MYRINGOTOMY,

MYRINGOTOMY,

• 1.
  Dr G AWaghmare MS
• 2.
  MYRINGOTOMY:- Myringotomy is incisionof the tympanic membrane & drainage of the middle ear.
• 3.
  Indications:-  Acute suppurativeotitis media:- a) With bulged tympanic membrane on the of rupture b) If severe earache persists in a child inspite of conservative treatment, & the child is restless & is having disturbed sleep. c) Inadequate drainage- small pulsating perforation. d) Acute otitis media with complication.  Secretory otitis media.  Unresolved otitis media.
• 4.
  Anaesthesia:-  General anaesthesiais indicated in acute otitis media & local anaesthesia in secretory otitis media & other infections. In children, general anaesthesia is necessary.
• 5.
  Operation:-  Is doneunder operating microscope.  Incision:-  In case of acute otitis media the incision is a Curvi-liner one between umbo & posterior meatal wall starting from below up, so that the line of incision is not obscured by the draining fluid or blood.  In secretory otitis media & other infections, the incision is radial at 7 o’ clock in the postero-inferior quadrant, or 5 o’ clock postion in the antero-inferior quadrant
• 7.
  Procedure:-  After incisionof the drum the middle ear is sucked out through the incision. Sometimes a grommet (ventilation tube) is inserted to prevent recurrence, which remains in place so long the Eustachian tube function does not return back to normal.  Complications:- Injury to the ossicles. Injury to the inner ear. Injury to the chorda tympani nerve.
• 9.
  Mastoidectomy:-  This isan operation for the radical clearance of the disease pathology from the middle ear cleft including epitympanum & mastoid temporal bone, making a single cavity communicating with the external canal. This is for good drainage & for inspection of the operated cavity. The ear is made dry & safe.
• 10.
  Indications:-  Unsafe chronicsupperative otitis media with extensive cholesteatoma.  Chronic suppurative otitis media with complications.  For labyrinthectomy in suppurative labyrinthitis.  Glomus tumor invading mastoid bone.  Malignant disease of the middle ear.
• 11.
  Operation:-  Incision:- Post-auricularor endaural incision is made about ¼ behind the post-auricular groove. The incision should extend from above the level of the auricle to near mastoid tip. The temporalis muscle above is elevated along with periosteum.  After the cortical cavity is made, aditus & attic are completely expose by drilling out the wall, but extreme care must be taken to the facial nerve which lies on the medial wall of the aditus. Cholesteatoma & other diseased tissues are thoroughly removed.
• 13.
   The posteriormeatal wall (bony facial bridge) between the external canal & antrum, is progressively removed.  The stapes is retained. The whole cavity is carefully inspected so as not to leave any pockets of squamos epithelium. It is made smooth by polishing burs. The wound is closed by interrupted sutures.
• 14.
  Tympanoplasty:-  Tympanoplasty meanseradication of diseased pathology from the tympano-mostoid segment in chronic suppurative otitis media & to reconstruct the hearing mechanism.  Principles of the operation are:- 1.Complete disease clearance. 2.Preservation of hearing mechanism 3.Preservation of the posterior meatal wall.
• 15.
  Indications:-  Cholesteatomous mastoiditiswithout complications.  There are five types:-  Type I- Simple closure of the perforation.  Type II-Defect is perforation of tympanic membrane with erosion of malleus.  Type III- Mallus & incus are removed along with disease clearance.
• 17.
   Type IV-Only the footplate of stapes is present. It is exposed to the external ear, & graft is placed between the oval & round window.  Type V- Is by-passing the fixed stapes & making a fenestra on the lateral semicircular canal.  Homograft Tympanoplasty:- Homograft Tympanic membrane with or without ossicles are collected & preserved in homograft bank. Depending on the type of tympano ossicular defect, the homograft material is used. But this surgery has some long term complications & pit falls & is not much performed now a day.
• 18.
   Combined ApprochTympanoplasty Operation (CAT):-  The operation is perfomed through posterior tympanotomy approach & posterior canal wall is preserved. This operation has fallen in rapute due to recurrence of cholesteatoma in long term.  Tympano-ossiculoplasty Operation:-  Here the tympanic membrane & ossicular chain repair is performed by various autograft or auto-ossicles or cartilage. Type III & Type IV are now avoided & a normal sized neotympanum is created by homocraft or autograft ossiculoplasty with columellar effect.