title: Transnasal endoscopic medial maxillectomy as the initial oncologic approach to sinonasal neoplasms: the anatomic basis.
abstract: OBJECTIVE
  To demonstrate an anatomic basis for endoscopic medial maxillectomy with excision of the lateral nasal wall to the nasal floor, including the inferior turbinate, and nasolacrimal duct. Transnasal endoscopic medial maxillectomy involves complete resection of the lateral nasal wall with boundaries that are inferior to the nasal floor; superior to the cribriform plate and fovea ethmoidalis; anterior to the anterior maxillary wall, including the nasolacrimal duct; and posterior to within 5 mm of the eustachian tube. Transnasal endoscopic medial maxillectomy provides exposure for endoscopic resection of the orbital wall, pterygopalatine fossa, pterygoid plates, nasopharynx, and anterior skull base when indicated.
  
  
  METHODS
  Volumetric analysis of the maxillary sinus was performed on axial and coronal computed tomographic scans of 19 adult patients for a total of 38 maxillary sinuses.
  
  
  METHODS
  Tertiary care medical center.
  
  
  METHODS
  Nineteen adult patients with tumors of the head (but outside the sinonasal region).
  
  
  METHODS
  Radiographic analysis.
  
  
  METHODS
  The total volume of the maxillary sinus, volume above and below the superior attachment of the inferior turbinate, and volume anterior to the nasolacrimal duct were measured.
  
  
  RESULTS
  The mean (SD) total volume of the maxillary sinus was 20.1 (4.2) cm(3), whereas its volume inferior to the superior attachment of the inferior turbinate was 12.9 (3.7) cm(3) and anterior to the nasolacrimal duct was 1.1 (0.6) cm(3). The mean (SD) volume of the maxillary sinus inferior to the superior attachment of the inferior turbinate was 64% (12%), whereas the nasolacrimal duct obscured the transnasal anterior exposure of the maxillary sinus.
  
  
  CONCLUSIONS
  Without excision of the lateral nasal wall inferiorly to the nasal floor and anteriorly, including the nasolacrimal duct, over half of the maxillary sinus would be inaccessible for procedures directed at neoplasms within the maxillary sinus.
authors.affiliation: The George Washington University, 2475 Virginia Avenue NW, Washington, DC 20037, USA. ntanna@gwu.edu
authors.forename: Neil
authors.initials: N
authors.lastname: Tanna
authors.forename: John D
authors.initials: JD
authors.lastname: Edwards
authors.forename: Hamid
authors.initials: H
authors.lastname: Aghdam
authors.forename: Nader
authors.initials: N
authors.lastname: Sadeghi
mesh_terms: D000328:Adult; D004724:Endoscopy; D005240:Feasibility Studies; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008443:Maxillary Sinus / Q000000981:diagnostic imaging / Q000473:pathology*; D008444:Maxillary Sinus Neoplasms / Q000601:surgery; D009929:Organ Size; D013517:Otorhinolaryngologic Surgical Procedures / Q000379:methods; D014057:Tomography, X-Ray Computed