title: The bipedicled anterior septal flap: a radioanatomic and cadaveric study.
abstract: OBJECTIVE
  Pedicled mucosal flaps are the preferred method of endoscopic skull base reconstruction. Vascularized coverage of the anterior and posterior frontal tables remains a challenge given the lack of large caliber vessels supplying the anterior septum. The objective of this study was to define a novel bipedicled anterior septal (BAS) flap that is hypothesized to be capable of providing reproducible coverage of these difficult areas.
  
  
  METHODS
  Radioanatomic and cadaveric study.
  
  
  METHODS
  The flap outline was superimposed over nine midline sagittal computed tomography images. The pedicles are comprised of the septal branch of the superior labial artery and the nasopalatine artery. The flap length subtended the distance from the incisive canal to the sphenoid face at the level of the choanal arch. Radiometric analysis of the flap length to base ratio and anterior/posterior frontal table coverage were calculated. These projected values were confirmed in four cadaveric dissection specimens.
  
  
  RESULTS
  The mean flap length was 39.64 ± 4.26 mm with a mean length:base ratio of 3.29 ± 0.70 and a total surface area of 916.46 ± 262.66 mm(2) . The flap was estimated to provide coverage of 100.31 ± 21.34% of the frontal beak and 50.74 ± 32.54% of the posterior frontal table. In all cadaveric specimens the flap extended beyond the superior aspect of the frontal beak and at least 50% of the posterior table.
  
  
  CONCLUSIONS
  The BAS flap represents a novel septal mucosal flap based on two well-defined arterial inputs. This flap is capable of providing reliable vascularized coverage of the posterior frontal table and the frontal beak following frontal drillout.
authors.affiliation: Department of Otology and Laryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA. benjamin_bleier@meei.harvard.edu
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Bleier
authors.forename: William T
authors.initials: WT
authors.lastname: Curry
authors.forename: Eric W
authors.initials: EW
authors.lastname: Wang
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Schlosser
mesh_terms: D000328:Adult; D002102:Cadaver; D065634:Cerebrospinal Fluid Leak; D002559:Cerebrospinal Fluid Rhinorrhea / Q000000981:diagnostic imaging / Q000601:surgery; D035262:Cranial Fossa, Anterior / Q000000981:diagnostic imaging / Q000601:surgery; D004210:Dissection; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D019651:Plastic Surgery Procedures / Q000379:methods*; D012016:Reference Values; D012494:Sampling Studies; D019291:Skull Base / Q000000981:diagnostic imaging / Q000601:surgery; D013524:Surgical Flaps / Q000098:blood supply*; D014057:Tomography, X-Ray Computed / Q000379:methods*