High Resolution Computed Tomography (HRCT) Imaging Findings of Oval Window Atresia with Surgical Correlation

The purpose of this study is to categorize anomalous tympanic facial nerve (FN) on high-resolution computed tomography (HRCT) and to determinate the significance of associated temporal bone anomalies and congenital syndromes without microtia in patients with hearing loss. A retrospective analysis of HRCT findings in 30 temporal bones in 18 patients with anomalous FN was performed. Abnormalities of the tympanic FN were categorized as follows: category 1: FN medially positioned, but above the oval window; category 2: FN in the oval window niche; and category 3: FN below the oval window. Potential associated findings that were assessed included stapes abnormalities, oval window atresia, and inner ear anomalies, as well as the presence of a known congenital syndrome with hearing loss. The most common type of anomalous tympanic FN was category 1 (67%, n = 20), following by group 2 (20%, n = 6) and group 3 (13%, n = 4). Stapes anomalies were detected in 77% of temporal bones (n = 23), oval window atresia was detected in 43% of temporal bones (n = 13), and inner ear anomalies were detected in 70% of temporal bones (n = 21). Anomalous tympanic facial nerves in temporal bone with conductive hearing loss were often (60%) not associated with oval window atresia. The combination of aberrant tympanic FN and inner ear anomalies was significantly (P = .038) associated with a known congenital syndrome (6 patients), including CHARGE syndrome, oculo-auriculo-vertebral spectrum, Pierre-Robin sequences, and Down syndrome. Therefore, an anomalous tympanic FN in conjunction with inner ear anomalies appears to be a biomarker for certain congenital syndromes with hearing loss in the absence of microtia.

Objective: To summarize the clinical features and postoperative efficacy of patients with oval window atresia accompanied by facial nerve aberration. Methods: The clinical data of patients with congenital middle ear malformation with facial nerve aberration admitted to our hospital from January 2015 to March 2023 were retrospectively analyzed. There were 97 cases (133 ears) in total. Among them, 39 patients (44 ears) had complete follow-up data, including 27 male patients and 12 females, aged 7-48 years old, with an average age of 17.8 years old. Of these, 14 cases (16 ears) were patients combined with facial nerve aberration, and 25 cases (28 ears) were without facial nerve aberration. The results of imaging examination, pure-tone audiometry, selection of surgical strategy, intraoperative findings and postoperative hearing improvement were summarized and analyzed. The malformations of malleus, incus, stapes, oval window and facial nerve were recorded. Prism 9 software was used to statistically analyze the mean bone conductance and air-bone gap of patients before and after surgery. Results: All the 14 patients (16 ears) with middle ear malformation accompanied by facial nerve aberration and oval window atresia showed poor hearing and no facial palsy since childhood. High resolution CT (HRCT) examination of temporal bone, pure tone audiometry and Gelle test were performed before surgery. The malformations of malleus, incus, stapes, oval window and facial nerve were recorded. Preoperative high-resolution CT (HRCT) examination of temporal bone found 12 ears with 4 or more deformities, accounting for 75.00%, in the group of patients with facial nerve malformation. The preoperative average bone conductive threshold was (15.3±10.4) dB and the average air-bone gap was (46.3±10.6) dB in pure-tone audiometry (0.5, 1, 2, 4kHz). According to the different degrees of facial nerve and ossicle malformation, we performed three different hearing reconstruction strategies for the 14 patients (16 ears) with facial nerve aberration and oval window atresia, including 7 ears of incus bypass artificial stape implantation, 7 ears of Malleostapedotomy (MS) and 2 ears of Malleus-cochlear-prothesis (MCP). After 3 months to 18 months of follow-up, all patients showed no facial paralysis. The postoperative mean bone conductive threshold was (15.7±7.9) dB and air-bone gap was (19.8±8.5) dB. There were significant differences in mean air-bone gap before and after operation (t=7.766, P<0.05), and there was no significant difference between the mean bone conductive threshold before and after surgery (t=0.225, P=0.824). There was no significant difference of mean reduction of air-bone gap between patients with and without facial nerve aberration (t=1.412, P=0.165). There was no significant difference between the three hearing reconstruction strategies. There was no significant displacement of the Piston examined by U-HRCT. Conclusion: For patients of middle ear malformation whose facial nerve cover the oval window partially, incus bypass artificial stape implantation or Malleostapedotomy (MS) can be selected according to the specific condition of auditory ossis malformation, and for patients whose facial nerve completely covers the oval window area, Malleus-cochlear-prothesis (MCP) can be selected. Three types of stapes surgery are safe and reliable for patients with oval window atresia accompanied by facial nerve aberration. There was no significant difference in efficacy between them. Preoperative HRCT assessment of middle ear malformation is effective. There is no significant difference of surgical effect with or without facial nerve aberration. The U-HRCT can be used to evaluate the middle ear malformation before surgery and the Piston implantation status after surgery. Due to the risks of surgery, those who do not want to undergo surgery can choose artificial hearing AIDS, such as hearing aid, vibrating soundbridge, bone bridge or bone-anchored hearing aid.

Oval window atresia (OWA) is a rare otologic condition often associated with a maximal conductive hearing loss, and variable ossicular and facial nerve canal (FNC) anomalies, which have contributed to suboptimal middle ear surgical outcomes. No grading scheme exists to detail the spectrum of associated temporal bone anomalies in OWA; therefore, our objectives were to complete an audiometric and radiographic review to characterize audiometric patterns of hearing loss, and refine the classification system for OWA to determine suitability for middle ear surgery. A retrospective audiometric and radiographic review was conducted at a pediatric tertiary care institution. Patients with OWA identified on temporal bone computerized tomography (CT) scans obtained from 01/2010 to 06/2024 were included. Audiological, radiological, and patient factors were analyzed. Thirty-one patients (48 ears) with OWA were identified. Across frequencies, the air-bone gap decreased significantly as frequency increased (ANOVA with pairwise comparisons, p < 0.001) due to a worsening of bone conduction thresholds and improvement in air conduction thresholds. The FNC was abnormal in 43/48 ears and was determined to overlay the oval window in 6 ears. Additional anomalies included inferiorly displaced, dehiscent, and duplicated canals. Ossicular anomalies were reported in 46/48 ears, and stapedial anomalies were most common. Our findings indicate OWA may manifest audiometrically with consistent and specific hearing loss characterized by a 60-80 dB ABG at lower frequencies that decreases above 2 kHz. CT findings of OWA show considerable variability. We propose a new classification system for OWA based on facial nerve position as this directly influences middle ear surgical feasibility.

High Resolution Computed Tomography (HRCT), a modification of routine CT, provides a direct visual window in the temporal bone providing minute structural details. Purpose of the present study was to evaluate the normal variations, pathological processes (infections and congenital anomalies) and their extent involving the temporal bone along with their complications on HRCT and to correlate these imaging findings surgically, wherever available. The prospective study included 50 patients who were referred to the radiology department with clinically suspected temporal bone or ear pathologies. After detailed clinical examination, the patients were subjected to high resolution computed tomography (HRCT) examination. The imaging findings were correlated with the surgical findings wherever available. The surgical findings were considered as final. From a total of 50 cases, 83.33% had cholesteatoma. The surgical and radiological findings showed a high level of sensitivity (89.29%) in the identification of cholesteatoma. HRCT provides a good sensitivity of 80.65% in the identification of changes to the ossicular chain despite the presence of surrounding soft tissue. HRCT was highly informative in identification of erosion of lateral semicircular canal. In diagnosis of facial canal dehiscence HRCT had a low sensitivity of 33.33%. In the evaluation of any congenital abnormality of the ear HRCT proved to be beneficial in depicting the anatomical details. The clinical and radiological findings showed a high level sensitivity with intraoperative findings as regards to the presence of cholesteatoma, changes of the ossicular chain and erosion of the lateral semicircular canal. HRCT findings, in the treatment of any congenital abnormality of the ear were a good guide to the surgeon for planning and management.

Oval window atresia: A novel surgical approach and pathognomonic radiological finding

Background Simple congenital middle ear malformations (SCMEMs) are a group of congenital ear malformations. The study aims to analyze the multi-slice spiral computer tomography (MSCT) manifestations of normal ears and SCMEM ears. Objectives This study aimed to investigate the MSCT manifestations of normal ears and SCMEM ears and to evaluate the relationship between the SCMEM and the tympanic segment of the FNC pathway. Methods This was a retrospective case-control study. Patients who were diagnosed with SCMEM were included in the SCMEM group. Patients with vertigo, pulsatile tinnitus, or other symptoms were included in the control group. MSCT examination and image processing of the ossicular chain, facial nerve canal, and related structures were performed and compared between the two groups. Results There were 94 cases in the SCMEM group (125 ears) and 97 cases in the control group (190 ears). Sixty-three cases (67.0%) were unilateral malformations (36 right ears and 27 left ears). MSCT showed congenital stapes malformation in 107 ears (85.6%) and incus long process malformation in 84 ears (67.2%). Among these, simple stapes malformations were found in 41 ears (32.8%), simple incus malformation in 18 ears (14.4%), and stapes malformation complicated with incus malformation in 66 ears (52.8%). The distance between the facial nerve and lateral semicircular canal (FNC-LSC) in the SCMEM group was 1.30 ± 0.64 mm compared to 0.79 ± 0.11 mm in the control group (P < 0.001), and the distance between facial nerve canal and oval window (FNC-OW) was 0.67 ± 0.53 mm in the SCMEM group and 1.13 ± 0.18 mm in the control group (P < 0.001). Conclusion SCMEM occurred mainly in ossicular chain abnormalities. MSCT clearly showed the slight structural changes in the middle ear and provided an accurate basis for preoperative diagnosis.

View Video S1 Laryngoscope, 131:E961–E965, 2021

Objective: To conclude the clinical features and the postoperative efficacy of congenital middle ear malformation treated with Malleostapedotomy (MS), and to explore the security and effectiveness of MS surgery. Methods: The clinical data of 17 patients (18 ears) with congenital middle ear malformation undergoing MS procedure were analyzed. There were 10 males (11 ears) and 7 females (7 ears), aged from 7 to 48 years. The imaging examination, pure-tone audiometry, intraoperative findings and postoperative hearing improvement of these patients were analyzed and summarized, and software SPSS23.0 was used for statistical analysis. Rusults All the 17 patients (18 ears) presented with hearing loss since childhood on the affected sides. Preoperative high resolution CT (HRCT) of the temporal bone revealed definite malformations in 9 ears (6 ears with incus long process dysplasia and 3 ears with anterior and posterior crus dysplasia). Before surgery, the mean bone conductive hearing threshold at 500, 1 000, 2 000 and 4 000 Hz was (15.6±10.2) dB HL, the mean air conductive hearing threshold was (60.6±9.7) dB HL, and the mean air-bone gap was (45.0±8.9) dB. During the surgery, all 18 ears were found to be accompanied by absence or hypoplasia of incus long process. 12 ears had stapes fixation, 6 ears had oval window atresia. All patients were treated with MS procedure by using Piston. The patients were followed up for 3 months to 1 year. The mean bone conductive hearing threshold was (14.7±8.8) dB HL. The mean air conductive hearing threshold was (37.7±11.6) dB HL, and the mean air-bone gap was (23.0±8.0) dB. There were statistically significant differences in the mean air conductive hearing threshold and mean air-bone gap before and after surgery (P<0.05). While there were no statistically significant differences in the mean bone conductive hearing threshold before and after surgery (P=0.550). Conclusions: MS procedure is safe and reliable in patients with congenital middle ear malformation of incus long process dysplasia, stapes fixation or oval window atresia. HRCT is useful in evaluating the major deformity of ossicular chain and facial nerve deformity. However, it is not enough to evaluate the joint of incus-stapes and oval window atresia. MS surgery in middle ear malformation requires advanced surgical experience and skills. The hearing improvement can be significant, even though some air-bone gap after surgery exist.

Objective: To analyze the clinical characteristics and appropriate surgical procedures, and discuss the classification of congenital middle ear malformation. Methods: All cases were from the Center of Otorhinolaryngology, the Sixth Medical Center of Department of PLA General Hospital. All of these cases, including 26 male patients (ears) , 10 female patients (11 ears) , aged from 7 to 57 years old, had normal external auditory canal, tympanic membrane, conductive hearing loss, type A tympanogram and negative Gelle's test. Tympanoplasty was performed in all cases. The deformity was classified to three types,i.e., Type I (stapes foot plate mobility): Ⅰa, ossicular chain deformity with normal stapes suprastructure; Ⅰb, ossicular chain deformity with abnormal stapes suprastructure; Type Ⅱ (stapes foot plate fixation): Ⅱ a,normal ossicular chain, Ⅱ b, ossicular chain malformation; and Type Ⅲ: vestibular window osseous atresia or undeveloped, or with round window atresia. The malformation of type Ⅱ and Ⅲ may be accompanied with abnormal facial nerve. In addition, the papers on middle ear malformation published from 1982 to 2017 were analyzed retrospectively. The clinical data of 451 ears malformation were summarized. Results: According to the revisional classification criteria in 37 ear samples from our hospital, 20 ears were type I. 6 type Ⅰa cases were used PORP (partial ossicular replacement prosthesis) to reconstruct the ossicular chain; 14 type Ⅰb cases were used TORP (total ossicular replacement prosthesis) to reconstruct the ossicular chain. For the 5 ears of type Ⅱ, 2 of which were type Ⅱ a and 3 were type Ⅱ b. 4 ear samples of type Ⅱ were implanted with Piston ossicular prosthesis, 1 was implanted with TORP in which the ossificated foot plate was removed with periosteum preserved. 12 ear samples were type Ⅲ, with vestibular window osseous atresia, facial nerve malformation, and stapes suprastructure malformation. The pistons ossicular prosthesis were implanted in vestibular window in 3 ears with facial nerve covering vestibular window partially. The surgery had to be given up in 5 ears, and TORP was implanted in 4 ears at the opening with preserved periosteum at the beginning of the tympanic scala because of facial nerve covering vestibular window totally. 30 ears with complete follow-up data had no sensorineural hearing loss and the average air-bone conduction decreased 23.3±10.7 dB (P<0.05).There were 234 ears of type Ⅰ in 451 ears of congenital middle ear malformation reported in the literature. 113 of which were type Ⅰa, the basic surgery was ossicular chain shaking and artificial or autogenous PORP implantation. Type Ⅰb was 121 ears, with autogenous or artificial TORP and PORP. Type Ⅱ was125 ears, including type Ⅱa 22 ears, Ⅱb 60 ears, and no subclassification for 43 ears. The surgery of type Ⅱ was the same as otosclerosis. The vestibular window atresia of type Ⅲ was 92 ears, the surgery of 17 ears had to be abandoned, the other ears underwent vestibular window, promontory or semicircular canal opening to reconstruct hearing with Piston, autogenous or artificial TORP. Conclusion: Referring to the classification of congenital middle ear malformation combining with appropriate surgical materials and methods, otologists can better understand and choose appropriate surgical method to the middle ear malformation.

Scala tympani drill-out technique for oval window atresia with malformed facial nerve: A report of three cases

The aim was to compare high-resolution computed tomography (HRCT) and thin-section magnetic resonance imaging (MRI) findings of facial nerve hemangioma. The HRCT and MRI characteristics of 17 facial nerve hemangiomas diagnosed between 2006 and 2013 were retrospectively analyzed. All patients included in the study suffered from a space-occupying lesion of soft tissues at the geniculate ganglion fossa. Affected nerve was compared for size and shape with the contralateral unaffected nerve. HRCT showed irregular expansion and broadening of the facial nerve canal, damage of the bone wall and destruction of adjacent bone, with "point"-like or "needle"-like calcifications in 14 cases. The average CT value was 320.9 ± 141.8 Hu. Fourteen patients had a widened labyrinthine segment; 6/17 had a tympanic segment widening; 2/17 had a greater superficial petrosal nerve canal involvement, and 2/17 had an affected internal auditory canal (IAC) segment. On MRI, all lesions were significantly enhanced due to high blood supply. Using 2D FSE T2WI, the lesion detection rate was 82.4 % (14/17). 3D fast imaging employing steady-state acquisition (3D FIESTA) revealed the lesions in all patients. HRCT showed that the average number of involved segments in the facial nerve canal was 2.41, while MRI revealed an average of 2.70 segments (P < 0.05). HRCT and MR findings of facial nerve hemangioma were typical, revealing irregular masses growing along the facial nerve canal, with calcifications and rich blood supply. Thin-section enhanced MRI was more accurate in lesion detection and assessment compared with HRCT.

Oval window atresia is often accompanied by malpositioned facial nerve, when inferiorly located facial nerve occupies the expected site of oval window, the ossicular chain reconstruction will always be abandoned. We report the case of a 12-year-old boy with one-side middle ear deformity and hearing loss. Under surgical exploration, the tympanic segment of facial nerve occupied the entire atresia plate, we created a hole on the bony basal turn of the cochlear immediately above the round window, a hand modeled titanium stapes prosthesis was used between the handle of malleus and cochleostomy opening. The audiogram showed an average hearing improvement of 36 dBHL three months later postoperatively. For the case with oval window atresia and inferiorly located facial nerve, cochleostomy could be an effective alternative fenestration site for ossicular chain reconstruction. The prosthesis shaping is always needed for better sound conduction.

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Chronic suppurative otitis media (CSOM) because of disease nature and location of vital structures like middle ear ossicles, facial nerve, and lateral semicircular canal poses clinical as well as radiological challenge in diagnosis, especially the squamosal variety. Hence this study to evaluate radio-surgical correlation in cases of CSOM.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; We retrospectively analysed 92 case records who met the inclusion criteria. Their pre-operative high-resolution computed tomography (HRCT) temporal bone imaging was evaluated for erosion of the ossicular chain and the fallopian canal. This was correlated with the surgical findings noted intra-operatively. The appropriate statistical analysis was carried out. The radio-surgical correlation was evaluated by Cohen’s kappa value. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The kappa value for status of ossicular chain was 0.805 and 0.384 for status of fallopian canal. HRCT imaging had a positive predictive value and negative predictive value of 94.3% and 85.3% respectively, in detecting ossicular chain erosion. In detecting fallopian canal erosion, HRCT showed a sensitivity of 33.3%. Analysing the individual ossicles, we found kappa to be 0.266 for malleus, 0.463 for incus and 0.827 for stapes.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; There was excellent radio-surgical correlation for ossicular chain erosion while it was poor for fallopian canal erosion. HRCT showed excellent radio-surgical correlation for stapes, moderate for incus and poor for malleus. In-spite of its shortcomings in differentiating cholesteatoma and non-cholesteatomatous pathologies of the middle ear cleft, HRCT imaging plays a key role in assessing the status of the ossicles and fallopian canal.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Introduction: Since in 1995 the first case of absence of stapes was described, several cases were reported. However, its etiology remains unknown. Some authors suggest a genetic cause, without excludingthe possibility of embryopathy due to infections or chemical agents. The existence of an associated palatal cleft, in this case, reinforces the hypothesis of a multifactorial origin. Objective: Describe a rare condition in order to know how to suspect it. This condition is frequently associated with facial nerve malposition, that difficult the surgery and so, the most frequenttreatment is providing hearing aids or a bone anchored hearing aid. Case report: We present a case of a 10 years old girl who complains of left hearing loss since childhood, accompanied by tinnitus and frequent left ear otorrhea episodes. We studied symptoms, complementary exams, treatment and course. Discussion and conclusions: A middle ear malformation should be suspected with the presence of a history of conductive hearing loss since birth or more frequently between the 7 and 12years old, fixed-type, which often affects conversational or low frequencies, which are more intense than other acquired hearing loss, with no history of ear infections or without improvement despite different kinds of treatments, and witha family history of hearing loss. Conclusion: Congenital absence of stapes and oval window associated with anomalous course of the facial nerve is a rare entity. It presents as a conductive hearing loss non-progressive with 60 dB tone airthreshold, often presented during childhood. Diagnosis is based on clinical suspicion by a correct medical history and audiological examination, confirmed by Computed Tomography (CT) scan. The anomalous course of the facial nerve supports the diagnosis and guides treatment. Initial treatment with hearing aids provides good hearing gain with adequate adaptation.

We present a rare adult case of bilateral oval and round window atresia. Clinical and audiologic findings were suggestive of otosclerosis. High resolution CT Temporal bones showed unequivocal findings of bilateral oval and round window atresia. Atresia of these windows is a rare temporal bone anomaly. Presentation as an adult can confound the clinicians and warranting a closer look on the CT for atretic windows and subtle signs of otosclerosis in patients with conductive hearing loss.