Tympanoplasty (type I) with ossicular assessment
Indications
Dry central perforation of the pars tensa with conductive hearing loss or recurrent discharge, after the ear has been dry for several weeks and the audiogram confirms the air–bone gap.
Approach
Endoscopic transcanal for most anterior and central perforations; microscopic post-aural when the canal is narrow, the anterior margin is hidden or the mastoid must be explored.
Operative steps
- Freshen the perforation margin and remove the rim of epithelium.
- Elevate the tympanomeatal flap from about the 6 to 12 o'clock position and enter the middle ear at the annulus.
- Inspect the ossicular chain: mobility of the malleus, continuity of the incudostapedial joint and mobility of the stapes.
- Harvest temporalis fascia or tragal perichondrium and dry it.
- Place the graft as an underlay medial to the remnant and malleus handle, supported by absorbable gelatin sponge in the middle ear.
- Replace the flap and pack the canal.
Landmarks and safety
- Chorda tympani lies just under the posterosuperior annulus; elevate it with the flap.
- Avoid suction on a mobile stapes.
- The facial nerve can be dehiscent over the oval window.
After surgery
Keep the ear dry; canal pack removed at two to three weeks; audiogram at about three months.
