A meta-analysis of primary external dacryocystorhinostomy with and without mitomycin C

To assess the efficacy and safety of local application of intraoperative mitomycin C (MMC) at the osteotomy site in primary external dacryocystorhinostomy (EX-DCR).

A comprehensive literature search of the Cochrane Library, PubMed and Embase was undertaken to identify relevant trials comparing EX-DCR with MMC (MMC group, from 0.2-1.0 mg/mL) and without MMC (control group). A total of nine randomized controlled trials (RCTs) were selected and a meta-analysis performed on the results of success rates, which were defined as patency of the nasolacrimal canal and symptomatic improvement. Statistical analysis was performed using RevMan 5.0 software.

Nine RCTs reporting on a total of 562 DCRs including patients in the age range 30-57 years were included in the meta-analysis. However, the total number of males and females could not be determined as only four RCTs reported on this aspect. There was a significantly higher success rate in the MMC group in comparison with the control group (odds ratio, OR, 2.11; 95% confidence interval, CI, 1.19-3.74, P = 0. 01). In two RCTs, the mean osteotomy size 6 months postoperatively was significantly larger in the MMC group than in the control group (about 27mm(2) in the MMC group versus about 12mm(2) in the control group in the first study, and about 22mm(2) in the MMC group versus about 18mm(2) in the control group in the second study, P < 0.005). No intraoperative or postoperative complications except two cases with delayed healing of the external skin wound were recorded in the MMC group.

Intraoperative MMC application seems to be a safe adjuvant that could reduce the closure rate of the osteotomy site after primary EX-DCR. Further well-organized, prospective, randomized studies involving larger patient numbers divided into subgroups for different concentrations of locally applied MMC are warranted.