CHRONIC OTITIS MEDIA
Definition: Chronic otitis media is the permanent abnormality of the Pars Tensa or Pars Flaccida due to previous otitis media with effusion, negative middle ear pressure or acute suppurative otitis media. Classification:
|Healed COM||Healed perforation with or without Tympanosclerosis /Myringosclerosis||Thinning with or without local or generalized opacity of the Pars tensa without any perforation or retraction.|
|Inactive (mucosal) COM||Perforation||There is permanent perforation of pars tensa but there is no inflammation of the middle ear mucosa.|
|Inactive (squamous) COM||Retraction||Retraction present in pars flaccida or pars tensa (usually postero-superior) which may become active with retained debris.|
|Active (mucosal) COM||There is permanent defect of pars tensa with inflammation of the middle ear mucosa resulting in production of mucopus.|
|Active (squamous) COM||Cholesteatoma with attic destruction||There is retraction of pars flaccida or pars tensa with retained squamous epithelial debris (hallmark of cholesteatoma) with inflamed middle ear mucosa and pus formation.|
➣ Active mucosal and active squamous epithelial COM (cholesteatoma) is characterized by resorption of bone. ➣ Inactive COM is characterized by retraction pocket, which consists of invagination of eardrum into the middle ear space. It may be fixed (adherent to structures in the middle ear) or free (move medially or laterally). ➣ Retraction can occur in the pars tensa or the pars flaccida. ➣ Sade classification of Pars Tensa retraction include:
- Grade 1– Slight retraction of TM over the annulus.
- Grade 2– Severe retraction, here TM touches the long process of incus.
- Grade 3– Atelectasis, here TM touches the promontory.
- Grade 4– Adhesive otitis, here TM is adherent to the promontory.
- Stage 1– Small attic dimple.
- Stage 2– The retraction is adherent to the neck of the malleus and the full extent of the retraction can be seen.
- Stage 3– Part of the retraction is out of view and there may be partial erosion of the outer bony attic wall (scutum).
- Stage 4– There is definite erosion of the attic wall with the full extent of the retraction being uncertain because it is out of view.
- Acute otitis media and otitis media with effusion.
- Eustachian tube dysfunction.
- Genetics and race- Highest in Eskimos, native Americans, New Zealand Maoris and Australian aborigines.
- Environment- COM is higher in low socioeconomic status.
- Gastro-esophageal reflux disease.
- Craniofacial abnormalities like cleft palate.
- Autoimmune disease- COM is seen to be associated with patients with ankylosing spondylitis.
- Immune deficiency- patients with AIDS have a higher rate of COM.
- Congenital: There are squamous epithelial cell nests arising within the temporal bone.
- a) Primary:
- Invagination of pars flaccida.
- Basal cell hyperplasia.
- Squamous metaplasia.
- b) Secondary:
- Migration of squamous epithelium from external auditory canal and tympanic membrane through the perforation present in the tympanic membrane.
- Metaplasia due to repeated infections of middle ear through the pre-existing tympanic membrane perforation.
- Suction microscopy done to clear out any discharge, confirm clinical findings and examination of the discharge for pus culture and antibiotic sensitivity.
- Tuning fork tests: They help in clinical evaluation of hearing loss.
- Pure tone audiometry: This is useful for a qualitative and quantitative analysis of the patients hearing. It also helps for pre-operative and post-operative assessment of the hearing loss and for medico-legal purposes.
- X-ray mastoid Schuller’s view: To diagnose the extent of the disease and status of the mastoid air cells.
- Routine blood investigations from fitness point of view.
- HRCT temporal bone is extremely useful in patients with complications or impending complications.
- An MRI diffusion test useful to differentiate between Cholesteatoma and other soft tissue. Cholesteatoma restricts diffusion (appears bright).
- Gadolinium MRI scan is useful for delineation of any Intracranial complication.
i. In healed Chronic Otitis Media like Tympanosclerosis or Myringosclerosis, management is only indicated in the presence of significant hearing disability. Hearing aids can be considered as an option in unfit patients.
- Surgical treatment includes tympanoplasty with or without mastoidectomy where removal of the tympanosclerotic foci from the tympanic membrane, ossicular chain and mastoid is done. Finally, restoration of ossicular chain by ossiculoplasty is done.
- Success rates of surgery are usually good but limited.
ii. In Inactive Mucosal chronic otitis media management options are surgery, hearing aid or no treatment:
- Hearing aids should always be considered in the management of hearing disability.
- Dry small perforations that are symptom free do not usually require closure.
- In patients with a history of intermittent infection, surgery to close the perforation is probably indicated to minimize future progression of disease.
- Those patients whose main symptom is discomfort when swimming should be encouraged to wear ear plugs.
- Surgery includes Myringoplasty or Tympanoplasty +/- Ossiculoplasty.
- The most common pathology in the middle ear is erosion of the long process incus. Ossiculoplasty can be done by various techniques. (Discussed in Ossiculoplasty chapter)
iii. In Active Mucosal chronic otitis media management include:
- Aural toileting with the help of suction under microscope.
- Topical antibiotics with steroids.
- Surgical options include Myringoplasty +/- Tympanoplasty, Cortical Mastoidectomy +/- Ossiculoplasty.
- In case of aural polyp, it should be remembered that polyps can be attached to the stapes superstructure or to the facial nerve.
iv. In Inactive Squamosal Chronic otitis media management includes:
- Treat any sino-nasal disease like sinusitis, sino-nasal polyposis, adenoid enlargement, sino-nasal infections etc.
- Aural Toileting with the help of suction under microscope.
- Surgical treatment includes excision of retraction pocket with Tympanoplasty and Cortical Mastoidectomy +/- Ossiculoplasty. Cartilage may be place in the attic to prevent retraction of tympanic membrane in future.
v. In Active Squamosal chronic otitis media, surgical removal is the only effective treatment for cholesteatoma.
Surgical options include:
- Canal wall up Modified Radical Mastoidectomy.
- Canal wall down Modified Radical Mastoidectomy.
- Radical Mastoidectomy.
- Ossiculoplasty +/-.
- Wide Meatoplasty.
- Canaloplasty +/-.