Tympanoplasty — Overview

Tympanoplasty is one of the foundational procedures in otological surgery. The term is broad by design — it describes any operation that restores the sound-conducting mechanism of the middle ear, ranging from a straightforward drum graft to full ossicular chain reconstruction. Understanding the classification, indication criteria, and technical variables is essential before approaching any individual case.

Wullstein Classification

The Wullstein classification, introduced in 1956, remains the standard framework for describing tympanoplasty type and surgical intent. It defines five types based on which elements of the middle-ear sound-conducting system are present and reconstructed.

Type	Drum	Ossicular Chain	Surgical Goal
I (Myringoplasty)	Perforated	Intact and mobile	Repair drum only
II	Perforated / damaged	Malleus eroded or absent; incus and stapes intact	Graft onto incus
III	Absent or non-functional	Malleus and incus absent; stapes present and mobile	Graft directly onto stapes head (myringostapediopexy)
IV	Absent	Stapes footplate only remains mobile	Sound shield: graft over oval window only; round window baffled
V	Absent	Fixed footplate; mobile round window	Fenestration of semicircular canal (largely historical)

Type I is by far the most common in general ENT practice. Types III and IV are encountered in revision cases, cholesteatoma surgery, and complex chronic otitis media. Type V is largely of historical interest.

Indications

The decision to operate depends on a combination of clinical, audiological, and patient factors — not perforation size alone.

Absolute indications

• Chronic tympanic membrane perforation with recurrent or continuous otorrhoea not controlled by medical management
• Conductive hearing loss attributable to perforation or ossicular discontinuity

Relative indications

• Dry central perforation with patient preference for closure (activity-related, e.g. swimming)
• Perforation preventing hearing aid fitting
• Pre-ossiculoplasty drum stabilisation

Contraindications

• Active middle-ear infection (ear must be dry for at least 6 weeks pre-operatively as a general principle)
• Significant Eustachian tube dysfunction without planned correction — poor tube function is a leading cause of graft failure
• Only-hearing ear — requires careful risk discussion
• Contralateral active disease in paediatric cases (consider deferring until contralateral ear is treated)

Pre-operative Assessment

Audiometry is mandatory. A pure-tone audiogram establishes the pre-operative air-bone gap and confirms the hearing is at least partially conductive. A large sensorineural component changes the prognosis conversation with the patient.

HRCT of the temporal bones is not routine for straightforward type I cases but is indicated when there is suspicion of cholesteatoma, ossicular erosion, dehiscent tegmen, or a canal wall defect. It also guides surgical approach planning.

Eustachian tube function should be assessed clinically. A Eustachian tube that cannot equilibrate pressure will load the new graft and is the single most important patient-side predictor of failure. In children, concurrent adenoidectomy may improve tube function.

Dry ear — most units require the ear to be infection-free for a minimum of 6 weeks before surgery. Operating through an infected field increases the risk of graft failure and post-operative infection.

Surgical Approaches

Three approaches are available, each with distinct access profiles.

Transcanal — instruments pass through the ear canal under the operating microscope or endoscope. No external incision. Appropriate for smaller central perforations with adequate canal space and visualisation. Limits access to the anterior tympanomeatal angle in narrow or tortuous canals.

Endaural — a Lempert-type incision extends superiorly from the canal into the incisura terminalis. Widens access without a full postauricular incision. Useful for moderate perforations or when graft harvest from the canal skin is planned.

Postauricular — the standard open approach. Full access to the mastoid, tympanomeatal angle, and ossicular chain. Required for type III and IV procedures, cholesteatoma, and combined approach tympanoplasty. Longer operative time; postauricular scar.

The Operative Sequence

flowchart TD
    A["1 · Flap definition — flap knife, sickle knife"] --> B["2 · Middle-ear inspection — probe, cup/crocodile forceps, suction"]
    B --> C["3 · Perforation edge freshening — circular knife"]
    C --> D["4 · Graft placement — underlay/overlay + gelatine packing"]

1. Flap definition The tympanomeatal flap is the route to the middle ear in transcanal and endaural approaches. The round-bladed flap knife makes the canal-wall incision and elevates the flap from the underlying bone toward the fibrous annulus; the sickle knife is then used for the finer cuts at the annulus and the middle-ear mucosa. The quality of these steps determines how cleanly the flap elevates and how well it re-drapes at closure.

2. Middle-ear inspection Once the flap is reflected, the ossicular chain is assessed under magnification. Mobility is tested with a fine probe. Granulation tissue, polyps, and cholesteatoma matrix are removed with cup forceps, crocodile forceps, and suction.

3. Perforation edge freshening The epithelialised rim around a chronic perforation must be removed before graft placement. The circular knife performs this circumferential dénudement in a single controlled pass, exposing the vascular fibrous layer that will incorporate the graft.

4. Graft placement The graft is positioned medial (underlay) or lateral (overlay) to the tympanic membrane remnant depending on perforation type and surgeon preference. Underlay is the more widely used technique; overlay has higher rates of anterior blunting but may be preferred for large or anterior perforations. The tympanomeatal flap is returned to position over the graft and supported with gelatine sponge packing.

Graft Material

Temporalis fascia is the most commonly used graft material. It is thin, robust, and available in abundance through the same operative field via a small postauricular or temporal extension. Success rates with temporalis fascia are well established. A 2022 meta-analysis found no significant difference in closure or audiological outcomes between dry and wet fascia preparation, though wet fascia marginally reduced operative time (Albazee et al., Eur Arch Otorhinolaryngol, 2022).

Tragal perichondrium is harvested from the tragus and provides a stiffer graft — useful for atelectatic drums, revision cases, or when drum rigidity is preferred. Harvest is simple and adds minimal time to the procedure.

Cartilage with perichondrium is the preferred material in revision tympanoplasty and when Eustachian tube function is poor. Cartilage grafts are more resistant to retraction and have demonstrated higher success rates in revision and paediatric high-risk cases. The trade-off is a slight mass effect on the ossicular chain, which may modestly reduce high-frequency transmission.

Microscopic vs Endoscopic Approach

Endoscopic ear surgery has moved from experimental to mainstream over the past decade. A 2024 systematic review and meta-analysis (Gkrinia et al., Laryngoscope) found comparable graft success rates between endoscopic and microscopic tympanoplasty across 33 studies and 2,646 patients. The endoscopic approach showed statistically significant advantages in operative duration, post-operative wound infection, dysgeusia, and auricular numbness — most of which relate to the avoidance of a postauricular incision.

The practical implications for instrument selection: endoscopic tympanoplasty uses the same microsurgical instruments (knives, forceps, suction) but requires a longer working length and angled shaft design for the non-dominant hand, since the endoscope occupies one hand throughout.

Outcomes and Prognostic Factors

Graft take rates in the literature for type I tympanoplasty in adults typically range from 85 to 95% in primary surgery in well-selected patients. In the paediatric population, a systematic review by Hardman et al. (Otol Neurotol, 2015) reported a weighted mean closure rate of 83.4% across 2,609 cases. Key predictors of failure were larger perforation size and abnormal contralateral ear findings — emphasising that Eustachian tube status on both sides matters.

Audiological success (meaningful air-bone gap closure, typically defined as closure to ≤20 dB) is reported in 70–85% of type I cases where the ossicular chain is intact pre-operatively.

Complications

Complication	Notes
Graft failure / re-perforation	Most common; related to Eustachian dysfunction, infection, technique
Sensorineural hearing loss	Rare; risk increases with ossicular manipulation and cholesteatoma
Tinnitus	Usually transient; new-onset permanent tinnitus uncommon
Dysgeusia	Chorda tympani injury; more frequent with postauricular approach
Facial nerve injury	Very rare in type I; risk higher with canal wall down procedures
Otitis externa	Canal packing-related; managed with topical treatment
Blunting (anterior)	Adhesion at anterior tympanomeatal angle; more common with overlay technique

Post-operative Care

Canal packing (gelatine sponge or bismuth iodoform paraffin paste) is removed at 3–6 weeks. Patients are advised to keep the ear dry until the graft is confirmed incorporated. Audiometry is repeated at 3 months. If the perforation has closed and the ossicular chain was intact pre-operatively, a further audiogram at 6 months establishes the functional outcome. In combined approach cases or where ossicular reconstruction was performed, follow-up extends to at least 12 months.

Key Points for PG Examinations

• Wullstein type I = myringoplasty. Types II–V all involve some form of ossicular reconstruction.
• The term “myringoplasty” describes drum repair only — the middle ear is not entered or the ossicular chain is not assessed beyond confirming integrity. Tympanoplasty enters the middle ear.
• A dry ear for 6 weeks pre-operatively is standard practice; operating through infection is a significant risk factor for graft failure.
• Temporalis fascia and tragal perichondrium have comparable success rates; cartilage is preferred for revision and high-risk cases.
• Eustachian tube function is the most important patient-side prognostic factor — a drum graft placed in an ear with poor tube function will retract.
• Endoscopic and microscopic approaches have equivalent graft success rates; the endoscopic technique has morbidity advantages but is more technically demanding in the early learning curve.