title: Biofilm colonisation in nasolacrimal stents.
abstract: OBJECTIVE
  Nasolacrimal duct obstruction is a common problem. A Song stent is a useful and simple treatment with low morbidity. However, the success rate is limited, especially in long-term follow-up. The aim of the present study is to determine the presence of biofilms in failing nasolacrimal stents.
  
  
  METHODS
  Thirty-three polyurethane nasolacrimal stents were implanted between January 2006 and December 2007 using Song's technique. Patients were followed for a mean of 21.5 months (range 11-30 months). Removed nasolacrimal stents were preserved in saline and examined using environmental scanning electron microscopy (ESEM).
  
  
  RESULTS
  Eighteen nasolacrimal stents were removed because of the failure of the device (follow-up range 11-30 months). Seven stents were recovered for this study. Biofilms were identified in all the specimens studied. Five prostheses showed occlusion caused by mucus or granulation tissue.
  
  
  CONCLUSIONS
  Biofilm colonisation of nasolacrimal stents could play a major role in prosthetic failure leading to stent occlusion. Mucus, granulation tissue and irregularities of the biomaterial are factors that facilitate biofilm colonisation. Non-stick material for newly developed stents or drugs capable of destroying the polysaccharide matrix should be considered as future therapeutic options.
authors.affiliation: Department of Otorhinolaryngology, Hospital Universitario Puerta de Hierro-Majadahonda, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ibáñez
authors.forename: A
authors.initials: A
authors.lastname: Trinidad
authors.forename: J R
authors.initials: JR
authors.lastname: García-Berrocal
authors.forename: D
authors.initials: D
authors.lastname: Gómez
authors.forename: J
authors.initials: J
authors.lastname: San Román
authors.forename: R
authors.initials: R
authors.lastname: Ramírez-Camacho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018441:Biofilms; D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011475:Prosthesis Failure; D015607:Stents / Q000382:microbiology*