title: Quantitative anatomic study of three surgical approaches to the anterior communicating artery complex.
abstract: OBJECTIVE
  To compare the angles of approach and area of exposure to the anterior communicating artery (AComA) complex associated with pterional (PT), orbitopterional (OPT), and orbitozygomatic (OZ) craniotomies before and after gyrus rectus resection.
  
  
  METHODS
  PT, OPT, and OZ craniotomies were performed on both sides of four heads, and the angles of approach and area of exposure to the AComA complex were measured before and after resection of the gyrus rectus.
  
  
  RESULTS
  The vertical angle of approach increased significantly among the PT and OPT (P = 0.001), PT and OZ (P = 0.001), and OPT and OZ approaches (P = 0.005). The horizontal angle of approach was significantly larger between the PT to OPT (P = 0.001) and PT to OZ (P = 0.001) approaches but not between the OPT and OZ approaches (P = 0.757). After gyrus rectus resection, the vertical and horizontal angles of approach increased significantly for the PT approach but not for the OPT and OZ approaches. The area of exposure to the AComA complex increased progressively from the PT to OPT to OZ approach but did not reach statistical significance (P = 0.124). Resection of the gyrus rectus resulted in significant relative gains in the area of exposure for the PT (P = 0.01) and OPT (P = 0.04) approaches but not for the OZ approach (P = 0.88).
  
  
  CONCLUSIONS
  The vertical and horizontal angles of approach to the AComA complex are significantly larger for the OPT and OZ approaches compared with the PT approach. Use of the OZ approach may decrease the need for frontal lobe retraction and resection of the gyrus rectus.
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013, USA.
authors.forename: Eberval Gadelha
authors.initials: EG
authors.lastname: Figueiredo
authors.forename: Pushpa
authors.initials: P
authors.lastname: Deshmukh
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Zabramski
authors.forename: Mark C
authors.initials: MC
authors.lastname: Preul
authors.forename: Neil R
authors.initials: NR
authors.lastname: Crawford
authors.forename: Rungsak
authors.initials: R
authors.lastname: Siwanuwatn
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spetzler
mesh_terms: D020771:Anterior Cerebral Artery / Q000033:anatomy & histology*; D002102:Cadaver; D003399:Craniotomy; D006801:Humans; D019635:Neurosurgical Procedures