Comparison between the microscope and endoscope in the direct endonasal extended transsphenoidal approach: anatomical study.

Object: The authors compare the views afforded by the operating microscope and the endoscope in the direct endonasal extended transsphenoidal approach to the sellar, suprasellar, and parasellar regions.

Methods: Five formalin-fixed, silicone-injected adult cadaveric heads were studied. A direct endonasal transsphenoidal approach was performed via the right nostril, pushing aside the nasal septum. The approach was performed with the microscope first, then with the endoscope. For each step (sellar, suprasellar, and clival), the exposure afforded by direct microscopic view was measured and then compared with that obtained using the endoscope. The direct endonasal approach provides a slightly off-midline view. Although the microscope provides an adequate view of the midline structures and part of the contralateral parasellar areas, the addition of the endoscope allows for a more panoramic view and permits widening of the approach in all directions.

Conclusions: An adequate exposure of the sellar, suprasellar, and infrasellar/upper clival regions can be achieved via a simple, direct endonasal approach. From a direct endonasal route, there is a preferential visualization of the structures contralateral to the approach. The endoscope affords a more panoramic view that extends the area covered by the operating microscope.