S A Estrem1, T J Baker. 1. Division of Otolaryngology, Department of Surgery, University of Missouri School of Medicine, Columbia, MO 65212, USA.
Abstract
OBJECTIVES: Ventilation tubes are the mainstay of surgical treatment for eustachian tube dysfunction and have been used successfully for many years. Certain disadvantages of ventilation tubes, however, have prompted research into alternative techniques including laser myringotomy. We investigated the use of KTP laser myringotomy in conjunction with topical mitomycin C to delay healing and prolong the patency of the myringotomy. METHODS: Twenty myringotomies were created in 10 Sprague-Dawley rats. A solution of mitomycin C was applied to the intact tympanic membrane for 15 minutes. The solution was then suctioned free, and a myringotomy was created with a KTP laser. Fifty-three rats with saline application serving as controls from a previous study were used to allow statistical assessment. RESULTS: The myringotomies remained open for a median of 9.5 weeks. Control myringotomies, which received saline solution instead of mitomycin C, healed within a median of 1.5 weeks. The difference was statistically significant at P < 0.0001. No complications were noted. CONCLUSION: Topically administered mitomycin C before laser myringotomy is effective in prolonging the patency of laser myringotomies in rats. The patency rate is similar to that achieved in experiments in which topical mitomycin C is placed into the myringotomy site created by the laser.
OBJECTIVES: Ventilation tubes are the mainstay of surgical treatment for eustachian tube dysfunction and have been used successfully for many years. Certain disadvantages of ventilation tubes, however, have prompted research into alternative techniques including laser myringotomy. We investigated the use of KTP laser myringotomy in conjunction with topical mitomycin C to delay healing and prolong the patency of the myringotomy. METHODS: Twenty myringotomies were created in 10 Sprague-Dawley rats. A solution of mitomycin C was applied to the intact tympanic membrane for 15 minutes. The solution was then suctioned free, and a myringotomy was created with a KTP laser. Fifty-three rats with saline application serving as controls from a previous study were used to allow statistical assessment. RESULTS: The myringotomies remained open for a median of 9.5 weeks. Control myringotomies, which received saline solution instead of mitomycin C, healed within a median of 1.5 weeks. The difference was statistically significant at P < 0.0001. No complications were noted. CONCLUSION: Topically administered mitomycin C before laser myringotomy is effective in prolonging the patency of laser myringotomies in rats. The patency rate is similar to that achieved in experiments in which topical mitomycin C is placed into the myringotomy site created by the laser.