This document discusses chronic otitis media, including the histology and pathogenesis. It notes that chronic inflammation is characterized by both tissue destruction and attempts at healing. Repeated infections from the nasopharynx or external ear canal can prevent resolution of otitis media. Persistent bacterial biofilms and chronic perforations of the tympanic membrane also contribute. Chronic retraction of the pars tensa portion of the eardrum can lead to atrophy and complications like cholesteatoma formation over time if not addressed. Early intervention may be warranted for more advanced retractions to prevent future problems.

1. Chronic otitis media in childhood
Histology & pathogenesis of chronic otitis media
1. All forms of otitis media display submucosal inflammatory infiltrates & mucosal metaplasia
with the development of glandular structures, mucus-producing cells & ciliated cells on
histological examination.
2. Chronic inflammation is characterized by tissue destruction as well as attempts at healing.
3. The general histlological features include mononuclear cell infiltrates, submucosal fibrosis,
the formation of highly vascular granulation tissue& ostitis.
4. Mucosal complications such as cholesterol granuloma & tympanosclerosis may be seen.
5. Changes in special structures associated with the middle ear cleft, such as tympanic
membrane are also seen.
6. It is of particular importance that histological discernible chronic otitis media occurs quite
frequently in the absence of tympanic membrane perforation.
7. Animal experiments indicate that features of chronic inflammation appear within 14 days if
acute otitis media fails to resolve.
What may prevent resolution of otitis media?
Repeated infection from nasopharynx
Acute upper respiratory infections may spread to the middle ear cleft from the nasopharynx via the
Eustachian tube. The following mechanism are suggested to chance transfer between the
nasopharynx & middle ear.
1. In the presence of an intact tympanic membrane, inflammation of the pharyngeal end of the
Eustachian may prevent ventilation>absorbed gas of middle ear left> lower pressure of
middle ear cleft> this may predispose to aspiration of nasopharyngeal microbes into the
middle ear cleft.
2. In presence of perforated tympanic membrane, middle ear air cushion no longer impedes
the movement of gas from the nasopharynx into a closed box, predisposing to reflux from
the nasopharynx to the middle ear cleft.
Repeated infection from the external ear canal
In the presence of a perforated tympanic membrane, microbes can be transported in fluid from the
ear canal into the middle ear. In particular, water that gains access to the external ear canal can
flow without impediment into the middle ear through the perforation. In addition mucus from
middle ear may straddle the tympanic membrane& provide a vehicle for transfer of microbes from
the external ear into the mesotympanum.

2. Persistent colonization by bacterial biofilms
There is evidence that many chronic infections are caused by the ability of bacteria to alter their
form to create nonmotile communities adherent to mucosa and protected by polysaccharide matrix.
Such biofilm are able to resist most forms of the host resistance as well as antibiotics.
Chronic perforation of the tympanic membrane
Perforation of tympanic membrane is deemed to be chronic if present for three months. Chronic
suppurative otitis media is defined by otorrhoea of at least six weeks duration in presence of a
chronic tympanic membrane perforation.
Atrophy of the pars tensa of the
tympanic membrane (including
retraction pockets)
Atrophy of the pars tensa of the tympanic membrane occurs through loss of the collagenous fibrous
layer. Pars tensa atrophy is associated with chronic middle ear inflammatory changes .
There is also evidence that some cases of tympanic membrane atrophy are associated with sniffing.
In the presence of an open Eustachian tube, sniffing results in a sharp reduction in Eustachian tube &
middle ear pressure.
Pars tensa atrophy with retraction may focally affect any segment of the tympanic membrane & may
affect the entire tympanic membrane.
The tendency of retraction pockets caused by chronic otitis media to form in the posterosuperior
part of the tympanic membrane due to a combination of the following factors. The posterosuperior
pars tensa is more vascular than others areas of the tympanic membrane & marked inflammatory
reactions. Fibrous layer in this region is less complete & can be devoid of circular fibres.
Atrophy of the pars tensa ranges from mild to severe retraction with fixation of the atrophic
segment to bony walls of the middle ear. Some cases of tympanic membrane collapse are
progressive. They may become associated with erosion of the ossicles. A small proportion of
advanced pars tensa retraction pockets progress to become cholesteatoma.
Sade’s classification of retraction of the pars tensa
1. Atelectasis , defined as diffuse retraction of the tympanic membrane towards promontory.
2. Retraction pocket, defined as focal retraction of the pars tensa towards or into the attic.
Grade Title Description

3. 1 Retracted ear Slight retraction of the TM
2 Severe retraction TM touching the incus or
stapes
3 Atelectasis TM touching the promontotium
4 Adhesive otitis media TM adherent to the
promontorium
Natural history of progression of retraction of the tympanic membrane
Follow up of patients with tympanic membrane retraction over a mean of three to five years using
the sade classifications has established the following.
1. Retraction without atrophy (grade I atelectasis) is uaually transitory condition. It rarely
progress to more advanced stages & frequently reverts to a normal tympanic membrane.
2. Grade II &III of the disease are quite dynamic, having the ability to improve, deteriorate or
remain the same. Over three to five years, 16% may be expected to deteriorate.
3. Grade IV atelectasis , on the other hand, does not spontaneously revert back to earlier
stages of the disease.
4. 16% of grade IV retraction towards the promontory will progress to perforation.
5. 10% of clean pockets retracting towards the attic will progress to accumulation of keratin
debris.
6. A large numbers of retraction pockets which progress towards the attic present at a late
stage.
Symptoms
Retraction of the tympanic membrane may be associated with a complex & highly variable set of
symptoms & signs.
1. Symptoms due to atrophy of the TM
2. Due to underlying COM.
3. Eustachian tube dysfunction;
4. Erosion of ossicles;
5. Infection of keratin.
There may be no symptom at all. Variable hearing loss due to chronic inflammation with
accumulation of a middle ear effusion may occur. Persistent hearing loss may occur if the tip of the
long process of incus has been eroded.
In general , hearing loss is mild when retracted TM is in contact with an intact stapes.

4. Significant conductive hearing loss when erosion of stapes superstructure.
There may be episode of acute otitis media or infection of debris within the pocket.
Variable sound perception due to variable Eustachian tube patency also occurs. For a similar reason,
some patient experience a feeling of fullness or pressure in the ear. Sniffing which reduces the
middle ear pressure & locks the Eustachian tube, eases this sensation.
Signs
Examination of the retracted tympanic membrane requires the following steps:
1. Obtaining the adequate view of the tympanic membrane.
2. Establishing the diagnosis; care is needed to differentiate a retraction pocket from a
perforated tympanic membrane & two dimensional view provided by a otoscopy may not be
sufficient. Microscope will help determine if retracted area is perforated.
If keratin is accumulating within retraction pocket, some authors considered as a cholesteatoma.
however a minor accumulation of dry keratin, associated with streaming of the keratin out of
the retraction pocket,usually remains asymptomatic& is not always associated disease
progression.
3. Staging the retraction pocket; it is important to attempt to identify the margins& entire
fundus of the retraction pocket. it may disappear behind the posterior annulus,the
manubrium or the chorda tympani.
A) If there is posterior tympanic membrane, the abnormalities is readily recognised because
the long process of the incus will be clearly visible.
B) The retraction may envelop the incus & stapes like clingfilm
C) Stapes superstructure may be absent so that the oval window is visible.
D) There may be keratin accumulation within the pocket. An early sign of this accumulation is a
stream of wax emanating from the pocket around the posterior annulus & along the
posterior canal wall.
E) There may be granulation tissue associated with the retraction if this accumulating keratin
becomes infected.
Investigations
1. Pure tone audiometry;
Pars tensa retraction pockets cause morbidity not just through progression to cholesteatoma
but also by eroding the ossicular chain resulting in hearing loss.
Quantitative assessment of hearing status is an important parameter in the complex process of
deciding whether to offer intervention for retraction pocket.
2. Examination under anaesthetic

5. If the child cannot tolerate aural toileting in the clinic & inspection of the entire tympanic membrane
cannot be performed, examination of the ear under anaesthetic should be arranged.
Management of retraction of the pars tensa of the tympanic membrane
The data presented above under natural history of progression of retraction of the tympanic
membrane indicate that most cases do not progress. Nonetheless, some retracted tympanic
membranes progress to form cholesteatoma. At present we can not predict with certainty which
cases will progress. As result there are two possible management strategies.
1. The simplier is to wait until cholesteatoma has developed, at which stage intervention is clearly
justifiable.
2. The more controversial is to intervene before cholesteatoma develops, using the best available
risk factors.
The augument for early intervention;
1. Fixation of the tympanic membrane to the promontory is an indication for surgical intervention,
since gradeIV retractions do not spontaneously improve.
2. Grade III retractions which are progressing are the ideal indication for surgical intervention since
fixation of the tympanic membrane is itself ,associated with a higher incidence of post-operative
cholesteatoma.
Specific risks associated with surgery for tympanic membrane retraction include the following;
1. Surgical elevation of the collapse tympanic membrane from the ossicles carries some risk of
cochlear injury.
2. Failure of the tympanic membrane to heal after surgery may result in an iatrogenic perforation.
3. There is also a risk of spawning an iatrogenic cholesteatoma by leaving epithelium capable of
generating keratin in the mesotympanum in those cases with adherence of the tympanic
membrane to the wall of the middle ear.
4. Even if the tympanic membrane heals, the tympanic membrane may retract again.
Surgical intervention for retraction pockets
Grommet insertion:Treatment of the tympanic membrane atelectasis with insertion of a ventilation
tube into the remaining healthy tympanic membrane is widely practised.
Insertion of multiple ventilation tubes results in more tympanic membrane scarring & no benefit in
limiting the progression of tympanic membrane retraction.

6. Reinforcement tympanoplasty: excision of the retraction pocket with grafting of the tympanic
membrane is also widely performed. The graft is usually temporalis fascia, perichondrium or
cartilage.
If the pocket is intact there need to be no concern about residual disease. If the pocket is adherent
to the middle ear walls & tears during removal , a second-look procedure may be necessary since the
risk of the residual disease is as high as with cholesteatoma surgery.
If retraction pocket is firmly adherent to the ossicles, particularly the stapes, there is risk of
sensorineural hearing loss while removing the disease.
Retraction pocket excision: simple excision of the retraction is usually associated with spontaneous
healing of the tympanic membrane has introduced a less invasive procedure for management of
pars tensa retraction pockets. As this simple operation
- does not require insertion of a graft ,
- can be performed permeatally ,
-does not require packing of the ear;
-can be performed as a day case procedure;
-excision of the retraction pocket can be genuinely offered as prophylaxis against the
development of cholesteatoma.
Ossicular chain defect associated with retraction pockets
The commonest ossicular defect associated with pars tensa tympanic membrane atrophy is erosion
of the tip of the long process of the incus. This can be directly repaired by interposing a graft or
prosthesis between the residual long process & the capitulum.
Larger defects of the long process can be repaired by removal of the incus and repositioning it as a
malleus-stapes assembly.
Cholesteatoma
Definition :the stratified squamous epithelium of the tympanic membrane & external ear canal
migrate prior to being shed at the entrance to the external meatus. In this way, the ear canal
protects itself from filling with shed keratinocytes.

7. If the squamous epithelium &accumulating kerationcytes are within the middle ear space, this
condition is termed cholesteatoma.
Failure to epithelial migration & accumultating of keratin within the ear canal is not
cholesteatoma.however , if there is focal erosion of the external ear canal bone in association with
keratin accumulation the term is external canal cholesteatoma.
Pathogenesis & classification
1)Congenital cholesteatoma
Criteria for diagnosis:
-white mass medial to the intact tympanic membrane;
-normal pars tensa & flaccid;
- no previous history of ear discharge, perforation or previous ontological procedures;
-it has been proposed that prior bouts of acute otitis media are not grounds for excluding
the possibility ofg congenital cholesteatoma. since it is very rare for a child to have no episodes of
otitis media in its first five years.
A vestigial structure, the epidermoid formation,from which congenital cholesteatoma may originate
has been identified in the anterior epitympanum.
Some epithelial cysts that satisfy the definition of a congenital cholesteatoma do not present until
the fourth or fifth decade. It has been suggested that origins of these may in infact be metaplastic.
Or acquired from the aberrant resolution of a pars tensa retraction pocket.
2)Acquired cholesteatoma
1. Immigration ; migration of squamous epithelium into the middle ear through a defect in the
tympanic membrane. It is responsible for only a very small proportion of cholesteatoma.
2. Retraction: progressive retraction of the tympanic membrane, either in the pars flaccida or
associated with atrophy of the pars tensa.
3. Basal cell hyperplasia: proliferation of the basal layers of the keratinzing epithelium of pars
flaccida.
3)Iatrogenic cholesteatoma
Implantation of squamous epithelium as a result of blunt or sharp trauma to the tympanic
membrane may result in a cholesteatoma.
Failure to remove all squamous epithelium from middle ear during cholesteatoma allows the disease
to persist & return. This iatrogenic form is known as residual cholesteatoma.
Cholesteatoma that returns de novo after surgery is termed recurrent cholesteatoma.

8. Classification of cholesteatoma by aetiology
Congential Acquired
Vestigial
Harmartoma
Metaplasia
Invagination
Amniotic migration
Invagination
Invasion
Basal cell hyperplasia
Metaplasia
Trauma
Iatrogenic(residual)
Epidemiology
1. Prevalence : a survey in Jerusalem has been suggested a prevalence of cholesteatoma as
high as 7/10000 children, with a survery in Vietnam suggesting a similar prevalence of
6/10000.
2. Change of prevalence: the change in the incidence of cholesteatoma over recent decades
varies from report to report.
3. Age distribution: the peak incidence of cholesteatoma is second decade of life.
4. Sex: Cholesteatoma affects approximately three males for every two females.
5. Anatomical features of cholesteatoma : In children there is a significant higher rate of
cholesteatoma associated with pars tensa pathology than in adults. In adults attic
choleateatoma is more frequent.
6. Extent of cholesteatoma : paediatric cholesteatoma more frequently involves the extremes
of the middle ear space(the Eustachian tube, anterior mesotympanum, retrolabyrinthine
area & the mastoid tip). Adult cholesteatoma however, more frequently involves the
anterior epitympanum.
Symptoms
Children with cholesteatoma are nearly always affected by either ear discharge or hearing loss or
both.
Signs
Obtaining a good view of the tympanic membrane: mucus, keratin, polyps or even wax may
prevent a clear view of the drum. Once the debris has been removed from the child’s ear, further
inspection may reveal the presence of a polyp filling the lumen.

9. Aural polyps associated with mucopus are almost always due to exuberant granulation tissue. The
collagen content of the polyps is very low so that most can be avulsed painlessly using microsuction.
Once the polyp has been removed its base can be cauterized with silver nitrate to obtain
haemostasis.
Inspection of the tympanic membrane:
1. Some ear canals are narrow & tortuous & only part of the tympanic membrane can be seen.
It is minimum reqirement that the entire tympanic membrane be inspected. If not possible
in the out patient department the child’s ear should be inspected under general anaesthesia.
2. Most important of all to note is whether the defect is a perforation or a retraction pocket.
this can not always be reliably determined using a hand held otoscope, so inspection using
the otological microscope is essential.
3. If pars tensa is normal, pars flaccid should be fully inspected. In most cases, retraction of the
pars flaccida can be readily identified. Some attic retractions,however, can barely be seen
even on prolonged & careful examination. They may have very narrow opening. The
anatomy of the ear canal may limit the view of the area. If the attic area cannot be seen then
a further examination with the otoendoscope may improve the view.
4. Attic area may be obscured by polyps, keratin, or even apparently innocuous mucus or wax.
Wax or mucus covering the attic area should be removed. Granulation tissue & moist
keratin within this area confirms the diagnosis.
5. On occasion, a cholesteatoma sac can be seen through an otherwise normal tympanic
membrane as a vague white mass with a convex border. A myringotomy to remove any
middle ear mucus may help to clarify this sign. Occasionally , a limited tympanotomy may be
required to confirm the diagnosis.
6. Rarely such mesotympanic disease may have an attic origin so a further inspection of the
attic should be performed.
Investigation of cholesteatoma
1)Audiology
1. It is essential to obtain a measure of the hearing in both ear prior to surgery.
2. In all cases the patient should be advised that the hearing in the operated ear may
deteriorate.
3. If the preoperative ipsilateral air conduction is normal, loss of hearing in the operated ear
will have more impact if the contralateral hearing hearing is impaired. It is therefore
essential that the opposite air conduction threshold be determined so that any appropriate
mitigating action, such as the provision of a hearing aid can be planned.

10. 4. If the preoperative ipsilateral air conduction is impaired, the possibility of improving the
hearing through surgery should be determined. If bone conduction threshold is normal,
there remains a chance that the hearing can be improved by surgery,
2) Examination under anaesthesia
This procedure may be essential in small children in order to inspect the tympanic membrane
closely. It may be difficult to identify & systematic & careful exploration of the tympanic membrane,
including the attic area, is essential. A fine sucker is a useful multipurpose probe, retractor &
elevator, as well as microsucker in this venture.
3) CT scan of temporal bone
In most cases, cholesteatoma is diagnosed by direct inspection of the tympanic membrane closely.
CT scaning helpful under the following cases;
-indeterminate examination under anaesthesia;
- suspected epidermal cyst;
-symptomatic ear with apparently clear attic retraction pocket.
CT scaning also helpful ;
-revision cholesteatoma surgery;
- suspected inner ear complications;
-suspected intracranial complication.
Treatment
Aims of cholesteatoma surgery:
-Removal of all cholesteatoma;
-prevention of recurrent cholesteatoma;
- to obtain a robust ear which means dry, selfcleaning & free of infection after exposure to
water.
-restoring of hearing.
Removal of all cholesteatoma
It is well established that there is a high rate of disease left within the temporal bone(residual
disease) after primary surgery. It is particularly difficult to remove disease from the posterior
mesotympanum/sinus tympani & from around the ossicular chain.
Angled endoscopes or mirrors must be available in order that cholesteatoma in the sinus tympani or
behind the ossicles can be clearly seen.

11. The most significant improvement has come from the introduction of the fibre-guided laser(KTP
laser) as a tool for removing cholesteatoma from around the ossicles, sinus tympani, behind the
ossiclcular chain.
Obtain a robust,dry ear
The presence of an unstable ear after surgery is an ongoing burden to the affected child. The ear
may feel uncomfortable & may be associated with otitis externa ort excoriation of the pinna. Ths
stability of the ear is depend upon the self-cleaning mechanism, a dry ear after cholesteatoma
surgery can be achieved by :
-gaining access to the disease using combined approach through mastoid air cells & ear
canal.
-lowering the ear canal wall & incorporating the mastoid space into the canal.
-partially obliterating the mastoid bowl after its exposure by removing the canal wall.
The greatest advantage of intact canal wall surgery is that the resultant ear is almost ear almost
always dry.
Adequate lowering of the facial ridge is the most important factor influencing the out come of a dry
ear in canal wall down surgery.
Prevention of recurrent cholesteatoma
Chlesteatoma has a tendency to return de novo. This is particularly the case if there exists the
combination of a large space behind the plane of the keratinizing epithelium as well as small opening
through which the keratinizing epithelium can retract. This will allow the formation of a new narrow-neck
sac with subsequent accumulation of keratin(recurrent cholesteatoma).
Higher rate of recurrent cholesteatoma in canal wall up surgery.
Reconstruction of the lateral attic wall with bone pate stabilized on a rigid support such as the
silastic strut in the plate has resulted in recurrence rates after intact canal wall surgery being
reduced to the levels associated with canal wall down surgery. Nonetheless, recurrence in children
remains higher than in adults.
Ossicular chain in chronic otitis media
Epidemiology
Chronic otitis media is media associated with erosion of the ossicles. Pars tensa retraction pockets &
cholesteatoma are often associated with ossicular erosion. The commonest defect is ersion of the
long process of the incus.

12. Pathology
Loss of ossicular integrity secondary to chronic otittis media has been termed resorptive osteitis. The
cause of this erosion appears to involve inflammatory cells secreting collagenases.
Outcome measures
Belfast rules of thumb which state that the postoperative hearing in the operated ear will be useful
to the patient if:
- Air conduction threshold is less than 30 dbHL (regardless of the hearing in the opposite
ear).
- Air conduction threshold is within 15dbHL of the air conduction threshold in a better
contralateral ear.
Risk factors
1. Presence of the manubrium & stapes superstructure together is the most important
predictor of good hearing outcome after surgery.
2. Absence of the stapes superstructure predicted strongly against a good outcome.
3. Preoperative air –bone gap > 50db is a negative indicator.
Guideline for surgical technique
Factor
Adhesion Adhesion to the promontory have a profound
adverse effect.
Displacement To prevent displacement & rotation of the
prosthesis, ensure secure attachment to stapes
head or footplates.
Tension Low tension is best, do not stretch the tympanic
membrane
Malleus Using the malleus handle gives better results
Prosthesis High mass has an adverse effect on high
frequencies
Prosthesis stiffness Low stiffness(cartilage, polyethylene) has an
adverse effect at all frequencies

13. Conclusion:
Chronic suppurative otitis media defined as the presence of chronic ear discharge in presence of a
chronic tympanic membrane perforation. The prevalence of chronic otitis media is highest in
children in aboriginal communities.
The prevalence of TM perforation is higher in adults than in children.
Medical treatment of CSOM is best treated with aural toileting& topical fluoroquinolones.
Below the age 13years, the rate of successful tympanic membrane repair diminishes with younger
age. The repair of the tympanic membrane depend on the size of the tympanic membrane& state of
the middle ear cleft.
Pars tensa retraction starts in childhood. The progression of atrophy of the tympanic membrane is
slow but may result in ossicular erosion or cholesteatoma. Tympanic membrane retraction without
atrophy does not progress.
Tympanic membrane retraction pocket excision is a surgical procedure which act as prophylaxis
against the development of cholesteatoma. Selection of suitable cases for this procedure remains
controversial.
Cholesteatoma reaches peak prevalence in the second decade. It is more extensive in children than
adults but less commonly erodes into important temporal bone structures. In general surgical
treatment of cholesteatoma in children is associated with higher rate of residual & recurrent
disease.
Cholesteatoma in children differs from that in adults in that it is more often arises from pars tensa &
it is more extensive. It is more difficult to remove in children & has tendency to recur.