Kobayashi Toshimitsu, Hasegawa Jun, Kikuchi Toshiaki, Suzuki Takahiro, Oshima Takeshi, Kawase Tetsuaki
Department of Otolaryngology-Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan.
Tohoku J Exp Med. 2009 Aug;218(4):317-24. doi: 10.1620/tjem.218.317.
The Eustachian tube is normally closed, but it opens upon swallowing for only less than one second to equalize the middle ear pressure with the atmospheric pressure, and immediately closes again. Patients with patulous Eustachian tube (PET) suffer from annoying symptoms, such as aural fullness (sensation of fullness in the ear), autophonia (abnormally loud audition of own voice), audition of breathing sound, and fluctuating sensation of the tympanic membrane upon respiration. The diagnosis of PET is not difficult when patients complain of such typical symptoms. However, there is an unexpected pitfall, in which the symptoms of PET are masked by the presence of conductive hearing loss and obvious middle ear pathology. Here, we propose that this condition be termed 'masked patulous Eustachian tube' to promote correct diagnosis prior to planning the middle ear surgery. Four representative patients with 'masked patulous Eustachian tube' are presented: two exhibited symptoms after repair of chronic perforation of the tympanic membrane, one after stapes surgery for otosclerosis, and one after cholesteatoma surgery. In these patients, the symptoms of PET became evident only after surgery due to the improvement of hearing. The degree of hearing improvement varied among the patients from 15 to 40 dB in average hearing level. It is therefore important to examine the presence of 'masked patulous Eustachian tube', in addition to a middle ear disease for which surgery is planned. The surgeon should inform the patient of the possibility of 'masked patulous Eustachian tube' to avoid the postoperative disappointment.
咽鼓管通常是闭合的，但在吞咽时会打开不到一秒钟，以使中耳压力与大气压力平衡，然后立即再次闭合。咽鼓管异常开放（PET）的患者会出现令人烦恼的症状，如耳闷（耳部胀满感）、自听过强（异常清晰地听到自己的声音）、呼吸音听觉、以及呼吸时鼓膜的波动感。当患者诉说这些典型症状时，PET的诊断并不困难。然而，存在一个意想不到的陷阱，即PET的症状被传导性听力损失和明显的中耳病变所掩盖。在此，我们建议将这种情况称为“隐匿性咽鼓管异常开放”，以便在计划中耳手术之前促进正确诊断。本文介绍了4例具有“隐匿性咽鼓管异常开放”的代表性患者：2例在鼓膜慢性穿孔修复后出现症状，1例在耳硬化症的镫骨手术后出现症状，1例在胆脂瘤手术后出现症状。在这些患者中，PET的症状仅在听力改善后的手术后才变得明显。患者的听力改善程度各不相同，平均听力水平提高了15至40分贝。因此，除了计划进行手术的中耳疾病外，检查“隐匿性咽鼓管异常开放”的存在也很重要。外科医生应告知患者“隐匿性咽鼓管异常开放”的可能性，以避免术后的失望。
