Clinical outcomes and factors associated with recurrence after bicanalicular silicone tube intubation: a large retrospective cohort study
Abstract
Aims: To evaluate long-term clinical outcomes and factors associated with recurrence after nasolacrimal drainage procedures with bicanalicular silicone intubation. Methods: This retrospective cohort included 1576 patients (2094 eyes) treated between 2008 and 2025 at a tertiary referral center. All tubes underwent square-knot fixation without additional intranasal fixation; no comparator group was available. Success required a Munk score of 0–1 and patent irrigation at final follow-up, coinciding with tube removal for eyes followed for only three months. Generalized estimating equation (GEE) logistic regression accounted for bilateral eye correlation. Sensitivity analyses compared pediatric and adult patients, repeated multivariable GEE in adults, and stratified follow-up (3–12, 13–24, and >24 months). Results: Recurrence occurred in 5.9% of eyes (123/2094), ranging from 5.5% after external dacryocystorhinostomy to 13.2% after probing with intubation (p=0.016). External dacryocystorhinostomy comprised over 90% of procedures, limiting comparisons. Epiphora, postoperative complications, and tube exposure occurred in 6.7%, 11.0%, and 5.3%, respectively; exposure was not significantly associated with recurrence. Multivariable GEE identified associatio with probing [odds ratio (OR) 2.79, 95% confidence interval (CI) 1.22–6.37; p=0.015], increasing age (OR 1.01, 95% CI 1.00–1.03; p=0.048), and attending-surgeon procedures (OR 1.69, 95% CI 1.07–2.69; p=0.026). Recurrence was higher with longer documented follow-up. Conclusion: Standardized square-knot fixation was accompanied by 5.9% recurrence and 11.0% postoperative complications. Associations are descriptive and hypothesis-generating given subgroup imbalance, incomplete covariate information, variable follow-up, and residual confounding. The attending-surgeon association may reflect case selection or other unmeasured factors. These findings do not establish causality, fixation superiority, comparative effectiveness, or surgeon performance.