CHRONIC OTITIS MEDIA: MANAGEMENT STRATEGIES

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Chronic otitis media is a clinical condition that involves long standing ear disease in which there is chronic inflammation of the middle ear and mastoid cavity. The disease causes impairment of hearing temporary/permanently and persistent discomfort due to its cadre of ear symptoms affects quality of life across all age groups.

It has a global estimate of 31 million episodes per year with 4.8 new episodes per 1000 people of all ages.(1) the prevalence is higher in low to middle income countries like india and seen more in lower socio-economic strata (2)

Classically the disease spectrum may involve persistent ear discharge for 2-6weeks or may have other symptoms such as reduced hearing, blood-stained foul-smelling discharge or simply recurrent ear infections. The continuous ongoing infection and inflammation cycle causes breakdown of epithelial lining and infection, granulations or bone destroying pathogenesis where they may be granuloma formation that throws itself into polyp like growths in the middle ear. There is no universally accepted duration for definition of Chronicity but a minimum of two six weeks duration is considered standard (3) It usually starts as a complication of acute otitis media that persists with perforation of the tympanic membrane. Eustachian tube dysfunction has been strongly linked to the disease and requires addressal in the treatment regimen as whole.

If not treated in a timely manner, there may be varied complications to this disease including life threatening conditions such as Meningitis, petrositis, facial paralysis, brain abscess, Lateral sinus Thrombophlebitis etc.

Depending on the disease pattern Chronic otitis media can be classified as Mucosal variant or Squamosal variant. Mucosal variant also called COM without cholesteatoma/ Tubotympanic disease/ safe ear can be either active or inactive depending on presence of active infection. Squamosal variant also called COM with cholesteatoma/ Atticoantral disease/Unsafe ear is a more sinister and destructive disease of the ear.

Management protocol: 1. Investigation:

1. Ear swab: a swab of the ear discharge if present in the ear canal not only helps in giving the appropriate antibiotic in the active disease stage but also help to rule out antibiotic resistance accurately and avoid trial and failures.

2. Audiological evaluation: Pure tone audiometry helps to quantify the degree of hearing loss and pattern in both affected or non affected ear. Associated tests to rule out involvement of the vestibulocochlear apparatus becomes important to chart the extent of disease involvement

3. HRCT of the Temporal bone provides a detailed structuring of bone erosion due to cholesteatoma, erosion of bones of the middle ear (ossicles) and extent of involvement of the tegmen plate.

4. MRI gives a more detailed analysis of complications related to COM such as sigmoid sinus thrombophlebitis or labyrinthitis. Cholesteatoma appears hypointense on T1, hyperintense on T2 and does not enhance with gadolinium and hence can be used as a marker to differentiate it from other diseases in the same region. (4)

Treatment of CSOM may include a varied combination of any or all of the following:

• Topical antibiotics (administered into the ear) are recommended as a first line of treatment for COM as it achieves high local concentration of antibiotics (5) It also helps to reduce local granuloma formation when used in combination with steroid preparations. Quinolone are effective resolvers f otorrhea with are free of ototoxicity (6)

• Systemic antibiotics (oral or IV) usually reserved for cases that fail to respond to topical treatment. However, it can be given in adjunct as sometimes topical therapy fails to reach mastoid cavity regions and is unable to penetrate in sufficient quantity.

• Thorough Aural toileting with our without antiseptic washout is also done in many centres that help eliminate the infection in actively discharging ear.

• Surgical management in Chronic otitis media is the only definitive and curative treatment to the disease as it aims to completely eradicate all the disease in its entirety to render a dry healthy ear. The secondary effect of surgical intervention is to preserve or reconstruct the hearing but this should never be done at the cost of disease clearance and hence each approach of surgical treatment is very patient specific.

Depending on the severity of involvement it may involve:

1. Tympanoplasty which may be simply myringoplasty (ear drum perforation repair using patient’s temporalis fascia) or Tympanoplasty (repair of ear drum perforation along with reconstructing the middle ear bones called ossicles aka Ossiculoplasty which can be done as a primary surgery or as a second stage surgery)

2. If cholesteatoma is present that a more radical procedure needs to be done. It can broadly be classified as

a. Canal wall down procedures: they make the mastoid cavity open into the External ear canal such that the diseased area is fully exteriorised. Under this category are included- atticotomy, modified radical mastoidectomy and less commonly the most aggressive variant i.e. radical mastoidectomy

b. Canal wall up procedures: the posterior meatal wall is left intact and there is a combined meatus and mastoid approach taken such that an open mastoid cavity is avoided. Although this provides a dry ear, there are higher chances of residual and recurrent cholesteatoma and long term follow up becomes imperative. In combined approach mastoidectomy, permeatal disease removal is combined with cortical mastoidectomy and posterior tympanotomy in which a window is created between the mastoid and middle ear through the facial recess to reach the sinus tympani.

Images illustrating Tympanic membrane perforation and repair by cortical mastoidectomy and myringoplasty in a case of Chronic Otitis media Tubotympanic type

References:

(1) Schilder AG, Chonmaitree T, Cripps AW, Rosenfeld RM, Casselbrant ML, Haggard MP, et al. Otitis media. Nature Reviews Disease Primers 2016;2:16063. [DOI: 10.1038/nrdp.2016.63]

(2) Mahadevan M, Navarro‐Locsin G, Tan HK, Yamanaka N, Sonsuwan N, Wang PC, et al. A review of the burden of disease due to otitis media in the Asia‐Pacific. International Journal of Pediatric Otorhinolaryngology 2012;76(5):623‐35. [DOI: 10.1016/j.ijporl.2012.02.031]

(3) Verhoeff M, Veen EL, Rovers MM, Sanders EA, Schilder AG. Chronic suppurative otitis media: a review. International Journal of Pediatric Otorhinolaryngology 2006;70(1):1‐12.

(4) McJunkin, J., Chole, R. Clinical Utility of MRI for Cholesteatoma Recurrence. Curr Surg Rep 2, 63 (2014). https://doi.org/10.1007/s40137-014-0063-0

(5) Macfadyen CA, Acuin JM, Gamble C; Systemic antibiotics versus topical treatments for chronically discharging ears with underlying eardrum perforations. Cochrane Database Syst Rev. 2006 Jan 25(1):CD005608.

(6) Harris AS, Elhassan HA, Flook EP. Why are ototopical aminoglycosides still first-line therapy for chronic suppurative otitis media? A systematic review and discussion of aminoglycosides versus quinolones. J Laryngol Otol. 2016 Jan;130(1):2-7.