Szpak Kamila, Wiatr Agnieszka, Wiatr Maciej
Department of Otolaryngology, University Hospital, Cracow, Poland.
Department of Otolaryngology, Jagiellonian University Medical College, Cracow, Poland.
Med Sci Monit. 2025 Jan 22;31:e947061. doi: 10.12659/MSM.947061.
BACKGROUND The Carhart effect consists of a reduction in bone conduction thresholds associated with conductive hearing loss. The aim of this study was to evaluate the role of the Carhart effect in predicting outcomes from surgery in 3 age groups. MATERIAL AND METHODS This study included 532 patients with conductive hearing loss due to otosclerosis, otitis media with effusion, and chronic otitis media who underwent surgery between 2010 and 2020. RESULTS The depth of the Carhart effect is a favorable prognostic factor for changes in BC (bone conduction) thresholds after ear surgery in younger patients. A deep Carhart effect in older people is an unfavorable prognostic factor for improving BC thresholds. The restoration of physiological amplification of the sound that was transmitted through the ossicular chain led to a statistically significant change in the Carhart effect and a strong positive correlation between the change in the Carhart effect and the change in average BC thresholds. The influence of the Carhart effect on the postoperative change in the ABG (air-bone gap) is most noticeable when the physiological strengthening of the middle ear is maintained. CONCLUSIONS This findings from this study have shown that the depth of the Carhart effect is one of many factors that should be considered when predicting the results of ear surgery. The depth of the Carhart effect is a favorable prognostic factor for the postoperative changes in BC threshold and for change in the ABG when the physiological strengthening of the middle ear is maintained.
背景 卡哈特效应表现为与传导性听力损失相关的骨导阈值降低。本研究的目的是评估卡哈特效应在预测3个年龄组手术结果中的作用。材料与方法 本研究纳入了2010年至2020年间因耳硬化症、分泌性中耳炎和慢性中耳炎接受手术的532例传导性听力损失患者。结果 卡哈特效应的深度是年轻患者耳部手术后骨导（BC）阈值变化的有利预后因素。老年人中卡哈特效应明显是骨导阈值改善的不利预后因素。通过听骨链传导的声音生理放大的恢复导致卡哈特效应有统计学意义的变化，且卡哈特效应变化与平均骨导阈值变化之间存在强正相关。当维持中耳的生理强化时，卡哈特效应对气骨导间距（ABG）术后变化的影响最为明显。结论 本研究结果表明，卡哈特效应的深度是预测耳部手术结果时应考虑的众多因素之一。当维持中耳的生理强化时，卡哈特效应的深度是骨导阈值术后变化和气骨导间距变化的有利预后因素。
