title: Trephination for canalicular obstruction: experience in 45 eyes.
abstract: OBJECTIVE
  To evaluate efficacy of a trephination procedure for resolution of primary canalicular obstruction or obstruction secondary to failed dacryocystorhinostomy (DCR).
  
  
  METHODS
  Retrospective review of patients in a single surgeon's practice who underwent trephination with Crawford tube insertion between 2001 and 2011, with a minimum follow-up period of 12 months. Indications for surgery included symptomatic patients either with primary canalicular obstruction or secondary obstruction after a failed DCR.
  
  
  RESULTS
  Trephination was carried out on 45 eyes of 43 patients; 78% were female, and average age at trephination was 61.0 years (range 32 to 89). Thirty-two eyes had previous DCR (75% endonasal, 25% external); mean interval of trephination after DCR was 1.4 years (range 0.3-9.1). Crawford stent tubes were left in-situ in 2 patients; in the remainder, tubes were removed at a mean interval of 5.6 months (range 0.3-20.6). The vast majority of presenting canalicular obstructions were in the common canalicus (73%). Sixteen eyes (36%) underwent a single trephination, and 29 eyes (64%) required repeat intervention; of these, 16 eyes had DCR (3 endonasal, 13 external) and 13 eyes had either repeat trephination with stenting (10 eyes) or repeat stenting alone (3 eyes). When separated into those with primary versus secondary obstruction, re-operation rate was similar in both groups (63% versus 69%). No patients developed complications after trephination.
  
  
  CONCLUSIONS
  Trephination is a simple and effective intervention for canalicular obstruction that allowed 64% of patients, through one or two procedures, to avoid the morbidity of DCR.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia , Vancouver , Canada and.
authors.forename: Nawaaz A
authors.initials: NA
authors.lastname: Nathoo
authors.forename: Suryasnata
authors.initials: S
authors.lastname: Rath
authors.forename: Darwin
authors.initials: D
authors.lastname: Wan
authors.forename: Frank
authors.initials: F
authors.lastname: Buffam
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D007440:Intubation / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome