Objective: To examine the clinical findings of acquired bilateral cholesteatoma with special reference to incidence of habitual sniffing and sniff-related negative middle ear pressure.
Methods: Eighty-eight fresh cases of unilateral cholesteatoma and 33 fresh cases of bilateral cholesteatoma, which were operated on at Department of Otolaryngology, Hyogo College of Medicine, were examined in this study. Responses to a detailed questionnaire were obtained from the patients concerning about the habit of habitual sniffing to relieve aural symptoms such as aural fullness, autophonia or hyperacusis. The same questionnaire was obtained from unilateral cholesteatoma patients to compare the incidence of habitual sniffing with that of patients with bilateral cholesteatoma. We measured the negative middle ear pressure at the time of sniffing by using TTAG (tubo-tympano aerodynamic graphy, Nagashima Co. Ltd, Tokyo). We also compared the positive percentage of the sniff test in bilateral cholesteatoma with in unilateral cholesteatoma and normal controls. Sniff test was performed in 30 patients with bilateral cholesteatoma, 20 patients with unilateral cholesteatoma and 20 normal controls.
Results: In 33 patients with bilateral cholesteatoma (66 ears), 57 ears had the pars flaccida type (86.4%) and 9 ears had the pars tensa type (13.6%). Cholesteatoma of pars flaccida type were predominant in bilateral cholesteatoma. The rate of habitual sniffing of bilateral cholesteatoma (23/33, 69.7%) was significantly higher than that of unilateral cholesteatoma (21/88, 23.9%). The incidence of positive sniff test in bilateral cholesteatoma (19/30, 63.3%) was significantly higher than in unilateral one (6/20, 30%) and normal control (3/20, 15%).
Conclusions: Habitual sniffing was closely related to the pathogenesis of bilateral cholesteatoma, especially in cases with bilateral pars flaccida type.