5 on VAS was equivalent to the corresponding quality of the SM. The learning effect of the exoscope was evaluated using mean VAS scores in the first and last 3 cases for each neurosurgeon.

RESULTS

The functionality of the exoscope in MVD was superior to that in SM (P < 0.001). In the last 3 surgeries, the mean VAS scores of the exoscope were excellent in terms of ease of arm handling, exchange of surgical instruments, ease of surgical procedure, and intraoperative physical stress. The mean VAS scores of the exoscope in intraoperative asthenopia were significantly higher than those of the SM (P < 0.001). No statistical significance was found in operation time, discharge outcome, and 1-year post-surgery outcome between MVD performed using the exoscope and SM.

CONCLUSIONS

Neurosurgeons may experience reduced stress levels during MVD when using the exoscope. As the outcome of MVD using the exoscope did not demonstrate a statistical difference compared with MVD using the SM, the exoscope may prove to be a useful tool for performing MVD.

Ultrahigh-Definition-3-Dimensional Exoscope-Assisted Clipping of a Right Middle Cerebral Artery Unruptured Aneurysm with Indocyanine Green Video Angiography: Operative Video

Ultrahigh-definition 3-dimensional exoscopes represent an excellent technologic innovation in contemporary neurosurgery. They combine the advantages of operating microscopes and endoscopes, offering excellent magnification and lighting, maintaining a relatively small footprint and optimal ergonomic features.1-5 One of the most interesting employments of exoscopes in neurosurgery is represented by intracranial vascular surgery. Reports in this field are still limited, but recent experience has shown that ultrahigh definition 3-dimensional exoscopes for aneurysm surgery are noninferior to operating microscopes for surgery duration, complication rate, and patient outcomes.6 In addition, many intraoperative techniques such as the indocyanine green videoangiography (ICG-VA) have been successfully implemented to exoscope-based surgery.7 We present herein the case of a 66-year-old woman that came to our attention for the incidental finding of 3 unruptured brain aneurysms. After neurosurgical consultation, the one located at the right middle cerebral artery bifurcation was considered eligible for surgery.8,9 As shown in Video 1, ICG-VA was employed after permanent clipping to allow immediate quality assurance of occlusion and distal vessel integrity. Postoperative course was uneventful, and follow-up examinations demonstrated the complete occlusion of the aneurysm. This report highlights the feasibility of exoscopic-based ICG-VA in vascular neurosurgery, given its ease of use, ergonomics, and excellent quality of vision provided to both surgeons and operating staff.

Evaluating the exoscope as an alternative to the operating microscope in plastic surgery

BACKGROUND

Microsurgery is most commonly used in the anastomosis of vessels, flap harvesting, lymphedema, and nerve reconstruction, among others. During the 1920s the first microscope was invented by Nylen and Holmgren, quickly becoming the gold standard for microsurgery. However, technological advances have come forth in the form of exoscopes.

METHODS

A search for full-text articles where using an exoscope was compared with a traditional operating microscope was conducted on the databases PubMed, Scopus, Web of Science, and Embase. The following terms were used to guide our search: Microscope AND exoscope AND plastic surgery; Microscope AND exoscope AND microvascular surgery.

RESULTS

Our search yielded 69 studies, of which 12 were included. Five exoscope systems were used by the authors. All studies reported the exoscope as a valid alternative to the standard operating microscope. The exoscope was reported as non-inferior to the operating microscope. Although some studies reported lower quality of image, this did not seem to influence the outcome of surgeries. Newer models may have bridged the gap between the operating microscope's image quality and the exoscope. Superior ergonomics was always reported among the included studies.

CONCLUSION

Based on our search, we conclude that the exoscope is a safe and valid alternative to the operating microscope in plastic surgery. As newer models are now commercially available, these have overcome difficulties in image quality and zoom capabilities, responsible for the main drawbacks of the first exoscope systems.

Spinal navigation for small thoracic intradural tumors: The challenge between minimally invasive and exoscopic magnification

Background

Spinal navigation offers significant benefits in the surgical treatment of small thoracic intradural tumors. It enables precise tumor localization without subjecting the patient to high radiation doses. In addition, it allows for a smaller skin incision, reduced muscle stripping, and limited bone removal, thereby minimizing the risk of iatrogenic instability, blood loss, postoperative pain, and enabling shorter hospital stays.

Case Description

This video presents two cases demonstrating the application of spinal navigation technique for thoracic intradural tumors measuring <20 mm. In the first case, which involves a small calcified tumor, navigation can be performed using 3D fluoroscopy or computed tomography images obtained intraoperatively. Notably, as illustrated in the second case, the merging of preoperative magnetic resonance imaging images with intraoperative 3D fluoroscopy enables navigation in the context of soft intradural lesions as well. The setup of the operating room for these procedures is also depicted.

Conclusion

In these procedures, the use of an exoscope, in addition to the well-known advantages in terms of magnification and ergonomics, provides a large space of movement around the surgical field, with greater ease in the use of navigation devices and ultrasound. The minimal invasiveness of the surgical approach is in no way a hindrance to exoscopic visualization and surgical dissection.

Taming the exoscope: a one-year prospective laboratory training study

PURPOSE

Digital 3D exoscopes have been recently introduced as an alternative to a surgical microscope in microneurosurgery. We designed a laboratory training program to facilitate and measure the transition from microscope to exoscope. Our aim was to observe the effect of a one-year active training on microsurgical skills with the exoscope by repeating a standardized test task at several time points during the training program.

METHODS

Two board-certified neurosurgeons with no previous exoscope experience performed the same test tasks in February, July, and November during a 12-month period. In between the test tasks, both participants worked with the exoscope in the laboratory and assisted during clinical surgeries on daily basis. Each of the test segments consisted of repeating the same task 10 times during one week. Altogether, 60 test tasks were performed, 30 each. The test task consisted of dissecting and harvesting the ulnar and radial arteries of the second segment of a chicken wing using an exoscope (Aesculap AEOS). Each dissection was recorded on video and analyzed by two independent evaluators. We measured the time required to complete the task as well as several metrics for evaluating the manual skills of the dissection and handling of the exoscope system.

RESULT

There was a clear reduction in dissection time between the first and the last session, mean 34 min (SD 5.96) vs. 26 min (SD 8.69), respectively. At the end of the training, both neurosurgeons used the exoscope more efficiently utilizing more available options of the device. There was correlation between the dissection time and several of the factors we used for evaluating the work flow: staying in focus, zoom control, reduction of unnecessary movements or repetitive manual motions, manipulation technique of the vessel under dissection, handling of the instruments, and using them for multiple dissection purposes (stretching, cutting, and splitting).

CONCLUSION

Continuous, dedicated long-term training program is effective for microsurgical skill development when switching from a microscope to an exoscope. With practice, the micromotor movements become more efficient and the use of microinstruments more versatile.

Musculoskeletal demands in microsurgery-an explorative study comparing the ergonomics of microscope and 3D exoscope

To assess neurosurgeons' physical demands and investigate ergonomic aspects when using microsurgical visualization devices. Six neurosurgeons performed micro-surgical procedures on cadaveric specimens using the prototype of a digital 3D exoscope system (Aeos®, Aesculap, Tuttlingen, Germany) and a standard operating microscope (Pentero 900, Zeiss, Oberkochen, Germany) at two different patient positions (semisitting (SS), supine (SP)). The activities of the bilateral upper trapezius (UTM), anterior deltoid (ADM), and lumbar erector spinae (LEM) muscles were recorded using bipolar surface electromyography and neck flexion, arm abduction, and arm anteversion angles by gravimetrical posture sensors. Perceived discomfort frequency was assessed and subjects compared the two systems in terms of usability, posture, physical and mental demands, and working precision. Using the exoscope led to reduced ADM activity and increased UTM and LEM activity during SS position. The neck was extended when using the exoscope system with lower arm anteversion and abduction angles during the SS position. Subjects reported discomfort at the shoulder-neck area less frequently and lower physical demands when using the Aeos®. However, mental demands were slightly higher and two subjects reported lower working precision. The exoscope system has the potential to reduce the activity of the ADM by changing surgeons arm posture which may be accompanied by less discomfort in the shoulder-neck area. However, dependent on the applied patient position higher muscle activities could occur in the UTM and LEM.

Spinal cord compression in thoracolumbar burst fractures: application of high-definition three-dimensional exoscope in minimally invasive lateral surgery

STUDY DESIGN

Spinal cord decompression in thoracolumbar burst fractures is challenging. Development of minimally invasive approaches and the improvement in new magnification technologies allowed a better and safer surgical treatment for these complex spinal injuries. We reported our experience in the minimally invasive surgical treatment of thoracolumbar burst fractures with spinal cord compression supported by high-definition (HD) three-dimensional (3D) Video-assisted telescope operating monitor (VITOM) or exoscope.

OBJECTIVES

To assess the role and potential advantages of exoscope in the minimally invasive surgery of traumatic thoracolumbar spinal cord compression comparing traditional magnification systems.

SETTING

The study was conducted in a Northern Italy Spinal Trauma Center.

METHODS

We reported 10 consecutive thoracolumbar (T11-L2) burst fractures associated with spinal cord compression treated with minimally invasive corpectomy and exoscope-assisted spinal decompression. Three main indicators were retrospectively analyzed: surgical time, blood loss, and intraoperative complications. The data were compared with those obtained from an equal sample of 10 procedures performed by the same surgeon with the same technique, but traditional microscope assisted. User impressions in terms of ergonomics, magnification, and image quality were rated differently.

RESULTS

A small reduction of surgical time and blood loss were observed in the exoscope assisted group. There were no intraoperative complications attributed to visualization mode or conversion to the traditional microscope in any procedure. In our experience the exoscope allowed a better magnification and image definition with better ergonomics and user-friendliness.

CONCLUSIONS

In our preliminary experience the exoscope new technology is a safe and effective tool for spinal cord minimally invasive decompression in thoracolumbar burst fractures. The stereoscopic vision provided by 3D images seems to be crucial in hand eye coordination. There are clear advantages in terms of maneuverability, wide field of view, deep focus, and more comfortable posture for the spinal surgeon.

Improving Surgeon Well-Being: Ergonomics in Neurosurgery

BACKGROUND

Musculoskeletal disorders are common among surgeons, and affect most neurosurgeons over the course of their career. Although all subspecialist neurosurgeons may be affected by physical strain, spine surgeons and skull base surgeons have a high propensity for workplace injury as a result of long procedures with repetitive movements in strained physical positions.

METHODS

In this review, the prevalence of musculoskeletal disorders in neurosurgery, the state of innovation to improve ergonomics in the operating room for neurosurgeons, and potential limitations in advancing technology with the goal of maximizing neurosurgeon longevity are discussed.

RESULTS

Innovations such as robotics, the exoscope, and handheld devices with more degrees of freedom have allowed surgeons to maneuver instruments without exerting excessive effort, all while maintaining neutral body positioning, avoiding joint and muscle strain.

CONCLUSIONS

As new technology and innovation in the operating room develop, there has been a larger emphasis placed on maximizing surgeon comfort and neutral positioning, by minimizing force exertion and fatigue.

Surgical resection of glioblastoma in basal ganglia and utility of exoscope: Technical case reports

Background

Due to the presence of many perforating arteries and the deep location of basal ganglia tumors, dissection of the perforating arteries is critical during tumor resection. However, this is challenging as these arteries are deeply embedded in the cerebrum. Surgeons need to bend their heads for a long time using operative microscope and it is uncomfortable for the operating surgeon. A high-definition (4K-HD) 3D exoscope system can significantly improve the surgeon's posture during resection and widen the operating view field considerably by adjusting the camera angle.

Methods

We report two cases of glioblastoma (GBM) involving basal ganglia. We used a 4K-HD 3D exoscope system for resecting the tumor and analyzed the intraoperative visualization of the operative fields.

Results

We could approach the deeply located feeding arteries before successfully resecting the tumor using a 4K-HD 3D exoscope system which would have been difficult with the sole use of an operative microscope. The postoperative recoveries were uneventful in both cases. However, postoperative magnetic resonance imaging showed infarction around the caudate head and corona radiata in one of the cases.

Conclusion

This study has highlighted using a 4K-HD 3D exoscope system in dissecting GBM involving basal ganglia. Although postoperative infarction is a risk, we could successfully visualize and dissect the tumors with minimal neurological deficits.

Beyond Magnification and Illumination: Ergonomics with a 3D Exoscope in Lumbar Spine Microsurgery to Reduce Musculoskeletal Injuries

OBJECTIVE

The risk of musculoskeletal injuries (MSIs) increases over years of practice which may lead to career-ending among surgeons. Exoscopes represent a new generation of imaging systems that help surgeons operate in a more comfortable posture. This article aimed to assess advantages and limitations, especially ergonomics with a 3D exoscope in lumbar spine microsurgery versus an operating microscope (OM) to reduce MSIs.

METHODS

From March 2018 to May 2020, 90 patients with lumbar disc herniation undergoing a single-level minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) procedure were included. Forty-seven patients were operated with the assistance of the exoscope and 43 patients were operated with the assistance of the OM. Clinical data, magnification, and illumination were evaluated. In particular, the ergonomics of surgeons was evaluated by a questionnaire (subjective) and a rapid entire body assessment (REBA; objective).

RESULTS

The postoperative outcomes were reasonably well balanced between the two groups. The handling of the exoscope was comparable to that of the OM. The depth perception, image quality, and illumination of the exoscope were inferior to those of the OM in MIS-TLIF with long and deep approaches. The educational and training function of the exoscope was superior to that of the OM. Importantly, surgeons rated the ergonomics of the exoscope as very high on the questionnaire and the REBA to the OM (P = 0.017).

CONCLUSIONS

This study showed that the exoscope was a safe and effective alternative to the OM for assisting the MIS-TLIF procedure with the unique advantage of ergonomics to reduce musculoskeletal injuries.

How I do it: surgery for spinal arteriovenous malformations

BACKGROUND

Spinal arteriovenous malformations (AVM) are rare lesions. They may present with intramedullary hemorrhage or edema, often inducing severe neurological deficits. Active treatment of spinal AVMs is challenging even for experienced neurosurgeons.

METHOD

Anticipation of anatomy and AVM angiocharacteristics from preoperative imaging is key for successful treatment. Information gathered from MRI and DSA has to be then matched to intraoperative findings. This is a prerequisite for reasonably safe and structured lesion removal.

CONCLUSION

We provide a structured approach for surgical treatment of spinal AVMs, supplemented by high-resolution video and imaging material.

Exoscopic supracerebellar approach to the pineal region

The advent of the 3D exoscope represents a significant technological breakthrough in contemporary surgical practice. While the operating microscope has long been the preferred surgical visualization tool, its limitations in accessibility and ergonomics have prompted the development of a more advanced, 3D version [1,2]. The 3D exoscope has been one such recent development aimed at addressing these limitations. By delivering intense illumination and magnification to the deepest parts of the surgical field, 3D exoscopes are high-definition digital camera systems that give surgeons high-magnification views of the operative field [2]. Additionally, the design of the 3D exoscope allows for improved surgeon ergonomics, decreasing overall fatigue while providing a similar view of the procedure for all personnel in the operating room [3,4]. In this article, we discuss the advantages and limitations of the 3D exoscope in neurosurgery and highlight its use in a patient case. This is a case of a 25-year old female who was noted to have an incidental 13 mm pineal cystic mass on imaging work up for a first time generalized seizure. We discuss the use of an exoscopic supracerebellar approach to the pineal gland for resection of the mass and highlight the various considerations for use of an exoscope in such a case.

Right gyrus cinguli low-grade astrocytoma recurrence removed through a contralateral transfalcine approach with a 4K-3D exoscope

BACKGROUND

Brain tumor surgery has been using operative microscope for years. Recently, thanks to developments in surgical technology with procedures performed on head-up displays, exoscopes have been introduced as an alternative to microscopic vision.

CASE PRESENTATION

We present a case of a 46-year-old patient with a low-grade glioma recurrence of the right gyrus cinguli removed with a contralateral transfalcine approach using an exoscope (ORBEYE 4K-three-dimensional (3D) exoscope, Sony Olympus Medical Solutions Inc., Tokyo, Japan). The operating room setup for this approach is illustrated. During the procedure, the surgeon was seated with head and back in an upright position, while the camera was aligned with the surgical corridor. The exoscope provided detailed, high-quality 4K-3D images of the anatomical structures and optimal depth perception, making surgery accurate and precise. At the end of the resection, an intraoperative MRI scan showed complete removal of the lesion. The patient was discharged on postoperative day 4 with an excellent performance on neuropsychological examination.

CONCLUSIONS

In this clinical case the contralateral approach was favorable because the glioma was located close to the midline and because it offered a straight path to the tumor, minimizing retraction on the brain. The exoscope provided the surgeon with important advantages in terms of anatomical visualization and ergonomics during the entire procedure.

Treatment of Chiari III Malformation in Infant with 4K 3D ORBEYE Exoscope

Chiari malformation (CM)-III is the rarest anomaly among CMs.¹ Treatment of choice is surgical repair,² although poor outcome and postoperative mortality has been reported.³ Surgical timing is still debated.^4,5 We present the case of a male infant with a prenatal diagnosis of encephalocele. Presentation was characterized by hemodynamic instability, horizontal nystagmus, and left shoulder dystocia due to caesarean section, with a 64 mm × 49 mm × 76 mm soft, fluctuant, and translucent suboccipital-cervical sac. Magnetic resonance imaging revealed a median occipital bone defect with the meningoencephalic sac communicating with the vermian cistern and the fourth ventricle, moderate hydrocephalus, reduction of the posterior cranial fossa volume, hypoplasia of cerebellar hemispheric, vermian structures, and corpus callosum hypoplasia. The patient underwent surgery on day 4 with the use of a 4K 3D ORBEYE exoscope (Video 1). Surgery consisted of disengagement of nervous structures and repair of the neurocutaneous defect, followed on day 12 by a ventriculoperitoneal shunt with a programmable valve. The procedures were well tolerated. At the 14-month follow-up visit he was in range with growth charts (weight, height, and cranic circumference) and gained the physiologic stages of growth. He had no motor impairment but still present were convergent strabismus and mild left C5-C6 radiculopathy, secondary to shoulder dystocia. This is the first case reported in the literature of CM-III treated with the 4K 3D ORBEYE exoscope. Advantages of the exoscope were ergonomic positions for operative staff, possibility for the team to assist in the 4K 3D view, especially in cases with a narrow operative field, with a clear and detailed vision, although a learning curve is required⁶ to become a valid alternative in pediatric neurosurgery.

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.

3D Exoscopes in Experimental Microanastomosis: A Comparison of Different Systems

Background: In recent years, three-dimensional exoscopes have been increasingly applied in neurosurgery. Multiple exoscopic systems are available, all offering specific features. In this study, we assessed practical and visualization performance of four different exoscopic systems in a highly challenging microsurgical procedure, and evaluated whether these affected the quality of work. Methods: We included four different exoscopes: Olympus ORBEYE, Zeiss KINEVO, Storz VITOM, and Aesculap AEOS. With each exoscope, ten experimental bypass procedures were carried out on chicken wing vessels at a depth of 3 cm. We evaluated the quality of the anastomoses, the practical considerations for the setup of the exoscopic systems, and the visualization quality by tracking the number of unnecessary movements. Results: All included exoscopes enabled us to perform the bypass procedures with mostly adequate or excellent results. Surgically, the most pronounced difference between the exoscopes was the duration of the procedure, which was mainly due to the number of unnecessary movements. Practically, the exoscopes differ highly which is important when considering which exoscope to apply. Conclusions: This is the first study comparing different exoscope systems while performing the same challenging microsurgical procedure. We found major practical differences between the exoscopes that determine the suitability of an exoscope based on the demands and conditions of the surgical procedure. Therefore, preprocedural practical training with the exoscope is required.

Experience with 2D Exoscope System for Bilateral Simultaneous Cochlear Implant Surgery in the Era of the COVID-19 Pandemic

We report the first case series utilizing the exoscope exclusively for bilateral simultaneous cochlear implant surgery and discuss the advantages, disadvantages, as well as surgical outcomes in the Covid-19 era. The VITOM® 2D is compatible with enhanced PPE and draping techniques which can improve safety while providing comparable surgical outcomes.

Optimization of novel exoscopic blue light filter during fluorescence-guided resection of Glioblastoma

PURPOSE

Operative guidelines and use optimization for new surgical exoscopes are not well described in the literature. In this study, we evaluated use of the ORBEYE (Olympus) surgical exoscope system during 5-ALA fluorescence-guided resection of GBMs to optimize workflow and exoscope settings.

METHODS

The ORBEYE exoscope system was fitted with a blue light filter for 5-ALA mediated fluorescence-guided surgery (FGS). Intraoperative images were obtained during 5-ALA FGS in 9 patients with primary or recurrent GBM. The exoscope was set up at constant, increasing focal distances from the target tissue, and light source intensity varied. High-resolution 4 K images were captured and analyzed. Comparisons of fluorescence to background were then generated for use optimization.

RESULTS

Light intensity did not significantly influence tumor fluorescence (P = 0.878). However, focal distance significantly impacted relative fluorescent intensity (P = 0.007). Maximum average fluorescence was seen consistently at a focal length of 220 mm and a light intensity of approximately 75% maximum. Decreasing focal distance from 400 mm to 220 mm significantly increased visualized fluorescence (P = 0.0038).

CONCLUSIONS

The ORBEYE surgical exoscope system with blue light filter is a powerful imaging tool for 5-ALA FGS in GBM. The ORBEYE blue filter performs optimally at shorter focal distance with moderate light intensity. Similar to microscope systems, decreasing focal distance significantly influences visualized fluorescence.

Use of a Novel Three-dimensional Head-mounted Digital Visualization Platform in Corneal Endothelial Transplantation

INTRODUCTION

To report the first endothelial keratoplasty procedures performed using a 3D digital head-mounted ophthalmic exoscope.

METHODS

Three patients underwent Descemet stripping automated endothelial keratoplasty (DSAEK) using a 3D digital ophthalmic exoscope (Beyeonics One, Beyeonics Vision, Haifa, Israel) at the Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.

RESULTS

All procedures were uneventful, leading to resolution of corneal edema and vision improvement. Surgeons reported excellent visualization and minimal lag, almost negligible, with the benefits of improved ergonomics and the use of head gestures to control zoom, focus, brightness, and panning. There were no postoperative complications.

CONCLUSION

The new 3D digital ophthalmic exoscope system can be successfully used in DSAEK surgery with potential advantages in ergonomics, picture quality, and image control. Further studies can compare this system with either standard operating microscopes or 3D heads-up display systems.

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.

A Comparative Analysis with Exoscope and Optical Microscope for Intraoperative Visualization and Surgical Workflow in 5-Aminolevulinic Acid-Guided Resection of High-Grade Gliomas

BACKGROUND

The exoscope has been proposed as a valid tool in 5-aminolevulinic acid-guided resection of high-grade gliomas. However, it is not clear if, beyond ergonomics, the exoscope provides a real benefit over the optical microscope (OM). The aim of this study was to compare the exoscope with the OM in terms of surgical visualization and workflow in 5-aminolevulinic acid-guided brain surgery.

METHODS

Surgical videos of patients diagnosed with histopathologically confirmed, Shinoda stage I, high-grade gliomas who underwent surgery in from January to April 2022 were studied. Visualization under a 5-aminolevulinic acid blue filter for vessels, parenchyma, surgical instruments, and fluorescence was categorized for both superficial and deep fields. The following data were also recorded: median number of switches between white light and blue filter, average duration per switch, and amount of work under blue filter.

RESULTS

There were 5 surgeries performed under OM guidance and 5 performed under exoscope guidance. Under a blue filter, the exoscope was significantly better than the OM in visualizing vessels, parenchyma, and surgical instruments for both superficial and deep surgical fields. The median number of switches between blue and white light was lower compared with the OM. Both median switch duration and percentage of work under the blue filter were superior when using the exoscope.

CONCLUSIONS

Within the limitations of a preliminary analysis, use of the exoscope in fluorescence-guided surgery for high-grade gliomas provided significant advantages in terms of visualization of the surgical field under a blue filter and linearity of surgical flow.

The Impact of a Robotic Digital Microscope on the Ergonomics in a Neurosurgical Operating Theatre (A Single-Centre Experience)

Ergonomics is an emerging concept in the neurosurgical operating theatre, where neurosurgeons work under great concentration and frequently neglect their uncomfortable body posture. Work-related musculoskeletal disorders (WMSD) are becoming a widespread burden in the neurosurgical community. WMSD have a negative impact on surgical performance and decrease the surgeons' quality of life. Here we present our single-centre 2-month experience with the Aesculap AEOS® Robotic Digital Microscope (RDM) and prospectively calculate the REBA (Rapid Entire Body Assessment) scores and compare them with similar neurosurgical cases operated with a conventional operative microscope (OPMI).Materials and Methods: For a period of 2 months at the Department of Neurosurgery of the University Hospital Pirogov, Sofia, Bulgaria, 41 consecutive patients were operated on using RDM. The REBA employee assessment worksheets were filled in prospectively to assess the ergonomics of the senior author (N.G.) while using the RDM and the OPMI.Results and Conclusion: The ergonomics during neurosurgical operations could be substantially improved with the implementation of the exoscope. For challenging cranial approaches, where the operator must frequently "look around corners" the exoscope has a major advantage compared with the OPMI-the REBA score is 2.6 times lower for the exoscope and reaches a low risk for WMSD. For spinal operations, the neck score as part of the REBA score is three times lower for the exoscope.

Surgeon's Eyes on the Relevant Surgical Target

The resolution of the naked eye has been a challenge for the neurosurgical endeavor since the very first attempts of cranial surgery, and advances have been achieved over the centuries, driven by a synergism between the application of emerging technology into the surgical environment and the expansion of the capabilities of neurosurgery. The understanding of the principles of the optical properties of lenses by Abbè (1840-1905) led to the introduction of loupes in the surgical practice, increasing the visual performance during macroscopic procedures. Modern neurosurgery began with the possibility of illumination and magnification of the surgical field as provided by the microscope. Pioneering contributions from Donaghy and Yasargil opened the way to the era of minimalism with reduction of operative corridors and surgical trauma through the adoption of the microsurgical technique. Almost at the same time, engineering mirabilia of Hopkins in terms of optics and lenses allowed for introduction of rigid and flexible endoscopes as a viable tool in neurosurgery. Nowadays, neurosurgeons are aware of and confident using effective and modern tools of visualization in their armamentarium. Herein we present a cogent review of the evolution of visualization tools in neurosurgery, with a special glimpse into the current development and future achievements.

Exoscope improves visualization and extent of hippocampal resection in temporal lobectomy

INTRODUCTION

Anterior temporal lobectomy (ATL) is a safe and well-validated procedure in the treatment of temporal lobe epilepsy (TLE), but is a challenging technique to master and still confers a risk of morbidity and mortality due to the complex anatomy of the mesial temporal lobe structures. Automated robotic 3D exoscopes have been developed to address limitations traditionally associated with microscopic visualization, allowing for ergonomic, high-definition 3D visualization with hands-free control of the robot. Given the potential advantages of using such a system for visualization of complex anatomy seen during mesial structure resection in ATL, this group sought to investigate impact on the percentage of hippocampal resection in both exoscope and microscope guided procedures.

METHODS

We conducted a retrospective analysis of 20 consecutive patients undergoing standard ATL for treatment of medically refractory TLE at our institution. Using pre-operative and post-operative imaging, the coronal plane cuts in which either the head, body, or tail of the hippocampus appeared were counted. The number of cuts in which the hippocampus appeared were multiplied by slice thickness to estimate hippocampal length.

RESULTS

Mean percentage of hippocampal resection was 61.1 (SD 13.1) and 76.5 (SD 6.5) for microscope and exoscope visualization, respectively (p = 0.0037).

CONCLUSION

Use of exoscope for mesial resection during ATL has provided good visualization for those in the operating room and the potential for a safe increase in hippocampal resection in our series. Further investigation of its applications should be evaluated to see if it will improve outcomes.

Expanding access to microneurosurgery in low-resource settings: Feasibility of a low-cost exoscope in transforaminal lumbar interbody fusion

Objectives

Less than a quarter of the world population has access to microneurosurgical care within a range of 2 h. We introduce a simplified exoscopic visualization system for low-resource settings.

Materials and Methods

We purchased a 48 megapixels microscope camera with a c-mount lens and a ring light at a total cost of US$ 125. Sixteen patients with lumbar degenerative disk disease were divided into an exoscope group and a microscope group. In each group, we performed four open and four minimally invasive transforaminal lumbar interbody fusions (TLIF). We conducted a questionnaire-based assessment of the user experience.

Results

The exoscope achieved similar outcomes with comparable blood loss and operating time as the microscope. It provided similar image quality and magnification. Yet, it lacked stereoscopic perception and the adjustability of the camera position was cumbersome. Most users strongly agreed the exoscope would significantly improve surgical teaching. Over 75% reported that they would recommend the exoscope to colleagues and all users saw its great potential for low-resource environments.

Conclusion

Our low-budget exoscope is safe and feasible for TLIF and purchasable at a fraction of the cost of conventional microscopes. It may thus help expand access to neurosurgical care and training worldwide.

High definition 4K-three-dimensional exoscope for removal of a C1-C2 meningioma: Technical case report

In recent years, the exoscope has been proposed as an alternative to the microscope when a magnified view of the surgical field is required in spinal surgery. We present a case of a 52-year-old patient in which a meningioma in the upper cervical spine (C1-C2) was removed using a 4K-three-dimensional (3D) exoscope. The advantages of surgical removal of an intradural spinal tumor using an exoscope are illustrated, focusing mainly on vision quality and ergonomics. In addition, some technical details regarding the operating room setup are provided. Based on this experience, a 4K-3D exoscope can be useful for spinal tumor surgery when high magnification of anatomical details is required, allowing the surgeon to operate in a comfortable position throughout the surgical procedure.

New Trends in an Old-Fashioned Approach

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Systematic Review of Otologic and Neurotologic Surgery Using the 3-dimensional Exoscope

Objective

The 3D exoscope is an emerging technology that has been met with success in neurosurgery and is now increasingly used in otologic and neurotologic surgery. There is currently no consensus on its safety, efficiency, and utility, compared to the traditional microscope for these procedures. This systematic review aims to evaluate the use of the 3-dimensional (3D) exoscope for otologic and neurotologic surgery.

Databases Reviewed

MEDLINE/PubMed, Web of Science, Scopus, and EMBASE.

Methods

A systematic search of the databases was conducted for otologic and neurotologic surgery using the 3D exoscope. English language papers with no limit on the date of publication were considered. Inclusion criteria: full articles studying otologic or neurotologic/skull base surgery using exoscopes. Exclusion criteria: non-otologic surgery and non-neurotologic/skull base surgery, exclusive use of the traditional microscope, editorials, video reports, and letters. Two authors independently reviewed papers for inclusion; discrepancies were settled by consensus. Extracted variables included: number of patients, types of surgical procedures, operative and postoperative complications, setup and operative time, and visualization and ergonomic rating.

Results

Six articles containing 128 surgical cases (103 exoscopic and 25 microscopic) were analyzed. Of the exoscopic cases, 21% were surgeries for chronic ear disease, 5% were cochlear implants, and 74% were lateral skull base procedures encompassing a wide variety of approaches.

Conclusion

Based on preliminary studies, the exoscope appears to be comparable in safety, visualization, and efficiency compared to the operating microscope, with the potential for increased comfort and ease of use.

Three-dimensional High-definition Exoscope in Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Retrospective Cohort Study

OBJECTIVES

The operative microscope (OM) has revolutionized the field of modern spine surgery, however, it remains limited by several drawbacks. Recently, the exoscope (EX) system has been designed to assistant spine surgery. It provides a three-dimensional (3D) high-definition (HD) operative experience and becomes an alternative to the OM. The aim of the study was to evaluate the clinical outcomes, advantages and limitations of EX-assisted minimally invasive transforaminal lumbar interbody fusion (EMIS-TLIF) and OM-assisted MIS-TLIF (OMIS-TLIF).

METHODS

The clinical outcomes were assessed in 47 patients with lumbar degenerative diseases (LDD) who underwent MIS-TLIF assisted with the OM or EX between January 2019 and September 2020. A total of 22 were treated with EMIS-TLIF, and 25 received OMIS-TLIF. Perioperative parameters (including sex, age, number of fusion levels and body mass index), perioperative parameters (operation time, intraoperative blood loss, postoperative drainage, postoperative hospitalization stay, and duration of follow-up), visual analogue scale (VAS) of back pain, VAS of leg pain, Oswestry disability index (ODI) scores and clinical outcomes were assessed and compared. Image quality, handling of equipment, ergonomics, 3D glasses and educational usefulness were scored according to a questionnaire.

RESULTS

Operation time in the OMIS-TLIF group (121.92 ± 16.92 min) was significantly increased compared with that in the EMIS-TLIF group (111.00 ± 19.87 min) (P < 0.05). The VAS of the back pain and ODI scores in the EMIS-TLIF group were significantly lower compared with the OMIS-TLIF group at 1 week postoperatively (P < 0.05). The good-excellent outcomes rate was 90.91% in the EMIS-TLIF group and 88.00% in the OMIS-TLIF group, and there was no significant difference. A total of 44 visits completed the questionnaire. The results of the questionnaire showed that the EX has exhibited advantages regarding handing of equipment, ergonomics and educational usefulness, and comparable image quality as compared with the OM, however, operating surgeons complained uncomfortable sensation when wearing 3D glasses.

CONCLUSIONS

The EMIS-TLIF was a safe and effective procedure in the management of LDD as compared with the OMIS-LIF. Meanwhile, EMIS-TLIF might resulted in a short operation time.

The Characteristic of Light Sources and Fluorescence in the 3-Dimensional Digital Exoscope "ORBEYE" for 5-Aminolevulinic Acid-Induced Fluorescence-Guided Surgery Compared with a Conventional Microscope

BACKGROUND

The ORBEYE (ORB), an innovative 3-dimensional digital exoscope, is an equipped system for fluorescence-guided surgery with 5-aminolevulinic acid. Therefore, this study aimed to verify the characteristics of fluorescence-guided surgery with 5-aminolevulinic acid and excitation light source with ORB.

METHODS

The same operative field of glioblastoma was recorded under blue light (BL) excitation using a conventional microscope (MS) and ORB. For in vitro studies, the energy of 405-nm wavelength light in white light and BL modes of each scope was examined in various focal lengths. To examine the degree of photobleaching with BL for each scope, protoporphyrin IX-soaked filter papers were continuously exposed with BL of an MS and ORB, and the video-recorded red fluorescence intensity was analyzed.

RESULTS

The color tone of tumor-induced red fluorescence was remarkably different under each scope. Furthermore, nonfluorescent normal structures without red fluorescence were well recognized under ORB. The energy of 405-nm wavelength light in BL was significantly higher in ORB than that in an MS, especially in the short focal length. With continuous BL excitation to filter papers, the relative red fluorescence intensity of filter papers was significantly decreased over time in ORB than in an MS. In low protoporphyrin IX concentration, the difference was more significant.

CONCLUSIONS

With ORB, the good visibility due to BL energy as compared with an MS might improve the surgical manipulation even in BL mode. However, the weak fluorescent tissue and short focal length should be carefully considered because photobleaching might be critical for FGS.

Combined Exoscopic- and Endoscopic-Assisted Resection of an Interpeduncular and Middle Fossa Epidermoid Cyst via a Transcavernous Approach: Technical Note

OBJECTIVE

The endoscope and exoscope are gaining momentum as alternative visualization tools in the neurosurgical field, trying to overcome the limitations of an operative microscope and support minimally invasive approaches. However, few case series are available in the literature regarding their use in skull base surgery, especially in combined assisted resection, and their usefulness still needs to be proved.

METHODS

An illustrative case to present the feasibility and minimally invasive advantages of a combined exoscopic- and endoscopic-assisted resection is reported.

RESULTS

A 22-year-old man presented with a history of seizures and dizziness. Brain imaging showed a lesion involving the anteromedial middle fossa invading the interpeduncular cistern and impinging the brainstem, suggestive of an epidermoid cyst. A combined exoscopic- and endoscopic-assisted resection through a pterional transcavernous approach was planned and performed. No neurologic deficit occurred after the surgery, providing further evidence about the usefulness and safety of this hybrid technique.

CONCLUSIONS

Combined exoscopic and endoscopic resection is also feasible and safe in complex skull base surgery. Moreover, this technique seems to be effective for minimizing the surgical invasiveness in skull base lesions.

High-definition two-dimension video telescope operating monitor-assisted brain and spinal surgery in pediatrics: is it an acceptable substitute for microscopic surgery?

PURPOSE

Vision and ergonomics are crucial variables for successful outcomes during neurosurgery procedures. Two-dimension video telescope operating monitor (VITOM) exoscope has emerged as an alternative, which is cheaper than microscope. The aim of this study is to evaluate the clinical utility of 2D VITOM and to compare its merits and demerits with respect to microscope.

METHODS

VITOM 2D (Karl Storz, Germany) was used in 9 cranial and 5 spinal pediatric cases. While KINEVO operative microscope (Carl Zeiss, Germany) was used in 12 cranial and 6 spinal pediatric patients. All surgeries were performed by single senior neurosurgeon. The author's experience and opinions, as well as qualitative data, were analyzed. A comparison was made on image quality, illumination, field of view, and magnification of the operative field and ergonomics.

RESULTS

Seven out of 9 cranial pediatric cases were switched from VITOM 2D to operative microscope due to low-image definition in depth of cranial cavity. Poor visualization of bleeding source in surgical field was another major drawback. Two cranial cases in which exoscope were used exclusively, included superficial tumors. In all 5 spinal cases, VITOM 2D was successfully used without any major difficulty. The exoscope's advantages were observed in ergonomics and ease in switching to naked eyes, but the microscope's field of view, illumination, magnification, and user-friendliness was considered superior.

CONCLUSION

2D-VITOM is best suited for spinal and superficial cranial tumors. However, a lot of modifications are to be done especially in optics to become a substitute for operative microscope.