Abstract
Object: As a minimally invasive surgical strategy, endonasal endoscopy has been implemented
for the surgical treatment of clival and midline posterior fossa lesions which conventionally
require radical and extensive surgical exposures. A cadaver study was performed and,
subsequently, this technique was adopted into patient treatment.
Methods: Six cadaver head specimens were used in this study. Anterior sphenoidotomy was attained
by either a paraseptal or middle turbinectomy approach. The ideal head positioning
was measured. The clival bone was removed with a high-speed drill from sella to foramen
magnum in the vertical dimension and from carotid artery to carotid artery in the
transverse dimension. The width of the clival bony window between the carotid arteries
was measured at the level of the sellar floor and the caudal end of the carotid artery.
The surgical anatomy was studied.
Results: Although the middle turbinectomy approach provided a wider surgical corridor, exposure
with the paraseptal approach was sufficiently ample. Ideal head positioning was at
15-degree flexion of the forehead-chin line. The average width between carotid arteries
at the sellar floor level was 16 mm (range 12 - 22 mm) and at the lower end of the
carotid arteries it was 19 mm (range 14 - 23 mm). When the dura mater was opened,
the anterior view of the pons and medulla with corresponding cranial nerves and vasculature
was encountered. Four illustrative patient cases are presented.
Conclusions: This endonasal endoscopy provided excellent surgical exposure from the sella to the
foramen magnum at the midline clivus and posterior fossa. Surgical techniques and
illustrations of four patients are presented.
Key words
Clivus - chordoma - endoscopy - meningioma - skull base surgery - transsphenoidal
surgery
References
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