title: [Intradural anterior clinoidectomy. Anatmoclinical study and its usefulness in the treatment of trans-segmentary C5-C6 trans-segmentary paraclinoid aneurysms].
abstract: OBJECTIVE
  To present an anatomoclinical study of the intradural anterior clinoidectomy and to evaluate the usefulness of this procedure in the microsurgical management of paraclinoid aneurysms. To describe two cases of a subtype of paraclinoid aneurysms arising from and with their fundus growing both in the clinoidal and subarachnoidal segments of the internal carotid artery (paraclinoid trans-segmentary C5-C6 aneurysms).
  
  
  METHODS
  The microanatomy of the clinodal region has been studied in dried and fixed specimens. The steps of the intradural anterior clinoidectomy are showed. The imaging and microsurgical findings in two cases of trans-segmentary C5-C6 aneurysms are also described.
  
  
  RESULTS
  The C5 clinoid segment of the internal carotid artery is exposed intradurally after anterior intradural clinoidectomy. The transtion between the C5 clinoid and C6 ophthalmic is also exposed and it is movilized only after the section of the carotid distal ring. These manoeuvres allows the microsurgical management and dipping of the trans-segmentary C5-05 aneurysms.
  
  
  CONCLUSIONS
  The nomenclature of the internal carotid artery segments and paraclinoid aneurysms remains confuse. Therefore, each lesion should be idetified by the location of the neck (extradural: C4 and C5 segments; intradural: C6 segment), fundus projection and location (intradural / extradural). The microsurgical clipping of the paraclinoid aneurysms is made easier after intradural anterior clinoidectomy, but this manoeuvre is mandatory for trans-segmentary C5-C6 lesions.
authors.affiliation: Servicio de Neurocirugía. Hospital General de Castellón, Castellón de la Plana.
authors.forename: J M
authors.initials: JM
authors.lastname: González-Darder
mesh_terms: D000783:Aneurysm / Q000473:pathology / Q000601:surgery; D000792:Angiography; D001344:Autopsy; D002343:Carotid Artery, Internal / Q000033:anatomy & histology / Q000601:surgery; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000601:surgery; D006801:Humans; D019635:Neurosurgical Procedures