Use of adjunctive mitomycin C in external dacryocystorhinostomy surgery compared with surgery alone in patients with nasolacrimal duct obstruction: A prospective, double-masked, randomized, controlled trial

Abstract

Background: The most common cause for the failure of external dacryocystorhinostomy (DCR) surgery is the formation of granulation tissue at the osteotomy site or common canaliculus. Objectives: The aims of this study were to assess the efficacy of intraoperative adjunctive mitomycin C (MMC) treatment in external DCR surgery and to compare this procedure with the standard DCR procedure alone in the long term (1 year). Methods: In this prospective, double-masked, randomized, controlled trial, patients with primary acquired nasolacrimal duct obstruction were randomized (using a random number table) into 2 groups based on surgical procedure. In the MMC group, intraoperative adjunctive MMC 0.2 mg/mL was applied to the osteotomy site for 30 minutes. The control group underwent standard DCR procedure only. The results of the DCR surgeries were assessed using objective findings (eg, cessation of excessive tearing via nasolacrimal duct irrigation and the improvement in height of tear meniscus) and subjective symptoms (asking patients to describe the degree of tearing improvement). Both the patients and the researchers who were assessing the study outcomes were masked to treatment group. Results: One hundred eyes of 100 Turkish patients were assessed and equally randomized to the MMC (27 women, 23 men; mean [SD] age, 47.0 [7.6] years) and control (26 women, 24 men; mean age, 46.6 [8.8] years) groups. The follow-up period was not significantly different between the MMC and the control groups (13.1 [1.1] vs 13.2 [1.4] months). Significantly more eyes in the MMC group than the control group remained symptom-free throughout the 1-year follow-up period (45/50 [90%] vs 33/50 [66%]; P=0.005). Significantly more patients in the control group than the MMC group had an improvement in symptoms at the 1-year follow-up (8/50 [16%] vs 2/50 [4%] eyes; P=0.005). Based on the patency of the drainage system, the success rate was significantly greater in the MMC group than the control group (48/50 [96%] vs 42/50 [84%]; P=0.005). Based on nasolacrimal duct irrigation, significantly fewer patients in the MMC group than the control group had an enclosed naso-lacrimal duct (2/50 [4%] vs 8/50 [16%]). No adverse effects (eg, abnormal nasal bleeding, mucosal necrosis, infection) or any other surgical adverse events were observed. Conclusions: In the management of these patients with primary acquired nasolacrimal duct obstruction, adjunctive intraoperative MMC application with standard DCR surgery had a significantly higher success rate than did standard DCR surgery alone. Further large, double-masked, randomized studies are needed to confirm these findings.