Cortical Mastoidectomy

🦻 Cortical Mastoidectomy

📌 Definition of Cortical Mastoidectomy

Cortical mastoidectomy removes accessible mastoid air cells and converts them into one cavity, maintaining the posterior canal wall and preserving tympanic membrane/ossicles.

What are the other names of Cortical Mastoidectomy?

What are the aims of Cortical Mastoidectomy?

🩺 Indications of Cortical Mastoidectomy

• Acute coalescent mastoiditis ± subperiosteal abscess
• Masked mastoiditis
• Acute otitis media with reservoir sign not resolving on antibiotics
• CSOM (mucosal type) with sclerotic mastoid and persistent infection
• Limited cholesteatoma confined to antrum/aditus
• As an access step for other procedures
• Part of combined-approach tympanoplasty

What are the different surgeries of which Cortical Mastoidectomy is a part of?

⛔ Contraindications of Cortical Mastoidectomy

• Medically unfit for surgery.
• Extensive/recurrent cholesteatoma requiring canal-wall-down surgery.
• Posterior canal wall defect not reconstructable.

Is active ear discharge a contraindication of Cortical Mastoidectomy?

🛠️ Preop preparation & anaesthesia

• General anesthesia preferred.

• Position: supine, face turned away, ear to be operated facing upward.

• Local infiltration: 1% lignocaine + adrenaline to tragus, postauricular skin, selected EAC quadrants.

🔪 Steps of Cortical Mastoidectomy

1. Incision: Wilde's curved post-auricular incision ~1 cm behind & parallel to retroauricular sulcus

2. Periosteal exposure: T-shaped periosteal incision (horizontal along linea temporalis + vertical down to mastoid tip). Elevate periosteum to expose mastoid cortex.

3. Identify McEwan’s triangle → drill ~12–15 mm deep to reach mastoid antrum.

4. Drill mastoid cortex & remove air cells:

   • Remove Korner septum to access true antrum.
   • Exenterate all accessible mastoid, zygomatic & retrosinus cells.
   • Drill mastoid tip → expose digastric ridge.

5. Identify deep landmarks: lateral semicircular canal, incus, tegmen plate, sinus plate, sinodural angle, Trautmann’s triangle, endolymphatic sac (via Donaldson’s line).

6. Saucerize cavity

7. Closure: Layered closure + mastoid dressing.

What are the limits of cortical mastoidectomy?

What is Korner's septum? What is it's clinical significance?

What are the boundaries of McEwan's triangle?

🩹 Post-operative care of Cortical Mastoidectomy

• Mastoid dressing off after 24–48 hrs.

• Water precautions for ~6 weeks.

• Continue antibiotics for 7 days; analgesics.

• Remove sutures at ~7 days.

• First otoscopic exam at 3 weeks.

• Pure-tone audiometry at 6–8 weeks.

⚠️ Complications of Cortical Mastoidectomy

• Bleeding, wound infection.
• Facial nerve injury.
• Dural tear / CSF leak.
• Sigmoid sinus injury/thrombosis.
• Residual disease if Korner septum missed.
• Post-op hearing changes.