Endonasal Neuroendoscopy

Abstract

Objective: To provide a detailed description of the extended endoscopic endonasal approach to the ventral skull base, evaluate its advantages and limitations and to understand better the complex anatomic relationships of the structures involved in the approach from an endoscopic endonasal perspective.

Method: Anatomic dissection study from January 2011 to October 2011. Materials: Three fresh, latex-injected cadaver heads were dissected. Setting: Dissection laboratory, Tanta University School of Medicine. Intervention: An endoscopic endonasal approach was performed on midline skull base. Outcome measurements: Anatomic relationships of endonasal endoscopic skull base approach.

Results: The extended endoscopic endonasal approach allows surgeons to access the entire ventral midline skull base from the crista galli to foramen magnum. A complete visualization of the carotid and vertebrobasilar arterial systems and of all 12 cranial nerves is obtainable. The major potential advantage of the extended endoscopic endonasal approach to skull base is that it provides a direct anatomic route to the lesion without traversing any major neurovascular structures, obviating brain retraction. The disadvantages of this procedure include the relatively restricted working space and the danger of an inadequate dural repair with a potential for cerebrospinal fluid leakage and meningitis.

Conclusion: The extended endoscopic endonasal approach allows surgeons to access the entire ventral midline skull base from crista galli to foramen magnum and deal with a diverse array of intra- and extradural lesions through a rostro-caudal trajectory.