The Microsurgical Anatomy Of The Skull Base And Parasellar Region Associated With Extend Transsphenoidal Approach And The Plastination Technique For Preservation Of The Specimen

Part 1. the Microsurgical Anatomy of the Skull Base and Parasellar Region Associated with Extended Transsphenoidal ApproachObjectThe anatomic features of a transsphenoidal approach are reviewed, focusing on the microsurgical anatomy of parasellar structures. Pertinent microsurgical anatomy is described in sufficient detail for the neurosurgeon to successfully extend a standard transsphenoidal approach for treatment of lesions involving the region of the tuberculum sellae, planum sphenoidale, supradiaphragmatic intradural space, and medial cavernous sinus.MethodMicrosurgical anatomy in sellar region and parasellar region according to the three operating direction of extend transsphenoidal approach. We observed 15 specimens (30 sides) from formalin fixed cadaveric heads, and also observed 20 adult dry skulls (40 sides). According to the purpose of the extend transsphenoidal approach, we studied 3 main area of the sellar and parasellar region: the planum sphenoidale and the supradiaphragmatic area, medial part of cavernous sinus and the upper or middle part of the Clivus. Emphasized on the relation of the nerve and blood vessel structures surrounding the sellar. Meanwhile, we made the cast specimen of the blood vessel, studied the structure character of the internal carotid artery are cavernous sinus.ResultsImportant anatomic landmarks identified in the roof of the sphenoid sinus. The carotid and optic canal prominence. The diaphragma sella is actually comprised of two layers of dura, with a venous system (anterior intercavernous sinus). The dura mater of the pituitary gland separates the gland from the medial compartment of the cavernous sinus. The microanatomic detail necessary to extend the transsphenoidal approach to the supradiaphragmatic intradural space and medial compartment of the cavernous sinus is described.ConclusionThe traditional boundaries of the transsphenoidal approach may be expanded to include the region from the cribriform plate of the anterior cranial base to the inferior clivus in the anteroposterior plane, and laterally to expose the cavernous cranial nerves and optic canal.The posterior ethmoidectomy may be helpful to expand the visualization of the operation area.