1) Chronic otitis media (COM) refers to permanent abnormalities of the eardrum or middle ear bones caused by previous ear infections. It is classified into several subtypes based on symptoms and examination findings. 2) Inactive mucosal COM involves a dry perforation of the eardrum, while active mucosal COM shows inflammation and discharge through a perforation. Inactive squamous COM includes retraction pockets without debris, while active squamous COM features cholesteatoma with retained skin and potential to destroy local bones. 3) Complications of COM can arise from the spread of infection through direct bone erosion, preformed pathways, or blood vessels. This may lead to labyrinth

1. Chronic otitis media
Definition:The diagnosis of chr. Otitis media implies a permanent abnormality of the pars tensa or
pars flaccida,most likely a result earlier acute otitis media ,negative middle ear pressure or otitis
media with effusion. COM equates with the classic term chronic suppurative otitis media that is no
longer advocated as COM is not necessarily a result of the gathering of pus.However ,the distinction
remains between active COM, where there is inflammation& production of pus,&inactive COM
where this is not a case though there is potential for the ear to become active at some time. A third
clinical entity is healed COM where there are permanent abnormalities of the pars tensa but ear
doesn’t have the propensity to become active because the pars tensa is intact &there are no
significant retractions of the pars tensa or flaccid.
Healed COM can also be the end result of successful surgery.
Classificaton of COM
COM classification Synonyms Otoscopic finding
Healed COM Tympanosclerosis : healed
perforation.
Thining and /or local or
generalised opacification of the
pars tensa without perforation
or retraction.
Inactive (mucosal) COM Perforation Permanant perforation of the
pars tensa but middle ear
mucosa is not inflamed.
Inctive (squamous) COM Retraction Retraction of the pars flaccid or
pars tensa which has the
potential to become active with
retained debris.
Active (mucosal) COM Permanaent defect of the pars
tensa with an inflamed middle
ear mucosa which produces
mucopus .
Active (squamous) COM Cholesteatoma Retraction of the pars flaccid or
tensa that has retained
squamous epithelial debris .
1)Inactive mucosal COM >dry perforation
2)Active mucosal COM>Perforation with otorrhoea.
3)Inactive squamous COM>Retraction/atelectasis/Epidermization.
4)Active squamous epithelial COM >Cholesteatoma.
5)Healed COM> Healed perforation(dimeric membrane,epidermis+ mucosa) Tympanosclerosis
;Hyaline deposition (white plaque)
Pathology of subtypes of COM

2. 1)Inactive mucosal COM(dry perforation)
There is a permanent perforation of the pars tensa, but the middle ear & mastoid is not inflamed. A
perforation may be completely surrounded by a remnant of the pars tensa or a part of perforation
may extend to the fibrous annulus.
The lamina propria around a perforation is sometimes thickened due to proliferation of fibrous
tissue.
The mucocutaneous junction is usually located at the margin of the perforation but necessarily.
Squamous epithelium can migrate medially into the middle ear. Although the incidence of medial
migration is higher with a perforation that extends to the annulus. Medial migration is sometimes
also occurred in a perforation that is completely surrounded by a remnant of the pars tensa.
At the time of tympanoplasty, it is necessary for a surgeon to excise such ingrown squamous
epithelium, which can be recognised by its velvety appearance under the operating microscopy.
2)Active mucosal COM(perforation with otorrhoea)
There is chronic inflammation within the mucosa of the middle ear & mastoid, with varying degrees
of oedema, submucosal fibrosis, hypervascularity & infiltration with lymphocytes, plasma cells &
histocytes.
Areas of the mucosa may ulcerate with proliferation of blood vessels,fibroblasts & inflammation
cells, leading to the formation of granulation tissue.
There is production of mucopurulent discharge which drain via a tympanic membrane perofration.
The mucosal changes may progress & coalesce to form aural polyps that can protrude the defects of
the tympanic membrane.
Active mucosal COM is often associated with resorption of parts or all of the ossicular chain
(resorptive osteitis). The ossicles thus affected typically show hyperaemia with proliferation of
capillaries. The long process of the incus, stapes crurae, body of the incus & manubrium are involed
in that order of frequency.
Mechanism of bone erosion: It appears that infection, inflammation, pressure & keratin can lead to
elaboration cytokines such as interleukin-1, interleukin-6 & TNF,growth factors. Nonproetin
mediators such as prostaglandin, neurotransmitter & nitric oxide. These moeculars factors provide
the initiating signals that lead to the recruitment, development& activation of osteoclasts. These
activated osteoclasts then result in bone resorption.
Some ear with active (both mucosal & squamousal) demonstrate focal area of cholesterol granuloma
which is histologic feature a giant cell granuloma around cholesterol crystals. Cholesterol crystals are
breakdown products of haemorrhage.

3. 3)Inactive squamous epithelial COM(retraction pocket, atelectasis&
epidermisation)
Atelectasis: negative middle ear pressure can result in retraction of the tympanic membrane.
Retraction pocket: consists of an invagination into the middle ear space of a part of the tympanic
membrane which may be fixed or free.
Epidermization: is a more advanced type of retraction& refers to replacement of middle ear mucosa
by keratinizing squamous epithelium without retention of keratin debris. Epidermization may involve
a part or all of middle ear mucosa & does not progress to cholesteatoma or active suppuration. So it
is not indication for surgical intervention.
4)Active squamous epithelial COM(cholesteotoma)
Cholsteatoma :consist of centre to periphery;
1. The hallmark of cholesteatoma is its retention of keratinous debris. So keratoma is
appropriate term.
2. Squamous epithelial lining or matrix of cholesteatoma is similar to skin.
3. The matrix is surrounded by a layer of inflamed, vascular, subepithelial connective tissue.
Active bacterial infection leading to profuse malodorous otorrhoea. Cholesteatoma is potentially
dangerous because it incite resorption of bone, leading to intratemporal or intracranial infection.
5)Healed COM
1. Healed perforation(dimorphic membrane): loss of lamina propria of the TM due to atrophy
or failure to reform during healing of a perforation leads to a dermeric membrane, consists
of epidermis & mucosa. Such a thin membrane is prone to retraction if there is negative
static middle ear pressure.
2. Tympanosclerosis : collagen of fibrous tissue hyalinises & deposition of calcium visible as
white plaques in the tympanic membrane. Tympanosclerosis can occur within TM, middle
ear mucosa, epitympanum, ossicular ligaments, & muscle tendons. Tympanosclerosis
involving in the TM has little effect on sound conduction. Tympanosclerosis surrounding the
ossicles in the epitypanum & stapes superstructure or footplate in the oval window causing
varying degree of immobility of the ossicular chain & well-recognised adverse factor in
tympanoplasty.
3. Fibrocystic & fibro-osseus sclerosis: some cases of healed COM in the end stage pathology
characterised by fibrosis & cyst formation (fibrocystic sclerosis). There is often deposition of
new bone in the mastoid antrum& mastoid cells tracts( fibro-osseous sclerosis), eventually
resulting in sclerotic mastoid. Neo-osteogenesis around the ossicles leading to conductive
deafness. Fibrocystic & fibro-osseous sclerosis nonprogressive, end stage pathology that is
contraindication to tympanoplasty.

4. Pathology of complications of COM
Route of spread of infection
The route of spread of infection include the following:
1. Natural communications between the middle ear & labyrinth such as oval window& round
windows. The round window & annular ligament are natural barrier to spread of infection
from the middle ear to the labyrinth. These barrier can be breached by inflammatory
cytokines, bacterial toxins, & infectious organisms.
2. Direct bone erosion: can occur in both active mucosal disease& cholesteatoma.
3. Abnormal preformed pathways: either congenital or acquired including aberrant arachnoid
granulation tissue,meingo-encephalococeles & temporal bone fracture.
4. Vascular channels:progressive thrombophebitis of small venules may result in spread of
infection through intact bone.
1)Labyrinth fistula
A fistula in the bony labyrinth is the most common complication of COM. The lateral semicircular
canal most commonly affected site. Labyrinth fistula can be caused not only by cholesteatoma but
also by active mucosal COM without cholesteatoma. Even by localized infection in a canal wall down
mastoidectomy.
2)Labyrinthitis
Inflammation of labyrinth has been classified as serous or toxic & suppurative.
1. Serous labyrinthitis is assumed to represent a sterile inflammatory response of the labyrinth
to bacterial toxin.
2. Suppurative labyrinthitis is caused by invasion of bacteria of inner ear. Inflammation
>endolymphatic hydrops> necrosis of membranous labyrinth.
Hearing loss both in early stages of both serous & suppurative labyrinthitis is metabolic in
nature, indicates that treatment of suppurative labyrinthitis should involve antibiotic & steroids
directed to attenuate the host response. Timely institution of such appropriate therapy can
reverse the sensorineural hearing loss of suppurative labyrinthitis.
It has been traditionally assumed that serous labyrinthitis results in reversible hearing loss,
whereas the hearing deficit in suppurative labyrinthitis is permanent.
3)Facial nerve paralysis
Involvement of facial nerve in active COM usually occurs by direct erosion of bone of facial canal by
cholesteatoma ort granulation tissue.

5. 4)Petrositis
In 1904, Gradenigo recognized that the triad of persistent otorrhoea,severe periorbital pain, &
abducent nerve paralysis is characteristic of infection of the petrous apex.
1. Acute petrositis: acute inflammation in the mucous membrane of petrous apex cells, it may
progress to an abscess .
2. Chronic petrositis: chronic inflammatory changes & there is resorption of bone as well as
new bone formation. Chronic petrositis may be an indolent infection that can persist for
month ort year. Chronic petrositis causes serous complications because of anatomical
proximity of the petrous apex to the meninges, trigeminal nerve, & carotid artery. Serous
complication including meningitis, extradural abscess, multiple cranial nerve paralysis &
carotid artery thrombosis.
5) Otogenic intracranial complications
The dura covering is a strong barrier that protect the intracranial complications. Intracranial
complications depends on including the type & nature of the COM, offending organism& anatomical
location. These complication are meningitis, extradural abscess,subdural abscess, cerebellar &
temporal lobe abscess, sigmoid sinus thrombophlebitis.
Surgical pathology
A)Tympanic membrane grafts
Tympanic membrane perforations can be successful repair using a variety of graft materials.
Commonly used grafts include autologous temporalis fascia, perichondrium, cartilage, adipose
tissue.
Histologically , tympanic membrane grafts become lined by squamous epithilum on the ear canal
side& middle ear mucosa on the tympanic cavity side. The graft becomes middle or connective
tissue portion of reconstructed drum.
B)Ossicular grafts & implants
Autologous ossicle grafts (incus or head of malleus) maintain morphologic contour, size, shape&
physical integrity for long periods of time over 25 years. They do not incite formation of new bone
nor do they undergo resorption(in absence of infection). They undergo slow replacement of non-viable
bone by new bone formation through a process of creeping substitution.
Cartilage grafts are not optimal for ossicular reconstruction. Cartilage often develop chondromalacia
with loss of stiffness & tendency to resorbed over time.
Porous high density polyethylene( plastipore) elicit an intense foreign body giant cell reaction that
becomes well established within a few weeks. Microdegradation of plastic material also occurs.
More recently many others synthetic material are used bioactive glass(bioglass), aluminium oxide
ceramic, carbon, hydroxylapatite, gold, titanium.

6. C)Mastoidectomy cavities
A canal wall-down mastoidectomy cavity that is dry & well healed characterized histologically by a
lining of keratinized epithelium on a layer of subepithelial fibrous tissue & underlying sclerotic
mastoid bone.
Discharging mastoid due to
1. Recurrent or residual cholesteatoma;
2. A high facial ridge, meatal or canal stenosis &
3. Suppuration in unexenterated cells of the mastoid & middle ear especially the tegmental
cells, cells of sinodural angle, mastoid tip & facial recess.
If part of cholesteatoma matrix is left in the middle ear cleft:
1. It may undergo metaplasia to middle ear mucosa type.
2. Squamous epithelial retention cyst or cholesteatoma pearl.
Biological & pathological factors
determining success of
tympanomastoid surgery for COM
1. The primary objective of surgery for COM is to eradicate infection, disease & make the ear
safe & dry.
2. A second objective of surgery for COM is to restore hearing to serviceable levels by mean of
tympanoplasty.
Success after tympanoplasty depend on
1. Operation after controlling infection
2. Surgeon’s technical skill.
3. As a sequel to surgical trauma or healing response to COM, deposition of fibrous
tissue, formation of adhesions, neo-osteogenesis. These tissues cause fixation of
stapes footplate, ankylosis or displacement of ossicle strut. Gelfom prevent the
formation of adhesion or fibrous tissue.
4. Total or partial non-aeration of the middle ear & development of negative
middle ear pressure due to Eustachian tube dysfunction> OME> severe
atelectasis. It causes displacement or exclusion of ossicular grafts. The negative
pressure can also lead to recurrent cholesteatoma which is disadvantage for
canal wall-up procedure.

7. In some patients the problem is selective non-aeration of the posterior
mesotympanonum while anterior mesotympanonum remain aerated.