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

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.

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.

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.

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.

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.

Selective dorsal rhizotomy using a 3D high definition exoscope

Selective dorsal rhizotomy (SDR) is an established neurosurgical technique for children with spastic diplegia secondary to cerebral palsy. Meticulous intraoperative testing of individual nerve roots with electromyography in tandem with the on-site neurorehabilitation team is recommended for good clinical outcomes. The standard approach requires the neurosurgeons to spend extended time under the traditional operating microscope. In this video, the authors describe the use of a 3D exoscope system for SDR. Overall, the 3D exoscope improves ergonomics and reduces musculoskeletal fatigue for the operating neurosurgeons. Furthermore, it provides excellent visualization of important structures, allowing safe and efficient completion of the procedure. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23105.