Congenital Middle Ear Abnormalities With Absence of the Oval Window: Diagnosis, Surgery, and Audiometric Outcomes

Diagnosis and Management of Unexplained Conductive Hearing Loss With Intact Tympanic Membrane: A Systematic Review

Objective: To analyze the etiology, diagnosis, and treatment of unexplained conductive hearing loss (UCHL) with intact tympanic membrane. Methods: A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 642 articles were retrieved from databases such as PubMed, Embase, Web of Science, and Cochrane. Fifty-four research articles and 21 case reports were screened out according to the inclusion and exclusion criteria for analysis of the etiology of UCHL. Seven research articles with UCHL who underwent exploratory tympanotomy were selected for data extraction and analysis of clinical characteristics. Results: UCHL is a common manifestation of various diseases, including congenital ossicular anomalies (COA), otosclerosis (OTS), congenital middle ear cholesteatoma (CMEC), oval window atresia, superior semicircular-canal dehiscence, congenital stapedial footplate fixation, middle ear osteoma or adenoma, congenital ossification of stapedial tendon, and so on. A total of 522 patients were included in the 7 articles; among whom OTS showed a tendency to increase with age. The main symptoms were hearing loss, followed by tinnitus, dizziness, ear fullness, ear pain, facial paralysis. A total of 87.5% to 93.0% patients with COA manifested as nonprogressive deafness that occurred since childhood, with tinnitus incidence of 15.6% to 30.2%, and 86.4% to 96.4% patients with OTS presented with progressive hearing loss, with tinnitus incidence of 60.1% to 90.9%. The diagnosis positive rate of high-resolution computed tomography (HRCT) was 33.8% to 87.1%, and CMEC was higher than that of COA (83.3%-100% vs 28.6%-64%). All the articles reported good hearing recovery. The most common surgical complications included taste abnormalities, tinnitus, and dizziness. Conclusion: UCHL presents with similar clinical manifestations and poses challenges in preoperative diagnosis. Exploratory tympanotomy is the primary method for diagnosis and treatment, with good prognosis after removing the lesion and reconstructing hearing during the operation. Children can also safely undergo the surgery.

Audiologic Outcomes After Vestibulotomy in Patients With Congenital Absence of the Oval Window

OBJECTIVE

To examine the clinical features and surgical outcomes in patients with congenital absence of the oval window (CAOW), and to investigate the potential factors that affect audiologic results.

STUDY DESIGN

A retrospective chart review.

SETTING

A tertiary academic center.

PATIENTS AND INTERVENTION

A total of 17 ears among 16 patients were confirmed to have CAOW. Among them, 13 ears underwent vestibulotomy for hearing reconstruction. Clinical parameters associated with the hearing outcomes were analyzed.

MAIN OUTCOME MEASURES

A mean air-bone gap (ABG) after 6-month and long-term follow-up was compared with preoperative measurements.

RESULTS

Intraoperative findings showed that anomalies of the malleus or incus were observed in 11 ears (64.7%), stapes anomalies were present in all ears (100%), and facial nerve anomalies were present in 10 ears (58.8%). Because of unfavorable facial nerve anomalies, hearing reconstruction was aborted in four cases (23.5%). In the hearing reconstruction group, the mean ABG at 6 months postoperation was significantly reduced after compared with the preoperative value (44.0 ± 8.4 dB versus 58.8 ± 9.1 dB, p = 0.006). After dividing ears into a success subgroup (ABG ≤ 30 dB, seven ears) and non-success subgroup (ABG > 30 dB, six ears), the use of a drill during vestibulotomy was significantly related to a poor hearing outcome (100% versus 16.7%, p = 0.015). The long-term follow-up result (mean, 60 mo) revealed no deterioration compared with the 6-month postoperative result. Five ears (29.4%) underwent revision surgery, and three of them showed ABG improvements. No serious complications were reported.

CONCLUSION

Vestibulotomy is an effective and safe option for hearing restoration in patients with CAOW, particularly when the use of a drill is not required. The long-term audiologic outcome is also reliable.

Pure tone audiometry is a new method for evaluating congenital malformation of the middle and outer ear (CMMOE)

Background: The preoperative evaluation of Congenital Malformation of the Middle and Outer Ear (CMMOE) is very important. Jahrsdoerfer score commonly used at present, based on CT scanning images of the temporal bone, is often unable to accurately evaluate deformity and hearing level.Aims/Objectives: To investigate and promote a straightforward and easily accessible assessment method, pure tone audiometry, for the evaluation of CMMOE.Material and Methods: A total of 223 cases (244 ears) CMMOE with hearing data were retrospectively analyzed. Among them, 180 cases (197 ears) underwent exploratory tympanoplasty with clear conditions: ossicle numbers in 136 cases (147 ears) and morphology in 128 cases (138 ears) and vestibular window development in 137 cases (146 ears), and CT scans of temporal bone in 113 cases (120 ears). 1). The correlation was analyzed between ossicle numbers, ossicle morphology, Jahrsdoerfer score groups and their corresponding Average Air-Conduction Threshold of pure tone (AACT) at 0.5-4 KHz. 2) The AACT difference is compared among the above groups respectively and between the developed and undeveloped groups of vestibular window at 0.5-4 KHz and each frequency of 0.125-8 KHz. Spearman method was used for correlation analysis (calculating coefficient r and p values). For the data followed a normal distribution, a one-way analysis of variance (ANOVA) and t-test were employed, otherwise, Kruskal Wallis multiple local rank coincidence test and Wilcoxon rank sum test were used. p <0 .05 was considered statistically significant.Results: 1) The correlation coefficients between the groups of ossicle number scores, ossicle morphology scores, Jahrsdoerfer scores and their corresponding AACT are r = -0.187 (p <0 .05), r = -0.073 (p >0 .05) and r = -0.079 (p > 0.05), respectively. 2) Comparison of AACT difference based on ossicle number or morphological scores and Jahrsdoerfer scores with p > 0.05 among all groups, respectively. The AACT difference between the developed and undeveloped vestibular window groups is 5.5 (63.5/69.0) dB HL(p < .05) at 0.5-4KHz, out of 0.125-8 KHz frequency 1, 2, 4 KHz were 5.7 (65.0/70.7) dB HL, 8.4 (60.7/69.1) dB HL and 2 (61.5/63.5) dB HL, respectively, all p < 0.05, the other frequencies with all p > 0.05.Conclusions and Significance: 1) Ossicle number was correlated with AACT, but not for ossicle morphology and Jahrsdoerfer scores. 2) There was no significant difference in AACT corresponding to ossicle number or morphology scores and Jahrsdoerfer scores groups, but the patients with undeveloped vestibular window had poorer hearing than those with developed ones. Therefore, the AACT can evaluate the development of ossicle and vestibular window, and more directly reflect the hearing level than Jahrsdoerfer score. Pure tone audiometry is simple, widely used, and easily accessible, which making it a new assessment method of CMMOE.

Surgical outcome in class 4 congenital anomalies of the ossicular chain: a systematic review of the literature

OBJECTIVE

To review hearing and surgical outcomes after reconstructive middle ear surgery in class 4 congenital middle ear anomalies (CMEA), e.g., patients with oval- or round window atresia of dysplasia.

DATA SOURCES

Pubmed/Medline, Embase and Cochrane library.

REVIEW METHODS

Articles containing data on hearing outcomes and complications after reconstructive ear surgery in class 4 anomalies were analyzed and critically appraised. The following data were included and reviewed: patient demographics, audiometric testing, surgical techniques, complications, revision surgeries and their outcomes. Risk of bias was determined, and GRADE certainty of evidence was assessed. Primary outcomes were postoperative air conduction thresholds (AC), change in AC, and success rates (closure of the ABG to within 20 dB), the occurrence of complications (most importantly sensorineural hearing loss) and the long-term stability of hearing results (> 6-month follow-up) and occurrence of recurrence of preoperative hearing loss.

RESULTS

Success rates varied from 12.5 to 75% at long-term follow-up with larger cohorts reporting success rates around 50%, mean postoperative gain in AC varied from 4.7 to 30 dB and - 8.6 to 23.6 dB at, respectively, short- and long-term follow-up. No postoperative change in hearing occurred in 0-33.3% of ears, and recurrence of hearing loss occurred in 0-66.7% of ears. SNHL occurred in a total of seven ears across all studies of which three experienced complete hearing loss.

CONCLUSION

Reconstructive surgery can be an effective treatment option which should be considered in patients with very favorable baseline parameters, while also considering the substantial risk of recurrence of hearing loss, the possibility of unchanged hearing despite surgery and the rare occurrence of SNHL.

LEVEL OF EVIDENCE

2c.

Multislice Spiral Computer Tomography Findings of Simple Congenital Middle Ear Malformations

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.

Comparative study of unilateral conductive hearing loss in patients with an intact tympanic membrane

BACKGROUND

The ossicular chain status is directly associated with the severity of conductive hearing loss (CHL) when the tympanic membrane (TM) is intact.

AIMS/OBJECTIVES

To analyze the relationship between intraoperative findings and audiological data in patients with unilateral CHL and an intact TM.

MATERIAL AND METHODS

Forty-three patients who underwent surgery at Xinhua hospital from January 1, 2012, to December 31, 2019, were included and categorized based on their intraoperative findings. Demographic data, intraoperative findings, and preoperative and postoperative audiological results of these patients were analyzed.

RESULTS

Patients with ossicular chain disruption had significantly better outcomes than those with ossicular chain fixation (air conduction threshold [ACT]: 26.51 ± 8.82 vs. 44.08 ± 14.41 dB, p < .01; air-bone gap [ABG]: 10.66 ± 6.47 vs. 18.91 ± 9.32 dB, p = .04). Patients with ossicular chain deformities had a higher ACT (56.95 ± 13.81 vs. 44.56 ± 15.44 dB, p = .048) and a larger ABG (43.17 ± 9.94 vs. 33.02 ± 13.41 dB, p = .047) preoperatively than those with cholesteatoma; however, the postoperative outcomes between both patient groups were similar.

CONCLUSIONS

Congenital ossicular chain anomalies had similar surgical outcome regardless of the pathology. In acquired cases, ossicular chain disruption had better audiological outcomes than ossicular chain fixation.

SIGNIFICANCE

Ossicular chain reconstruction can significantly improve the hearing in patients with UCHL with intact TM.

Surgical Management for Dysplastic or Congenitally Absent Oval Window

OBJECTIVE

To evaluate surgical findings and hearing results for patient's undergoing the described surgical approach for congenitally absent or dysplastic oval window (OW).

STUDY DESIGN

The Institutional Review Board approved retrospective review of patients with conductive hearing loss (CHL) operated on from 1992 to 2016.

SETTING

Academic tertiary center.

PATIENTS

Patients with CHL, an intact tympanic membrane (TM), and without history of chronic infection underwent middle ear exploration. Eleven patients and 13 ears underwent an oval window drill-out (OWD) procedure.

INTERVENTION

Eleven patients presented, all with dysplastic or congenitally absent oval window (CAOW). CHL was identified using audiometry and tuning forks, many patients also had preoperative computed tomography temporal bones. A transcanal approach was used and an OWD was performed with a variety of prostheses placed.

MAIN OUTCOME MEASURE

Audiometric studies before and after intervention were compared with 12 month and long-term follow-up (1-22 yr).

RESULTS

Preoperative air-bone gaps ranged from 40 to 60 dB and averaged 55.1 dB. Postoperative air-bone gaps ranged from 0 to 60 dB and averaged 24.1 dB. The preoperative pure-tone average (PTA) ranged from 55 to 99 dB and averaged 71.3 dB. Postoperative PTA ranged from 21 to 108 dB and averaged 49.6 dB.

CONCLUSION

Dysplastic and CAOW are uncommon congenital major ear anomalies. OWD is a viable treatment option, though careful counseling is critical, as significant complications are possible, especially with facial nerve (FN) abnormalities. This series demonstrates successful closure of the air-bone gap for many patients with this technique.

Effect of Oval Window Blockage on Bone Conduction in Cadaver Heads

OBJECTIVE

This study aimed to explore the feasibility of medical adhesive in the molding of oval window (OW) blockage in cadaver heads and to study the effect on bone conduction (BC).

METHODS

Four cadaver heads were selected to establish OW blockage model. The daub type of medical adhesive was used to immobilize OW. The vibration properties of the round window membrane (VRWM) in response to the acoustic stimulation, and the vibration properties of the round window membrane and cochlear promontory (VCP) in response to the BC transducer B-71 stimulation were assessed by laser Doppler vibrometer in both pre-OW blockage and post-OW blockage.

RESULTS

After blocking the oval window, the mean values of the sound-induced velocities amplitude responses of the round window membrane by air conduction were decreased significantly beyond 30 dB in all measured frequencies (p < 0.05). The round window membrane relative velocity (VRWM/VCP) shows a decrease of about 1 dB at 1 and 3 kHz frequencies and a slight increase of around 0.5 dB from 4 to 8 kHz frequencies in post-OW blockage. However, it should also be noted that the VRWM/VCP is a significant decrease of 1.2 dB at 3 kHz in post-OW blockage compared with pre-OW blockage (p < 0.05).

CONCLUSION

Medical adhesive was available for the immobilization of oval window. In cadaver heads, the effect of OW blockage on the BC was the notching at 3 kHz.

Bone conduction hearing in the blockage of oval and/or round windows in cats

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.

Reporting and Description for Congenital Middle Ear Malformations to Facilitate Surgical Management

Introduction:

The aim of this work was to report and describe the different types of congenital middle ear malformations in order to guide surgical treatment approaches and improve outcomes for affected patients.

Methods:

The authors reviewed patients with congenital middle ear malformations who received surgical treatment between September 2010 and March 2017. Patient characteristics, middle ear deformities, and surgical procedures were documented.

Results:

In this retrospective study, 35 patients were reviewed. A description of middle ear malformation was proposed that considers ear embryogenesis and focuses on stapes deformity, with the main purpose of facilitating surgical approach selection to reconstruct the ossicular chain. Patients were classified into 3 categories: type I (19 cases), mobile stapes footplate, which included type Ia with normal stapes suprastructure and type Ib with abnormal stapes suprastructure; type II (4 cases), fixed stapes footplate, which included type IIa with normal ossicular chain and type IIb with abnormal ossicular chain; and type III (12 cases), oval window bony atresia or aplasia, with or without round window atresia. Types II and III could have concomitant aberrant facial nerve. Different surgical approaches are described.

Conclusions:

The authors describe the different types of congenital middle ear malformations. This category description considers ear embryogenesis and is focused on stapes deformity. It may provide better understanding of disease development and guide modern hearing reconstructive surgery.

Middle ear abnormalities in Van Maldergem syndrome

Van Maldergem syndrome (VMS) is a very rare syndrome that was first described in 1992. The main features of this syndrome comprise intellectual disability, blepharo-naso-facial malformation, and hand anomalies. Almost all nine described patients have been shown to be affected by conductive hearing impairment attributed to microtia, and atresia of the outer ear canal. Here, we present a VMS patient with congenital malformations of the middle ear as the main reason for severe conductive bilateral hearing impairment. To our knowledge, this is the first report to describe middle ear abnormalities in VMS. These malformations were seen on high resolution Computed Tomography scanning and during an exploratory tympanotomy. Due to the severity of the middle ear abnormalities and the risk for facial nerve damage, the patient was not offered an ossicular chain reconstruction but a bone conduction device after this exploratory tympanotomy. © 2016 Wiley Periodicals, Inc.

Congenital oval or round window malformations in children: Surgical findings and results in 17 cases

OBJECTIVES/HYPOTHESIS

To prospectively evaluate surgical findings and hearing results in children undergoing surgery for congenital oval or round window malformations (class IV malformations).

STUDY DESIGN

A nonrandomized, nonblinded, case series of prospectively collected data.

METHODS

Fourteen consecutive pediatric patients who underwent 17 surgical procedures for congenital oval or round window malformations in a tertiary referral center were included. Postoperative pure-tone audiometry was available in 15 cases. The surgical technique for repair of the ossicular chain was dictated by the surgical findings at the time of surgery. The majority of the cases underwent ossiculoplasty using a Teflon piston, bucket-handle prosthesis, or total ossicular replacement prosthesis. Associated surgical techniques included malleus relocation and oval window drill-out procedure. The main outcome measures were preoperative and postoperative hearing status using four-frequency (0.5, 1, 2, and 4 kHz) audiometry. Air-conduction thresholds, bone-conduction thresholds, and air-bone gap were measured. Postoperative audiometry was performed at 3, 6, 9, 12, 18, and 24 months after surgery and at a yearly interval thereafter.

RESULTS

Postoperative air-bone gap closure to 10 dB or less was achieved in 47%. A postoperative air-bone gap closure to within 20 dB or less was achieved in 60%. Postoperative sensorineural hearing loss did not occur in this series.

CONCLUSIONS

Middle ear surgery for class IV abnormalities is feasible, but success percentages are much lower compared to other types of congenital ossicular malformations. Surgeons should be particularly careful in case of facial nerve abnormalities on computed tomography or during middle ear exploration.

LEVEL OF EVIDENCE

4 Laryngoscope, 126:2552-2558, 2016.

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

Objective

To report a scala tympani drill-out technique for managing malformed facial nerve covering the entire oval window (OW).

Methods

Data from three cases with OW atresia, malformed stapes and abnormal facial nerve courses were reported, in which a scala tympani drill-out technique was employed with a TORP between the tympanic membrane and scala tympani fenestration for hearing reconstruction.

Results

Air conduction hearing improved in two of the three cases following surgery. In the third case, there was no improvement in air conduction hearing following a canal wall up mastoidectomy and tympanoplasty. There were no vertigo, tinnitus or sensorineural hearing loss in the three cases.

Conclusion

The scala tympani drill-out technique, which is basically fenestration at the initial part of the basal turn, provides a choice in hearing reconstruction when the OW is completely covered by abarrently coursed facial nerve.