Exoscopic carotid endarterectomy using movable 4K 3D monitor: Technical note

Microsurgical Resection of Meningiomas Using a 4K Three-Dimensional Exoscope: A Descriptive Observational Study

Background Prior to using the exoscope, we speculated that it represented an intermediate tool between a loupe and a microscope and had concerns about its visibility of deep, fine structures. Objective To evaluate the depths of meningioma for which the exoscope was suitable, and to clarify its disadvantages in meningioma resection. Methods Findings of consecutive meningioma surgeries using a 4K three-dimensional (3D) exoscope over a one-year period were evaluated for visibility of the surgical field, comfort of the surgeon's arm posture, the surgeon's head orientation, and perception of the image delay, accounting for the depth of the tumor. Results Seven meningiomas were resected using a 4K 3D exoscope (three superficial, three intermediate, and one deep). The exoscope allowed the surgeon to observe deeply located fine structures as clearly as with a conventional microscope and to operate more comfortably on meningiomas of all depths with arms flexed. On the contrary, the exoscope occasionally required the surgeon to operate with his head unnaturally turned to one side because of the immobility of its large monitor, despite the wide insertion availability of its camera from various directions to meningiomas located superficially or within the middle cranial fossa. No time delays between the surgeon's manipulations and the 3D images were perceived in all meningioma surgeries. Conclusions The 4K 3D exoscope was suitable for operations on all depths of meningiomas. The discrepancy between the surgeon's manipulation and gaze directions was its disadvantage. It is anticipated that further development of the 3D monitor will address this issue.

A Keyhole Approach for Intracranial Hematoma Removal Using ORBEYE

OBJECTIVE

By maximizing the advantages of exoscopy, we developed a keyhole approach for intracranial hematoma removal. Herein, we validated the utility of this procedure, and compared it with conventional microscopic hematoma removal and endoscopic hematoma removal in our institution.

METHODS

We included 12 consecutive patients who underwent this procedure from June 2022 to March 2024. A 4-cm-long skin incision was made, and a keyhole craniotomy (diameter, 2.5 cm) was performed. An assistant manipulated a spatula, and an operator performed hematoma removal and hemostasis using typical microsurgical techniques under an exoscope. The dura mater was reconstructed without sutures using collagen matrix and fibrin glue. The outcomes of this series were compared with those of 12 consecutive endoscopic hematoma removals and 19 consecutive conventional microscopic hematoma removals from October 2018 to March 2024.

RESULTS

The mean age was 72±10 years, and 7 (58%) patients were men. Hematoma location was the putamen in 5 patients and subcortical in 7 patients. The mean operative time was 122±34 min, the mean hematoma removal rate was 95%±8%, and the mortality rate was 0%. Although the preoperative hematoma volume was similar between the 3 groups, the operative time and total time in the operating room was significantly shorter in the exoscope group than in the microscope group (P<0.0001).

CONCLUSIONS

This procedure may be simpler and faster than conventional microscopic hematoma removal, and comparable to endoscopic hematoma removal.

The Usefulness of Surgical Titanium Microclips for Mucosal Repair in the Frontal Sinus Using ORBEYE: A Technical Note

Bifrontal craniotomy frequently involves opening the frontal sinus and mucosal injury. We report a new technique for mucosal repair in the frontal sinus using surgical titanium microclips. Six consecutive patients who underwent bifrontal craniotomy with frontal sinus exposure and mucosal injury underwent mucosal repair using surgical titanium microclips between April 2019 and August 2022. In all cases, the frontal sinus mucosa was peeled from the inner walls of the frontal sinus to ensure sufficient mucosal margin for clipping using ORBEYE. The repair was accomplished with the microclips in all cases. We also sealed the mucosal wound using fibrin glue and sufficiently filled the frontal sinus with bone debris, resulting in zero incidence of postoperative liquorrhea in all cases. Repairing the mucosa using surgical titanium microclips using ORBEYE may be a simple and quick technique when the frontal sinus mucosa is injured during craniotomy.

Functionality and Usability of the Exoscope in Microvascular Decompression for Hemifacial Spasm and Trigeminal Neuralgia

BACKGROUND

Studies on the functionality and usability of the exoscope in neurosurgical procedures against surgical microscopes (SMs) are limited. This study aimed to examine the functionality and usability of the exoscope during microvascular decompression (MVD) surgery.

METHODS

Seven neurosurgeons evaluated the usefulness of a 4 K, 3-dimension digital exoscope in MVD by answering a questionnaire. The questionnaire inquired about the functionality and usability of the exoscope by utilizing a visual analog scale (VAS; 1-10). A score of 5 on VAS was equivalent to the corresponding quality of the SM. The learning effect of the exoscope was evaluated using mean VAS scores in the first and last 3 cases for each neurosurgeon.

RESULTS

The functionality of the exoscope in MVD was superior to that in SM (P < 0.001). In the last 3 surgeries, the mean VAS scores of the exoscope were excellent in terms of ease of arm handling, exchange of surgical instruments, ease of surgical procedure, and intraoperative physical stress. The mean VAS scores of the exoscope in intraoperative asthenopia were significantly higher than those of the SM (P < 0.001). No statistical significance was found in operation time, discharge outcome, and 1-year post-surgery outcome between MVD performed using the exoscope and SM.

CONCLUSIONS

Neurosurgeons may experience reduced stress levels during MVD when using the exoscope. As the outcome of MVD using the exoscope did not demonstrate a statistical difference compared with MVD using the SM, the exoscope may prove to be a useful tool for performing MVD.

Multiscope Technique Combining an Endoscope and Exoscope for Neck Clipping of Cerebral Aneurysms

OBJECTIVE

In aneurysm clipping, the use of an endoscope improves the visualization of the anatomic structures around the aneurysm, allowing for improved dissection and clipping techniques. Furthermore, it makes the surgery less invasive. The disadvantage of using the endoscope and microscope together is that the surgeon must move the line of sight significantly between viewing the operative field through the eyepiece of the microscope and viewing the endoscope monitor. This disadvantage makes it difficult for the surgeon to safely insert the endoscope in the optimal position. This study presents a new method for observing the surgical field with a picture-in-picture system using both an endoscope and an exoscope that can overcome the disadvantage of multiscope surgery.

METHODS

The endoscope was used when the anatomic structures around the aneurysm could not be observed with the exoscope only. An image from the endoscopic monitor was inserted into the exoscopic monitor. The surgeon inserted the endoscope in the optimal position while viewing the endoscope monitor and ensured that the structures in the path of the endoscope were not damaged while they viewed the exoscope monitor.

RESULTS

Three patients underwent aneurysm clipping. The use of an endoscope made the procedure less invasive, and the surgeon was able to safely insert the endoscope in the optimal position. Only slight movement of the line of sight was required to view the 2 monitors.

CONCLUSIONS

The endoscope and exoscope multiscope picture-in-picture system can facilitate safer aneurysm clipping compared with combined microscopic and endoscopic surgery.

3D Exoscopes are Noninferior to Operating Microscopes in Aneurysm Surgery: Comparative Single-Surgeon Series of 52 Consecutive Cases

OBJECTIVE

The literature on exoscope use in cerebrovascular neurosurgery is scarce, mainly comprising small case series and focused on visualization quality and ergonomics. As these devices become widely used, direct comparison to the operating microscope regarding efficacy and patient safety is necessary.

METHODS

Fifty-two consecutive clipping procedures, performed by 1 senior vascular neurosurgeon, were analyzed. Either an operating microscope with a mouth switch (25 cases with 27 aneurysms; 13 ruptured) or a three-dimensional exoscope with a foot switch (27 cases with 34 aneurysms; 6 ruptured) were used. Durations of major surgical stages, number of device adjustments, numbers of clip repositionings and clips implanted were extracted from surgical videos. Demographic data, imaging characteristics, clinical course and outcomes were extracted from digital patient records.

RESULTS

Duration of surgery and different stages did not differ between devices, except for final site inspection. The number of device adjustments was higher with the exoscope. With progressive experience in exoscope use, the number of device adjustments increased significantly, whereas surgery duration remained unchanged. Favorable outcome (modified Rankin Scale score 0-2) was observed in 80% and 88% of patients in the microscope and exoscope groups, respectively. Ischemic events were found in 2 patients in each group; no other complications occurred.

CONCLUSIONS

In aneurysm clipping, three-dimensional exoscopes are noninferior to operating microscopes in terms of surgery duration, safety, and outcomes, based on our limited series. Progressive experience enables the surgeon to perform significantly more device adjustments within the same amount of surgical time.

Midline suboccipital approach to a vertebral artery–posterior inferior cerebellar artery aneurysm from the rostral end of the patient using ORBEYE

Background:

The midline suboccipital approach with the patient in the prone position is safe and effective for clipping vertebral artery–posterior inferior cerebellar artery (VA–PICA) aneurysms. Using a conventional surgical microscope from the rostral end of the patient for this approach without an extreme head-down position requires the surgeon to overhang the visual axis of the microscope and perform surgical manipulations in an uncomfortable posture. We report performing the midline suboccipital approach from the rostral end with slight head-down position using ORBEYE, a new high-definition (4K) three-dimensional exoscope.

Case Description:

A 65-year-old woman was admitted for clipping of a right unruptured VA–PICA aneurysm (maximum diameter, 5mm) located medially and ventral to the hypoglossal canal. After induction of general anesthesia, the patient was placed in the prone position with the head titled slightly downward. A midline suboccipital approach was performed from the rostral end of the patient using ORBEYE. Clipping was safely accomplished in a comfortable posture. No operative complications occurred. Postoperative computed tomography angiography showed complete aneurysmal obstruction.

Conclusion:

Exoscopic surgery using ORBEYE is feasible for a midline suboccipital approach to VA–PICA aneurysms from the rostral end of the patient with the patient in the prone with slight head-down position.