title: Anterior maxillary wall and lacrimal duct relationship - CT analysis for prelacrimal access to the maxillary sinus.
abstract: The distance between the anterior wall of the maxillary sinus and the nasolacrimal duct shows a large individual variation.
  
  
  
  To evaluate the feasibility of accessing the maxillary sinus through a prelacrimal window access (PLWA), a series of 100 paranasal CT scans from adult patients was analysed retrospectively. The distance between the anterior maxillary wall and the anterior border of the lacrimal duct (= prelacrimal window) were measured in 200 sides.
  
  
  
  A distance of more the 7 mm was found in 12.5% maxillary sinuses and would enable straight forward PLWA. A distance between smaller than 7mm and larger than 3mm was present in 56.5% of sinuses, and would make surgical access more demanding. In 31.5% of maxillary sinuses the distance was smaller than or equal to 3mm and in these patients this approach would be difficult without transecting the nasolacrimal duct.
  
  
  
  Only in 12.5% of sinuses a prelacrimal endoscopic access is readily feasible, while in 56.5% temporary tear sac dislocation is required and in 31.5% lacrimal sac dislocation is always needed along with a significant amount of bone removal to enable PLWA.
authors.affiliation: Center for Otorhinolaryngology, Head and Neck Surgery, Hirslanden Clinic, Zurich, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Simmen
authors.affiliation: Center for Otorhinolaryngology, Head and Neck Surgery, Hirslanden Clinic, Zurich, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Veerasigamani
authors.affiliation: Center for Otorhinolaryngology, Head and Neck Surgery, Hirslanden Clinic, Zurich, Switzerland.
authors.forename: H R
authors.initials: HR
authors.lastname: Briner
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Queens Medical Centre, Nottingham, United Kingdom.
authors.forename: N
authors.initials: N
authors.lastname: Jones
authors.affiliation: Medical Radiological Institute MRI, Zurich, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Schuknecht
mesh_terms: D006801:Humans; D007765:Lacrimal Apparatus / Q000000981:diagnostic imaging* / Q000601:surgery; D008443:Maxillary Sinus / Q000000981:diagnostic imaging* / Q000601:surgery; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed