Applied anatomy of the endoscopic endonasal approach to the ventral middle-lower part of clivus

Abstract

Objective To establish the surgical landmarks of the endoscopic endonasal approach to the ventral region of middle-lower part of clivus and provide anatomic basis. Methods Twenty 10% formalin-fixed intact adult head specimens were used to dissect and observe the anatomic feature of this access in order to establish the surgical landmarks of the approach, and some relative anatomic data were measured. Five fresh and intact head specimens injected with colored latex were used, and completely analogical operation via endoscopic endonasal approach to the middle-lower part of clivus was performed in all cases. Results Anatomic landmarks of the approach included middle turbinate, choana narium, eustachian tube ostium, nasopharynx mucosa, longus capitis and longus colli, pharyngeal tubercle, and basi-on. To expose the ventral region of middle-lower part of clivus completely, the shortest distance was ( 89.60 ± 2. 52) mm. The ranges of stripping the inferior wall of sphenoid sinus and the lower clivus were bounded by pterygoid canal and foramen lacerum, and the distances from the median line were (9. 37 ± 0.59) mm and (10. 75 ± 0. 63 ) mm, respectively. Conclusions The structures of the ventral middle-lower part of clivus can be revealed sufficiently via an endoscopic endonasal approach. Key words: Endoscopy; Cranial fossa, posterior/AH/SU; Nose/SU