Microsurgical Maneuvers under Side-Viewing Endoscope in the Treatment of Skull Base Lesions

The objective of the present study is to elucidate the feasibility of surgical maneuvers under the side-viewing endoscope during skull base tumor removal. The study focused on 51 patients who underwent tumor removal with the assistance of a side-viewing endoscope. The side-viewing endoscope enabled visualization and removal of residual tumors obscured by the skull base bone, cranial nerves, and other vital structures after a microscopic procedure. If the surgical field is surrounded by the dura or skull base tissue, not only curettage of a tumor but also semisharp dissection and bipolar coagulation are shown to be feasible. In the subarachnoid space, however, the primary feasible surgical maneuver was suctioning of the tumor. The extent of skull base resection could be reduced in 25 cases and additional tumor removal became possible in 47 cases. Application of the side-viewing endoscope enabled removal of the tumor compartment, the exposure of which has conventionally required an extensive skull base resection. This technique is a promising option for the treatment of skull base tumors