title: Mechanical endonasal dacryocystorhinostomy versus external dacryocystorhinostomy.
abstract: OBJECTIVE
  To compare the success rates of a new mechanical endonasal dacryocystorhinostomy (MENDCR) technique and the conventional external dacryocystorhinostomy technique (Ext-DCR).
  
  
  METHODS
  A prospective, nonrandomized interventional comparative case series of 31 consecutive MENDCRs and 24 Ext-DCRs performed from January 1999 to December 2000. Patients with anatomic nasolacrimal duct obstruction were included in the study; previous lacrimal surgery and functional nasolacrimal and canalicular obstruction were exclusion criteria. Two surgeons performed the MENDCRs, using a standardized operative technique, which involved creation of a large bony ostium and mucosal flaps between the lacrimal sac mucosa and nasal mucosa. One surgeon performed all Ext-DCRs.
  
  
  RESULTS
  Twenty-seven patients (8 men, 19 women) underwent 31 MENDCRs. The average age of the patients was 62.9 years (range, 15 to 86 years; SD, 19.1 years). In 11 cases (35.4%), a septoplasty was required at the time of surgery, and in 6 cases (19%), further endoscopic sinus surgery was performed. In the Ext-DCR group, 23 patients (7 men, 16 women) underwent 24 DCRs. The average age was 59.6 years (range, 22 to 86 years; SD, 18.5 years). No other nasal procedures were performed at the time of surgery in this group. The average follow-up time was 13 months for the MENDCR group and 12.4 months for the Ext-DCR group. Success was defined as relief of symptoms and by anatomic patency, which was assessed by history, fluorescein flow on nasal endoscopy, and lacrimal syringing. In the MENDCR group, surgery was successful in 29 of 31 DCRs (93.5%); 1 of 2 failed cases was anatomically patent but symptomatic, yielding an anatomic patency rate of 96.8%. In the Ext-DCR group, the success rate was 95.8% (23/24 DCRs); the failed case was anatomically patent but symptomatic, giving an anatomic patency rate of 100%. The differences in overall success and anatomic patency were not statistically significant (P = 0.6 and P = 0.56, 1-tailed Fisher exact test).
  
  
  CONCLUSIONS
  The success rate of MENDCR (93.5%) compares favorably with that of standard external DCR (95.8% in this study). MENDCR relies on the creation of a large ostium and mucosal flap apposition. A larger, randomized prospective trial is needed to fully assess the efficacy of this new technique.
authors.affiliation: Department of Ophthalmology, Flinders Medical Centre and Queen Elizabeth Hospital, Adelaide, South Australia. Ophthalmology@fmc.sa.gov.au
authors.forename: Angelo
authors.initials: A
authors.lastname: Tsirbas
authors.forename: Garry
authors.initials: G
authors.lastname: Davis
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Wormald
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003608:Dacryocystorhinostomy / Q000379:methods*; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies