Minimally Invasive Approaches to the Anterior Skull Base

The use of minimally invasive approaches to the anterior skull base is a valuable tool to improving the treatment in patients with aggressive anterior skull base neoplasms. This article discusses the history, advantages and disadvantages relative to open approaches, the corridors and pathways used in approach, the equipment and operating room setup, perioperative care, and complication avoidance. Although outcomes are difficult to compare to open approaches, due to often small and varying patient cohorts, these approaches continue to gain acceptance as an effective treatment of anterior skull base tumors in the experienced surgeon’s hands with proper patient selection.

Key points

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The advantages of minimally invasive endoscopic approaches to the skull base are: (1) devascularization of the skull base blood supply before tumor resection, (2) avoidance of brain manipulation and retraction, (3) protecting the vascular supply of the optic apparatus as the tumor is approached from below by maintaining arachnoid planes, and (4) providing a better cosmetic result.
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Limitations of minimally invasive approaches include: (1) instrumentation that may be associated with greater application of force on surrounding structures than when using microinstruments; (2) difficulty accessing large tumors with significant lateral extension; (3) difficulty resecting the entire dural attachment, potentially limiting gross total resections; (4) difficulty with resection of tumor that completely encase vascular structures; and (5) lack of three-dimensional visualization.
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Selection of the appropriate minimally invasive approach depends on identification of the appropriate entry point and surgical corridor.
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Through careful surgical planning to avoid complications and select appropriate patients, minimally invasive techniques can be used to improve the function and prognosis of patients with skull base malignancies.