Interruption Of Ossicular Chain Research Articles

Diagnostic Value of Cone-Beam Computed Tomography in Conductive or Mixed Hearing Loss with Intact Tympanic Membrane.

Conductive or mixed hearing loss with an intact tympanic membrane is a group of diseases characterized by similar clinical symptoms. Definitive diagnosis depends on the findings of exploratory tympanic surgery. Cone-beam computed tomography (CBCT) has great potential for middle ear imaging. This study evaluated the diagnostic value of CBCT for conductive or mixed hearing loss with an intact tympanic membrane. CBCT and high-resolution computed tomography (HRCT) imaging data were collected from patients with an intact eardrum who received medical treatment in our hospital for conductive or mixed hearing loss from October 2020 to May 2023. The imaging characteristics and diagnostic values of CBCT and HRCT were analyzed. A total of 137 patients who met the inclusion criteria and underwent CBCT were enrolled, including 89 with otosclerosis, 41 with ossicular chain interruption, and 7 with tympanosclerosis. CBCT clearly displayed a middle ear focus, such as low-density lesions located in the fissula ante fenestram, ossicular chain malformation or dislocation, and tympanic calcification foci. The area under the curve values for otosclerosis, ossicular chain interruption, and tympanic sclerosis were 0.934, 0.967, and 0.850, respectively. CBCT was more effective than HRCT for visualizing the lenticular process, incudostapedial joint, and stapes footplate. CBCT of the middle ear demonstrated higher-quality imaging to improve the diagnosis of conductive or mixed hearing loss with an intact tympanic membrane. Therefore, CBCT is recommended for further investigation of noninflammatory diseases of the middle ear with no special findings on HRCT.

Indications of and Efficacy of Facial Nerve Decompression Through Endoscopic Transcanal Approach for Patients with Traumatic Facial Paralysis.

The aim of this study is to evaluate the indications and efficacy of facial nerve decompression through an endoscopic transcanal approach for patients with traumatic facial paralysis. This single-center retrospective study included 11 patients with traumatic facial paralysis from February 2018 to April 2019. We compared the facial nerve and auditory function before and after operation so as to reveal the feasibility and effect of the surgical approach. All 11 patients have successfully received facial nerve decompression through endoscopic transcanal approach. Facial nerve function was objectively evaluated by electroneurography test and House-Brackmann facial nerve grading system. All patients were graded HB-VI with electroneurography ≥ 95% before surgery. The recovery of facial nerve function was good (HB-I or II) (90.9%) a year after surgery with only one case (9.1%) for HB-III. Preoperative high-resolution computed tomography showed that 1 patient had ossicular chain interruption, which was confirmed during operation. Meanwhile, 2 patients with air-bone gap >35 dBHL and whose computed tomography failed to diagnose were found with ossicular chain interruption during operation. The air-bone gap of patients with normal ossicular chain connection was all <30 dBHL. The average air-bone gap was reduced from 27.5 ± 10.1 dBHL to 7.8 ± 3.3 dBHL after operation. Preoperative high-resolution computed tomography combined with localization test can accurately estimate the location of facial nerve injury. Facial nerve decompression through endoscopic transcanal approach can decompress the geniculate ganglion to pyramidal segment of facial nerve, which is suitable for patients with traumatic facial paralysis of this segment. In addition, air-bone gap >35 dBHL may indicate the ossicular chain interruption when it is difficult to be completely judged by high-resolution computed tomography.

Effect of ossicular chain deformity on reverse stimulation considering the overflow characteristics of third windows

Stimulating the round window membrane via an active actuator of the middle ear implant, named the reverse stimulation, has become an option to help patients with ossicular chain deformity (OCD) to restore hearing. However, there is still no concise description of how OCD affects reverse stimulation considering the overflow characteristics of third windows. In the present study, an impedance model considering the vestibular and cochlear aqueducts was used to investigate the dynamic response of the cochlea to reverse stimulation under OCD. First, a finite-element (FE) model of the middle ear and the ear canal was used to estimate the changes in reverse middle-ear impedance caused by ossicular chain fixation and ossicular chain interruption. Then, the impedance model was used to predict the reverse transfer function, which characterizes the effect of OCD on the dynamic response of the cochlea. The results show that ossicular chain fixation reduces the reverse stimulation’s performance. Moreover, the existence of the third windows complicates the effect of ossicular chain fixation on the reverse stimulation and boosts obviously the reverse stimulation’s performance at low frequencies. In contrast, regardless of the existence of third windows, ossicular chain interruption enhances the effect of reverse stimulation.

Surgical Management of Retraction Pockets: Does Mastoidectomy have a Role?

Introduction Retraction pocket is a condition in which the eardrum lies deeper within the middle ear. Its management has no consensus in literature. Objective To assess the role of mastoidectomy in the management of retraction pockets added to a tympanoplasty. Methods Prospective study of patients with retraction pocket and referred to surgery. The patients were randomly assigned to two groups: one managed with tympanoplasty and mastoidectomy and the other group with tympanoplasty only. The minimum follow-up considered was 12 months. The outcomes were: integrity of eardrum, recurrence, and hearing status. Results This study included 43 patients. In 24 cases retraction occurred in the posterior half of the eardrum, and in 19 patients there was clinical evidence of ossicular interruption. The two groups of treatment were composed by: 21 patients that underwent tympanoplasty with mastoidectomy and 22 patients had only tympanoplasty. One case of the first group had a recurrence. In 32 cases patients follow up was longer than 48 months. The average air-bone gap changed from 22.1 dB to 5 dB. The percentage of air-bone gap improvement was assessed at 60% in those patients treated with mastoidectomy, and 64.3% in those without it ( p > 0.5). Conclusion Tympanoplasty and ossiculoplasty should be considered to treat atelectatic middle ear and ossicular chain interruption. Mastoidectomy as a way to increase air volume in the ear seems to be a paradox; it does not add favorable prognostic factor to management of retraction pockets.

Clinical application of HRCT three-dimensional reconstruction in traumatic ossicular chain interruption

Objective:To investigate the clinical value of HRCT three-dimensional reconstruction technique in traumatic auditory chain traumatic fracture. Method:The clinical data of 14 patients with traumatic ear ossicular chain interruption were analyzed retrospectively. To evaluate the injury site and degree of the auditory chain before surgery, all the 14 patients underwent,HRCT scanning and three-dimensional reconstruction. The reconstructed auditory chain was observed from multiple angles and compared with the surgical exploration results under microscope. Result:The coincidence rate between ossicular chain injury observed by temporal bone HRCT scan before operation and ossicular chain injury observed during surgery was only 28.57%, the coincidence rate between ossicular chain injury observed during surgery and ossicular chain injury observed by three-dimensional reconstruction is 85.71%.Therefore, three-dimensional reconstruction imaging technique could give the doctor more clearly and stereoscopic images for the destruction of ossicular chain. Conclusion:Preoperative three-dimensional reconstruction can display and diagnosis of auditory ossicular chain destruction more clearly. It can be used to accurately evaluate auditory ossicular chain pathological changes, to develop individualized surgical plans and assess the risk of surgery.

A Case of Incus Extrusion into the External Auditory Canal after Head Trauma

Various types of ossicular chain interruption may occur in temporal bone fractures. The most common type is incudostapedial joint disruption. Incus is the most vulnerable to traumatic injury as compared with malleus or stapes, because it is suspended only by ligamentous structures and connected to the incudomalleolar and incudostapedial joints. Incus may rarely be pushed through tympanic membrane or pass through a fracture of posterosuperior external auditory canal. However, a case of complete extrusion of incus into the external auditory canal has not been reported. The author presents a rare case of incus extrusion into the external auditory canal with temporal bone fracture after head trauma. Key words: Incus; Extrusion; Ear canal; Skull fracture

Standardized surgical approaches to ear surgery in rats

ObjectiveTo describe several approaches of ear surgeries for experimental studies in rats. MethodsAnesthetized rats were prepared for demonstration of various ear surgery approaches designed to optimize experimental outcomes in studies with specific goals and exposure requirements. The surgical approaches included the posterior tympanum, superior tympanum, inferior tympanum and occipital approaches. ResultsThe middle ear cavity and inner ear were successfully exposed from different angles via the mentioned surgical approaches. For example, electrode placement for recording of cochlear bioelectric responses was easily achieved through the posterior tympanum or inferior tympanum approach. Alternatively, drug delivery or gene transfection via round window membrane was most easily accomplished using the posterior tympanum approach. Cochlear perfusion of protective or ototoxic drugs was best performed using the inferior tympanum approach. Ossicular chain interruption to induce a prolonged conductive hearing loss was readily achieved using a superior tympanum approach. Lastly, surgical destruction of the endolymphatic sac to induce experimental endolymphatic hydrops was readily performed via an occipital surgical approach. ConclusionThese standardized surgical approaches can be applied in scientific studies of the ear with different purposes covering electrophysiology, conductive hearing loss, intra-cochlear drug perfusion and experimental studies relevant to Meniere's disease.

Acoustic tensor tympani response and vestibular-evoked myogenic potential.

To investigate the acoustic response properties and the vestibular-evoked myogenic potential (VEMP) in various lesions. Retrospective study of the clinical records of patients. Neurotological tests including acoustic response and VEMP were performed and analyzed in 62 patients with facial palsy, otosclerosis, ossicular chain interruption, sensorineural hearing loss, or acoustic tumor. Inverted acoustic responses were observed in 25 of 38 (65.8%) patients with facial palsy, in 5 of 6 (83.3%) patients with acoustic tumor, and in all patients with otosclerosis, ossicular chain interruption, or sensorineural hearing loss. These inverted responses were obtained only when ipsilateral stimulation was used. The thresholds of the inverted responses were statistically significantly higher than those of the normal response. The vibration of the eardrum is thought to stimulate the ipsilateral trigeminal nerve, leading to contraction of the tensor tympani muscle. The stapedius response had an inhibitory effect on the inverted response. Vibration of the stapes footplate (which requires a normal middle ear conduction system) is necessary to induce the VEMP, whereas the functioning of the facial and cochlear nerves is independent of the VEMP response.

Blast Injury of the Ear

The course of middle ear injuries secondary to blast effect was evaluated in 147 soldier-patients (210 ears) during the years 1967-1986. All perforations were in the pars tensa of the tympanic membrane. Ossicular chain interruption (11 ears) was associated mainly with dislocation of the incudo-stapedial joint. Mixed-type hearing loss was most prevalent (37%). Spontaneous closure occurred in 155 ears (73.8%), most of them (65.5%) within a 3-month period. Seven ears (3.3%) developed simple chronic suppurative otitis media; in 10 (4.8%), an invasive cholesteatoma developed, and in 6 others (2.8%), epithelial pearls were encountered behind an intact eardrum. Thirty-two patients were treated by immediate patching of the perforated drum, with an 84% rate of spontaneous closure; no cholesteatoma developed among this group, emphasizing the need for immediate patching. Tympanoplasty is recommended 1 year following the injury, and a 4-year follow-up period for detection of late complications is also recommended.

Multiple Branchial Anomalies Consisting of Bilateral Cervical Fistulas and Ossicular Chain Inter-ruption

Multiple Branchial Anomalies Consisting of Bilateral Cervical Fistulas and Ossicular Chain Inter-ruption

WEDGING OF THE STAPES FOR LENTICULAR PROCESS NECROSIS.

Introduction CONDUCTIVE deafness caused by OSsicular chain lesions can be of two main types: (1) fixation of ligaments, joints, and tendons as seen in otosclerosis 1 and tympanosclerosis 2 ; (2) destruction of whole or part of one or more ossicles as seen following chronic otitis media, 3 cholesteatoma, or trauma. 4 In this last group it is the incus which is probably mostly affected (Fig 1), as a result of the precarious blood supply of its long process, 5,6 and will bring about important hearing loss due to ossicular chain interruption. Originally, such isolated lesions were treated by performing a tympanoplasty type 3. 7,8 With the experience gained in the last decade in reconstructive middle ear surgery it was found more useful to leave the middle ear as near as possible to its original functional form and size and avoid a smaller tympanic cavity which was by necessity formed in

Repair of traumatic interruption of ossicular chain.

A unilateral, conductive-type hearing loss, with a marked air-bone gap of up to 60 db., and with the tympanic membrane intact, should arouse one's suspicion that there has been an interruption of the ossicular chain. 6 This suspicion would be fortified by a history of surgical intervention in the mastoid or middle ear. Besides the now frequently performed tympanotomies for stapes surgery with injury to the ossicular chain, a long-forgotten simple mastoidectomy may have to be blamed for such an interruption of the ossicular continuity. Displacement of the incus in an anterior-inferior direction easily occurs if the antrum and the epitympanic space is not approached with the necessary care when the simple mastoidectomy is performed. Utmost care should be exercised when the curet in this area is used. In the absence of a history of surgical intervention, the differential diagnosis includes congenital abnormalities of the ossicles, subluxation of the incudostapedial