Randomized Controlled Trial on Silicone Intubation in Endoscopic Mechanical Dacryocystorhinostomy (SEND): An 11-year Outcome Report

Purpose: To compare the long-term outcomes of mucosal-sparing mechanical endoscopic dacryocystorhinostomy (MMED) for primary acquired nasolacrimal duct obstruction (PANDO) with or without silicone intubation.

Methods: An 11-year follow-up study of the Silicone intubation in Endoscopic Dacryocystorhinostomy (SEND) randomized controlled trial (RCT) was conducted at a university-affiliated dacryology clinic from December 2019 to March 2023. Questionnaires on symptoms, anterior segment examination, endoscopic examination with functional endoscopic dye test (FEDT) and FICI grading, and ostial size measurements using Image J software were performed by a masked ophthalmologist. The primary outcome was surgical success, defined by Munk's score ≤1 and a positive fluorescein endoscopic dye test. Secondary outcomes included risk factors for failure and outcomes of revision surgeries.

Results: Fifty-three of the original 118 patients were evaluated at 155 ± 21 (136-218) months postoperatively. Seventy-seven percent (46/60) ostia remained successful, including 70% (19/27) of unstented and 82% (27/33) of stented ostia (p = .3). Stented ostia had larger size (p = .003), but this did not confer higher success (p = .14). Successful ostia had higher FICI scores and better ostial dynamicity (p < .05). Ostium movement was the only parameter associated with surgical success on multivariate analysis (OR 13.1, p = .01). Four (1 stented) underwent revision MMED, intraoperative mitomycin-C, and 12-week intubation. All revision ostia were functional after 141 ± 43 months.

Conclusions: Surgical success of MMED after 11-years was 77%, a notable reduction compared to 96% success at 1-year. Statistical advantage of silicone intubation for primary MMED was not demonstrated, though clinically, stented ostia had a higher success (82% vs 70%). The presence of a dynamic internal common opening was highly associated with long-term surgical success.