title: Randomized trial on silicone intubation in endoscopic mechanical dacryocystorhinostomy (SEND) for primary nasolacrimal duct obstruction.
abstract: OBJECTIVE
  To study the effect of bicanalicular silicone intubation on endonasal endoscopic mechanical dacryocystorhinostomy (EEM-DCR) for primary acquired nasolacrimal duct obstruction (PANDO).
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  A total of 120 consecutive adults (103 females) with a presenting age of 64 ± 13.7 years (range, 39-92 years) underwent EEM-DCR for PANDO from November 2005 to May 2009 in a lacrimal referral center.
  
  
  METHODS
  The EEM-DCR was performed by 2 lacrimal surgeons using standard techniques. Patients were randomly assigned to receive or not receive bicanalicular silicone intubation for 8 weeks. No antimetabolite was used. All patients received a course of oral antibiotics during nonabsorbable nasal packing for flaps tamponade, which was removed at the first postoperative visit. Patients were assessed at 1, 3, 6, 12, 26, and 52 weeks after the operation.
  
  
  METHODS
  Surgical success was defined by symptomatic relief of epiphora, reestablishment of nasolacrimal drainage confirmed by irrigation by 1 masked observer, and positive functional endoscopic dye test by the operative surgeon at 12 months postoperatively. Intraoperative and postoperative complications were recorded.
  
  
  RESULTS
  A total of 118 of the 120 randomized cases completed 12 months of follow-up. Two patients died of unrelated medical illnesses during follow-up. At 12 months postoperatively, there was no statistical difference in the success rate between patients with (96.3%) and without (95.3%) intubation (P=0.79). The odds ratio of failure without silicone intubation was 1.28 (95% confidence interval, 0.21-7.95). There was no difference in the incidence (P=0.97) or the time to develop (P=0.12) granulation tissue between the 2 groups. No significant difference was found between successful and failed cases in terms of age (P=0.21), sex (P=0.37), laterality (P=0.46), mode of anesthesia (P=0.14), surgeon (P=0.26), use of stent (P=0.79), or presence of granulation tissue postoperatively (P=0.39).
  
  
  CONCLUSIONS
  The current study design provided 90% statistical power to detect more than 21% difference in surgical outcome, and no such difference was found whether intubation was used or not used in EEM-DCR for PANDO at the 12-month follow-up.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong, HKSAR, China; Department of Ophthalmology and Visual Science, The Chinese University of Hong Kong, HKSAR, China. Electronic address: chongkamlung@cuhk.edu.hk.
authors.forename: Kelvin K L
authors.initials: KK
authors.lastname: Chong
authors.forename: Frank H P
authors.initials: FH
authors.lastname: Lai
authors.forename: Mary
authors.initials: M
authors.lastname: Ho
authors.forename: Abbie
authors.initials: A
authors.lastname: Luk
authors.forename: Ben W
authors.initials: BW
authors.lastname: Wong
authors.forename: Alvin
authors.initials: A
authors.lastname: Young
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003608:Dacryocystorhinostomy / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007440:Intubation / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000601:surgery*; D012826:Silicone Elastomers; D015607:Stents
chemical_list: D012826:Silicone Elastomers