Multimodality, Multidirectional Resection of Craniopharyngioma: Versatility in Alternating the Principal and Auxiliary Surgical Corridors and Visualization Modalities.

BACKGROUND: Large tumors of the skull base may require multiple approaches for safe removal, as unidirectional approaches may require excessive brain retraction.

METHODS: Two patients underwent simultaneous, endoscopic and microscopic resection of tumors using 2 anatomic corridors. The corridor used for most of the tumor dissection was designated as "principal," whereas the secondary corridor used for assisting the main operation was designated "auxiliary." The endoscope and microscope were used interchangeably in the 2 corridors.

RESULTS: For the first patient, the principal corridor was transventricular, and the auxiliary corridor was orbitofrontal. The endoscope was used exclusively in the latter and yielded visual information of the undersurface of the tumor, used for protection of the optic chiasm. For the second case, the corridors were reversed. Tumor resection was performed using the microscope and endoscope in alternating fashion. The endoscope, when used in the auxiliary ventricular corridor, was useful in delivering tumor components into the principal operative field.

CONCLUSIONS: Multidirectional approaches to large tumors can be considered less invasive if the surgical corridors are combined in a way to minimize traction forces on both brain and tumor and maximize visualization and protection of critical structures. These combination approaches can be made simpler with the seamless integration of the endoscope and microscope. The choice between the principal and auxiliary corridors should alternate just as smoothly as the visual modality and must be dictated by the anatomy and minute-to-minute tactical situation during the operation.