Comparison between microscope and endoscope in the endonasal transsphenoidal approach to the sellar: Anatomical study / 中华显微外科杂志

ABSTRACT

Objective To compraison the of exposure in the endonasal transsphenoidal approach to the sellar between microscope and endoscope. Methods Ten formalin-fixed, silicone-injected adult cadveric heads were studied. A direct endonasal transsphenoidal approach was performed via the right nostril, pushing aside the nasal septum, then reach the sphenoidal sinus. The approach was performed with the operating microscope first, then with the endoscope. For each step (sellar, suprasellar, parasellar and clival), the operative region afforded by direct microscopic view was measured and then compared with that obtained by using the edndoscope. Results It was found that the endoscope provided greater view than microscope in this approach. Although the microscope provides an adequate view of the midline structures and part of the contralateral parasellar areas; under direct endoscopic vision, the lateral extension could be widened by an additional 6.5 mm on the ipsilateral and 4 mm on the contralateral side. At suprasellar region, the microscope provides could expose the posterior part of, optic nerve and optic chiasma; but could not expose the areas anterior and superior the interspace superior the optic chiasma. Compare with the microscope, the endoscope allowed extension of bone removal and dual opening for an additional 4 mm anteriorly at the sagittal axis and an additional 3.5 mm on the ipsilateral and 4 mm on the contralateral side. At the clivus region, the medial surface of the vertical segment of the ICA and the basilar artery could be partially 7 exposed by the microscope. By the endoscope, it could gain an additional 4 mm on the ipsilateral side and 2.5 mm on the contralateral side in width. Because of the anatomical boundaries of the sphenoid sinus, the anatomincal exposure by the microscope same as the endocope at the sagittal axis. Conclusion The endoscope allows for a panoramic view and permits widening of the operative exposure in all directions. The endoscope is more suitable in the the minimal and expanded endonasal transsphenoial approach.