title: Modified endoscopic dacryocystorhinostomy with posterior lacrimal sac flap for nasolacrimal duct obstruction.
abstract: OBJECTIVE
  To evaluate a new technique of modified endoscopic dacryocystorhinostomy involving the creation of a large posterior flap at the lacrimal sac and to compare its success rate with that of the conventional endoscopic method of excising the entire medial lacrimal sac wall as a surgical treatment for epiphora caused by nasolacrimal duct obstruction.
  
  
  METHODS
  Retrospective, interventional, and comparative case series.
  
  
  METHODS
  University teaching hospital, Hong Kong.
  
  
  METHODS
  Only adults with primary nasolacrimal duct obstruction were included. Consecutive endoscopic dacryocystorhinostomy was performed using two different techniques from July 1999 to June 2001. The new technique involved the creation of a large posterior flap at the medial lacrimal sac wall, reflecting it posteriorly, followed by removal of the remaining small anterior flap (the LSF group). Other patients had the entire medial lacrimal sac wall excised (the ELS group).
  
  
  METHODS
  Surgical success was defined by free fluorescein drainage from the conjunctival sac into the rhinostomy site at least 3 months after silicone stent removal.
  
  
  RESULTS
  Ninety-nine procedures were performed in 99 patients. The success rate was 89.1% (41/46) in the LSF group and 71.7% (38/53) in the ELS group. The difference between the two groups was statistically significant (Chi squared test, P=0.031).
  
  
  CONCLUSIONS
  Our new and modified technique of endonasal dacryocystorhinostomy has a greater success rate than conventional endonasal dacryocystorhinostomy. A large-scale prospective randomised controlled trial to further evaluate the efficacy and safety of this surgical technique is under way.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: K S C
authors.initials: KS
authors.lastname: Yuen
authors.forename: L Y M
authors.initials: LY
authors.lastname: Lam
authors.forename: M W Y
authors.initials: MW
authors.lastname: Tse
authors.forename: D D N
authors.initials: DD
authors.lastname: Chan
authors.forename: B W C
authors.initials: BW
authors.lastname: Wong
authors.forename: W M
authors.initials: WM
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003608:Dacryocystorhinostomy / Q000379:methods*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013524:Surgical Flaps; D016896:Treatment Outcome