title: The polyurethane nasolacrimal duct stent for lower tear duct obstruction: long-term success rate and complications.
abstract: BACKGROUND
  The polyurethane nasolacrimal duct stent is used as an alternative to conventional techniques for treatment of lower tear duct obstruction. The aim of this study was to evaluate the clinical success rate after a follow-up of 2 years.
  
  
  METHODS
  Nasolacrimal duct stent implantation was attempted in 19 patients with nasolacrimal duct obstruction proven by digital substraction dacryocystography. The median age of the patients was 50 years, and the minimum duration of symptoms was 3 months. Patients were followed up 1 week, 6 months, 1 year and 2 years after the procedure.
  
  
  RESULTS
  Eighteen stents were implanted in 17 patients without surgical complications. All stents were proven to be patent at the end of the procedure. Success rate, defined as proportion of patients free of symptoms, was 66.6%, 55.5% and 50% after 1 week, 6 months and I year, respectively, and remained unchanged thereafter. Three stents had to be removed between 6 months and 2 years after implantation. Histological examination showed granulation tissue growing into the opening and obstructing the stent in one case.
  
  
  CONCLUSIONS
  Implantation of a polyurethane nasolacrimal duct stent is an alternative to conventional techniques in lower tear duct obstruction. Its overall success rate is lower than that reported after conventional dacryocystorhinostomy, but the procedure is fast, safe and reversible. Refinement of the surface and stent design may improve results in the future.
authors.affiliation: Universitäts-Krankenhaus Eppendorf, Hamburg, Germany. Schaudig@uke.uni-hamburg.de
authors.forename: U
authors.initials: U
authors.lastname: Schaudig
authors.forename: R
authors.initials: R
authors.lastname: Maas
mesh_terms: D000328:Adult; D000368:Aged; D001672:Biocompatible Materials; D003608:Dacryocystorhinostomy; D020878:Device Removal; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007767:Lacrimal Duct Obstruction / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D011140:Polyurethanes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000295:instrumentation*; D011859:Radiography; D012008:Recurrence; D012086:Reoperation; D015607:Stents
chemical_list: D001672:Biocompatible Materials; D011140:Polyurethanes