Exoscope System Research Articles

Enhanced transanal surgery training through a 4K 3D surgical exoscope: a novel approach for transanal surgery.

Recently, exoscope was introduced as a more ergonomic alternative to microscope, mainly in nerve and spinal surgery. Exoscope use in general surgery is still experimental and just few reports are present in literature. Here, we describe for the first time its application in transanal surgery, specifically during the transanal transection and single-stapled anastomosis in ileal-pouch anal anastomosis. After completing the proctectomy and pouch formation laparoscopically, two surgeons performed the transanal transection and single-stapled anastomosis using the vision provided by the ORBEYE™ exoscope system with a 3D 4K orbital camera and a 55-inches 3D screen. The transanal procedure was carried out with the surgeons looking at the 3D screen rather than at the operating field. The system subjectively provided excellent operative view thanks to the magnification capacity and the high resolution. The ergonomics was improved compared to classical transanal surgery, allowing the operators and observers to have the same view in a comfortable position. In particular, the exoscope magnified vision allowed for clearer demonstration of techniques to trainees. This is the first report on the intraoperative application of the ORBEYE™ surgical exoscope in transanal surgery. The magnified vision allowed precise movements and the system appeared potentially a ground-breaking tool for surgical training. The ability to project high-quality images to observers make it ideal for teaching complex transanal procedures. Further studies are encouraged to validate this approach into standard colorectal practice.

Computational image analysis of distortion, sharpness, and depth of field in a next-generation hybrid exoscopic and microsurgical operative platform.

The development of surgical microscope-associated cameras has given rise to a new operating style embodied by hybrid microsurgical and exoscopic operative systems. These platforms utilize specialized camera systems to visualize cranial neuroanatomy at various depths. Our study aims to understand how different camera settings in a novel hybrid exoscope system influence image quality in the context of neurosurgical procedures. We built an image database using captured cadaveric dissection images obtained with a prototype version of a hybrid (microsurgical/exoscopic) operative platform. We performed comprehensive 4K-resolution image capture using 76 camera settings across three magnification levels and two working distances. Computer algorithms such as structural similarity (SSIM) and mean squared error (MSE) were used to measure image distortion across different camera settings. We utilized a Laplacian filter to compute the overall sharpness of the acquired images. Additionally, a monocular depth estimation deep learning model was used to examine the image's capability to visualize the depth of deeper structures accurately. A total of 1,368 high-resolution pictures were captured. The SSIM index ranged from 0.63 to 0.85. The MSE was nearly zero for all image batches. It was determined that the exoscope could accurately detect both the sharpness and depth based on the Laplacian filter and depth maps, respectively. Our findings demonstrate that users can utilize the full range of camera settings available on the exoscope, including adjustments to aperture, color saturation, contrast, sharpness, and brilliance, without introducing significant image distortions relative to the standard mode. The evolution of the camera incorporated into a surgical microscope enables exoscopic visualization during cranial base surgery. Our result should encourage surgeons to take full advantage of the exoscope's extensive range of camera settings to match their personal preferences or specific clinical requirements of the surgical scenario. This places the exoscope as an invaluable asset in contemporary surgical practice, merging high-definition imaging with ergonomic design and adaptable operability.

Clinical Application of the 4K-3D Exoscope System in Cochlear Implantation.

To evaluate a system for otomicrosurgery based on 4K three-dimensional (3D) exoscope technology and apply it to cochlear implantation. An open stereoscopic vision-based surgical system, which differs from traditional surgical microscopes, was created by utilizing 4K stereo imaging technology and combining it with low-latency 4K ultra-high-definition 3D display. The system underwent evaluation based on 57 cochlear implantation operations, three designed microscopic manipulations, and a questionnaire survey. The surgical images displayed by the 4K-3D exoscope system (4K-3D-ES) are stereoscopic, clear, and smooth. The use of 4K-3D-ES in cochlear implantation is not inferior to traditional microscopes in terms of intraoperative bleeding and surgical complications, and the surgical duration is not slower or may even be faster than when using traditional microscopes. The results of micromanipulation experiments conducted on 16 students also confirmed this and demonstrated that 4K-3D-ES can be easily adapted. Furthermore, additional advantages of 4K-3D-ES were gathered. Significantly enlarged and high-definition stereoscopic images contribute to the visualization of finer anatomical microstructures such as chordae tympani, ensuring safer surgery. Users feel more comfortable in their necks, shoulders, waists, and backs. Real-time shared stereoscopic view for multiple people, convenient for collaboration and teaching. The ear endoscope and 4K-3D-ES enable seamless switching on the same screen. High-definition 3D images and videos can be saved with just one click, making future publication and communication convenient. The feasibility and safety of 4K-3D-ES for cochlear implantation surgery have been demonstrated. The 4K-3D-ES also offers numerous unique advantages and holds clinical application and promotional value.

How a Robotic Visualization System Can Facilitate Targeted Muscle Reinnervation

Abstract Background Innovations in medical technologies have impacted surgery sustainably in the last decades. To enable and further improve microsurgical outcomes, different loupes and optic-based microscopes have been proposed in recent years. In amputation surgery continuous progress and prosthetic developments have provided amputees with an improved degree of function and quality of life.Herein, we present a 17-year-old patient who suffered a traumatic loss of the left upper limb and underwent target muscle reinnervation surgery facilitated by a three-dimensional (3D) robotic exoscope system. Methods The rerouting of the distal ends of the arm nerves (TMR) was performed in the upper limb of a traumatic transhumeral amputee patient using a 3D robotic exoscope system (RS, RoboticScope, BHS Technologies, Innsbruck, Austria). Perioperative data was collected and compared to standard. Users' perspective evaluation of the system during the surgical procedure was done using a 5-point Likert scale. Results Operation time was 311 minutes, the robotic system was used for 101 minutes. Overall users' evaluation revealed a 4.5 for the selected items on the Likert scale. The evaluation showed similar results in the evaluation of the system by the main and assistant surgeons. No special training was required beforehand. The bimanual control allowed for improved personal freedom in the surgical field at a comfortable position. The imaging of colors will need future improvements until an authentic representation of in situ structures is achieved. Conclusion Major advantages of a robotic scope 3D exoscope system are improved image quality, ergonomic position, and increased accessibility in a wider operating field due to system-implied features. Another benefit is digital documentation and simultaneous education through the possibility of capturing images and videos, as well as easy transportation in between operating rooms without risk to harm the vulnerable optic. Digital microscopes are still associated with high acquisition costs, and they are not yet implemented as standard of care due to limited experience.

Exoscopic microvascular decompression for hemifacial spasm and trigeminal neuralgia.

The 4K 3D exoscope system is becoming increasingly used in neurosurgery. Its 3D ultra-high-definition image is valuable in identifying and dissecting the delicate neural and vascular structures during microvascular decompression. In this video, the authors describe several nuances and details to perform the exoscopic microvascular decompression, including the exoscope layout and the modified supine position. Several illustrative case presentations highlight the benefits of exoscopic surgery. The authors' exoscopic microvascular decompression series of 159 patients showed noninferior surgical outcomes compared to the operative microscope with no significant increase in surgical risk. In conclusion, an exoscope can be a practical alternative to performing microvascular decompression. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23122.

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.

Utility of a novel Exoscope, ORBEYE, in re-resection for recurrent brain tumor

BackgroundRe-resections is one of the treatment options for recurrence brain tumors, including both benign and malignant brain tumors, such as meningioma and glioblastoma. Re-resection for recurrent brain tumor sometimes needs extension of original craniotomy. However, extending original craniotomy is troublesome and can easily damage the adhered brain tissue and reconstruct of bone flap sometimes cause cosmetic problems, thus ideal way to re-resect recurrent brain tumor is to use the same original craniotomy.However, when using an operative microscope, performing re-resections without extending craniotomy requires the surgeon to operate in an awkward position. A recently developed high-definition (4 K-HD) 3-D exoscope system, ORBEYE, can improve this problem. In this study, we analyzed the utility of 4 K-HD 3-D exoscope system, ORBEYE, for re-resecting recurrent brain tumor. MethodsWe report 32 cases managed by re-resecting recurrent brain tumor by ORBEYE. Perioperative clinical, surgical, and radiographic data were retrospectively examined. ResultsRe-resecting tumors for recurrent brain tumor by ORBEYE were successfully performed for all 32 resections, using ORBEYE, without any severe postoperative neurological deficit. In addition, we could avoid extending original craniotomy as much as possible by adjusting the ORBEYE camera angle. ConclusionRe-resecting tumors for recurrent brain tumors by ORBEYE are feasible and can avoid extending original craniotomy as much as possible.

#61 : Frugal Exoscope: A Potential Option for Microsurgery and Training Program in Male Infertility in the Context of Emerging Markets

Background and Aims: Conventional microscopes and exoscopes currently play pivotal roles in the microsurgery or training of male infertility. However, they are expensive and unaffordable in low resource settings which limits training or application of advanced methods. The study aimed to introduce a new, low–cost exoscope system and evaluate its frugal innovation. Method: Using animal models, we evaluated a new frugal exoscope system (called DKTA) in experimental microsurgery of vas deferens repair. Five experts in male infertility surgery undertook an anonymous survey to elucidate their experience with DKTA system use. Three crucial criteria (i.e., substantial cost reduction, concentration on core functionalities, optimised performance level) were evaluated to determine whether the DKTA is effective as frugal innovation. The survey used a 5-point Likert scaling of responses to eight statements investigating surgical, ergonomic, and educational aspects. Results: The DKTA system, including an optical microscope and ultrahigh definition camera (4K), was an exoscope placed between 20–40 cm from the surgical field. It was held in position with a camera support arm on casters and connected to a 65-inches smart TV. DKTA system met the three crucial criteria of frugal innovation, including substantial cost reduction, concentration on core functionalities, and optimised performance level. Five male infertility microsurgeons reported positive evaluations of the DKTA system (use modal scores) when performing experimental vasovasostomy. Conclusions: DKTA system, a frugal innovation, has a valuable contribution to the training programme and performance of male infertility microsurgery in low–resource settings. Acknowledgements: We want to send special thanks to the Centre for Training and Scientific Research staff, Tam Anh General Hospital for their logistics support.

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.

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

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. 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. 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). 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.

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

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. 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. 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. 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.

Frugal Exoscope: A Minimal Cost Option for Microsurgery and Training Program in Male Infertility

Background: Conventional microscopes and exoscopes currently play pivotal roles in the microsurgery or training for male infertility. However, they are expensive and unaffordable in low-resource settings, which limits training or application of advanced methods. Objectives: To introduce a new, low-cost exoscope system and to determine whether it is an effective frugal innovation. Methods: Using animal models, we evaluated a new frugal exoscope system named DKTA in experimental microsurgery of vas deferens repair. Five experts in male infertility surgery undertook an anonymous survey to elucidate their experience with DKTA system use. Three crucial criteria (i.e., substantial cost reduction, concentration on core functionalities, and optimized performance level) were evaluated to determine whether the DKTA is effective as frugal innovation. The survey used a 5-point Likert scale of responses to eight statements investigating surgical, ergonomic, and educational aspects. Results: The DKTA system, including an optical microscope and ultra-high-definition (UHD) camera (4K), was an exoscope placed between 20 and 40 cm from the surgical field. It was held in position with a camera support arm on casters and connected to a 65-in. smart TV. DKTA system met the three crucial criteria of frugal innovation. Five male infertility microsurgeons reported positive evaluations based on modal scores of the DKTA system when performing experimental vasovasostomy. Conclusions: DKTA system, a frugal innovation, has a valuable contribution to the training program and performance of male infertility microsurgery in low-resource settings.

Radical resection of trigeminal schwannoma at the cerebellopontine angle with support of the digital robotic exoscope Synaptive Modus V system: A case report and literature review

We report on a 67-year-old woman who experienced drowsy mental status, facial numbness, and hearing loss on the right side; the symptom gradually worsened over the last 4 years. Brain magnetic resonance imaging revealed a 4.8 × 1.8 × 2.6 cm lesion located in the right cerebellopontine angle. She underwent surgery with the retrosigmoid suboccipital approach and support from the digital robotic exoscope Synaptive Modus V system. To the best of our knowledge, this is the first reported case that used the robotic exoscope system in Vietnam, and also in Asia. We performed radical resection of the tumor, the surgery position and the pathology result concluded the diagnosis was trigeminal schwannoma. After 30 months of follow-up, she fully recovered and the magnetic resonance imaging showed radical resection of the tumor. The aim of this study is to share our experience with the robotic exoscope system, which can improve optical field and image resolution, hence creating an opportunity for surgery that otherwise is impossible. The application of this robotic exoscope system is a breakthrough in neurosurgery in developing countries, such as Vietnam.

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.

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. 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 4K images were captured and analyzed. Comparisons of fluorescence to background were then generated for use optimization. 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 220mm and a light intensity of approximately 75% maximum. Decreasing focal distance from 400mm to 220mm significantly increased visualized fluorescence (P = 0.0038). 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.

Improvement of Surgical View and Working Space at the Lower Pole by Three-Dimensional Exoscope-Assisted Coblation Tonsillectomy: A Case Series

Advantages of hot devices for tonsillectomy, represented by coblation, have been highlighted in recent years. During hot technique tonsillectomy it is important to identify and coagulate the vessels of the tonsillar capsule, especially at the lower pole of the tonsil. Hot technique tonsillectomy under microscope or endoscope has therefore been recommended to achieve accurate identification of the microstructure of the surgical field. We have applied ORBEYE, a three-dimensional surgical exoscope system, to coblation tonsillectomy. Advantages of using ORBEYE include high definition and high magnification images, and flexibility of camera position and angle. This means there is an improved surgical view and working space, particularly at the lower pole during performance of coblation tonsillectomy. Here, we demonstrate that ORBEYE can be an effective surgical instrument in coblation tonsillectomy.

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

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

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

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). 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. 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. 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.

Experiences with a 3D4K Digital Exoscope System (ORBEYE) in a Wide Range of Neurosurgical Procedures.

Exoscopic 3D4K video systems (EX) have recently been introduced as an alternative to conventional operating microscopes (OM). However, experience in handling and setup remains scarce. This study evaluated the practicability of exoscopic surgery in a wide range of procedures. All EX operations performed between August 2018 and May 2020 were evaluated and compared with procedures using OM. A standardized questionnaire was used to evaluate surgeons' comfort, image quality (including fluorescence modes), and handling. In all, 513 EX operations were performed during the investigated period. EX was generally rated as a valuable surgical tool. In particular, the digital 5-aminolevulinic acid (5-ALA) fluorescence and the comfort level of posture during surgery were stated to be superior to OM (100 and 83%, respectively). EX has been used for a significant number of neurosurgical procedures. While presuming that the technical methodology as such will not influence outcome of glioma surgery, proof of equipoise between different techniques expands the spectrum of surgical environments giving neurosurgeons a choice to work according to their preferred ergonomics.

Assessment and Comparison of Three Dimensional Exoscopes for Near-Infrared Fluorescence-Guided Surgery Using Second-Window Indocyanine-Green.

ObjectiveCompared to microscopes, exoscopes have advantages in field-depth, ergonomics, and educational value. Exoscopes are especially well-poised for adaptation into fluorescence-guided surgery (FGS) due to their excitation source, light path, and image processing capabilities. We evaluated the feasibility of near-infrared FGS using a 3-dimensional (3D), 4 K exoscope with near-infrared fluorescence imaging capability. We then compared it to the most sensitive, commercially-available near-infrared exoscope system (3D and 960 p). In-vitro and intraoperative comparisons were performed. MethodsSerial dilutions of indocyanine-green (1–2000 μg/mL) were imaged with the 3D, 4 K Olympus Orbeye (system 1) and the 3D, 960 p VisionSense Iridium (system 2). Near-infrared sensitivity was calculated using signal-to-background ratios (SBRs). In addition, three patients with brain tumors were administered indocyanine-green and imaged with system 1, with two also imaged with system 2 for comparison. ResultsSystems 1 and 2 detected near-infrared fluorescence from indocyanine green concentrations of >250 μg/L and >31.3 μg/L, respectively. Intraoperatively, system 1 visualized strong near-infrared fluorescence from two, strongly gadolinium-enhancing meningiomas (SBR=2.4, 1.7). The high-resolution, bright images were sufficient for the surgeon to appreciate the underlying anatomy in the near-infrared mode. However, system 1 was not able to visualize fluorescence from a weakly-enhancing intraparenchymal metastasis. In contrast, system 2 successfully visualized both the meningioma and the metastasis but lacked high resolution stereopsis. ConclusionThree-dimensional exoscope systems provide an alternative visualization platform for both standard microsurgery and near-infrared fluorescent guided surgery. However, when tumor fluorescence is weak (i.e., low fluorophore uptake, deep tumors), highly sensitive near-infrared visualization systems may be required.