Body's Modified Radical Mastoidectomy (Bondy's Operation)

Definition and Historical Background [2 marks]

• The radical mastoidectomy was first described by Zaufa (1890), involving removal of the superior and posterior canal walls, tympanic membrane, and lateral ossicular chain.
• Bondy recognized that when disease was limited to the pars flaccida/epitympanum, the uninvolved middle ear could be left intact - a hearing-sparing modification.
• Today, the term "modified radical mastoidectomy" is frequently (though incorrectly) used interchangeably with canal wall-down (CWD) mastoidectomy - strictly, the classical MRM refers only to the Bondy procedure.

Aim of the Operation [1 mark]

1. Remove all bone-invading epitympanic disease (cholesteatoma)
2. Create an accessible, exteriorized cavity that promotes epithelialization and allows lifelong cleaning
3. Preserve hearing by leaving the uninvolved middle ear, tympanic membrane, and ossicular chain intact
4. Avoid chronic discharge from exposed middle ear mucosa (unlike radical mastoidectomy)

Indications [3 marks]

Absolute Indications

• Attic cholesteatoma strictly confined to the epitympanum with no extension into the mesotympanum or hypotympanum
• Pars flaccida retraction pocket with cholesteatoma matrix limited to the attic region
• Failed conservative management of attic cholesteatoma:
  1. Radiographic evidence of an enlarged, smooth-walled antrum indicating a large cholesteatoma cavity
  2. Persistent otorrhea after several attempts at cleaning
  3. Cholesteatoma extending into bone/vital structures on CT
• Single only ear with potentially dangerous disease (hearing preservation mandatory)
• Patients unwilling to undergo staged intact canal wall approach

Relative Indications

• Occasional otologic surgeon (not a high-volume ear surgeon) - MRM is technically less demanding than intact canal wall surgery
• Patients unable to attend for second-stage surgery
• Elderly or unfit patients in whom a single-stage approach is preferable
• Mastoid sclerosis making canal-wall-up technique impractical

Contraindications

• Acute otitis media with coalescent mastoiditis
• Persistent secretory otitis media or chronic allergic otitis media
• Tuberculous otitis media (primary chemotherapy)
• Disease extending beyond the attic (requires full CWD or radical mastoidectomy)

Preoperative Assessment [1 mark]

• Careful microscopic inspection and cleaning of the ear; removal of pus, mucus, polyps (gently - polyp may be attached to facial nerve or labyrinthine fistula)
• CT of temporal bone (non-contrast): defines erosion of the scutum, semicircular canals, cochlea, facial canal (fallopian canal), dural plates, sigmoid sinus; assesses mastoid sclerosis; extent of cholesteatoma in attic
• MRI with gadolinium: used when extensive tegmen erosion is suspected on CT to detect meningoencephalocele, dural inflammation, intracranial extension, or sigmoid sinus thrombosis
• Preoperative audiogram (pure tone + impedance)
• Control of active discharge: 1.5% acetic acid irrigations + antibiotic eardrops for several weeks preoperatively; oral fluoroquinolones for 10-14 days if extensive mucosal infection

Surgical Technique [8 marks]

Anesthesia and Preparation

• General anesthesia
• Ear canal flushed with povidone-iodine; auricle and postauricular area scrubbed
• 1% lidocaine with 1:100,000 epinephrine injected into the postauricular region and ear canal for hemostasis

Incision

• First incision: from "12 o'clock" on the superior canal wall, down the posterior canal wall in the incisura terminalis nearly to "6 o'clock," then at right angles outward 2-3 mm to (but not into) the conchal cartilage
• Second incision: from the same "12 o'clock" starting point, extending directly upward in the incisura terminalis halfway between meatus and upper edge of auricle
• The Shambaugh self-retaining endaural retractor is inserted; periosteum elevated widely from above and behind the osseous meatus (wide retraction essential - "mobilize the incision")

• C-shaped postauricular incision ~1 cm behind postauricular crease
• Horizontal incision through temporalis muscle superior to temporal line + vertical incision down to mastoid tip (T-incision)
• Mastoid bone exposed with Lempert elevator; vascular strip elevated and reflected anteriorly using self-retaining retractor
• Temporalis fascia harvested and set aside to dry (for grafting)

Atticotomy / Bone Removal

• Surgical cutting burr removes outer cortex just above and behind the meatus over a semilunar area (atticotomy)
• Surgeon deepens the groove watching for pink color of middle fossa dura; avoids unnecessary dural exposure
• Notch of Rivinus located by passing a narrow periosteal elevator along the superior osseous meatal wall
• Epitympanum entered - white smooth wall of cholesteatoma sac identified
• Cholesteatoma sac opened carefully (dura can mimic sac wall), contents evacuated by suction and instrumentation
• Cholesteatoma extensions explored anteriorly, superiorly, posteriorly with blunt mastoid searcher
• Entire matrix removed with the operating microscope - including finger-like extensions into small cells and Haversian canals

1. Matrix firmly adherent to exposed dura or sigmoid sinus (risk of injury)
2. Matrix over a labyrinthine fistula (risk of serous labyrinthitis; thin fascia graft applied by some)
3. Matrix firmly attached to exposed facial nerve
4. Matrix over the stapes footplate/oval window (remove at second-stage after ear is dry)

Bone Removal Beyond Cholesteatoma

• All infected, soft, osteitic bone is removed with the cholesteatoma
• In the Bondy operation: posterior canal wall removal is limited to what is needed for exteriorization - this is the key difference from full CWD mastoidectomy
• Complete mastoidectomy + posterior canal wall takedown + tympanoplasty = modern modified radical mastoidectomy (Shambaugh's version)

Canal Wall Down and Saucerization

• Posterior canal wall taken down with rongeur after incudostapedial joint disarticulation (if incus is involved)
• Facial ridge lowered until a thin layer of bone remains over the vertical segment of the facial nerve
• Chorda tympani identified and preserved if possible
• Mastoid bowl saucerized - smooth, gentle transition into depths without ledges (prevents epithelial trapping)
• Soft tissue obliteration of cavity space aided by careful saucerization

Meatoplasty (Essential Step)

• 1% lidocaine with epinephrine infiltrated into conchal bowl
• Posterior conchal bowl exposed using sharp dissection
• Semilunar/crescent-shaped incision made into cartilage posteriorly (~1.5 × 2 cm)
• Korner flap developed: inferior incision at 6 o'clock in canal carried into conchal bowl + superior incision at 12 o'clock between tragus and anterior helix
• Creates a wide meatal opening adequate for cavity inspection and cleaning
• A CWD meatoplasty ideally admits the surgeon's index finger

Grafting (in modern MRM with tympanoplasty)

• Dried temporalis fascia used to seal the middle ear (underlay technique)
• Eustachian tube obliterated if necessary to prevent chronic mucus discharge
• This is the key modification that distinguishes modern MRM from the Bondy procedure - sealing the middle ear eliminates discharge from exposed mucosa

Wound Closure

• Canal flaps rotated to line the cavity walls
• Cavity packed with antibiotic-soaked ribbon gauze or gel foam
• Postauricular wound closed in layers

Differences: Bondy MRM vs. Radical Mastoidectomy vs. Canal-Wall-Down (CWD) Mastoidectomy [2 marks]

Complications [2 marks]

Intraoperative

• Facial nerve injury - most feared; vertical segment at risk during posterior canal wall takedown and facial ridge lowering
• Labyrinthine fistula - inadvertent opening of lateral semicircular canal leading to sensorineural hearing loss or vertigo
• Injury to jugular bulb or sigmoid sinus - bleeding
• Tegmen dehiscence / CSF leak - especially in revision cases
• Dural exposure
• Damage to ossicular chain / stapedial superstructure

Postoperative

• Residual or recurrent cholesteatoma - the Bondy procedure is prone to this due to limited dissection (Shambaugh's key criticism)
• Chronic cavity discharge - if meatoplasty is inadequate or middle ear not sealed
• Sensorineural hearing loss
• Caloric vertigo with water exposure (cold water entering cavity)
• Wound infection, postauricular fistula
• Failure of tympanic membrane graft
• Keloid/hypertrophic scar

Postoperative Care and Cavity Maintenance [1 mark]

• Regular cavity cleaning (suction clearance) at clinic visits - every 6-12 months lifelong
• Water precautions: earplugs for bathing; avoid swimming
• Acetic acid eardrops for minor infections
• A well-made meatoplasty and saucerized cavity require minimal cleaning
• Hearing aid fitting if residual conductive loss is significant

Summary / Key Points

• Bondy's MRM is specifically indicated for cholesteatoma confined to the epitympanum, leaving the uninvolved middle ear intact - the hallmark is hearing preservation.
• The modern MRM (complete mastoidectomy + CWD + tympanoplasty) extends the concept to more advanced disease and adds middle ear reconstruction.
• The critical steps are: thorough atticotomy, complete matrix removal, adequate lowering of the facial ridge, saucerization of the cavity, and a generous meatoplasty.
• A wide meatoplasty is essential for cavity ventilation, self-cleaning, and adequate postoperative surveillance.
• Facial nerve identification and preservation is the most important safety concern throughout the procedure.