title: Cadaveric anatomical comparison of the lateral nasal wall after external and endonasal dacryocystorhinostomy.
abstract: OBJECTIVE
  Much literature has accumulated espousing the relative merits of endonasal and external dacryocystorhinostomy (DCR). However, there is comparatively little information on the relative anatomic differences between these 2 approaches. The purpose of this study is to investigate the anatomic relationships of the lateral nasal wall for endonasal and external DCR.
  
  
  METHODS
  Ten cadaver half heads were used in this study. Half were subject to endonasal and half to external DCR procedures. The lateral nasal wall was then dissected and measurements were taken of ostium and anastomosis size and position relative to other landmarks on the lateral nasal wall. Relationships were compared between the 2 procedures.
  
  
  RESULTS
  The dimensions and area of the ostium and the anastomosis were similar between the 2 procedures. The lower portion of the ostium was located more inferiorly in endonasal DCR. Additionally, the ostium was more likely to be found lateral to the axilla of the middle turbinate in endonasal DCR, when compared with anterior for external. External DCR was also more likely to involve opening the anterior ethmoid air cells than endonasal approach.
  
  
  CONCLUSIONS
  Endonasal and external DCR osteomies appear to be of similar size, with the endonasal opening being located slightly lower and more posterior on the lateral nasal wall.
authors.affiliation: Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Dan
authors.initials: D
authors.lastname: Rootman
authors.forename: Dan
authors.initials: D
authors.lastname: DeAngelis
authors.forename: Nancy
authors.initials: N
authors.lastname: Tucker
authors.forename: Albert
authors.initials: A
authors.lastname: Wu
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Hurwitz
mesh_terms: D002102:Cadaver; D003608:Dacryocystorhinostomy / Q000379:methods*; D006801:Humans; D009295:Nasal Bone / Q000033:anatomy & histology*; D009297:Nasal Mucosa / Q000601:surgery*; D009301:Nasolacrimal Duct / Q000601:surgery*; D010027:Osteotomy; D011446:Prospective Studies