High frequency hearing 25 years after transmyringeal ventilation tube treatment.

OBJECTIVES: The main aim of the study was to compare hearing outcome between a healthy control group and patients treated with transmyringeal ventilation tubes, 25 years after primary surgery. Another aim was to analyse the relation between ventilation tube treatment in childhood and the occurrence of persistent middle ear pathology 25 years later.

METHODS: In 1996, children treated with transmyringeal ventilation tubes were recruited for a prospective study on the outcome of ventilation tube treatment. In 2006, a healthy control group were recruited and examined together with the original participants (case group). All participants in the 2006 follow-up were eligible for this study. A clinical ear microscopy examination including eardrum pathology grading and high frequency audiometry (10-16 kHz) was carried out.

RESULTS: A total of 52 participants were available for analysis. Hearing outcome was worse in the treatment group (n = 29) compared to the control group (n = 29), both in regard to standard frequency range hearing, (0.5-4 kHz), and high frequency hearing (HPTA3 10-16 kHz). Almost half the case group (48%) had eardrum retraction to some extent, compared to 10% in the control group. No case of cholesteatoma was found in this study and eardrum perforation was rare (<2%).

CONCLUSION: In the long term, high frequency hearing (HPTA3 10-16 kHz) was more often affected in the patients with transmyringeal ventilation tube treatment during childhood compared with the healthy controls. Middle ear pathology of greater clinical significance was rare.