Abstract
OBJECTIVE: To investigate the eustachian tube (ET) function (ETF) in adults with ventilation tube (VT) inserted for the treatment of chronic otitis media with effusion (COME). MATERIALS AND METHODS: A total of 17 subjects with at least one VT were enrolled. A detailed history was obtained, and risk factors were assessed with questionnaires. Examination including nasopharyngeal video endoscopy and ETF tests, the forced response test (FRT), inflation-deflation test (IDT), and nasal/nasopharyngeal maneuvers (such as sniffing and Valsalva, Toynbee, and the diver's maneuvers) were performed. RESULTS: Averages for FRT were 580±333 daPa, 382±251 daPa, and 138±192 daPa for opening pressure, steady-state pressure, and closing pressure, respectively. Most subjects demonstrated minimal or weak active function during the FRT and IDT. While nasopharyngeal maneuvers changed the nasal/nasopharyngeal pressures, they did not significantly change the middle-ear pressures. These results indicated that most subjects had severe obstructive ET dysfunction (ETD) with an ET lumen that required high pressure differences to open and poor active muscular function inadequate for luminal dilation. These results imply that while any treatment to widen the ET, such as balloon dilation of the ET, is not expected to change the voluntary active muscular function, it may reduce the tissue pressures and resistance, thus facilitating luminal opening both passively and actively. CONCLUSION: Most patients with VT inserted for the treatment of COME appear to have an abnormal ETF with difficulty in passively opening the ET and weak active muscular function. Management of such patients addressing only passive properties may not be sufficient for the resolution of ETD.