Objectives: (1) To conduct an adequately powered randomized controlled trial investigating the safety and efficacy of mitomycin C-enhanced revision endoscopic dacryocystorhinostomy (DCR) and (2) to analyze causes of failure after primary endoscopic DCR.
Study design: A randomized controlled study.
Setting: General hospital.
Subjects and methods: Seventy-six revision endoscopic DCRs were randomized into 2 groups: endoscopic DCR with mitomycin (group I), where 0.5 mg/mL mitomycin C was applied for 10 minutes, and endoscopic DCR without mitomycin (group II). Follow-up settings were done to document the patient's subjective improvement, to judge ostium patency on irrigation, and to record any complications.
Results: Causes of failure in the original 92 patients included canalicular obstruction (14%), small misplaced bony window (43%), very small nasolacrimal stoma due to development of synechia (23%), and complete closure of nasolacrimal stoma with tough fibrous tissue (63%). There was no significant difference between the 2 groups in subjective and objective success rates and adverse events. Group I demonstrated a significantly longer operative time and a significantly lower number of debridement sessions (mean of 1.2 vs 1.9).
Conclusions: Recurrent nasolacrimal duct obstruction after primary endoscopic DCR is mainly due to reclosure of the nasolacrimal stoma with synechia and fashioning of the small misplaced bony window. Mitomycin C does not increase the success rate of revision endoscopic DCR. It is a safe procedure and may be of value only in patients inaccessible to strict follow-up because it induces a better healing profile in terms of mucosal recovery, wound healing, and less need for debridement sessions.