Transcranial extraventricular endoscopic surgeries: Expanding the role of endoscope in neurosurgery.

Background and Aim: Transcranial endoscopic surgeries are mainly limited to intraventricular lesions. This study aims to elaborate on the various benefits of transcranial endoscopic surgeries in extraventricular regions of the brain. Methods and Materials/Patients: It is a retrospective study of transcranial extraventricular endoscopic surgeries (TEESs) operated between June 2022 to May 2023. The authors described the surgeries done for brain lesions other than intraventricular lesions as extraventricular surgeries. Access to the intracranial region was obtained through the transcranial approach. The transnasal rigid endoscope was used for the surgeries. The surgery was performed as either pure endoscopic surgery or endoscopic-assisted microscopic surgery. Results: The authors have performed 6 microvascular decompressions using an endoscope. Three pineal tumors, 3 craniopharyngiomas, 1 cerebellopontine angle epidermoid cyst, and 1 petrous neurenteric cyst were excised using an endoscope by transcranial approach. One internal carotid artery bifurcation aneurysm was clipped using an endoscope. All patients improved in the postoperative period. Surgeries were done using the 0-degree and 30-degree endoscopes. The endoscopic eye was able to reach the deep-seated area of surgical interest and authors were able to visualize the structures in a wide panoramic view with good illumination and magnification. There was no misinterpretation of structures. Conclusion: Endoscope can reach the deep-seated extraventricular areas of the brain with a narrow corridor, giving good illumination and magnification at the site of surgery. An endoscope can reach beyond the obstructing anatomical structure and visualize the area behind it. It is used as a complimentary to microscope to access the microscopic invisible areas. It has increased the ease of doing surgery, decreased tissue dissection, decreased complications, and improved surgical results. TEES improves the hand-eye coordination of surgeons in transcranial surgeries and it will help in adapting to exoscope easily