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

Exoscope as a financially viable solution for micro neurosurgery in low-middle-income countries

Operating microscope is a backbone for the development of micro neurosurgery. In resource-limited setups and low-income countries, the volume of annual microsurgical procedures is low due to lack of the required equipment, one of which is the operating microscope. The price of currently available operating microscopes makes it difficult to address this issue in resource-constrained areas and low-income countries. Exoscope with a relatively lower price and the same even better imaging qualities can be used as an option for this problem.

Neurosurgical applications of the exoscope: from in vitro studies to real-life surgical use in selective dorsal rhizotomy

BACKGROUND

The microscope has been the gold standard in neurosurgical practice due to its ability to magnify anatomical structures. However, it has limitations, including restricted visual fields and ergonomic challenges that can lead to surgeon fatigue and musculoskeletal issues. The exoscope is an emerging technology that may address these limitations by offering comparable magnification with improved ergonomics.

METHODS

This study compares the traditional microscope (KINEVO 900) with a 3D digital exoscope (Aeos Digital Microscope) in visual field width, image sharpness, and ergonomic impact. Visual field assessments were conducted using millimeter paper at a fixed distance, while image sharpness was evaluated using graph paper with pins at different depths. Ergonomic evaluation involved simulating surgical positions using a spine anatomical model. The practical applicability was tested during Selective Dorsal Rhizotomy (SDR) procedures, comparing the surgeon's experience with both devices over 20 consecutive cases.

RESULTS

The exoscope provided a larger visual field (81.18 cm2) compared to the microscope's (54.10 cm2). Image sharpness was similar for both devices across various depths and zoom levels. Ergonomically, the exoscope allowed the surgeon to maintain a neutral posture while visualizing extreme angles, unlike the microscope, which required significant upper body movement. In SDR procedures, the exoscope improved surgeon comfort and interaction with the operating team, despite an initial learning curve.

CONCLUSIONS

The exoscope presents notable advantages in terms of visual field and ergonomics. The exoscope's ability to facilitate better posture and team communication without compromising image quality makes it an addition to neurosurgical practice, as in SDR.

How I do it: Exoscope assisted microsurgical ligation of type 1 spinal dural arteriovenous fistula

BACKGROUND

Type 1 Spinal dural arteriovenous fistula (dAVF) is a rare but curable vascular cause of myelopathy. Microneurosurgery is a very efficacious modality in treating them.

METHOD

A 26 year old gentleman with progressive flaccid paraparesis (LMN type) and urinary incontinence underwent surgery using exoscope for a right side T9-10 dAVF. A dilated vein was seen accompanying the exiting nerve root intraoperatively, consistent with the preoperative angiographic findings. The vein was ligated and divided leading to restitution of spinal cord vasculature on table and excellent postoperative outcome.

CONCLUSION

Surgical resection is a straightforward and highly effective treatment in spinal dAVF.

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.