Stapes fixation to the promontory and fallopian canal in a case of chronic otitis media: Implications on development and etiology

Kartikesh Gupta; Amit Kumar; Rachit Sood; Saurabh Varshney

doi:10.4103/indianjotol.INDIANJOTOL_35_20

CASE REPORT

Year : 2020 | Volume : 26 | Issue : 2 | Page : 109-111

Stapes fixation to the promontory and fallopian canal in a case of chronic otitis media: Implications on development and etiology

Kartikesh Gupta, Amit Kumar, Rachit Sood, Saurabh Varshney
Department of Otolaryngology and Head Neck Surgery, AIIMS, Rishikesh, Uttarakhand, India

Date of Submission	02-Mar-2020
Date of Decision	05-Mar-2020
Date of Acceptance	20-May-2020
Date of Web Publication	17-Jul-2020

Correspondence Address:
Dr. Amit Kumar
Department of Otolaryngology and Head Neck Surgery, AIIMS, Rishikesh, Uttarakhand
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/indianjotol.INDIANJOTOL_35_20

Abstract

Embryology of stapes has long been a topic of controversy. There are theories stating a single source to the dual origin of stapes. Chronic otitis media is also known to cause various acquired bony ossicular fixations. We present a case of an 11-year-old female with right chronic otitis media, active squamosal with cerebellar abscess who underwent drainage of cerebellar abscess followed by tympanomastoidectomy as a two-staged procedure. Intraoperatively, there were stapes suprastructure fusion to the fallopian canal and one crural attachment to the promontory. There are no clear criteria to differentiate bony fixation of congenital origin from acquired causes. This case also highlights the need to add a new subclass in the classification of minor middle ear anomalies given by Cremer, and our findings also support the dual origin for stapes development.

Keywords: Cholesteatoma, chronic otitis media, stapes fixation

How to cite this article:
Gupta K, Kumar A, Sood R, Varshney S. Stapes fixation to the promontory and fallopian canal in a case of chronic otitis media: Implications on development and etiology. Indian J Otol 2020;26:109-11

How to cite this URL:
Gupta K, Kumar A, Sood R, Varshney S. Stapes fixation to the promontory and fallopian canal in a case of chronic otitis media: Implications on development and etiology. Indian J Otol [serial online] 2020 [cited 2023 Mar 22];26:109-11. Available from: https://www.indianjotol.org/text.asp?2020/26/2/109/289948

Introduction

Stapes have always been a point of interest for an otologist regarding its development, disease, or management. Facial nerve is derived from the second branchial arch.^[1] The most accepted theory for stapes origin is from Reichert's cartilage.^[2] However, there is circumstantial literature for the dual origin of stapes as well as origin independent from Reichert's cartilage.^[2] We present a case of an 11-year-old female who had complaints of decreased hearing since childhood with isolated bony ankyloses of stapes with both promontory and Fallopian canal ^{More Details} simultaneously. Although ankyloses of stapes with fallopian canal and crura are reported separately,^[1],[3] such anomaly of stapes has never been reported in the literature, to the best of our knowledge. This anomaly of stapes also raises a question for some criteria to differentiate congenital versus acquired bony ankyloses of stapes, based on radiological and intraoperative findings. It also questions about the development of stapes. Our case supports the dual origin of stapes development and also suggests the possibility of a new subclass of isolated bony ankyloses of stapes in Cremer's classification of minor middle ear anomalies.

Case Report

An 11-year-old female presented to the emergency department with complaints of dizziness for 1½ months associated with difficulty walking, nausea, and vomiting. She also had a high-grade fever for 1½ months which was associated with headache. There was a history of right ear discharge and decreased hearing since childhood. Neurologic examination revealed inability to perform Romberg's test, dysdiadochokinesis, and pass pointing present, and right beating horizontal nystagmus was present with no other sensory or motor findings. On examination of the right ear, mucopurulent discharge was seen in the ear canal with Grade II retraction of pars tensa and flaccida with small central perforation anteriorly in pars tensa. Facial nerve was normal. Based on clinical examination, a diagnosis of complicated chronic otitis media with cerebellar abscess was made and all routine investigations along with contrast-enhanced computed tomography (CECT) head and temporal bone were done. Ophthalmology opinion was done, and on fundus examination, there was Grade 1 papilledema with right VI cranial nerve palsy. CECT of the head showed epidural empyema, hypodense collection with enhancing rim in the right cerebellar hemisphere [Figure 1], suggestive of cerebellar abscess with compression upon the fourth ventricle, dilation of third and both lateral ventricles, and midline shift toward left in the posterior fossa with right-sided tonsillar herniation. Urgent neurosurgery opinion was taken, and nearly, 30 ml of pus was drained after burr-hole drainage for right cerebellar abscess. The patient was started on broad-spectrum intravenous antibiotics with anaerobic cover. Pure tone audiogram of the patient showed right severe mixed hearing loss with average hearing loss of 70 dB and air–bone gap of 50 dB; the left side showed normal hearing threshold. High-resolution computed tomography temporal bone was done which showed soft tissue density involving the middle ear, mastoid with crural attachment of stapes over promontory, and partially obliterated oval window [Figure 2]a, on comparison with the other side [Figure 2]b. The patient was planned for right tympanomastoidectomy under general anesthesia, and intraoperatively, unhealthy granulation tissue was seen in the middle ear, aditus, and antrum and was removed. Stapes was found to be fixed with its one crus attached over promontory and its suprastructure attached to the fallopian canal [Figure 3]. The patient had improvement after 3 weeks and was able to sit on her own. The patient was discharged in clinically satisfactory condition, and she was able to walk and was symptom-free on follow-up after 6 months.

Figure 1: Contrast-enhanced computed tomography of the head with rim enhancing hypodense lesion with central necrosis suggestive of cerebellar abscess, marked red arrow

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Figure 2: High-resolution computed tomography of the temporal bone axial view (a) oval window on the right side partially obliterated and with crural attachment of stapes on promontory, marked in red circle, (b) normal oval window with footplate on the left side, marked in red circle

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Figure 3: Endoscopic view of postcanal wall down mastoidectomy, (a) promontory, (b) stapes, (c) fallopian canal; all fixed to each other

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Discussion

Chronic otitis media is one of the most common otological problems both in adults and children. Recent literature also suggests that pediatric disease is more aggressive than adults due to the presence of granulation tissue.^[4] The presence of granulation tissue indicates more osteitis which may lead to increased bony fixations. Thus, it can be said that chances of bony fixations are more in pediatric cholesteatomas. Other factors contributing to increased aggressiveness in pediatric cases are disturbed middle ear ventilation, reduced calcium salt content in children's bone, and higher proliferation rate.^[5],[6] The most common type of stapes anomaly found is footplate fixation with normal superstructure.^[7] In our case, there was a bony fixation of stapes superstructure with promontory which may be secondary to osteitis in a long-standing chronic otitis media or due to congenital anomaly. Postinflammatory ossicular fixation may take three forms of fixation. It can be due to fibrous tissue, hyalinized collagen, or new bone growth.^[8] Polypoid granulation tissue leads to adhesions, tympanosclerosis, or new bone formation as a sequel to chronic inflammation. Intraoperatively, these show polymorphism-like irregular new bone formation on one part of the bone, bridge formation on some other part, and resorption on some other part, demarcating the pathogenesis clearly.^[9]

In the congenital anomaly of stapes, as classified by Cremer's, modified by Tos and HEAR subcommittee, there are four classes with multiple subclasses.^[9] According to this classification, this case could be kept in Class 4 with dysplastic stapes (partially obliterated oval window) with slightly anterior displaced facial nerve (covering oval window).

One possible explanation for stapes superstructure–promontory fixation could be that during development, mesenchymal tissue from the lateral aspect of otic capsule bulges around the oval window region, making direct contact with the mesenchyme of stapes which later undergoes ossification. Stapes superstructure–fallopian canal fixation can be explained by the inability of stapes to lose its attachment with Reichert's cartilage after the formation of interhyale, through a mesenchymal tissue. There is mention in the literature about dual bony bar of stapes with the promontory and facial canal in Tos classification of “isolated stapes ankyloses without other deformities,” and in our case, there were other ossicular abnormalities also present such as absent malleus and incus with partially obliterated oval window.^[9] This case also supports the dual development of stapes from second branchial arch as well as the otic capsule like Henriques et al.^[10] Somewhat similar cases are also described by Martin et al. in 2006 which showed abnormal facial nerve course associated with stapes fixation and Whittemore et al. in 2013 with crural attachment to promontory.^[3],[11] Facial nerve course anomaly is well described by H. J. Gerhardt and H. D. Otto in 1981 and its association with stapes anomaly regarding its anterior and lateral displacement, but unlike this case without dual bony fixation in stapes.^[12] This classification is important as any abnormal facial nerve pathway may lead to conductive hearing loss.^[1] Another explanation for this anomaly can be ossicles outer enchondral ossification which completes by the time ossification in the fallopian canal starts, hence, if there is an anomaly in developing ossicles, it can be superimposed with fallopian canal ossification.^[13] Not just congenital, but there are reports of familial superstructure stapes fixation also.^[14] Gene identified for congenital stapes fixation in humans is associated with mutations in the NOGGIN gene.^[15] Despite all this, how the stapes become distinct from otic capsule or how the position of footplate is governed over oval window remains mysterious. Our intraoperative finding may be result of chronic inflammatory process or it might because of congenital origin.

Conclusion

Stapes anomaly is the most common ossicular anomaly. This case of stapes fixation with fallopian canal and promontory both supports the need to redefine the classification of minor middle ear anomalies. As other recent data suggest, it also indicates the dual origin of stapes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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