Fixation of the Stapes Footplate in Children: A Clinical and Temporal Bone Histopathologic Study

Conductive Hearing Loss in Children

A variety of congenital and acquired disorders result in pediatric conductive hearing loss. Malformations of the external auditory canal are invariably associated with malformations of the middle ear space and ossicles. Isolated ossicular malformations are uncommon. Syndromes associated with external and middle ear malformations are frequently associated with abnormal development of first and second pharyngeal arch derivatives. Chronic inflammatory disorders include cholesteatoma, cholesterol granuloma, and tympanosclerosis.

Absent Stapedial Tendon: Imaging Features of an Underrecognized Entity : Clinical Neuroradiology

PURPOSE

Congenital absence of the stapedial tendon is a rare entity with characteristic imaging findings, which can go unrecognized due the scarcity of the diagnosis and limited previous description in the imaging literature. We aim to characterize the imaging features of this entity.

METHODS

A series of 9 cases with surgical confirmation of stapedial tendon absence were retrospectively reviewed and the most common abnormalities on high resolution computed tomography (CT) of the temporal bone described.

RESULTS

Congenital fixation of the stapes footplate was present in nearly all cases of stapedial tendon absence (n = 8, 89%), a clinically important association because the stapes footplate abnormality was not detectable on preoperative CT. Absence or hypoplasia of the pyramidal eminence and aperture was identified in almost all cases (n = 8, 89%), which may be the sole imaging finding to suggest stapedial tendon absence and associated stapes footplate fixation prior to surgery.

CONCLUSION

The most reliable indicator of stapedial muscle absence on temporal bone CT is the absence or hypoplasia of the pyramidal eminence and aperture. Importantly, most patients had congenital stapes footplate fixation confirmed intraoperatively with a normal stapes footplate on CT, meaning the pyramidal eminence/aperture abnormality was the only preoperative imaging finding that could have suggested the footplate fixation.

Juvenile otosclerosis and congenital stapes footplate fixation. A systematic review and meta-analysis of surgical outcomes and management

OBJECTIVE

Juvenile Otosclerosis (JO) and Congenital Stapes Footplate Fixation (CSFF) are rare ossicular chain disorders seen in the paediatric population and present with conductive hearing loss. Ongoing controversy exists regarding the role of surgical intervention in JO and CSFF given the poorer hearing outcomes and complications when compared with surgical intervention for adult otosclerosis. The objective of this study is to assess the published data on the surgical outcomes of JO and CSFF in order to guide clinicians and counsel patients on the various medical options for these disease entities.

METHODS

A systematic review of MEDLINE, EMBASE and Cochrane was performed with inclusion criteria of children with JO or CSFF and hearing outcomes following stapes surgery. Studies identified by the search were reviewed and assessed by two independent reviewers in line with the PRISMA guidelines.

RESULTS

464 articles were initially reviewed and 28 articles met inclusion in the systematic review and meta-analysis. A total of 810 ears (473 and 337 cases of JO and CSFF respectively) underwent stapes surgery. Average age at time of surgery for JO and CSFF was 14.3 and 10.2 years old respectively. The mean pre-operative Air-Bone-Gap (ABG) for JO and CSFF was 31.8 ± 5.2 dB and 39.4 ± 10 dB respectively. Following stapes surgery, the mean post-operative ABG for JO and CSFF was 9.6 ± 6 dB and 19.2 ± 12.5 dB respectively. Surgical success rate (defined as ABG <10 dB) was 81% for JO and 41% for CSFF. Mean ABG gain for JO and CSFF was 24.8 dB (95% CI: 18.6-33.1) and 22.6 dB (95% CI: 18.4-27.8) respectively. The reported number of dead ears was 4/473 (0.8%) for JO and 2/337 (0.6%) for CSFF. 23 cases (2.8%) reported sensorineural hearing loss (SNHL) >10 dB.

CONCLUSION

CSFF was associated with poorer hearing outcomes compared to JO, however both entities showed similar improvement in ABG post operatively. Counselling patients and their families on the surgical success rates and complications of JO or CSFF is an important part of the decision making process when deciding between a surgical option or conservative measures such as hearing aids.

Management of Juvenile Otosclerosis: A Systematic Review

Background. Otosclerosis can occur during childhood, resulting in the early onset of conductive hearing loss. The approach to a child with otosclerosis can present some difficulties in terms of diagnosis and treatment, and the literature on juvenile otosclerosis (JO) is still relatively limited. Aim. To explore the current approaches to JO, in order to clear the management of this condition and evaluate the outcomes and the possible complications of surgical treatment. Methods. A systematic review was performed according to PRISMA guidelines, searching Medline and Embase from January 2002 through to 30 September 2022. A total of 759 papers were identified but based on specified criteria, nine were included in this study. Results. There were 94 children affected by JO and treated by stapes surgery. According to the available data, Male: Female ratio was 1:3−4, whilst the mean ages ranged from 10 to 16.3 years at the time of stapes surgery. After stapes surgery, the target of ABG < 10 dB was achieved in most of the patients. Overall, the 4 complications were reported (4/94= 4%): stenosis of the external ear canal, deterioration of hearing, anacusis with vertigo, tinnitus. Conclusions. The heterogeneity of the available studies does not allow us to draw straight conclusions on this topic, currently. More data about the natural history of the disease in children could help in approaching the treatment correctly, and possibly in drawing guidelines. Studies with a prolonged follow-up could be helpful for assisting clinicians and families in taking the most favorable decision about treatment.

Is the Conductive Hearing Loss in NOG-Related Symphalangism Spectrum Disorder Congenital?

We describe a dominant Japanese patient with progressive conductive hearing loss who was diagnosed with NOG-related symphalangism spectrum disorder (NOG-SSD), a spectrum of congenital stapes fixation syndromes caused by NOG mutations. Based on the clinical features, including proximal symphalangism, conductive hearing loss, hyper-opia, and short, broad middle, and distal phalanges of the thumbs, his family was diagnosed with stapes ankylosis with broad thumbs and toes syndrome (SABTT). Genetic analysis revealed a heterozygous substitution in the NOG gene, c.645C>A, p.C215* in affected family individuals. He had normal hearing on auditory brainstem response (ABR) testing at ages 9 months and 1 and 2 years. He was followed up to evaluate the hearing level because of his family history of hearing loss caused by SABTT. Follow-up pure tone average testing revealed the development of progressive conductive hearing loss. Stapes surgery was performed, and his post-operative hearing threshold improved to normal in both ears. According to hearing test results, the stapes ankylosis in our SABTT patient seemed to be incomplete at birth and progressive in early childhood. The ABR results in our patient indicated the possibility that newborn hearing screening may not detect conductive hearing loss in patients with NOG-SSD. Hence, children with a family history and/or known congenital joint abnormality should undergo periodic hearing tests due to possible progressive hearing loss. Because of high success rates of stapes surgeries in cases of SABTT, early surgical interventions would help minimise the negative effect of hearing loss during school age. Identification of the nature of conductive hearing loss due to progressive stapes ankylosis allows for better genetic counselling and proper intervention in NOG-SSD patients.

Pediatric Stapes Surgery: Hearing and Surgical Outcomes in Endoscopic vs Microscopic Approaches

Objective

To compare endoscopic and microscopic pediatric stapes surgery.

Study Design

Case series with chart review.

Setting

Two academic otology practices.

Subjects and Methods

Surgical and hearing outcomes were compared for consecutive children (<18 years) undergoing microscopic and endoscopic stapes surgery. The main outcome measure was closure of the air-bone gap (ABG) to ≤20 dB.

Results

Twenty-two endoscopic surgeries (17 stapedectomies, 4 stapedotomies, and 1 stapes mobilization) and 52 microscopic surgeries (30 stapedectomies, 19 stapedotomies, and 3 stapes mobilizations) were performed. Patient demographics, history of ipsilateral middle ear surgery, and revision stapes surgery status were similar. The most common diagnosis for the endoscopic group and microscopic group were congenital stapes footplate fixation (45.5%) and juvenile otosclerosis (46.2%), respectively. Preoperative ABGs in the endoscopic (37.7 dB) and microscopic (32.8 dB) groups ( P = .170) were similar. There were no major complications, including facial nerve injury or anacusis, in the endoscopic group. Postoperative sensorineural hearing loss (>15 dB) did not occur in any patients in the endoscopic group but was present in 2 patients in the microscopic group ( P = .546). Improvement in pure-tone average (25.9 dB vs 18.5 dB, P = .382) and ABG (21.7 dB vs 14.7 dB, P = .181) was similar, and postoperatively, the median ABG was 11.3 dB and 15.0 dB for endoscopic and microscopic cases ( P = .703), respectively. ABG closure to ≤20 dB (72.7% vs 65.2%, P = .591) was also similar.

Conclusion

Pediatric endoscopic stapes surgery is safe and hearing outcomes are similar to the microscopic approach when performed by experienced endoscopic ear surgeons.

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.

Temporal Bone Histopathology in NOG-Symphalangism Spectrum Disorder

OBJECTIVE

To describe the human temporal bone histopathology in NOG-related symphalangism spectrum disorder, a spectrum of congenital stape fixation syndromes caused by mutations in the NOG gene. To discuss implications for clinical management.

PATIENT

A patient with a mutation in the NOG gene.

INTERVENTION(S)

Removal of temporal bones, postmortem temporal bone computed tomography, histologic processing, and review of temporal bones.

MAIN OUTCOME MEASURE(S)

Temporal bone histopathology and correlation with clinical, genetic, audiologic, and radiologic evaluations.

RESULTS

Both temporal bones demonstrated fixation of the stapes footplate to the otic capsule because of a circumferential bridge of calcified cartilage. In the right ear (unoperated), there was no additional abnormality of the ossicles or ossicular joints. In the left ear, fenestrations of the stapes footplate and the lateral semicircular canal were seen, consistent with a history of stapedectomy and fenestration procedure. Severe loss of spiral ganglion neurons throughout the left cochlea accounted for the profound sensorineural hearing loss; there was a normal number of spiral ganglion neurons in the right ear. In both ears, the cochleae demonstrated grossly preserved organs of Corti.

CONCLUSION

The temporal bone pathologic correlate for conductive hearing loss in this patient with a NOG mutation was circumferentially calcified cartilage bridging the stapedovestibular joint space. The temporal bone histopathology findings suggest that conductive hearing loss related to NOG mutation should be improved after stapedectomy; however, care must be taken in extrapolating to all patients with NOG mutations because there may be variability in the pathology, especially given the variability of NOG spectrum disorders.

Juvenile otosclerosis: a case presentation and review of the literature

Otosclerosis in childhood and adolescence or juvenile otosclerosis is a rare disorder resulting in conductive hearing loss. A 9-year-old boy presented to our clinic, suffering from moderate hearing loss. According to his parents, his hearing acuity had progressively deteriorated over the past 2 years. Otoscopy and tympanometry revealed bilateral secretory otitis media and the patient underwent bilateral grommet insertion. However, he continued to report of hearing loss and a right exploratory tympanotomy was performed. Stapedial fixation was confirmed, being compatible with juvenile otosclerosis, and we proceeded to a right stapedotomy. One year later, follow-up showed satisfactory outcome with an air-bone gap closure to 10 dB. Juvenile otosclerosis with the coexistence of persistent secretory otitis media can be overlooked. Affected children from 9 years of age are strongly motivated to undergo stapes surgery for juvenile otosclerosis, following parental consent.

Development and Integration of the Ear

The perception of our environment via sensory organs plays a crucial role in survival and evolution. Hearing, one of our most developed senses, depends on the proper function of the auditory system and plays a key role in social communication, integration, and learning ability. The ear is a composite structure, comprised of the external, middle, and inner ear. During development, the ear is formed from the integration of a number of tissues of different embryonic origin, which initiate in distinct areas of the embryo at different time points. Functional connections between the components of the hearing apparatus have to be established and maintained during development and adulthood to allow proper sound submission from the outer to the middle and inner ear. This highly organized and intimate connectivity depends on intricate spatiotemporal signaling between the various tissues that give rise to the structures of the ear. Any alterations in this chain of events can lead to the loss of integration, which can subsequently lead to conductive hearing loss, in case of outer and middle ear defects or sensorineural hearing loss, if inner ear structures are defective. This chapter aims to review the current knowledge concerning the development of the three ear compartments as well as mechanisms and signaling pathways that have been implicated in the coordination and integration process of the ear.

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

OBJECTIVES

The facial nerve usually occupies the oval window area in patients with oval window atresia. During exploration, if the facial nerve is discovered to lie in the oval window area, this is usually regarded as a contraindication for further surgical intervention. The aim of the present paper is to demonstrate the preoperative pathognomonic radiological sign and describe a new surgical approach for this difficult situation.

METHODS

3 patients and 4 ears were operated due to conductive hearing loss by the same surgeon in a tertiary referral center. Their clinical presentation, radiological findings, surgical findings and final outcomes were evaluated and correlated.

RESULTS

Surgical findings were identical in all 4 ears: facial nerve was running over the oval window and tympanic portion was completely dehiscent. Incus long arm was medially displaced due to abnormal development of the stapes suprastructure. In each ear a successful vestibulotomy and teflon piston placement was achieved. Preoperative mean air-bone gap of 47.5dB was improved to 21.5dB. There were no complications.

CONCLUSION

Oval window atresia is a rare middle ear anomaly usually regarded as a contraindication for surgical intervention. In this study we present a novel surgical approach with succesful results. However the best approach is to inform the family by showing the nerve on tomography, showing the operation video, informing the family about the sensorineural hearing loss and letting the family choose the treatment option.

Pediatric stapedectomy: does cause of fixation affect outcomes?

OBJECTIVE

To compare outcomes of stapedectomy in patients with congenital stapes fixation versus juvenile otosclerosis.

METHODS

A retrospective chart review was performed from January 1, 1999 until January 1, 2011 to identify patients under 18 years old who underwent a stapedectomy. Age, gender, pre- and postoperative audiograms, intraoperative findings including etiology of stapes fixation, prosthesis type, and complications were recorded.

RESULTS

Twenty-two children were identified who had undergone a stapedectomy (two patients underwent sequential bilateral surgery) resulting in a total of 24 ears. The cause of fixation included juvenile otosclerosis (n=7) and congenital stapes fixation (n=17). The overall mean pre-operative air-bone gap (ABG) was 34.7 dB (SD: 13.5) compared to a postoperative mean ABG of 9.0 (SD: 9.3) (p<0.001). The mean postoperative ABG of 9.6 (SD: 10.5) in the congenital stapes fixation group was similar to the mean postoperative ABG of 7.2dB (SD: 5.4) in children with juvenile otosclerosis (p=0.6). Two patients developed delayed profound sensorineural hearing loss approximately two weeks after surgery. One patient with profound sensorineural hearing loss recovered to a profound mixed hearing loss with a speech discrimination score of 80%.

CONCLUSIONS

Pediatric stapedectomy has comparable results to stapedectomy in adults regardless of the cause of stapes fixation; however, delayed sensorineural hearing loss may be higher in the pediatric population.

Histopathology of nonotosclerotic stapes fixations

HYPOTHESIS

Different diseases without exact histopathologic classification can cause stapes ankylosis.

BACKGROUND

Otosclerosis is a complex bone remodeling disorder of the otic capsule due to persisting measles virus infection and consecutive inflammatory reaction. In fact, clinical and demographic features of otosclerosis have reference to stapes ankylosis. In the clinical practice, otosclerosis and stapes ankylosis are incorrect synonyms.

METHODS

Nonotosclerotic stapes footplates (n = 284) removed during stapedectomy were analyzed histologically. Otosclerosis was excluded during the histologic preselection (n = 437). Total RNA was extracted, and measles virus-specific reverse-transcriptase-polymerase chain reaction was performed.

RESULTS

Nonotosclerotic stapes ankylosis was associated with total absence of measles virus RNA. Six main types of nonotosclerotic stapes fixations could be distinguished histologically: annular calcification (n = 152; 53.5%), globular fibrosis (n = 49; 17.25%), lymphocytic infiltration (n = 31; 10.9%), hemosiderosis (n = 22; 7.75%), granulomas (n = 17; 6%) and amyloidosis (n = 13; 4.6%). Fragmentation of nonotosclerotic stapes footplates was infrequent (7%) during stapes surgery. Only 1 floating footplate (0.35%) was reported.

CONCLUSION

Two thirds of nonotosclerotic stapes footplates represented complete pathologic bone remodeling. Unlike otosclerosis, nonotosclerotic stapes fixations were characterized by basic histopathologic findings without organ specificity that can also be identified in case of different diseases. Prevalence of nonotosclerotic stapes ankylosis is approximately 30 to 40% among stapes fixation cases. The long-term prognosis and surgical considerations theoretically differ from those of otosclerosis.

Hearing results of stapedotomy and malleo-vestibulopexy in congenital hearing loss

AIMS

To analyze hearing results of surgical treatment of hearing loss associated with the congenital stapes ankylosis with or without malformations of ossicular chain.

STUDY DESIGN

Retrospective chart review.

METHODS

The charts of 1369 stapedotomies performed by senior author (JH) from 1991 to 2006 were reviewed. In 40 cases operative findings were consistent with isolated congenital stapes fixation or associated with middle ear malformations. The modified stapedotomy technique was employed in 33 cases and malleo-vestibulopexy was used in 7 cases. Operative findings were standardized according to Cremers' classification. The outcomes of 40 surgeries were analyzed according to the 1995 AAO-HNS Committee on Hearing and Equilibrium guidelines. High frequency hearing results on 4, 8 and 12kHz were reported in addition to standard frequencies. Results of stapedotomies and malleo-vestibulopexies were calculated separately. Surgical complications were described.

RESULTS

The mean post-operative air conduction (AC) was 33 dB, bone conduction (BC) 22 dB and speech reception thresholds (SRT) 31 dB. Closure of the air-bone gap (ABG) to within 10 dB was achieved in 24/40 (60%) of cases. Lack of improvement was observed in 3/40 (8%) patients. In 26/32 (81%) of cases with potential for bilaterally serviceable hearing it was achieved. In 24/40 (60%) of cases symmetrical hearing with interaural difference of less than 10 dB was demonstrated.

CONCLUSION

Significant hearing gain in patients with congenital stapes ankylosis makes surgical treatment a valuable adjunct or an alternative to hearing aids in selected cases.

Optical coherence tomography of the oval window niche

OBJECTIVE

Optical coherence tomography was used to study the stapes footplate, both in cadaveric temporal bones and during middle-ear surgery.

MATERIALS AND METHODS

Optical coherence tomography was conducted on five temporal bone preparations (from two children and three adults) and in eight patients during middle-ear surgery. A specially equipped operating microscope with integrated spectral domain optical coherence tomography apparatus was used for standard middle-ear surgical procedures.

RESULTS

This optical coherence tomography investigation enabled in vivo visualisation and documentation of the annular ligament, the different layers of the footplate and the inner-ear structures, both in non-fixed and fixed stapes footplates. In cases of otosclerosis and tympanosclerosis, an inhomogeneous and irregularly thickened footplate was found, in contrast to the appearance of non-fixed footplates. In both fixed and non-fixed footplates, there was a lack of visualisation of the border between the footplate and the otic capsule.

CONCLUSIONS

Investigation of the relatively new technology of optical coherence tomography indicated that this imaging modality may assist the ear surgeon to assess the oval window niche intra-operatively.