2025 Poster Presentations
P366: ADVANTAGES OF EXOSCOPE FOR SKULL BASE SURGERY
Kyoichi Tomoto, MD1; Kentaro Watanabe, MD2; Nobuyuki Watanabe, MD1; Michihiro Tanaka, MD1; Yuichi Murayama, MD2; 1Kameda Medical Center, Chiba, Japan; 2Jikei University School of Medicine, Tokyo, Japan
Introduction: Neurosurgery has developed primarily through the use of visual devices that enable the magnification of the surgical field and stereoscopic vision. The magnification technology in visual devices has seen innovations approximately every 30 years, with the introduction of the microscope in the 1960s and the endoscope in the 1990s. Now, 30 years after the advent of neuroendoscopy, the 2020s have brought the introduction of exoscopes into the neurosurgical field. In recent years, high-resolution 3D exoscopes have become available and are being used for various scene, though their clinical use remains limited to certain facilities and lesions. In January 2023, our institution introduced the ORBEYE (Olympus Corporation, Tokyo, Japan), one of the exoscopes, and since then, we have fully transitioned from microscopic surgery to performing all craniotomies using ORBEYE. This report focuses on our experience with skull base surgery using the exoscope.
Subjects and Cases: We included 350 cases of surgeries (excluding endovascular treatment) performed for intracranial lesions between January 2023 and August 2024. Among the 129 cases that underwent craniotomy, skull base approaches using the exoscope were performed in 23 cases of meningioma, 7 cases of schwannoma, 7 cases of neurovascular compression syndrome, 2 cases of brainstem cavernous malformation, 2 cases of suprasellar arachnoid cyst, and 1 case of Pituitary Neuroendocrine Tumor. Representative cases include a giant pituitary adenoma treated with combined endonasal transcranial approach, a meningioma originating from the upper-middle clivus, and a jugular foramen schwannoma.
Discussion: The greatest advantage of the exoscope is its compact design, which provides the surgeon with a wide working space and allows for multiple viewing angles without the need to change body position. Compared to shallow and wide surgical fields, such as those encountered in skull base surgery, where the field is narrow and deep, the small size of the exoscope allows for quicker autofocusing. Additionally, its compact size makes it possible to perform combined endonasal transcranial approach without obstructing the view of either surgeon, and both can share the monitor during surgery. Another advantage of the exoscope is its ability to provide high-resolution, stereoscopic images of tissues. It allows for the creation of good dissection planes in various skull base tumors and maintains adequate brightness in the surgical field compared to traditional microscopes, which is particularly advantageous in deep skull base surgeries. The deeper the surgical field, the more it resembles microscope, providing a better view. The consistent brightness across the peripheral field provides a clearer and more delicate impression of the surgical field. Additionally, the use of an LED light source also permits long-duration skull base surgeries without the concern of thermal damage to tissues.
Conclusion: Neurosurgery using an exoscope can be performed as safely as surgery using a microscope, and its advantages are particularly evident in skull base surgery.
