This type of CSOM is associated with cholesteatoma
Cholesteatoma : It is a bag or sac which contains desquamated epithelium arranged in concentric layer that rests on matrix and erodes the bone.
Actually this is “ Skin in wrong place
”.
Types of cholesteatoma :
a)Congenital/ Developmental
b)Acquired- primary and secondary
Congenital- Some epithelial cell nest entrapped in temporal bone and erodes the underlying bone later on.
Primary acquired Cholesteatoma :
-No previous infection in the middle ear
-Due to E. tube obstruction(e.g. Adenoid)
-There will be negative pressure inside the middle ear cavity
-Pars flaccida will retract towards the antrum
Secondary acquired :
a.Metaplasia (squamous metaplasia)
b.Immigration
How cholesteatoma erodes bone :
1.Pressure necrosis( Ischemic necrosis)
2.Enzymatic destruction
3.Pyogenic osteitis
Pathology :
I.Blocked E.tube
II.Collection of keratin
III.Perforation
IV.Gradual expansion of the sac
V.Extrusion of a small attic or antral cholesteatoma
VI.Protrusion of finger-like processes of the cyst between ossicular chain.
Long process of incus is most susceptible.
VII. Encroachment into the mastoidVIII. Interference with the ventilationIX. Active infection of the keratotic mass
X. Provision of pathways facilitating the spread of infection.
Symptoms :
In uncomplicated cases –
-Discharge : scanty, thick, foetid, blood stained
-Hearing loss
-Tinnitus
Sign :
-Attic or postero-superior marginal perforation
-Aural discharge- Scanty, thick, purulent, mal-odourous, blood stained
-Cholesteatoma may be visible as a greyish paper like subs. or as typical pearly sheets of keratin
-Conductive deafness
Complications:
Headache,
earache,
vertigo,
vomiting,
facial nerve paralysis
Investigations :
•Aural swab for C/S
•X-ray mastoid towne’s view
•CT scan- if intracranial complications are suspected
•PTA(Pure tone audiometry)
Treatment :
A.When cholesteatoma is small and accessible :
- Suction cleaning under microscope
- Removal of polypi and/or granulation tissue with cup forceps
- Life long periodical check up
- Advises
B. Operative treatment is indicated if conservative treatment fails or when complications are present or threatening.
Modified radical mastoidectomy
Purpose of operation :
1.To eradicate the disease
2.To render the patient safe
3.To prevent complications
4.To make the ear dry
5.To restore or improve the hearing
Complications of CSOM A- A variety :
Minor :
1.Otitis externa
2.Aural polyp
3.Granulation tissue
Major :
1.Extracranial
2.Intracranial
Extracranial :
I.Chronic mastoiditis
II.Subperiosteal abscess
a) Postauricular or mastoid abscess
b) Zygomatic abscess
c) von Bezold’s abscess
d) Citelli’s abscess
e) Pharyngeal abscess- retropharyngeal or parapharyngeal abscess
III. Facial nerve palsy
IV. Labyrinthitis
V. Petrositis
VI. Gradenigo’s syndrome( deep temporal headache, paralysis of VI cranial nerve and mastoid infection)
VII. Bacteremia, septicaemia, pyaemia
VIII. Metastatic abscess or embolic abscess to lungs, joints, bones etc.
IX. Osteomyelitis
Intracranial complications :
1.Extradural abscess
2.Subdural abscess
3.Meningitis- Pachymeningitis/ Leptomeingitis
4.Lateral sinus thrombophlebitis
5.Perisinus abscess
6.Encephalitis
7.Brain abscess- Temporal lobe abscess/ cerebellar abscess
8.Otitic hydrocephalus
Types of Mastoidectomy :
1.Simple or cortical mastoidectomy
2.Radical mastoidectomy
3.Modified radical mastoidectomy
1.Simple or cortical mastoidectomy or Schwartz operation :
-When mastoid antrum and air cells are exenterated
-Middle ear cavity is not disturbed
-Posterior canal wall is left intact
Indications :
1.Acute mastoiditis not
responding to adequate medical treatment
2.In tubo-tympanic type of CSOM when mastoid antrum acts as reserviour
3.Masked mastoiditis
4.Routes for other operations :
- Endolymphatic sac decompression
- Decompression of facial nerve
- Translabyrinthine or retro-labyrinthine approach for acoustic neuroma
Modified radical mastoidectomy :
q All the diseased tissues are removed.
q Healthy tissues preserved
q Atleast Stapes superstructure is preserved
q.Mastoid antrum and air cells, middle ear and the external auditary canal are transferred into a single cavity and exteriorized into the meatus by removing the posterior meatal and lateral attic wall.
Indication :
Chronic suppurative otitis media with or without complications.
Radical mastoidectomy :
All the diseased tissues are removed without caring for the facial nerve, footplate of Stapes or other parts of the inner ear, without any attempt to reconstruct hearing.
Indications :
1.Carcinoma of the middle ear
2.CSOM- AA variety with dead labyrinth
3.Removal of Glomus tumour
4.Sometimes in Otitis externa malignans
Complications of Mastoidectomy :
1.Facial nerve paralysis
2.Hemorrhage
3.Damage to ossicular chain
4.Labyrinth injury
5.Labyrinthitis
6.Sensori-neural hearing loss
7.Intracranial spread of infection
8. Injury to dura and Brain herniation9. Perichondritis
10. Meatal stenosis
11. Injury to Chorda Tympani nerve
12. Mastoid cavity problem – 20-25% postop mastoid cavity do not heal and continue to discharge, requiring regular after care.
13. Injury to Tegmen tympani, tegmen antri, lateral sinus and sinus plate.
14. Postop. wound infection and wound break
No comments:
Post a Comment