title: [Endonasal anatomy of lacrimal sac and its clinical significance in dacryocystorhinostomy].
abstract: OBJECTIVE
  To explore the intranasal surface localization of the lacrimal sac in endoscopic dacryocystorhinostomy.
  
  
  METHODS
  Fifteen adult cadavers (30 sides) were studied, the data of projection position of the lacrimal sac on the lateral wall of nasal cavity were measured.
  
  
  RESULTS
  In 2/3 cadavers, the lacrimal sac is located above the axilla of the middle turbinate, and 1/3 lies below it. A majority of the lacrimal sac (2/3) are located below the entry point of the common lacrimal canaliculus, about 1/3 lies above it. Inner canthal ligament projects on the middle of the lacrimal sac, almost equal to the level of common lacrimal canaliculus. Thirty-two cases (thirty-nine sides) of chronic dacryocystitis were followed-up > 6 months after operation. Thirty-five sides were cured, 2 sides improved and 2 sides ineffective. The cure rate was 89.8%, improve rate 5.1% and ineffective rate 5.1%, respectively, and the total effective rate was 94.9%.
  
  
  CONCLUSIONS
  The central position of dacryocystorhinostomy should be 0.2 cm above the front of the axilla of the middle turbinate, to make an curved mucous membrane incision 0.8 cm above and 0. 4 cm below the front of the axilla of the middle turbinate and bone ostium about 1.2 cm x 1.0 cm. It is the best position in endoscopic dacryocystorhinostomy. Locating the inner canthal ligament with a bayonet type forceps to find the projection of lacrimal sac is also a simple and easy method.
authors.affiliation: Department of Otoyhinolaryngology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China. suq_zhang@163.com
authors.forename: Su-Qin
authors.initials: SQ
authors.lastname: Zhang
authors.forename: Pei-Liang
authors.initials: PL
authors.lastname: Jia
authors.forename: Hai-Hong
authors.initials: HH
authors.lastname: Tang
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Shen
authors.forename: Su-Min
authors.initials: SM
authors.lastname: Wang
authors.forename: Zhao-Ji
authors.initials: ZJ
authors.lastname: Li
authors.forename: Man-Jie
authors.initials: MJ
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000368:Aged; D000718:Anatomy, Regional; D002908:Chronic Disease; D003607:Dacryocystitis / Q000601:surgery*; D003608:Dacryocystorhinostomy / Q000379:methods*; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000033:anatomy & histology* / Q000601:surgery; D055815:Young Adult