So far, we have discussed Chronic Suppurative Otitis Media in general and its one type- Tubotympanic CSOM. In this section, we will be dealing with its second type, i.e, Atticoantral CSOM. Atticoantral is unsafe type of CSOM with several complications. Lets head to it and explain it.
The causes of of Atticoantral CSOM are quite indifferent than Cholesteatoma which has following theories:
- Congenital- Presence of congenital cell rests
- Primary acquuired cholesteatoma- Invagination of tympanic membrane from attic or posterosuperior part of pars tensa in for Retraaction Pockets.
- Theroy of Basal Cell hyperplasia
- Epithelial invasion
- Metaplasia of middle ear mucosa
Some points can be understood by the following images:
Retraction pockets/Primary acquired
- Osteitis and granulation tissue
- Ossicular necrosis- causes conductive deafness
- Cholesterol granuloma-It is a mass of granulation tissue with foreign body giant cells surrounding cholesterol crystals.
Same as tubotympanic type
- Aerobic- Pseudomonas aeruginosa, proteus, E.coli, Staph aureus
- Anaerobic- Bacteriodes fragilis and anaerobic streptococci
- Ear discharge- Scanty but always foul smelling due to bone destruction
- Hearing loss- Ossicular destruction causes Conductive deafness,sometime sensorineural, but hearing is normal when ossicular chain is intact or when cholesteatoma bridges gap between ossicular chain.
- Bleeding- It may occur from granulation or the polyp when cleaning ear.
- Perforation- Either attic or Posterosuperior perforation.
- Retraction pockets- An invagination of tympanic membrane is seen in attic or posterosuperior area of pars tensa.
- Cholesteatoma- Pearly white flakes of cholesteatoma can be sucked from retraction pockets.
- Examination under microscope- may reveal cholesteatoma, evidence of bone destruction, granuloma, condition of ossicles and pockets of discharge.
- Tuning fork tests and Audiogram- Essential for pre-operative assessment and to confirm degree and type of hearing loss.
- X-ray mastoid or CT scan temporal bone- indicate extent of bone destruction and degree of mastoid pneumatisation.
- Culture and sensitivity of ear discharge- for proper selection of antibiotic.
Features indicating complications
- Pain- Indicates extradural, perisinus or brain abscess or otitis media externa with discharging ear.
- Vertigo- Indicates erosion of lateral semicircular canal which may progress to labyrinthitis or meningitidis.
- Persistent headache- Intracranial complication
- Facial weakness- erosion of facial canal
- A listless child refusing to take feeds- extradural abscess
- Fever, nausea and vomitting (F+N+V)- intracranial infections
- Irritability and neck rigidity- Meningitidis
- Diplopia- Gradenigo syndrome,i.e, petrositis
- Ataxia- Labyrinthitis or cerebellar abscess
- Abscess around ear- Mastoiditis
This part is confusing to many about where and what is the exact difference between canal up and canal down procedures. We will explain that as we proceed:-
Primary aim is to remove disease and render ear safe while second aim is to preserve or reconstruct hearing but never at cost of primary aim.
There are two types of procedures which are followed in atticoantral csom surgeries:-
Canal wall down procedure
It leaves mastoid cavity open into external auditory canal so that diseased area is fully exteriorized.
It is named as canal wall down because posterior wall of external auditory canal is removed during the surgery. This removal of posterior wall makes ear canal and mastoid a single cavity called mastoid bowl. From this cavity, the cholesteatoma is allowed easy passage out of the ear.
Examples include Atticotomy, modified radical mastoidectomy and radical mastoidectomy.
Canal wall up procedure
Posterior bony meatal wall is kept intact while disease is removed through meatus and/or mastoid, thus, an open mastoid cavity is avoided. Reconstruction of hearing is easy but risk of leaving behind some cholesteatoma is high and hence, 6 months re-exploration is necessary.
Intact canal wall mastoidectomy > Cortical mastoidectomy + Posterior tympanoplasty
Let’s explain this abit deeper. First of all, the canal wall up procedure is to done such that posterior wall is intact, hence, we approach to FACIAL RECESS for this. This can be better explained by following images and do read the captions written just below each image:
Difference between canal wall up and canal wall down procedures
The simplest difference is that in canal wall down, the posterior wall is damaged and hence more invasive type whereas in canal wall up, there is minimal invasion. This, in turn, is complicated as in canal wall down, with more invasion, the cholesteatoma is generally removed to full with better prognosis whereas in canal wall up, with less invasion, the cholesteatoma can be left behind, hence a need for 6-month re-exploration is usually required to check cholesteatoma again.
Myringoplasty (closure of the perforation of pars tensa of the tympanic membrane) pr tympanoplasty (myringoplasty with ossicular reconstruction) is done.
Repeated suction clearance, aural toilet and other measures for mild cholesteatoma cases or in elderly or in a patient refusing for surgery can be tried.