Endoscope-assisted brain tumor removal overcomes the restriction of using intraoperative open magnetic resonance imaging in the suboccipital approach

Abstract

Intraoperative magnetic resonance imaging (iMRI) plays a crucial role in improving the precision of brain tumor surgeries. However, the use of iMRI can impose certain limitations on intraoperative head positioning. In regular microscopic surgery, head positioning is of utmost importance because an appropriate surgical field is important for the efficacy and safety of surgery. Therefore, in cases where adequate head positioning is difficult, usually, iMRI will not be utilized. Herein, we report an adult case of cerebellar astrocytoma whose tumor extended to the culmen of the cerebellum. Upon surgery via the suboccipital approach, the positional limitations imposed by iMRI led to an insufficient vertex-down position and limited surgical field, which hampered the removal of the upper portion of the tumor. However, this concern could be overcome when used in combination with an endoscope. The potential of iMRI applications is anticipated to be enhanced by overcoming positional limitations through combined endoscopic surgery. The use of multimodality in surgery is an optimal example of how surgical support equipment can also improve surgical outcomes. Here, we report on the new possibilities offered by multimodality.

Keywords: endoscope; intraoperative MRI; multimodality; positioning.

Fig. 1

Magnetic resonance imaging (MRI) obtained prior to second surgery at our institution Contrast-enhanced T1-weighted image acquired during admission (A), after first surgery at our hospital (B), and 6 months after first surgery (C, axial; D, sagittal).

Fig. 2

Second surgery at our institution Head position of the patient (A). Intraoperative view (B). The cerebellum is trailing caudally; however, the view of the superior surface of the cerebellum is restricted. View from endoscope, observing the dorsal brainstem from the inferior aspect of the cerebellar tentorium (C). Tumor removal was completed, leaving an area of tumor invasion on the dorsal brainstem (D).

Fig. 3

Contrast-enhanced T1-weighted image obtained after second surgery at our hospital Axial (A) and sagittal (B) images. After surgery, cyber knife therapy was performed on the residual lesion.