Three-dimensional high-definition exoscope (Kestrel View II) in anterior cervical discectomy and fusion: a valid alternative to operative microscope-assisted surgery

High-Definition 4K-3D Exoscope in Spine Surgery: A Single-Center Experience and Review of the Literature

Background and Objectives: Binocular optical microscopy (OM) paved the way for a new era in brain and spine neurosurgery fields with the introduction of microsurgery. Despite its enormous contribution to modern neurosurgery, OM presents some intrinsic limitations that surgeons need to face during procedures such as prolonged non-ergonomic positions and decreased vision quality to the assistant eyepiece. To overcome these limitations, in recent years, new operative tools have been introduced, such as exoscopes. Here, we present our experience with exoscopes in spine surgery. Materials and Methods: In the period between January 2022 and December 2023, we gradually implemented the use of a high-definition 4K-3D exoscope (ORBEYETM, Olympus, Japan) in patients undergoing spinal surgery. Results: A total of 243 patients underwent spine surgery with exoscope magnification (47 intradural tumors, 99 lumbar degenerative cases, 79 cervical degenerative cases, 5 dorsal calcified disk herniations, 4 dural arteriovenous fistulas (dAVFs), and 9 others). We compared this cohort with a similar cohort of patients operated in the same period using OM based on different endpoints: operating time, complication rate, and infection rate. We did not find any statistically significant difference in any of the endpoints between these two groups. Conclusions: In our experience, the exoscope provides a better resolution of spinal anatomy and higher quality real-time images of the surgery for the entire OR team and improves the ergonomic posture of both surgeons, without lengthening the operating time and without increasing the rate of adverse events. Prospective studies with a larger cohort of patients are needed to further validate these findings.

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.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

Advantages of 3-dimensional exoscope-assisted anterior cervical spine surgery: A meta-analysis

BACKGROUND

Visual instruments are essential to ensure high-quality surgical outcomes for minimally invasive procedures and have gradually become the focus of research. Recently, a novel visual auxiliary instrument, a 3-dimensional exoscope (EX), has been applied for spinal surgery. However, its advantages over other auxiliary means (OAMs) in anterior cervical surgery need to be assessed.

OBJECTIVE

To compare and evaluate the clinical outcomes of EX and OAMs in anterior cervical spine surgery using a meta-analysis and to provide the latest clinical evidence.

METHODS

PubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang Database were systematically reviewed for relevant literature published prior to January 21, 2023. Two researchers independently screened the literature, extracted data, and assessed bias risk in the included literature. Review Manager software (version 5.4; the Cochrane Collaboration) was used to conduct the meta-analysis.

RESULTS

five studies, one prospective and four retrospective cohort studies, with a total of 349 patients (154 in the EX group and 195 in the OAMs group) were included. A meta-analysis showed that compared to OAMs, EX-assisted anterior cervical spine surgery resulted in less intraoperative hemorrhage [WMD = -8.96, 95% CI (-14.21, -3.71), P = 0.0008]. Nevertheless, no significant differences in VAS scores, JOA scores, operation time, hospitalization time, and complication rate were observed between the two groups (P > 0.05).

CONCLUSION

EX and OAMs are equally safe and effective for anterior cervical spine surgery; however, compared to OAMs, EX results in less intraoperative hemorrhage.

Implementation of a three-dimensional (3D) robotic digital microscope (AEOS) in spinal procedures

Three-dimensional exoscopes have been designed to overcome certain insufficiencies of operative microscopes. We aimed to explore the clinical use in various spinal surgeries. We performed surgery on patients with different spine entities in a neurosurgical department according to the current standard operating procedures over a 4-week period of time. The microsurgical part has been performed with Aesculap AEOS 3D microscope. Three neurosurgeons with different degree of surgical expertise completed a questionnaire with 43 items based on intraoperative handling and feasibility after the procedures. We collected and analyzed data from seventeen patients (35% male/65% female) with a median age of 70 years [CI 47-86] and median BMI of 25.8 kg/m2 [range 21-33]. We included a variety of spinal pathologies (10 degenerative, 4 tumor and 3 infectious cases) with different level of complexity. Regarding setup conflicts we observed issues with adjustment of the monitor position or while using additional equipment (e.g. fluoroscopy in fusion surgery) (p = 0.007/p = 0.001). However image resolution and sharpness as well as 3D-depth perception were completely satisfactory for all surgeons in all procedures. The utilization of the exoscopic arm was easy for 76.5% of the surgeons, and all of them declared a significant improvement of the surgical corridor. The 3D-exoscope implementation appears to achieve very satisfactory results in spinal procedures especially with minimally invasive approaches.

Comparison of Percutaneous Endoscopic Cervical Keyhole Foraminotomy versus Microscopic Anterior Cervical Discectomy and Fusion for Single Level Unilateral Cervical Radiculopathy

Objective

To compare the clinical and radiological outcomes between microscopic anterior cervical discectomy and fusion (ACDF) and percutaneous endoscopic cervical keyhole foraminotomy (PECF) for single level unilateral cervical radiculopathy.

Methods

A total of 127 patients (59 in PECF VS 68 in ACDF) were enrolled in this study from April 2016 to May 2018 with a minimum follow-up of 2 years. Clinical data including baseline data, Neck Disability Index (NDI), and Visual Analogue Scale for neck and arm (VAS-n, VAS-a) were collected and compared. Radiological evaluation such as disc height, ROM of cervical, Cobb’s angle of cervical and Cobb’s angle of operated segment was measured by two experienced radiologists in twice.

Results

There was no significant difference between the two groups in the baseline data, and hospital stay was significantly decreased in PECF group than ACDF group (P < 0.001). PECF group did not yield superior better outcomes in NDI, VAS-a and VAS-n than ACDF group except at 1-month follow-up. As for radiological outcomes, PECF group has significantly better cervical motion, cervical angle and segmental angle than ADCF group at 12- and 24-month follow-up visit (P < 0.05); however, ACDF had shown better disc height restoration and maintenance than PECF (P < 0.05). More complications including surface hematoma and swallowing difficulty were occurred in ADCF group.

Conclusion

Percutaneous endoscopic cervical keyhole foraminotomy could be the alternative method for anterior cervical discectomy and fusion in selective cases. However, the indication should be fulfilled, more studies need to be conducted to further testify the efficacy of PECF.

Clinical comparison of three-dimensional exoscope vs. operative microscope in transforaminal lumbar interbody fusion: A retrospective case-control study

Purpose

Here, we sought to determine the safety and feasibility of three-dimensional exoscope (3D EX). We compared data on surgery, complications, postoperative drainage, hematology, and clinical outcomes in the group that underwent transforaminal lumbar interbody fusion (TLIF) using an operative microscope (OM) relative to those treated using 3D EX.

Methods

We retrospectively reviewed records on 74 patients who underwent one- or two-level TLIF from August 2019 to October 2020. Repeated measures analysis of variance was used to compare pre- and post-operative visual analogue scale (VAS) scores and oswestry disability index (ODI). We used analysis of covariance to compare pre- and post-operative erythrocyte count (RBC), hemoglobin (Hb), and hematocrit (Hct). Independent sample t-tests was used to compare postoperative drainage volume, total blood loss (TBL), visible blood loss (VBL) and hidden blood loss (HBL).

Results

There were no significant differences in VAS and ODI scores between the two groups at all time points (all p > 0.05). RBC and HBL did not differ significantly between the two groups (all p > 0.05). There were significant differences in postoperative drainage volume,TBL, Hb, and Hct values when using 3D EX relative to OM in two-level TLIF (all p < 0.05), but not for one-level TLIF (all p > 0.05). The two groups differed significantly with regards to VBL when used for one- or two-level TLIF (all p < 0.05).

Conclusion

Our data show that 3D EX is a suitable alternative to OM in TLIF. Relative to OM, 3D EX has important strengths in reducing perioperative bleeding in two-level TLIF.