Comparative study of laser versus radiofrequency myringotomy in rabbits: The effectiveness of mitomycin C application.

OBJECTIVE

To compare laser-assisted tympanostomy (LAT) with radiofrequency myringotomy (RFM), as well as the effectiveness of mitomycin C (MC) on the above techniques, in rabbits.

STUDY DESIGN

Experimental animal research protocol.

SETTING

University of Crete, School of Medicine, Medical Experimental Education and Research Center.

METHODS

Bilateral myringotomies were performed under general anesthesia on 40 rabbits. LAT was performed on 20 animals (40 ears) and RFM on the remaining 20 animals (40 ears). MC (0.3 mg/mL) pledgets were applied to the right ears and saline pledgets to the left ears. Animals were monitored weekly using otomicroscopy until myringotomy closure. Kaplan-Meier survival techniques were used to compare myringotomy patency times.

INTERVENTIONS

Under general anesthesia, bilateral LAT was performed on 20 rabbits and bilateral RFM on 20 rabbits.

MAIN OUTCOME MEASURES

Myringotomy patency time.

RESULTS

The mean patency times of the saline-treated ears were: 1.85 weeks (95% confidence interval [CI], 1.556-2.144 wk) for the LAT group and 1.70 weeks (95% CI, 1.494-1.906 wk) for the RFM group. This difference was not significant (p > 0.5). MC application significantly prolonged mean patency time (p < 0.0001) in both LAT and RFM groups. The mean patency times in the MC-treated ears were 5.45 weeks (95% CI, 5.226-5.674 wk) for the LAT group and 5.55 weeks (95% CI, 5.285-5.815 wk) for the RFM group. This difference was not significant (p > 0.5).

CONCLUSION

There is no significant difference in myringotomy patency times between LAT and RFM techniques in rabbits, whereas MC significantly prolongs the patency rate of either technique.