Oval window atresia with inferiorly located facial nerve: Successfully use of alternative fenestration site of cochleostomy for ossicular chain reconstruction

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.

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.

Objective To explore the method of demonstrating main operative section of facial recess approach with multi-slice CT by using double oblique muttiplanar reconstruction.Methods Similarly as surgical procedure of facial recess approach,30 (60 eras) normal temporal bones in cadavers were reconstructed to observe main operative sections and anatomical marks.Main images of operative section of facial recess approach were reconstructed using double oblique multiplanar reconstruction on multislice CT.With the reference of operative anatomical marks,the ratios of visibility of anatomical marks on the transverse plane,coronal plane,sagittal plane and double oblique were calculated and compared.The degree,of which major anatomical landmarks were displayed on the same plane ( axial,coronal,sagittal,or doubleoblique sagittal plane),was classified using the following criteria: level 4: 100％ of anatomical landmarks were presented in the same plane; level 3: 90％ to 99％ of anatomical landmarks were presented in the same plane; level 2: 80％ to 89％ of anatomical landmarks were presented in the same plane; level 1: 70％ to 79％ of anatomical landmarks were presented in the same plane ; level 0: ＜ 70％ of anatomical landmarks were presented in the same plane.Classification data were tested by chi-square test.Results Four key operative section were involved in facial recess approach,which were of oblique sagittal orientation.The central mark of the first key operative section was semicircular canal by using double oblique multi-planar reformation.On reconstructed images of the first key operative section,horizontal reference line was short process of incus,and the angle adjusting the reference line on the transverse plane was 22.15° ±5.22°.On the reconstructed images of the first key operative section,coronal reference line was tympanic segment of facial canal,and the angle adjusting the reference line on the coronal plane was 14.35° ± 4.02°.On the reconstructed images of the second key operative section,the central mark was fossa incudis,the horizontal reference line was short process of incus and the angle was 20.15° ± 5.52°,while the coronal reference line was tympanic segment of facial cana,and the angle was 13.15° ± 3.33°.On the reconstructed operative images of the third key section,the central mark was pyramidal eminence,the horizontal reference line was the horizontal portion of the facial nerve and the angle was 32.53° ±5.22°,while the coronal reference line was the tympanic segment of facial nerve,and the angle was 15.05° ± 4.43°.On the fourth reconstructed images of the key operative section,the central mark was the posterior border of round window,the horizontal reference line was the superior border of oval window,and the angle was 50.15° ± 8.02°,while the coronal reference line was the tympanic segment of facial nerve,and the angle was 15.25° ± 4.12°.For the four planes (double-oblique sagittal,axial,coronal,or sagittal plane),the results of the degree to which they could include the major anatomical landmarks in the same layer of the first section were: level 4 in 60 sides,level 2 in 12 sides and level 3 in 48 sides,level 2 in 15 sides and level 3 in 45 sides,level 3 in 10 sides and level 4 in 50 sides,respectively.The results of the second section were: level 4 in 60 sides,level 2 in 11 sides and level 3 in 49 sides,level 2 in 13 sides and level 3 in 47 sides,level 3 in 11 sides and level 4 in 49 sides,respectively.The results of the third section were: level 4 in 60 sides,level 2 in 10 sides and level 3 in 50 sides,level 2 in 11 sides and level 3 in 49 sides,level 3 in 9 sides and level 4 in 51 sides,respectively.The results of the fourth section were: level 4 in 60 sides,level 2 in 9 sides and level 3 in 51 sides,level 2 in 8 sides and level 3 in 52 sides,level 3 in 5 sides and level 4 in 55 sides,respectively.The four planes differed significantly in the degree to which they could include the major anatomical landmarks in the same layer ( x2 =123.3200,121.4231,122.4011,125.4213,all,P ＜ 0.05 ).The visibility ratio of every section is 100％ (60/60).Conclusion Double oblique multi-planar reformation is a new method to demonstrate landmarks of operative section of facial recess approach in one slice.The reconstructive images of operative section with double oblique multi-planer reconstruction may provide valuable information for operation. Key words: Temporal bone; Tomography, X-ray computed; Anatomy, regional; Otologic surgical procedures

To explore the technique of hearing reconstruction in the cases of conductive hearing loss with malformed tympanic segment of facial nerve. Data of 10 cases from July 2010 to March 2015 were collected.The status of tympanic segment of facial nerve, malformed ossicles and the reconstructed methods of ossicular chain were analyzed and discussed based on the embryo anatomy and surgical technique. All facial nerves in 10 cases were exposed and drooping to stapes or cover the oval window.Three patients who had normal stapes, pushed by the exposed facial nerve, were reconstructed with partial ossicular replacement prostheses (PORP). Two patients who had footplate, with partial fixation, were reconstructed with total ossicular replacement prostheses (TORP). Three patients who had atresia of the oval window were implanted with Piston after being made hole in the atresia plate.Another two cases who had atresia of the oval window were implanted with TORP after promontory being drilled out.All cases had no injury of facial nerve and nervous hearing, and no tinnitus.Nine cases had conductive hearing improvement, except one with promontory drilled out. Patients who had conductive hearing loss with malformed tympanic segment of facial nerve can be treated by the technique of hearing reconstruction.The fenestration technique in the bottom of the scala tympani of the basal turn provides us a new method for treating patients whose oval window was fully covered by malformed facial nerve.

Isolated oval window atresia (OWA) is a rare cause of congenital conductive middle ear deafness and may be overlooked owing to the normal appearance of the external ear. This anomaly has been previously described, although the published numbers with both imaging and surgical findings are few. Our aim is to correlate the imaging features of OWA with intraoperative findings. This is a single-centre retrospective evaluation of patients who were diagnosed with OWA and who received surgery from January 1999 to July 2006. No new case was diagnosed after 2006 to the time of preparation of this manuscript. High resolution computed tomography (HRCT) imaging of the temporal bones of the patients were retrospectively evaluated by 2 head and neck radiologists. Images were evaluated for the absence of the oval window, ossicular chain abnormalities, position of the facial nerve canal, and other malformations. Imaging findings were then correlated with surgical findings. A total of 9 ears in 7 patients (two of whom with bilateral lesions) had surgery for OWA. All patients had concomitant findings of absent stapes footplate with normal, deformed or absent stapes superstructure and an inferiorly displaced facial nerve canal. HRCT was sensitive in identifying OWA and associated ossicular chain and facial nerve abnormalities, which were documented surgically. OWA is a rare entity that can be diagnosed with certainty on HRCT, best visualised on coronal plane. Imaging findings of associated middle ear abnormalities, position of the facial nerve canal, which is invariably mal-positioned, and associated deformity of the incus are important for presurgical planning and consent.

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: A novel surgical approach and pathognomonic radiological finding

Background: Simple or non-syndromic types of oval window (OW) or round window (RW) atresia are relatively rare in clinical. Few studies have assessed bone conduction (BC) hearing in OW or RW atresia patients, with some reporting that BC hearing lies within the normal range, whereas others observing impaired BC hearing.Aims/Objectives: This study explored the effect of blocking the OW and RW during BC in cat models.Material and Methods: Twenty-four cats were randomly divided into three immobilization groups (OW blockage, RW blockage, and OW + RW blockage) and control group. Each immobilization group also had the initial control state before blockage. Medical adhesive and ear mould glue were used to immobilise the stapes footplate and RW, respectively. Comparisons were made of the auditory brainstem response (ABR) thresholds before and after immobilization for the three immobilization groups during three different stimuli [air conduction (AC) click, BC click, and BC pure tones].Results: The AC click thresholds increased after immobilisation in three experimental groups compared to the control group (p < .05). The AC click thresholds increased compared to their initial control state after all three immobilization groups (p < .05). With an increase in frequency from 2 to 8 kHz, there was a general decrease in the difference between pre- and post-immobilization BC hearing thresholds in all three immobilization groups. The BC click threshold and BC tone thresholds at 2–4 kHz in both OW blockage and OW + RW blockage groups exceeded those in RW blockage group (p < .05).Conclusions and Significance: The use of medical adhesive and ear mould glue for the blockages of OW and RW, respectively in cats was feasible. The effect of blocking the OW and RW in BC hearing was larger at low frequencies than high frequencies between 2 and 8 kHz. OW blockage had a greater effect than RW blockage on BC hearing at 2–4 kHz range.

Main limitation of classical technique is limited access to cochlea in terms of cochlear rotations and related structures, thus causing difficulty in electrode insertion. Veria technique allows full access to cochlea after raising tympanomeatal flap. To our best knowledge this is first clinic-radiological study for Veria technique studying distance between tympanic segment of facial nerve and posterior wall of external auditory canal (EAC) demonstrating facial nerve safety. Prospective study was done on 50 patients having bilateral sensori-neural hearing loss. Patients underwent cochlear implant surgery irrespective of age and gender. Preoperative high-resolution computed tomography temporal bone and magnetic resonance imaging head was done, distance between tympanic segment of facial nerve and posterior wall of EAC and basal turn angle were measured. Intraoperative NRT followed by orbito-meatal X-ray was done in post operative period. 25 (50%) were male, 25 (50%) female. 35 patients (70%) showed that the distance between tympanic segment of facial nerve and posterior wall of EAC was more than 3mm with mean 4.41mm (± 0.63 SD). Distance calculated was greater in older age group than younger group. Patient having inner ear malformation, mean was 3.96mm (± .44 SD). Whereas patients having acquired disease, mean distance was 4.30mm (± .47 SD). On gender comparison of basal turn angle score, no significant difference was observed male (54.34° ± 4.48°) versus female (55.66° ± 4.15°) (p = 0.282). Mean of basal turn angle (BTA) in ≤ 5years age group was 54.89° ± 3.65°, in 6-10years age group was 55.21° ± 5.23° and in age group ≥ 11years was 54.93° ± 4° with no significant difference in mean value between the groups (p = 0.282). High jugular bulb was seen in 4 patients (2 in right side, 2 in left side), hypoplastic jugular bulb was seen in 10 patients (9 in left, 1 in right), otosclerosis in 2 patients. Veria technique is safe for facial nerve, as preoperatively distance between tympanic segment of facial nerve and posterior canal wall can be identified. It is suitable method for rotated cochlea (identified preoperatively through BTA) and deformed cochlea as it offers a wide visibility and accessibility as compared to posterior tympanotomy approach. BTA and distance between posterior canal wall of EAC and tympanic segment of facial nerve should be done in all cases to see any cochlear rotation and feasibility of surgery.

Conclusion: Application of the Vibrant Soundbridge to the round window (RW) membrane can be utilized as an efficient therapy for congenital oval window (OW) atresia. Objective: To report the surgical technique and auditory outcome of an active middle ear implant (AMEI) system used in patients with congenital OW atresia. Methods: Nine subjects with congenital OW atresia (six males and three females, ranging in age from 5.5 to 25 years, average 12.5 years) were implanted with an AMEI (Vibrant Soundbridge) at the round window (RW-Vibroplasty). Five cases were diagnosed as having isolated congenital OW atresia while four patients presented with combined external/middle ear malformation. Results: An improvement of 30 dB in average pure-tone air conduction thresholds (0.5–4 kHz) was achieved, with the high frequencies showing greater results. The subjects achieved postoperative speech recognition scores of 80–100% on the Computerized Mandarin Speech Test System (CMSTS) sentence test. Bone conduction thresholds were confirmed as stable in all subjects postoperatively. Decline in auditory benefit was noticed in two subjects, who then underwent revision surgery. One of these revision surgery patients then experienced stable hearing recovery, while the other patient’s hearing declined.

The patient’s imaging features, especially the honeycomb pattern of ossific changes in the geniculate fossa, were virtually pathognomonic for ossifying hemangioma of the facial nerve.

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

What's Your Diagnosis? Symptoms: Middle Ear Mass and Unilateral Hearing Loss

Branchio-oto-renal syndrome (BOR) is an autosomal dominant mutation of the EYA1 and the more recently discovered the SIX1 gene.1 The phenotype and syndrome were comprehensively described by Melnick in 1975 to include hearing loss, auricular malformations, branchial arch remnants, and renal anomalies.2 The diagnosis of BOR is made using major and minor criteria as defined by Chang et al 2004.3 However, 60% of patients who meet phenotypic criteria do not have an identifiable mutation in the EYA1 gene, leading to recent interest in the EYA-SIX regulatory system.1 The most common manifestations include hearing loss (98.5%), preauricular pits (83.6%), branchial anomalies (68.5%), renal anomalies (38.2%), and external ear abnormalities (31.5%). In terms of the imaging characteristics, the most sensitive modality remains CT of the temporal bones. The most commonly reported anomalies on temporal bone imaging include but are not limited to 1)hypoplastic apical turn of the cochlea, 2) facial nerve deviated to the medial side of the cochlea, 3) funnel-shaped internal auditory canal, and 4) patulous eustachian tube. 4 The spectrum of hearing loss in BOR is variable but most commonly presents with mixed hearing loss (50%), pure sensorineural hearing loss (25%) and pure conductive hearing loss (25%) 5. The conductive component of the hearing loss is most often the result of ossicular chain abnormalities. A 42 year old male previously diagnosed with BOR using clinical criteria presented with a conductive hearing loss. His physical exam demonstrated small external auditory canals with a normal tympanic membrane. His audiogram demonstrated a mild left sensorineural hearing loss and a maximal conductive hearing loss in the right ear. Imaging with CT revealed several findings consisted with BOR: Bilateral enlarged air-filled eustachian tubes extending from the middle ear to the nasopharynx, a widened and flared internal acoustic meatus with the nervus intermedius extending into a funnel shaped labyrinthine segment of the temporal bone and hypo-plastic horizontal canal, hypo-plastic vestibular system/epitympanum, and lateral position of the facial nerve. The incus and malleus were malformed and fixed in the attic (Fig. 1). Figure 1 Computed tomography (CT) images. Panel A: Axial view of the head demonstrating enlarged eustachian tubes (arrow). Panel B: Axial view of right internal auditory (IAC) canal demonstrating hypoplastic horizontal semicircular canal(H), and funnel shaped ... Despite the findings on CT, the patient elected to pursue a middle ear exploration prior to pursuing other rehabilitative options. At surgery, middle ear exploration revealed a very small oval window niche with no clear oval window, or stapes footplate as shown on this view with a 30° endoscope (Fig. 2). The round window niche was visible. A dehiscent facial nerve was visible at the horizontal segment. Because no mobile footplate was found there was no attempt at ossiculoplasty. The patient recovered from surgery with no change in his hearing and later went on to a Baha which he found beneficial. Figure 2 Right middle ear as viewed through a 30° endoscope during surgery. There was no clear stapes footplate, but a narrow oval window (OW) niche. The round window (RW) niche was visible. The OW and RW are labeled to the right above the structures. ... The extreme ossicular abnormalities in this patient with BOR made his maximal conductive hearing loss not amenable to ossiculoplasty. We ultimately failed in our attempt to restore his conductive hearing loss due to agenesis of the oval window and lack of a mobile footplate. The intraoperative endoscopy revelaed the lack of suitable anatomy for an ossicular replacement prosthesis. The findings in our patient highlight the diagnostic findings in BOR on CT scan of the temporal bone and correlate well with his clinical findings. Although BOR patients may not be a homogeneous in terms of their middle ear anatomy, this patient suggests ossiculoplasty may not be a viable option in this population.

Background: The persistent stapedial artery (PSA) is a rare congenital vascular malformation involving the middle ear. It is usually associated with pulsatile tinnitus and/or conductive hearing loss and can account for multiple risks during middle ear surgery. Case Report: we present a case of a 9-year-old male child with conductive hearing loss and persistent stapedial artery in his right ear, who was admitted to our ENT Department for hearing loss. During surgery, we discovered PSA along with congenital stapes agenesis and oval window atresia, as well as an abnormal trajectory of the mastoid segment of the facial nerve. After ossicular reconstruction (transcanal total ossicular replacement prosthesis) with cochleostomy, no surgical complications were recorded and hearing improvement was monitored by pre- and postoperative audiometry. Conclusion: Stapedial artery is a rare anatomical middle ear abnormality that can prevent proper surgical hearing restoration and can be associated with other simultaneous temporal bone malformations.