Long-term results and factors affecting patency after removal of nasolacrimal stents

PURPOSE: To retrospectively evaluate the long-term patency and prognostic factors affecting patency after removal of nasolacrimal stents. MATERIALS AND METHODS: Lacrimal polyurethane stents were removed from 317 lacrimal drainage systems of 275 patients because the stent ceased to function, and immediate and maintained patency were determined with follow-up dacryocystography (DCG) after stent removal. Prognostic factors for patency after stent removal were evaluated by univariate and multivariate analyses for immediate patency and Kaplan-Meier survival analysis and multivariate analysis for maintained patency. RESULTS: All stents were successfully removed under fluoroscopic or endoscopic guidance. After stent removal, 243 lacrimal systems (77%) showed immediate patency. The size of the lacrimal sac was the same (65% of cases), widened (2%), or contracted (33%) after stent removal. The shape of the lacrimal sac was normal in 30% and irregular in 70% of cases after stent removal. Seven-day follow-up DCG was obtained in 169 cases, and maintained patency of the lacrimal system was confirmed on 7-day follow-up DCG in 125 cases. Epiphora recurred in 70 cases (56%) during the mean 8-month follow-up period (range, 1-48 months). The mean maintained patency period after stent removal was 15.7 ± 2.1 months. The maintained patency rates were 41% at 1 year, 31% at 2 years, and 14% at 4 years after stent removal. Multivariate analysis showed that the size of the lacrimal sac (P < .001) was the only factor affecting immediate and maintained patency after stent removal. CONCLUSIONS: After stent removal in patients with nasolacrimal stent obstruction, the immediate patency rate was 77%; however, the rate of maintained patency decreased progressively with time. The major factor negatively affecting immediate and maintained patency after stent removal was contraction of the lacrimal sac at the time of stent removal.