title: Systematic review and meta-analysis on outcomes for endoscopic versus external dacryocystorhinostomy.
abstract: BACKGROUND
  Dacryocystorhinostomy (DCR) is commonly performed for epiphora, dacryocystitis and during tumor surgery. External (EXT-DCR) and endoscopic DCR (END-DCR) are both practiced. END-DCR was initially performed with laser (EL-DCR) but has shifted to careful bone removal with mechanical drills (EM-DCR). High level evidence from comparative cohorts was sought to compare outcomes.
  
  
  METHODS
  Medline (1966 - January 28th, 2013) and Embase (1980 - January 28(th), 2013) were searched for comparative studies (RCT/cohorts) of END-DCR to EXT-DCR for acquired nasolacrimal duct (NLD) obstruction. Primary outcome was DCR success, defined as resolution of symptoms and/or patent NLD on irrigation or dacroscintography. Secondary outcomes were scarring, infection and post-operative bleeding. Meta-analysis was performed with the Mantel-Haenszel Method and presented as Risk Ratios (RR) with Confidence Intervals (CI).
  
  
  RESULTS
  The search identified 3582 studies and 355 were reviewed after screening. Full text review yielded 19 studies (4 RCTs and 15 cohorts). Overall, EXT-DCR had slightly better success rates than END-DCR (RR 0.96, CI 0.93-1.00). However, EM-DCR outcomes were comparable to EXT-DCR (RR 1.02, CI 0.98-1.06), whereas EL-DCR had poorer outcomes (RR 0.85, CI 0.79-0.91) when compared separately. The RR for scarring, bleeding and infection with END-DCR versus EXT-DCR was 0.07 (CI 0.02-0.22), 0.72 (CI 0.46-1.13) and 0.24 (CI 0.11- 0.54), respectively. The rates of reported revision surgery were similar.
  
  
  CONCLUSIONS
  DCR is a procedure with high success rates. Endoscopic procedures differ greatly by technique with EM-DCR offering comparable results to EXT-DCR, without the risk of cosmetically unacceptable scars.
authors.affiliation: Department of Otorhinolaryngology, Hornsby Hospital , Hornsby, New South Wales , Australia .
authors.forename: June
authors.initials: J
authors.lastname: Huang
authors.forename: Joanne
authors.initials: J
authors.lastname: Malek
authors.forename: David
authors.initials: D
authors.lastname: Chin
authors.forename: Kornkiat
authors.initials: K
authors.lastname: Snidvongs
authors.forename: Geoff
authors.initials: G
authors.lastname: Wilcsek
authors.forename: Krishna
authors.initials: K
authors.lastname: Tumuluri
authors.forename: Ray
authors.initials: R
authors.lastname: Sacks
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Harvey
mesh_terms: D003608:Dacryocystorhinostomy / Q000009:adverse effects / Q000379:methods*; D016208:Databases, Factual; D004724:Endoscopy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D009301:Nasolacrimal Duct / Q000601:surgery*; D016896:Treatment Outcome