Tympanoplasty

Definition

Indications

1. Chronic Suppurative Otitis Media (CSOM) — the most common indication; persistent TM perforation with or without discharge
2. CSOM with Cholesteatoma — requires tympanoplasty ± mastoidectomy
3. Traumatic TM perforation — mechanical or blast trauma; perforations that fail to heal spontaneously (approximately 80% of acute perforations heal without intervention)
4. Iatrogenic perforation — e.g., failed/persistent perforation after ventilation tube extrusion in children
5. Conductive hearing loss due to ossicular discontinuity or fixation amenable to reconstruction (ossiculoplasty)
6. Retraction pocket of the TM — to prevent progression to cholesteatoma
7. Atelectatic TM — reinforcement with cartilage tympanoplasty
8. Tympanosclerosis causing ossicular fixation and significant hearing loss

Contraindications

Absolute Contraindications

1. Uncontrolled cholesteatoma — disease must be eradicated before reconstruction
2. Uncontrolled intracranial complications of otitis media — intracranial abscess, meningitis, lateral sinus thrombosis
3. Malignancy of the middle ear/temporal bone
4. Patient-specific anaesthetic contraindications — uncontrolled systemic disease (severe cardiac disease, renal insufficiency, uncontrolled diabetes/hypertension/asthma)

Relative Contraindications

1. Non-functioning Eustachian tube — poor tubal function predicts graft failure
2. Extremes of age — especially very young children (repeated middle ear disease)
3. Only hearing ear — surgery on the patient's sole hearing ear requires careful risk-benefit discussion
4. Active infection/otorrhoea at time of surgery — ideally defer until ear is dry for at least 4–6 weeks
5. Alcoholism — affects healing and compliance

Types (Wullstein Classification)

Note: Types IV and V are rarely performed today. Modern ossiculoplasty with prostheses (PORP/TORP) has largely replaced these reconstructions.

Surgical Steps (Pointwise)

Pre-operative Preparation

1. Patient positioning — supine, head rotated 180° or to the opposite side; surgeon sits at the operative side
2. Anaesthesia — general anaesthesia (preferred in children and anxious adults) or local anaesthesia; ear canal skin infiltrated with 1% lidocaine + 1:100,000 epinephrine for vasoconstriction (under the microscope; allow time before incisions)
3. Preparation of operative field — hair removed ~2 cm above and behind the auricle; skin degreased with alcohol/acetone; plastic drapes applied; cotton ball placed in ear canal

Graft Harvesting (done early to allow preparation while operating)

1. Temporalis fascia harvest (most common) — postauricular incision exposes temporalis; a 1.5 × 1.5 cm piece of fascia harvested with scissors; placed on a Teflon block and allowed to dry/flatten
   • Alternatives: tragal perichondrium, cartilage-perichondrium composite (for atelectasis/reinforcement)

Approach & Exposure

1. Approach selection based on perforation size and anatomy:
   • Transcanal — small posterior perforations with favourable canal anatomy
   • Endaural — limited atticotomy cases; useful with endoscope
   • Postauricular (most common in USA) — all perforation sizes; best anterior TM visualisation; allows self-retaining retractors for bimanual technique
2. Postauricular incision (if used) — curved incision ~1 cm behind the postauricular sulcus through skin and subcutaneous tissue down to temporalis fascia; periosteum elevated; self-retaining retractor placed

Middle Ear Entry & Perforation Preparation

1. Excision of perforation edge — the epithelial union between the squamous outer layer and mucosal inner layer must be disrupted; a sharp pick creates small holes (like a postage stamp perimeter) around the perforation edge, then cupped forceps remove this outlined rim
2. Tympanomeatal flap elevation:
   • Canal incisions made at ~6 and 12 o'clock positions (triangular flap) or as a rectangular flap
   • The tympanomeatal flap is elevated from lateral to medial using a round knife and elevator, taking care to avoid injuring the chorda tympani nerve
3. Middle ear inspection — examine ossicular chain integrity and mobility; identify any pathology (cholesteatoma, tympanosclerosis, adhesions); assess stapes mobility

Graft Placement (Underlay / Medial Technique — most common)

1. Graft preparation — the dried fascia is trimmed to slightly larger than the perforation; a small anterior slit may be cut to slip it medial to the malleus handle
2. Middle ear packing — middle ear is packed with absorbable gelatin sponge (Gelfoam) to support the graft inferiorly and prevent medialization
3. Graft positioning — fascia is placed medial to the TM remnant (underlay) and medial to the malleus handle; graft edges must extend under all margins of the perforation and onto the bony canal wall
4. Tympanomeatal flap repositioning — the flap is laid back over the graft; anterior sulcus filled with gelatin sponge to prevent anterior blunting

Overlay (Lateral) Technique — used for challenging/revision cases, total perforations, anterior perforations. Graft placed lateral to the TM remnant. More technically demanding; requires canalplasty to prevent anterior blunting; better vascular ingrowth.

Ossiculoplasty (if needed — Types II–IV)

1. Assess ossicular chain — if incus eroded or discontinuity exists, plan interposition
2. PORP (Partial Ossicular Replacement Prosthesis) — used when stapes superstructure is present but incus is absent; placed between TM/malleus and stapes head
3. TORP (Total Ossicular Replacement Prosthesis) — used when stapes superstructure is absent; placed between TM and stapes footplate
4. Cartilage cap — a small piece of cartilage is placed between the prosthesis and the TM graft to prevent extrusion

Closure

1. Ear canal packing — canal filled with antibiotic-soaked gelatin sponge to hold graft in position; outer ear canal packed with ribbon gauze or pope wick
2. Wound closure — postauricular incision closed in layers (periosteum, subcutaneous, skin); mastoid dressing applied
3. Postauricular dressing — compressive bandage for 24 hours

Post-operative Care

1. Water precautions strictly maintained until healing confirmed (typically 6–8 weeks)
2. Topical antibiotic drops after packing removal
3. Audiometry at 3 months to assess hearing outcome
4. Avoid nose blowing / Valsalva to protect graft

Key Points

• No absolute indications exist for any single technique — the surgeon must tailor the approach to the disease
• Temporalis fascia and perichondrium are the standard graft materials; cartilage is preferred for atelectasis, retraction pockets, and reinforcement where failure risk is higher
• Titanium prostheses (PORP/TORP) have become dominant due to good hearing outcomes and low extrusion rates
• Graft success depends more on technique quality than on which technique is chosen