Microvascular anastomosis under 3D exoscope or endoscope magnification: A proof-of-concept study

Post-operative monitoring of tissue perfusion in murine skin flaps using enhanced thermal imaging

Inadequate tissue perfusion is a fundamental cause of early complications following a range of surgeries. We are developing a real-time infrared imaging technique, enhanced thermal imaging (ETI), to detect blood vessels embedded in soft tissue. This study evaluated the potential of ETI to detect capillary growth as an indicator of early wound healing in murine skin flaps. The relationship between vessel density and the thermal signal observed with ETI was explored using MATLAB simulations of a geometrically simplified vascularized tissue model. Simulations showed that increased vessel density corresponded to a greater thermal response at the tissue surface. This trend suggests experimental ETI measurements were related to angiogenesis during wound healing. Studies using a similarly grafted murine model confirmed the presence of angiogenesis with physical vessel counts in fluorescence-labeled frozen sections.

QEVO®-Assisted Anatomical Inspection of Adjacent Perforators in Microsurgical Clipping-Technical Note

INTRODUCTION

Aneurysms of brain vessels are life-threatening conditions with various adverse outcomes, some stemming from microsurgical intervention, particularly when major vessel perforators are inadequately protected. The use of endoscopes enhances the approach to aneurysms by providing closer visualization (180-360 degrees) of the local anatomy, potentially reducing accidental damage. To improve visualization and efficiency, a microscope-integrated 45-degree angled microinspection endoscopic tool (QEVO®, Carl Zeiss, OberkochenTM) has been developed and employed in various neurosurgical procedures.

METHODS

Between 2021 and 2025, 27 brain aneurysms were treated with QEVO® assistance at the Department of Neurosurgery, Clinical Center of the University of Sarajevo. The choice of the videos corresponds to the best image quality in videos and on the microscopic determination of adjacent vessel perforators, which were not adequately seen purely by the surgical microscope in specific cases. Exclusion criteria included cases without a need for QEVO® assistance in perforator visualization, severe brain edema, intraoperative aneurysm rupture, posterior circulation, or low video quality.

RESULTS

Case 1 demonstrates an anterior choroidal artery (AchA) aneurysm; Case 2 presents an anterior communicating artery (AcommA) aneurysm; and Case 3 features contralateral middle cerebral artery (MCA) microsurgical clipping with QEVO® assistance.

CONCLUSIONS

The QEVO® tool significantly improves the visualization of aneurysm-perforator relationships, increasing the likelihood of preserving perforators during standard microsurgical clipping. This innovative approach may reduce surgical complications and enhance patient outcomes, highlighting the tool's potential as an adjunct in aneurysm microsurgery.

INCREASING THE VISIBILITY DURING INTERNAL LIMITING MEMBRANE PEELING IN VITRECTOMY SURGERY: Evaluation of Monochrome Mode with Brilliant Blue G Staining Using the NGENUITY 3D Visualization System

PURPOSE

The aim of the study is to explore the effectiveness of using monochrome mode with Brilliant Blue G during vitrectomy surgery with the NGENUITY 3D Visualization System.

METHODS

Vitrectomy cases involving BBG-stained internal limiting membrane peeling with the NGENUITY 3D Visualization System (Alcon Laboratories, Inc.) at Juntendo University Urayasu Hospital from October 2022 to February 2023 were selected. The contrast ratios between peeled and stained internal limiting membrane areas under three settings were assessed: normal, yellow, and monochrome. In the monochrome setting, a yellow hue was used with zero saturation, while the Friedman test compared these ratios.

RESULTS

Nineteen patients (19 eyes; 7 males, 12 females; average age 68.5 ± 10.3 years) with retinal conditions such as epiretinal membrane (n = 11), macular hole (n = 4), macular traction syndrome (n = 3), and retinoschisis (n = 1) were included. We obtained contrast ratios of 1.57 ± 0.21 (normal), 1.60 ± 0.21 (yellow), and 1.92 ± 0.29 (monochrome). The monochrome setting showed significantly higher contrast than that shown by the normal and yellow settings (P = 0.0001, P = 0.0005), with no difference between the normal and yellow settings (P = 0.903).

CONCLUSION

Monochrome mode in NGENUITY with Brilliant Blue G potentially enhances contrast and increases visibility during internal limiting membrane peeling.

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.

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.

From Microscopic to Exoscopic Microsurgery: Are We Facing a Change of Paradigm?

BACKGROUND

Neurosurgery is a medical branch characterized by small and deep surgical field with the need of manipulation and dissection of anatomical structures. High light and magnification are required in order to avoid injuries to important anatomical structures and to avoid permanent neurological deficits. Introduction of operative microscope made a change of paradigm in neurosurgery allowing to better see what could not be seen with common light. Nowadays, introduction of several technologies have increased the safety and efficacy of neurosurgery. Among new technologies, the 3D exoscope is emerging pretending to shift the paradigm of microneurosurgery. In this work, we aim to show our first experience with the use of the exoscope showing advantages and disadvantages.

MATERIALS AND METHODS

We reviewed our surgical database from the introduction of the exoscope in our department (in November 2020 temporarily; then from November 2021 definitively) searching for all the microsurgery interventions performed in the period.

RESULTS

From the introduction of the exoscope in our department, we operated 244 cases with the OM and 228 with the exoscope. We operated 175 lesions located in the supratentorial compartment, 29 in the infratentorial, and 24 in the spinal column. Regarding the OM, the ratios were as follows: 122 females and 122 males; 235 adults and 9 children; 66 supratentorial lesions, 14 infratentorial lesions, and 164 spine surgeries. Our team showed a progressive switch from the microscope to the exoscope. Only one member of our team preferred to continue to use the standard operative microscope.

CONCLUSIONS

Our experience showed no complications related to the use of the exoscope that proved to be safe and effective both for surgery and teaching.

RoboticScope-Assisted Microanastomosis in a Chicken Leg Model

Background  Many recent studies show that exoscopes are safe and effective alternatives to operating microscopes (OM). Developments of robotics and automation are present in neurosurgery with the appearance of a newer device such as RoboticScope (RS) exoscope with a digital three-dimensional (3D) image and a head-mounted display. The body of the RS is connected to a six-axis robotic arm that contains two video cameras, and serves as stereovision. This robotic arm allows accurate 3D camera motions over the field of view, giving the user a great degree of freedom in viewpoint selection. The surgeons may specify the direction and speed of the robotic arm using simple head movements when the foot pedal is pressed. Since its development in 2020, the RS has occasionally been used in neurosurgery for a multitude of procedures. Methods  This study showcases vessel microanastomosis training on chicken legs using the RS. The aim of this study is to demonstrate the feasibility of the RS without a comparative analysis of the standard OM. The study was conducted in 2023 during a month-long trial period of the device at the Department of Neurosurgery of the Clinical Center of the University of Sarajevo. All procedures including RS-assisted anastomosis were performed by a neurosurgeon in anastomosis training (A.A.) supervised by a senior vascular neurosurgeon (E.B.). For the purpose of the study, we evaluated occlusion time in minutes, bypass patency with iodine, and overall satisfaction of the trainee in terms of light intensity, precision of automatic focus, mobility of the device, ergonomics, and convenience of the helmet. Results  Ten RS-assisted microanastomoses were performed by interrupted suturing technique with 10.0 nylon thread. Bypass training included seven "end-to-side," two "end-to-end," and one "side-to-side" microanastomoses. The smallest vessel diameter was 1 mm. Occlusion time improved by training from 50 to 24 minutes, with contrast patency of the anastomoses in all cases without notable leakage of the contrast, except one case. Complete satisfaction of the trainee was achieved in 7 out of 10 cases. During this period, we also performed different RS-assisted surgeries including a single indirect bypass, convexity brain tumor resection, and microdiscectomies. Conclusion  RS provides a new concept for microanastomosis training as an alternative or adjunct to the standard microscope. We found a full-time hands-on microsuturing without the need for manual readjustment of the device as an advantage as well as instant depth at automatic zooming and precise transposition of the focus via head movements. However, it takes time to adapt and get used to the digital image. With the evolution of the device helmet's shortcomings, the RS could represent a cutting-edge method in vessel microanastomosis in the future. Nevertheless, this article represents one of the first written reports on microanastomosis training on an animal model with the above-mentioned device.

A Combined Exoscopic and Endoscopic Approach for Radical Temporal Bone Resection and Usefulness of the Endoscopic Approach to the Medial Aspect of the Temporal Bone

Radical temporal bone resection (TBR) for lateral skull base malignancies is technically challenging because of the vital anatomical structures located at the medial part of the temporal bone and their limited exposure. A possible solution is to adopt an additional endoscopic approach for medial osteotomy to reduce blind spots. The authors aimed to describe a combined exoscopic and endoscopic approach (CEEA) for cranial dissection in radical TBR and to determine the usefulness of the endoscopic approach to the medial aspect of the temporal bone. Having utilized the CEEA in for cranial dissection in radical TBR since 2021, the authors included 5 consecutive patients who underwent the procedure between 2021 and 2022. All surgeries were successful and resulted in no significant complications. The additional use of an endoscope improved visualization of the middle ear in 4 patients and that of the inner ear and carotid canal in 1 patient, enabling precise and safe cranial dissection. Furthermore, surgeons experienced reduced intraoperative postural stress with CEEA than with a microscopic approach. The main advantage of CEEA in radical TBR was the extension of the viewing angles of the endoscope, which allowed observation of the medial aspect of the temporal bone and limited tumor exposure and injury to vital structures. Given the other benefits of exoscopes and endoscopes, including compact size, ergonomics, and surgical field accessibility, CEEA proved to be an efficient treatment option for cranial dissection in radical TBR.

Exoscope and operative microscope for training in microneurosurgery: A laboratory investigation on a model of cranial approach

Objective

To evaluate the viability of exoscopes in the context of neurosurgical education and compare the use of a 4k3D exoscope to a traditional operative microscope in the execution of a task of anatomic structure identification on a model of cranial approach.

Material and methods

A cohort of volunteer residents performed a task of anatomical structure identification with both devices three times across an experimental period of 2 months. We timed the residents’ performances, and the times achieved were analyzed. The volunteers answered two questionnaires concerning their opinions of the two devices.

Results

Across tries, execution speed improved for the whole cohort. When using the exoscopes, residents were quicker to identify a single anatomical structure starting from outside the surgical field when deep structures were included in the pool. In all other settings, the two devices did not differ in a statistically significant manner. The volunteers described the exoscope as superior to the microscope in all the aspects the questionnaires inquired about, besides the depth of field perception, which was felt to be better with the microscope. Volunteers furthermore showed overwhelming support for training on different devices and with models of surgical approaches.

Conclusion

The exoscope appeared to be non-inferior to the microscope in the execution of a task of timed identification of anatomical structures on a model of cranial approach carried out by our cohort of residents. In the questionnaires, the residents reported the exoscope to be superior to the microscope in eight of nine investigated domains. Further studies are needed to investigate the use of the exoscope in learning of microsurgical skills.

[VITOM 3D exoscopic system compared to microsurgical technique in spinal surgery]

3D exoscopy based on Video Telescope Operating Monitor (VITOM) technology provides good visualization quality and portability. There are few data on comparison of extracorporeal telescoping with microsurgical techniques in spinal surgery.

OBJECTIVE

To compare the effectiveness of VITOM 3D exoscopy and microsurgical techniques in spinal surgery.

MATERIAL AND METHODS

A prospective study included 80 patients (54 men and 26 women). Two groups were distinguished: group 1 (ES, n=40) - VITOM 3D exoscopy, group 2 (SM, n=40) - Pentero 900 surgical microscope. We analyzed surgery time, postoperative rehabilitation, hospital-stay and complications. ES and microsurgical technique were compared using the questionnaire by Takahashi S. and rapid upper limb assessment (RULA).

RESULTS

Conventional microsurgical technique was characterized by less surgery time (p<0.05) and morbidity (p=0.02). Postoperative rehabilitation and hospital-stay were similar (p=0.26 and p=0.39, respectively). Image quality in ES was comparable to microsurgical technique in shallow accesses and manipulations perpendicular to skin incision. Availability of neurosurgical instruments at different depths of the wound channel was comparable in both groups. The limitation of ES was length of skin incision, depth of the wound and its visualization at certain angle. These features required expansion of surgical approach or conversion of intervention. In general, surgeons rated intraoperative posture comfort as comparable in both groups that was consistent with the RULA scale.

CONCLUSION

VITOM 3D exoscopy is an alternative to traditional microscopy and more ergonomically beneficial in spinal surgery in case of manipulations perpendicular to skin incision and shallow wide accesses. There are several important limitations of this device including difficult manipulations in narrow deep wounds and visualization under certain angle.

High Definition Three-Dimensional Exoscope (VITOM 3D) in E.N.T. Surgery: A Systematic Review of Current Experience

Over the last decade, technological growth has developed new devices for more precise surgery based on improved maneuverability, minimally invasive approaches, and magnification of the operating field. In this context, the exoscope has opened a new phase for more accurate and safer microsurgery, improving the perception of the volume of objects and the depth of structures for planning, targeting, and controlling fine movements. The exoscope could be used for middle ear, transcanal, transmastoid, and craniotomy procedures that require two-handed dissection, both to perform both totally VITOM-based techniques and coupled to traditional procedures with an operating microscope or endoscope. In addition, the VITOM 3D system allows the surgeon to work with high-definition images, which is essential in facial nerve surgery or submandibular salivary stone or tear surgery approaches, where magnification plays a fundamental role in surgical success and in reducing operating times. The 3D exoscope approach could also be included in traditional transoral procedures for oropharyngeal carcinoma. The exoscope may provide a relevant approach in teaching surgeons and nurses, allowing adequate training in non-oncological surgical procedures such as a tonsillectomy or lateral pharyngoplasty.

Microsurgical training using an ex-vivo model: microscope vs 3D exoscope

Objective

The aim of this study is to evaluate the feasibility of the 3D exoscope in a microvascular anastomosis training setting and compare it with the gold-standard technique using the operating microscope (OM).

Methods

Participants were recruited among otorhinolaryngology head and neck surgery (OHNS) residents of two tertiary care hospitals. Trainees were asked to complete 4 microvascular end-to-end anastomoses on chicken thighs with the OM and VITOM 3D exoscope. The performances were scored by experienced microvascular surgeons; an objective evaluation of the anastomosis and a subjective assessment of the workload were conducted.

Results

8 OHNS residents were recruited. Considering the amount of time needed to complete (TTC) the anastomosis, an improvement was shown by all the participants throughout the training program. The objective evaluation of the anastomosis did not show a significant difference. No significant differences were found by analyzing the subjective workload with the different tools.

Conclusions

This article represents the first attempt to compare the use of the OM and the 3D exoscope during training for microsurgery. The results of our study demonstrate the noninferiority of microsurgical training obtained using the 3D exoscope compared to that offered by the OM.

Lateral Supracerebellar Infratentorial Approach for Superior Oblique Myokymia: A Case Series

BACKGROUND

Few reports have shown that superior oblique myokymia (SOM) may result from vascular compression of the trochlear nerve and may be curable using microvascular decompression (MVD).

OBJECTIVE

To report the clinical characteristics and surgical treatment of 2 cases of SOM and provide a review of the related literature.

METHODS

Two patients with SOM were treated using MVD with the lateral supracerebellar infratentorial approach. The patients underwent diagnostic magnetic resonance imaging and three-dimensional fusion imaging preoperatively. A lateral suboccipital craniotomy was performed in the park-bench position. The trochlear nerve and branches of the superior cerebellar artery were confirmed after opening the cerebellomesencephalic fissure over the tentorial surface of the cerebellum. The vessel, which compressed the root exit zone of the trochlear nerve, was transposed far from the nerve and attached to the surface of the midbrain using Teflon felt and fibrin glue.

RESULTS

The first case showed compression on both the ventral and rostral sides of the trochlear nerve root exit zone, and the second showed compression only on the ventral side. Large bridging veins on the tentorial surface of the cerebellum complicated the approach in the second case. Postoperatively, both patients had immediate and complete resolution of symptoms without recurrence at the 24-mo and 17-mo follow-ups, respectively. Five previous reports described the complete resolution of SOM after MVD.

CONCLUSION

A presentation of an intermittent fluttering ocular sensation should prompt magnetic resonance imaging for ipsilateral trochlear nerve compression. The lateral supracerebellar infratentorial approach allows safe and efficacious MVD for SOM.

Combined Exoscopic and Endoscopic Technique for Craniofacial Resection

We determined the feasibility of the combined exoscopic-endoscopic technique (CEE) as an alternative to the microscope in craniofacial resection (CFR). This retrospective study was conducted at a single institution and included eight consecutive patients with head and neck tumors who underwent CFR between September 2019 and July 2021. During the transcranial approach, microsurgery was performed using an exoscope in the same manner as in traditional microscopic surgery, and an endoscope was used at the blind spot of the exoscope. The exoscope provided images of sufficient quality to perform microsurgery, while the sphenoid sinus lumen was the blind spot of the exoscope during anterior (n = 3) and anterolateral CFR (n = 2), and the medial aspect of the temporal bone was the blind spot of the exoscope during temporal bone resection (n = 2). These blind spots were visualized by the endoscope to facilitate accurate transection of the skull base. The advantages of the exoscope and endoscope include compact size, ergonomics, surgical field accessibility, and equal visual experience for neurosurgeons and head and neck surgeons, which enabled simultaneous transcranial and transfacial surgical procedures. All the surgeries were successful without any relevant complications. CEE is effective in transcranial skull base surgery, especially CFR involving simultaneous surgical procedures.

4K 3-dimensional video microscope system (orbeye) for transsphenoidal pituitary surgery

Background

In previous reports on experiences with an exoscope, this new technology was not found to be applicable for transsphenoidal pituitary surgery. As a specialized center for pituitary surgery, we were using a 4K 3D video microscope (Orbeye, Olympus) to evaluate the system for its use in transsphenoidal pituitary surgery in comparison to conventional microscopy.

Method

We report on 296 cases performed with the Orbeye at a single institution. An observational study was conducted with standardized subjective evaluation by the surgeons after each procedure. An objective measurement was added to compare the exoscopic and microscopic methods, involving surgery time and the initial postoperative remission rate in matched cohorts.

Results

The patients presented with a wide range of pathologies. No serious events or minor complications occurred based on the usage of the 4K 3D exoscope. There was no need for switching back to the microscope in any of the cases. Compared to our microsurgically operated collective, there was no significant difference regarding duration of surgery, complications, or extent of resection. The surgeons rated the Orbeye beneficial in regard to instrument size, positioning, surgeon’s ergonomics, learning curve, image resolution, and high magnification.

Conclusions

The Orbeye exoscope presents with optical and digital zoom options as well as a 4K image resolution and 3D visualization resulting in better depth perception and flexibility in comparison to the microscope. Split screen mode offers the complementary benefit of the endoscope which may increase the possibilities of lateral view but has to be evaluated in comparison to endoscopic transsphenoidal procedures in the next step.

Is the 3D exoscope better than the surgical microscope in parotid surgery: a prospective, randomized single-center study

Background

High-definition, three-dimensional (3D) exoscopes are being used to perform a growing number of head and neck surgeries. However, the use of the 3D exoscope in parotid gland surgery has not been previously described. Our initial experience with the VITOM 3D exoscope in the surgical treatment of parotid gland tumors is detailed here.

Methods

We made a prospective study of patients with benign parotid gland tumors indicated for surgical resection. Between January and December 2018, patients were randomly assigned to undergo surgery assisted with the VITOM 3D system (n = 31) or an operating microscope (n = 40). Visualization quality (greater auricular nerve, digastric muscle, tragal pointer), operating time, conversion rates, and surgical outcomes were compared.

Results

A total of 71 patients underwent superficial (n = 18) or total parotidectomy (n = 53). No exoscope-related complications were observed. Five patients undergoing exoscope-guided deep lobe surgery required intraoperative conversion to a microscope. No differences were observed in the subjective quality of intraoperative visualization of key anatomical structures. However, a significantly higher percentage of patients in the exoscope group developed transient facial nerve paralysis (n = 9; 29% vs. n = 4, 10%).

Conclusions

These findings suggest that the VITOM 3D is a valid visualization tool for parotid gland surgery, comparable to the operating microscope but with higher resolution 3D visualization, an increased degree of freedom of movement, and better ergonomics. However, the high rate of transient nerve palsy, possibly related to decreased depth perception and the brief learning curve, merits further investigation.

Micro- and macro-borderless surgery using a newly developed high-resolution (4K) three-dimensional video system

Objective

Microsurgery using conventional optical microscopes or surgical loupes features a limited field of view and imposes a serious strain on surgeons especially during long surgeries. Here we advocate the micro- and macro-borderless surgery (MMBS) using a novel high-resolution (4K) three-dimensional (3D) video system. This study aimed to confirm the applicability of this concept in several surgical procedures.

Methods

We evaluated the possible use and efficacy of MMBS in the following experiments in porcine subjects. Experiment 1 (non-inferiority test) consisted of dissection and anastomosis of carotid artery, portal vein, proper hepatic artery, and pancreatoduodenectomy with surgical loupe versus MMBS. Experiment 2 (feasibility test) consisted of intra-abdominal and intra-thoracic smaller arteries anastomosed by MMBS as a pre-clinical setting. Experiment 3 (challenge on new surgery) consisted of orthotopic liver transplantation of the graft from a donor after circulatory death maintained by machine perfusion. Circulation of the cardiac sheet with a vascular bed in experiment 2 and liver graft during preservation in experiment 3 was evaluated with indocyanine green fluorescence imaging equipped with this system.

Results

Every procedure was completed by MMBS. The operator and assistants could share the same field of view in heads-up status. The focal depth was deep enough not to be disturbed by pulsing blood vessels or respiratory movement. The tissue circulation could be evaluated using fluorescence imaging of this system.

Conclusions

MMBS using the novel system is applicable to various surgeries and valuable for both fine surgical procedures and high-level surgical education.

Otosurgery with the High-Definition Three-Dimensional (3D) Exoscope: Advantages and Disadvantages

Background: The aim of the study was to describe our initial experience with the high-definition three-dimensional (3D) exoscope for middle ear surgery versus the operating microscope. Methods: The study included 60 randomly chosen patients diagnosed with otosclerosis (n = 30) or chronic otitis media (n = 30) with a clinical indication for surgery. The primary measurement was the subjective estimation of quality of the visibility of the operating field provided by the 3D exoscope—VITOM-3D (Karl Storz, Tuttlingen, Germany) in comparison to the operating microscope. Results: All procedures, except for two (3.3%) converted to the microscope, were successfully completed using a 3D exoscope. In both stapedotomy and tympanoplasty, the exoscope was superior to the microscope during more superficial portions of the procedures. By contrast, in deeper areas of the middle ear, the exoscope provided significantly worse visibility, but usually not suboptimal. Both intraoperative bleeding and the narrow surgical field substantially reduced the visibility with the 3D exoscope in comparison to the microscope. Conclusions: Overall, our study shows that the 3D exoscope offers excellent, highly magnified, and well-illuminated high-definition images of the surgical field. However, our experience revealed several important limitations of this system, including decreased depth perception in deep areas of the tympanic cavity and reduced visibility in a difficult surgical field, with subsequent need to switch to an operating microscope in select cases.

Monitor-based exoscopic 3D4k neurosurgical interventions: a two-phase prospective-randomized clinical evaluation of a novel hybrid device

Background

Promoting a disruptive innovation in microsurgery, exoscopes promise alleviation of physical strain and improved image quality through digital visualization during microneurosurgical interventions. This study investigates the impact of a novel 3D4k hybrid exoscope (i.e., combining digital and optical visualization) on surgical performance and team workflow in preclinical and clinical neurosurgical settings.

Methods

A pre-clinical workshop setting has been developed to assess usability and implementability through skill-based scenarios (neurosurgical participants n = 12). An intraoperative exploration in head and spine surgery (n = 9) and a randomized clinical study comparing ocular and monitor mode in supratentorial brain tumor cases (n = 20) followed within 12 months. Setup, procedure, case characteristics, surgical performance, and user experience have been analyzed for both ocular group (OG) and monitor group (MG).

Results

Brain tumor cases using frontal, frontoparietal, or temporal approaches have been identified as favorable use cases for introducing exoscopic neurosurgery. Mean monitor distance and angle were 180 cm and 10°. Surgical ergonomics when sitting improved significantly in MG compared with OG (P = .03). Hand-eye coordination required familiarization in MG. Preclinical data showed a positive correlation between lateral camera inclination and impact on hand-eye coordination (r_s = 0.756, P = .01). There was no significant added surgical time in MG. Image quality in current generation 3D4k monitors has been rated inferior to optic visualization yet awaits updates.

Conclusions

The hybrid exoscopic device can be integrated into established neurosurgical workflows. Currently, exoscopic interventions seem most suited for cranial tumor surgery in lesions that are not deep-seated. Ergonomics improve in monitor mode compared to conventional microsurgery.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04361-2) contains supplementary material, which is available to authorized users.

Home Program for Acquisition and Maintenance of Microsurgical Skills During the Coronavirus Disease 2019 Outbreak

BACKGROUND

During the current global crisis unleashed by the severe acute respiratory syndrome coronavirus 2 outbreak, surgical departments have considerably reduced the amount of elective surgeries. This decrease leads to less time in the surgical room to develop and improve the surgical skills of residents. In this study, we developed a training program to obtain and maintain microsurgical skills at home, using a smartphone camera and low-cost materials, affordable for everyone.

METHODS

Using a smartphone camera as a magnification device, 6 participants performed 5 exercises (coloring grids, grouping colors, unraveling of a gauze, knots with suture threads, and tower of Hanoi), both with the dominant and with the nondominant hand, for 4 weeks. We compared performance at the beginning and at the end of the training process. Each participant filled out an anonymous survey.

RESULTS

When we compared the performance at the beginning and at the end of the training process, we found significant improvements (P = 0.05) with the dominant as well as the nondominant hand in all the exercises. All participants were satisfied or very satisfied with the definition of the objectives of the training process, material availability, the exercises performed, the choice of the time to train, and general satisfaction with the training program.

CONCLUSIONS

We developed a microsurgical skills training program to be performed at home, which can be easily reproduced. It allows residents to improve manual coordination skills and is regarded as a feasible adjunct for ongoing training for surgical residents.

3D Exoscope-Assisted Microvascular Anastomosis: An Evaluation on Latex Vessel Models

Background. Over the last few years, advances in technologies and digital imaging have led to the introduction of systems that enable a new approach to microsurgery and supermicrosurgery. The exoscope is a new magnification system that provides a 3D image of the surgical field: microsurgical procedures can be performed with the aid of this instrument. Here, we describe our preliminary experience with a high-definition 3D exoscope (VITOM^®, Karl Storz, Tuttlingen, Germany), evaluating the characteristics of the instrument, and also its use as a magnification device for microanastomosis training. Methods. Six microsurgeons with various levels of experience were asked to perform three end-to-end anastomoses and two end-to-side anastomoses on latex vessel models, using, as a magnification system, the VITOM^® 3D 4K exoscope. None of the surgeons involved had previous experience with the exoscope, with robotic surgery, with endoscopic surgery, nor with training simulators. Results. The results of the reported evaluation of the tool’s qualities, (VITOM Quality Assessment Tool) included: a good focusing of the surgical field; high image quality; strong luminance; good magnification; clear stereoscopy; and excellent freedom of movement. The exoscope proved to be user-friendly. A constant reduction in the time needed to perform the microsurgical anastomosis at each exercise was recorded. Among other advantages were the easy switching from the magnified image to the macroscopic view, superior ergonomics allowing a relaxed posture while performing the anastomosis, adequate space, and a convenient setting for the assistants to view the operating field. Conclusions. Our study showed that the exoscope VITOM 3D can be successfully used as a magnification tool for microsurgical anastomosis on synthetic vessels, and that it can also be helpful during training courses in microsurgery.

3D-exoscopic visualization using the VITOM-3D in cranial and spinal neurosurgery. What are the limitations?

OBJECTIVE

3D exoscopic visualization in neurosurgical procedures is of interest for several reasons. The VITOM-3D exoscopic system is cheaper compared to the operating microscope (OM) and offers each person involved in the procedure the same image of the operative field. Little is known of limitations of this visualization technique.

PATIENTS AND METHODS

Prospectively, a consecutive series 34 procedures were assessed with focus on the following aspects: intraoperative limitation and the cause for a switch to the OM or endoscopy. A standardized questionnaire was answered by each individual involved in the procedure to assess the image quality, illumination, and magnification of the operative field. Intraoperative video recording and pre- and postoperative MRI and CT-scan were analyzed to assess the dimensions of the surgical approach.

RESULTS

Sixteen cranial and 18 spinal procedures (10 intra-axial, 6 extra-axial, 6 cervical, and 12 lumbar) were performed by seven neurosurgical attendings, twelve residents and twelve scrub nurses who all completed a standardized questionnaire after each procedure. Handling and identification of anatomical structures was rated equal or superior to the OM in 62 % and over 80 % of cases, respectively. The illumination and magnification of the operative field on the surface was rate in equal od superior in all cases and on the depth it was rated inferior to the OM over 60 % of cases. In one spinal and five cranial procedures a switch to the OM or endoscope were performed for the following reasons: poor illumination (4 cases), tissue identification (1 case), need for fluorescence imaging (1 case).

CONCLUSION

3D exoscopic visualization using the VITOM-3D is best suited for spinal procedures and for extra-axial cranial procedures. In case of small approach dimensions, the illumination and magnification of the depth of the operative field is rated inferior to the OM which resulted in difficulty of tissue identification and a switch to the OM.

Comparison of Conventional Microscopic and Exoscopic Experimental Bypass Anastomosis: A Technical Analysis

BACKGROUND

Recently, the use of digital exoscopes has been increasingly promoted as an alternative to microscopes. The aim of this study is to compare experimental bypass quality in both visualization methods.

METHODS

This study used two hundred 1-mm chicken wing vessels, which were used for either exoscopic or microscopic (100 samples each) bypass procedures. All procedures were recorded between July 2018 and September 2018. The bypass quality was evaluated according to our published practical scale (time, stitch distribution, intima-intima attachment, and orifice size).

RESULTS

Both methods are effective in doing bypass suturing (practical scale score was good, 86% vs. 85%; P = 0.84). There were no significant differences regarding intima-intima attachment (P = 0.26) and orifice size (P = 0.25). However, suturing time (P < 0.001) was less using the microscope, whereas stitch distribution (P = 0.001) was better using the exoscope. Different suturing techniques (interrupted vs. continuous) had overall comparable results (P = 0.55).

CONCLUSIONS

Both methods produced equally satisfactory results in experimental bypass procedures. The exoscope has the potential for better 3-dimensional visualization and sharing the surgeon's view with others for teaching purposes.

Pros and cons of using ORBEYE™ for microneurosurgery

OBJECTIVE

To evaluate the pros and cons of using a newly developed microscope, ORBEYE™, during microneurosurgery.

PATIENTS AND METHODS

ORBEYE™ use in 14 microneurosurgical procedures was retrospectively assessed by nine neurosurgeons after the procedure. A questionnaire comprising 20 questions was designed and used for evaluation.

RESULTS

Compared with the current gold standard, the binocular microscope, ease of setting up the equipment was scored the highest, whereas ease of conducting surgery in a position of an assistant was scored the lowest. Among characteristics of ORBEYE™ itself, the space-saving feature was scored the highest and was followed by the ability to perform procedures in a comfortable position. The only characteristic that was rated below average was ease of operation in a position of an assistant. Neurosurgeons with greater experience (more than five procedures using ORBEYE™) provided significantly higher scores (p = 0.0196) for characteristics of ORBEYE™ itself compared with neurosurgeon with fewer ORBEYE™ experience.

CONCLUSIONS

The main benefits of the ORBEYE^TM are its compact size and freedom from focusing through the eye lens of a conventional binocular microscope. However, it appears to be disadvantageous for operating in a position of an assistant because the surgical field has a rotated view on the monitor from a position of an assistant. Nonetheless, because of certain advantages, we believe the ORBEYE™ could be of additional help to use of conventional binocular microscope at the moment and will facilitate microneurosurgery in the future.