title: Intrasphenoid septations inserted into the internal carotid arteries: a frequent and risky relationship in transsphenoidal surgeries.
abstract: BACKGROUND
  When an expanded endonasal transsphenoidal surgical approach is performed, intrasphenoid septations must be completely resected. If these structures are close to the internal carotid artery (ICA), then their manipulation might cause vascular injury.
  
  
  OBJECTIVE
  The objective of this study is to describe the frequency of intrasphenoid septations in the internal carotid artery protuberance (ICAp).
  
  
  METHODS
  Computed tomography (CT) scans of 421 patients were analysed. Intrasphenoid septations (classified as intersphenoid or accessory) and their relationship to the ICAp were described. Additionally, a sphenoid sinus classification was performed based on their degree of pneumatisation to determine whether a difference exists in the frequency of intrasphenoid septations inserted into ICAp with regard to sinus type.
  
  
  RESULTS
  The patient mean age was 39±21.4 years. Overall, 219 patients (52%) had septations in the ICAp; 359 patients (85.3%) had intersphenoid septations; of the latter, 135 (37.6%) had septations in the ICAp. This frequency was higher among patients with sphenoid sinus type 4 or 5 (44.7% and 43.5%, respectively). Accessory septations were found in 255 patients (60.6%); 140 of these septations (54.9%) were in the ICAp. Among 351 patients with types 3, 4 or 5 sphenoid sinuses (i.e., only well-pneumatised sphenoid sinuses), 219 (62.4%) had septations in the ICAp. These frequencies are higher than those reported in most previous studies.
  
  
  CONCLUSIONS
  The frequency of intrasphenoid septations in the ICAp found is considerable. It is higher among patients with more pneumatised sinuses. This finding justifies an appropriate pre-operative study, and careful attention must be paid during transsphenoidal surgery.
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), Departamento de Neurocirurgia, São Paulo, SP, Brazil; Universidade Federal de São Paulo (UNIFESP), Programa de Pós-graduação do Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, São Paulo, SP, Brazil. Electronic address: clauderramalho@hotmail.com.
authors.forename: Clauder Oliveira
authors.initials: CO
authors.lastname: Ramalho
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), Departamento de Neurocirurgia, São Paulo, SP, Brazil; Universidade Federal de São Paulo (UNIFESP), Programa de Pós-graduação do Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, São Paulo, SP, Brazil.
authors.forename: Horacio Armando
authors.initials: HA
authors.lastname: Marenco
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Francisco
authors.initials: F
authors.lastname: de Assis Vaz Guimarães Filho
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), Departamento de Neurocirurgia, São Paulo, SP, Brazil.
authors.forename: Marcos Devanir Silva
authors.initials: MD
authors.lastname: da Costa
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), Departamento de Neurocirurgia, São Paulo, SP, Brazil.
authors.forename: Bruno Fernandes
authors.initials: BF
authors.lastname: de Oliveira Santos
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), Departamento de Otorrinolaringologia, São Paulo, SP, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: de Paula Santos
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), Departamento de Neurocirurgia, São Paulo, SP, Brazil; Universidade Federal de São Paulo (UNIFESP), Programa de Pós-graduação do Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, São Paulo, SP, Brazil.
authors.forename: Samuel Tau
authors.initials: ST
authors.lastname: Zymberg
mesh_terms: D000328:Adult; D002343:Carotid Artery, Internal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010256:Paranasal Sinuses / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery*; D013101:Sphenoid Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery*; D014057:Tomography, X-Ray Computed
keywords: Abordagem endonasal ampliada; Base do crânio; Cirurgia transesfenoidal; Expanded endonasal approach; Seio esfenoidal; Septações esfenoidais; Skull base; Sphenoid septations; Sphenoid sinus; Transsphenoidal surgery