Radiofrequency myringotomy with the topical use of mitomycin C: An experimental study

Department of Otolaryngology, University of Crete, School of Medicine, Heraklion, Crete, Greece.
Ontology & Neurotology (Impact Factor: 1.6). 02/2006; 27(1):4-7. DOI: 10.1097/01.mao.0000172411.80154.99
Source: PubMed

ABSTRACT To assess the use of radiofrequency myringotomy in combination with mitomycin C as an alternative myringotomy technique on rabbits.
Experimental animal research protocol.
University of Crete, School of Medicine, Medical Experimental Education and Research Center.
Radiofrequency myringotomies were performed under general anesthesia on both ears of 20 rabbits. Mitomycin C (0.3 mg/ml) pledgets were applied in the right ears (study group) and saline pledgets in the left ears (control group). Animals were monitored using otomicroscopy weekly until myringotomy closure. Kaplan-Meier survival techniques were used to compare myringotomy patency time between the two sides.
Radiofrequency myringotomy under general anesthesia on both ears of 20 rabbits.
Myringotomy patency time.
The mean patency time of the study group was 5.45 weeks (95% confidence interval, 5.185-5.715 weeks). The mean patency rate for the control side was 1.60 weeks (95% confidence interval, 1.38-1.82 weeks). The Breslow (generalized Wilcoxon) test showed the study group to have significantly longer patency of radiofrequency myringotomy than the control group (p<0.0001).
The patency period of radiofrequency myringotomy was not long enough to be proposed as an alternative to the insertion of ventilation tubes, although mitomycin C had a significant adjunct effect in prolonging the patency rate of radiofrequency myringotomy on rabbits.

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    Brazilian journal of otorhinolaryngology 12/2009; 75(6):847-51. · 0.62 Impact Factor
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    ABSTRACT: OBJECTIVE: A close relationship between reactive oxygen species (ROS) and myringosclerosis, which is a common complication of myringotomy, was recently reported. The objective of this study was to measure ROS levels directly in rat tympanic membranes using luminol-aided chemiluminescence (CL) in order to compare the levels of ROS after incisional and radiofrequency (RF) myringotomy. METHODS: Fifteen Sprague-Dawley rats were separated into three groups of five animals each. Bilateral myringotomies were made using an appropriate myringotomy lancet in Group 1 and RF in Group 2. Group 3 served as the control group with no myringotomy. Twenty-four hours after the procedure, all tympanic membranes were inspected with an otomicroscope and then excised for the measurement of ROS using luminol-aided CL. RESULTS: The mean ROS level in Group 1 was significantly higher than that in Groups 2 and 3 (p<0.05 for both). The difference in mean ROS level between Groups 2 and 3 was not significant (p>0.05). Otomicroscopy revealed increased vascularity and vessel dilation in all tympanic membranes that underwent myringotomy. Vascular dilation was observed in the annular region in the vessels that passed along the long arm of the malleus, in addition to the vessels feeding the anterior and posterior tympanomalleolar folds. CONCLUSIONS: Although the relationship between ROS and the development of myringosclerosis after myringotomy has been demonstrated, the present study is the first to compare incisional and RF myringotomy based on the measurement of ROS levels. Our results indicate that the increase in ROS due to myringotomy was greater following incisional myringotomy than RF myringotomy.
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