Problem/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.
Methodology: 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.