MIDDLE EAR ANOMALIES

1. DR.JINORAJ
2ND YEAR PG
MODERATOR-DR.VINAY RAJ
ANOMALIES OF
MIDDLE EAR

3. OBJECTIVES
1.INTRODUCTION
2.CLASSIFICATON
3.EPIDEMIOLOGY
4.ETHIOPATHOGENESIS
5.DIAGNOSIS
6.MANAGEMENT AND REHABILITATION

4. INTRODUCTION-EMBRYOLOGY
 The eustachian tubes and tympanic cavity develop from the
expanding terminal ends of the first pharyngeal pouch.
 Complete tympanic cavity at the 30th week.
 Three ossicles originate from the cartilage of the first arch
(mandibular or Meckel’s cartilage) and second arch (hyoidal or
Reichert’s cartilage).
 The malleus and incus are first formed in the 6th week of gestation
as mesenchymal condensations .
 The ossification begins in week 16, and is almost complete by
month 7. By week 22, the three ossicles have attained their adult
size.
 The antrum begins to develop at the 21st week from the
epitympanic recess and is well formed by week 34. Formation of
the mastoid air cell system begins late in fetal life or at birth and
continues until the 2nd year of life.

6. MIDDLE EAR
ANOMALIES
NON OSSICULAR
CONGENITAL MIDDLE
EAR ANOMALIES
CONGENITAL
OSSICULAR
ANOMALIES

7. CONGENITAL
OSSICULAR ABN
MINOR
MALFORMATION-
AFFECT THE
OSSICULAR CHAIN
ALONE (TM AND EAC
–NORMAL)
CREMERS
CLASSIFICATION
MAJOR
MALFORMATION
1.TC+EAC
MALFORMATION
2.ASSOCIATED WITH
SYNDROME
3.INNER EAR

8. CONGENITAL OSSICULAR ANOMALIES-
DEFINITION
 Congenital ossicular fixation and defect is defined as a malformation
affecting the ossicular chain, which leads to a dysfunction of the
ossicular mechanism due to immobility or discontinuity of the
ossicular chain.
 The incidence among children with conductive hearing impairment is
between 0.5% and 1.2%.

9. Embryogenesis
 Failure of mesenchymal absorption
 Failure of embryogenesis
 Failure of differentiation

10. INCIDENCE
 Bergstrom et al reported that out of a group of 687 children with congenital
hearing loss, only eight (1.2%) were found to have isolated middle ear
anomalies.
 Hashimoto et al. reported a much higher rate of incudostapedial joint defects,
either in isolation or with stapes fixation, making up nearly 50% of cases.
 Cremers and Teunissen’s series- stapes ankylosis with another associated
ossicular chain anomaly being the most common finding (38%) with isolated
stapes ankylosis being the other largest group (30%)

11. CLASSIFICATION- ISOLATED MIDDLE EAR
MALFORMATIONS
 Müllers classification:
Mild malformations are those in which normal configuration of the
tympanic cavity coexists with ossicular dysplasia.
Moderate malformations there is hypoplasia of the tympanic cavity
along with rudimentary or aplastic ossicles.
Severe malformations show aplastic or cleft-like tympanic cavity.

12. CLASSIFICATION-CREMERS’ CLASSIFICATION

13. ISOLATED STAPES ANKYLOSIS
 Tos subdivided Cremers’ basic classification to separate
stapes ankylosis into two main groups
 20% of cases the suprastructure may be abnormal, with
one crus being absent (monocrural) or there being no
recognizable crura but instead a single strut
(monopodial).
 Isolated congenital stapes ankylosis represents 20% to
35% of ossicular malformations.
Footplate fixation
Stapes suprastructure
fixation

14.  Stapes ankylosis is a cause of conductive deafness with a
normal tympanic membrane
 Differential diagnosis being other ossicular malformations,
oval or round window atresia, congenital cholesteatoma at
early stage or other middle ear tumors, and ossicular trauma.

15. PATHOPHYSIOLOGY
 The pathological processes leading to stapes footplate fixation are unclear.
 Lindsey et al concluded from a temporal bone study that fixation occurs
due to failure of the annular ligament to differentiate from the lamina
stapedialis. This leads to continuous ossification from the otic capsule to
the footplate.
 At the time of surgery, this may appear as a diffusely thickened white
footplate.
 An ossified stapedial tendon may develop because of a failure of its
precursor to form a tendon and instead become cartilaginous and
subsequently becomes ossified, fixing the stapes.

16. OTHER FOOTPLATE ABNORMALITIES-NOTED
 Malpositioned, malformed, or absent stapes crura
 Narrow oval window niche.
 Confluent oval and round windows.
 Prolapsed, bifid, or aberrant facial nerve.
These can occur in isolation, in combination with
footplate fixation, or in combination with other
ossicular abnormalities.

17.  Axial CT image shows absence of the posterior limb of the right stapes; (b) on the CT image of the
opposite side (normal), the posterior limb of the right stapes (arrow) cannot be identified

18. BIFID FACIAL NERVE IN CONGENITAL STAPES FOOTPLATE FIXATION
THEODORE R. MCRACKAN, MATTHEW L. CARLSON, FITSUM A. REDA, JACK H NOBLE,
AND ALEJANDRO RIVAS
7 year old presented with right-sided hearing
loss. The patient had no previous otologic
history.
Audiological evaluation—CHL without carhart
notch

19. NEED TO BE DIFFERENTIATED FROM JUVENILE
OTOSCLEROSIS
 History- Patients with progressive conductive or
mixed hearing loss with GENETIC association will be
seen.
 Audiometry
CSFF generally presented with a flat air conduction curve with a three tone PTA
of approximately 50 dB.
JO- Lesser degree of conductive loss in most patients.
They posited that once the degree of conductive loss exceeded 35 dB, the
diagnosis of CSFF was more likely.and mostly carhart notch also
present.

20. PTA JO VS CSFF

21. IMAGING
 High resolution computed tomography (CT) scanning remains the primary
imaging modality to attempt to identify the ossicular abnormality, but also to
visualize any other middle or inner ear abnormalities, such as an anomalous
facial nerve, congenital cholesteatoma, aberrant vascular structures or
labyrinthine dysplasia.
 MRI demonstrate associated labyrinthine and internal auditory meatal
abnormalities.
 CT virtual endoscopy may offer a further mode of presenting the images for
pre-operative.

22. CONGENITAL MALLEO-INCUDAL FIXATIONS
 Less common than stapes fixations.
 The malleus head and incus body are fixed to the
epitympanic wall by a fibrous band or a bar of bone.
 Rarely, the malleus handle is fixed to the posterior
tympanic wall by a bony bar.
 Other sites include the anterior, superior and lateral
malleolar ligaments

23. ETHIPATHOGENESIS
 Yoshihisa Kurosaki et al , it is presumed that the
mesenchyme behind the malleus handle is incompletely absorbed
and this persistent mesenchymal tissue differentiates into osseous
tissue
18-year-old man with a malleus bar.
A, Axial CT scan at a level slightly inferior to the incudostapedial joint shows a bony bar (arrow) between the malleus
neck (arrowhead)
and the posterior tympanic wall.
B, Axial CT scan at the level of the epitympanic recess shows normal incudomalleal joint. M 5 malleus head, I 5 incus
body.
C, Coronal CT scan shows a bony bar (arrow) below the incus (arrowhead).

24. HOUSE SYNDROME
 Aka Fixed malleus head syndrome.
 Fixation of the Malleus in tegmen
tympani by a bone bridge.
 Stapes footplate was normal.
 Audiometry shows a moderate
conductive hearing loss, not
exceeding 30 dB.
 Tt- ossiculoplasty was done, by
section of the Malleus neck with
interposition with Incus

25. MANAGEMENT OF SPECIFIC CONGENITAL
OSSICULAR ABNORMALITIES
PRINCIPLE OF MANAGEMENT
 Bilateral moderate hearing loss due to a maximal or near-maximal conductive
hearing loss-
Auditory rehabilitation with air conduction hearing aid.
 If the patient develops local complications in the external ear canal, such as
recurrent or chronic otitis externa, a bone-anchored hearing aid (BAHA) would
be a suitable alternative.
 Surgery for congenital ossicular abnormalities should only be undertaken by
dedicated otologists with experience of complex middle ear reconstruction.
 High risk of delayed SNHL to be explained.

26. ISOLATED STAPES FOOTPLATE FIXATION
 Pre-operative scanning may demonstrate labyrinthine dysplasia-
increased risk of inner ear damage.
Also a dilated fundus of the internal auditory meatus (IAM) should be a
feature of X-chromosome-linked progressive mixed deafness with
perilymphatic gusher.
 The surgical technique is similar to otosclerotic stapes ankylosis.
 A common feature of congenital fixation is the presence of thick
anterior and posterior crura.--can be vapourised by KTP LASER.
 Outcomes in the literature for adult series for otosclerosis, with more
than 70% closure of the ABG to 20 dB or less.

27. SURGERY FOR STAPES
SUPRASTRUCTURE FIXATIONS
 Very rare cases where the footplate is mobile but the
suprastructure is fixed, removal of the bony bar can be
achieved using a CO2, argon, potassium titanyl phosphate
(KTP) or erbium laser or with a microdrill.
 The safest surgery of isolated suprastructure fixation is laser
evaporation.

28. ISOLATED NON-STAPES MIDDLE
EAR ANOMALIES
Isolated malleus and/or incus fixation is currently treated
surgically by one of two techniques: ossicular chain mobilisation
or ossicular chain reconstruction.
Tympanoplasty
Attic fixation: atticotomy
Bony bar : laser , mircodrill or currette
Absence Ossicular chain mobilisation versus reconstruction in surgery for isolated malleus and/or incus
fixation: systematic review and meta-analysis W L Crutcher, P Tassone and S Pelosiof long process of incus
: prosthesis

29. STAPES ANKYLOSIS ASS WITH OTHER
DEFORMITY
- Stapedectomy/Stapedotomy
- Malleovestibulopexy

30. CONGENITAL APLASIA OR SEVERE DYSPLASIA
OF THE OVAL AND ROUND WINDOWS
 The stapes crura are usually poorly developed and do
not reach the region of the footplate and may be
embedded in the facial nerve.
 Facial nerve course is also anomalous.
 Auditory rehabilitation with hearing aids or a BAHA may
be most appropriate.
 Surgery- de novo entrance into the labyrinth
is either drilled on the promontorial or even on the
rostral side of the Fallopian canal.
 High risk of inner ear damage.

32. NON OSSICULAR MIDDLE EAR
CONGENITAL MALFORMATIONS
PERSISTENT SATAPEDIAL ARTERY
A PSA may present as a vascular mass within the
middle ear,found either during otoscopic examination
of the ear or during middle ear exploration.
 Incidence : 1 in 5000-10000
 Asymptomatic.
 Pulsatile tinnitus.
 CHL.

33. PERSISTENT SATAPEDIAL ARTERY

34. PERSISTENT SATAPEDIAL ARTERY

35. ANOMALOUS COURSE OF THE FACIAL NERVE
 The Fallopian canal arises from the otic capsule
and the second branchial arch.
 Dehiscent can occur because of failure of fusion of
the two.
 High association with ossicular abnormalities and
teratogenic effect.

36.  Rohrt and Lorentzen classified facial nerve
displacement in the middle ear into four groups:
I.Facial nerve partially obliterates the stapes footplate.
II. Bifurcation of the facial nerve.
III. facial nerve rests on the footplate with deformed stapes or
oval window.
IV.Facial nerve rests on the promontory.

38.  Congenital perilymphatic fistula (PLF) is an
abnormal communication between the middle and
inner ear. It may be associated with:
 microfissures around the oval and round windows
labyrinthine or IAM dysplasia.
CONGENITAL PERYLYMPHATIC
FISTULA

39. CONGENITAL PERYLYMPHATIC
FISTULA
 The diagnosis is controversial as there is no reliable
preoperative test.
Diagnosis
 -Controversial
 Fistula test, valsalva test , audiometry, ECOG,ENG, HRCT,
MRI scan
 -Weber et al define intraop diagnosis as being based on the
identification of clear fluid which reacumulates with
anesthetic valsalva or trendlenburg manoeuvre.
 -Beta transferrin positive samples

40. CONGENITAL PERYLYMPHATIC
FISTULA
 As a result of difficulty in diagnosis , weber et al
suggest packing temporalis muscle around oval
and round windows in all suspected cases, based
on the finding that packing does not cause
complications such as CHL.

41.  This may be associated with other vascular
abnormalities such as a PSA and likewise
present as a vascular middle ear mass.
 Present with flucuating tinnitus(objective).
 20% bilateral.
 An aberrant ICA is an important differential
diagnosis of a glomus tympanicum tumour.
Brisk bleeding, hemiparesis, aphasia, deafness,
Horner syndrome and intractable vertigo may
result if the vessel is unintentionally injured.
ABERRANT INTERNAL CAROTID ARTERY

42.  Check for TUBULARITY on axials! – DON’T
BIOPSY!

43. HIGH JUGULAR BULB
 A “high-riding jugular bulb” is defined as an
extension of the most cephalad portion of the jugular
bulb superior to the floor of the IAC.
 Present as as a blue mass behind an intact tympanic
membrane, which may become distended on
valsalva or ipsilateral jugular compression.
 If the sigmoid plate is deficient, the bulb is free to
protrude into the middle-ear cavity, and is then
known as a dehiscent jugular bulb.
 HRCT is the imaging modality of choice for
evaluating the Jugular bulb

44. REFERECES
 Scott brown
 Classification and diagnosis of ear malformations
Sylva Bartel-Friedrich*,1 and Cornelia Wulke1
 Congenital Stapes Fixation Joseph T. Breen et al.
 High-riding jugular bulb: A rare entity
Vivek Sasindran et al.
 Bilateral Malleus Ankylosis: a Case Report Tatari MM*, Abouelfadl
Absence Ossicular chain mobilisation versus reconstruction in surgery for isolated malleus
and/or incus fixation: systematic review and meta-analysis W L Crutcher, P Tassone and S
Pelosiof long process of incus : prosthesis