Modified Radical Mastoidectomy

🦻 Modified Radical Mastoidectomy (MRM)

📌 Definition of Modified Radical Mastoidectomy

Modified Radical Mastoidectomy (MRM) is a canal-wall-down procedure in which:

• The posterior meatal wall and lateral attic wall are removed.
• The mastoid cavity and external auditory canal (EAC) are converted into a single cavity.
• Tympanic membrane remnants, functioning ossicles, and Eustachian tube function are preserved.

🔑 It is a modified version of Radical Mastoidectomy - where all middle ear structures are removed and the ear is rendered non functional.

What are the aims of Modified Radical Mastoidectomy?

What are other canal wall down procedures you know?

🩺 Indications of Modified Radical Mastoidectomy

• Resectable cholesteatoma

• Recurrent/residual cholesteatoma after CWU surgery (e.g., cortical mastoidectomy)

• Chronic otitis media (mucosal type) with complications

• Only hearing ear with cholesteatoma

What is unresectable cholesteatoma?

⛔ Contraindications of Modified Radical Mastoidectomy

• COM without cholesteatoma → prefer canal-wall-up surgery (cortical mastoidectomy).

• Medically unfit patient (general anesthesia risk).

• Limited attic disease in a reliable patient → attempt cortical mastoidectomy instead.

Is active ear discharge a contraindication of Cortical Mastoidectomy?

💉 Anaesthesia & Position

• General anaesthesia.
• Patient supine, face turned to opposite side, ear to be operated facing upward.

🛠️ Operative Steps of Modified Radical Mastoidectomy

1. Incision & Exposure

• Wilde’s post-auricular incision: curved, 1 cm behind & parallel to retroauricular sulcus.

• Deepen incision → periosteum → T-shaped periosteal incision (horizontal along linea temporalis + vertical to mastoid tip).

• Elevate periosteum, retract with Mollison’s → expose mastoid cortex.

2. Cortical Mastoidectomy Steps

• Identify McEwan’s (suprameatal) triangle → antrum lies ~12–15 mm deep.

• Drill mastoid cortex.

• Exenterate mastoid, zygomatic, retrosinus cells → reach mastoid tip & expose digastric ridge.

3. MRM-Specific Steps

• Atticotomy

• Preserve canal wall skin

• Remove facial bridge

• Remove anterior buttress

• Remove posterior buttress

• Lower facial ridge

• Exenterate all disease** (epitympanum, aditus, sinus tympani, facial recess, mesotympanum)

• Saucerize cavity → smooth, shallow bowl for epithelialization & self-cleansing.

• Reconstruct hearing (ossiculoplasty, cartilage grafts, tympanoplasty).

• Meatoplasty → widen EAC via pinna to allow post-op cavity access, ventilation & self-cleansing.

• Reposition skin flap

• Close wound in 2 layers + mastoid dressing.

What are the limits of Modified Radical Mastoidectomy?

🩹 Post-operative Care of Modified Radical Mastoidectomy

• Mastoid dressing removed after 24–48 hrs.

• Keep ear dry; strict water precautions × 6 weeks.

• Antibiotics & analgesics × 7 days.

• Sutures out after 7 days.

• First otoscopic exam at 3–4 weeks → clean granulations if present.

• Audiometry at 6–8 weeks.

• Plan second-stage ossiculoplasty if needed.