title: Anatomical partition of the clival region and adjacent structures via extended endoscopic endonasal approach.
abstract: OBJECTIVE
  To explore the anatomy of the ventral clivus and adjacent structure in the endoscopic surgery through the anterior approach, particularly in accurate locating lesions in transnasal endoscopic surgery.
  
  
  METHODS
  A total of 9 formalin-fixed adult cadaver heads were injected with red and blue latex to observe the arteries and veins, respectively. The relationships between various parts of internal carotid artery (ICA) and anatomic structures of clivus were investigated, followed by the measurement of the posterior pharyngeal wall, anterior wall and posterior wall of clivus, cerebral dura mater, subdural space and adjacent regions to determine their correlations, as well as the clivus and adjacent structures.
  
  
  RESULTS
  The clivus structure was divided into the bone segment, the ICA segment and subdural segment for anatomic division according to the anatomic landmarks in the anatomic process. The clivus can be classified in a shape of '' with the ICA, including the middle superior region, middle inferior region, bilateral lateral superior and lateral inferior regions.
  
  
  CONCLUSIONS
  The ICA is closely related to the ventral clivus and adjacent structure, which can be used as the basis of anatomic division via anterior approach.
authors.affiliation: Department of Neurosurgery Center, Aviation General Hospital of China Medical University, Beijing 100012, China.
authors.forename: Jia-Ping
authors.initials: JP
authors.lastname: Zheng
authors.affiliation: Department of Neurosurgery, Sanbo Brain Hospital Affiliated with Capital Medical University, Beijing 100093, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Song
authors.affiliation: Department of Neurosurgery, Juxian Hospital of Traditional Chinese Medicine, Shandong Rizhao 276500, China.
authors.forename: Xiang-Xin
authors.initials: XX
authors.lastname: Zhan
authors.affiliation: Beijing Neurosurgical Institute, 6 Tiantan Xili, Beijing 100050, China.
authors.forename: Chu-Zhong
authors.initials: CZ
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, 6 Tiantan Xili, Beijing 100050, China.
authors.forename: Xu-Yi
authors.initials: XY
authors.lastname: Zong
authors.affiliation: Beijing Neurosurgical Institute, 6 Tiantan Xili, Beijing 100050, China. Electronic address: zhyazhuo@163.com.
authors.forename: Ya-Zhuo
authors.initials: YZ
authors.lastname: Zhang
mesh_terms: D002102:Cadaver; D002343:Carotid Artery, Internal / Q000033:anatomy & histology*; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology*; D006801:Humans; D009296:Nasal Cavity
keywords: Anatomy; Clivus; Extended endoscopic endonasal approach