Myringoplasty and Tympanoplasty

Introduction

Myringoplasty and tympanoplasty are surgical procedures designed to address pathology of the tympanic membrane and the middle ear, respectively. Both procedures restore the integrity of a perforated tympanic membrane, while tympanoplasty also addresses pathology in the middle ear, such as chronic infection, cholesteatoma, or ossicular chain problems. This most often implies and requires raising a tympanomeatal flap to facilitate middle ear manipulation. Zollner and Wullstein provided a classification of tympanoplasty based on the type of ossicular chain reconstruction required.

Acute tympanic membrane perforation or laceration may occur from a variety of causes. Local trauma, such as a slap on the ear, a cotton-tipped applicator inserted too far in the external canal, or barotrauma can cause a perforation of the tympanic membrane. Water compression, either from diving, falling onto a body of water, a wave hitting the ear, or even forceful irrigation during cerumen removal can also cause trauma. After acute trauma, the tympanic membrane may heal spontaneously or may require myringoplasty only. In contrast, patients requiring tympanoplasty often have a long-standing history of hearing loss, tympanic membrane perforation, and/or chronic otitis media with or without otorrhea.

Tympanoplasty and myringoplasty aim to eliminate recurrent disease, provide a dry ear canal and middle ear space with an intact tympanic membrane, and maintain or improve hearing. Achieving an intact tympanic membrane eliminates the need for patients to maintain strict water precautions.

Key Operative Learning Points

The most important factor in the success of tympanoplasty, regardless of method, is the skill and precision of the surgeon.
Anticipate and inform patients who may not achieve successful tympanoplasty results, including those with multiple failed previous procedures, persistent eustachian tube dysfunction, severe contralateral ear disease, or abnormalities of the soft palate.
In any technique, rimming the edges of the perforation is essential to ensure adequate healing.
Cartilage butterfly grafts avoid canal incisions, though these must be precisely sized to the perforation to ensure a secure fit.
Leaving remnants of squamous epithelium medial to the graft, or tucked edges of canal skin, can result in intratympanic or canal cholesteatoma.
Inadequate enlargement of the bony canal, and/or placement of a lateral graft onto the anterior or inferior canal wall, creates a high risk of blunting.
Injury to the chorda tympani nerve results in disturbance in taste noticeable to the patient.
Diligent postoperative care is necessary to recognize and treat early or late complications.

Preoperative Period

History

1.
History of present illness
- a.
  Hearing loss: Sudden versus gradual
- b.
  Drainage: Chronic or recurrent
- c.
  Trauma
- d.
  Pain should raise concern for other processes in the head and neck and prompt a thorough evaluation.
- e.
  Vertigo should be thoroughly investigated prior to surgery to avoid operating on an ear with an ongoing vestibulopathy.
2.
Past medical and surgical history
- a.
  Chronic or recurrent ear infections
- b.
  Previous ear surgeries, including PE tubes
- c.
  History of cleft palate surgery should raise concern for Eustachian tube dysfunction and chronic or recurrent infections.
3.
Medications
- a.
  Anticoagulants need to be addressed prior to surgery and stopped if possible.
4.
Allergies
- a.
  Severe seasonal allergies should raise concern for Eustachian tube dysfunction.
5.
Social history
- a.
  Smoking can lead to complications with general anesthesia and wound healing.

Physical Examination

Physical examination with a microscope enables thorough inspection of the canal and middle ear space.

1.
Problematic ear
- a.
  Size of perforation: Small, near-total, total
- b.
  Location of perforation: Central versus marginal
  - 1)
    Marginal perforations with a “trail sign,” or keratin migrating from the edge, suggest squamous epithelium in the middle ear.
- c.
  Draining versus dry
- d.
  Evaluate status of middle ear mucosa, if possible: Cholesteatoma, mucosal hypertrophy, or extensive granulation tissue suggest the need for concurrent mastoidectomy.
2.
Contralateral ear
- a.
  Look for signs of previous surgery and/or chronic Eustachian tube dysfunction, such as retraction of the tympanic membrane and negative middle ear pressure (atelectasis), otitis media with effusion, and/or tympanosclerosis, which may indicate chronic infections.
- b.
  Evidence of otitis media with effusion or negative middle ear pressure (atelectasis) in the contralateral ear demonstrated to be poor prognostic findings in a study of pediatric patients by Collins et al., and surgery in these children was less successful.

Audiogram

Not all tympanic membrane perforations are accompanied by conductive hearing loss. Small perforations may be associated with normal hearing, whereas a near-total perforation may cause a 35- to 40-dB conductive hearing loss. This amount of hearing loss in the setting of a small perforation should raise concern for a disrupted or fixed ossicular chain. The potential need for ossicular chain reconstruction must be anticipated prior to surgery.

Patients with mixed hearing loss require a different approach. Although surgery may close the air-bone gap, a sensorineural component may still require amplification, and surgery may not be in the patient’s best interest. If, however, a severe mixed loss precludes adequate gain and comfort from a hearing aid, surgical correction of the conductive component may better facilitate aural rehabilitation.

Imaging

1.
Computed tomography (CT) scan: Not routinely necessary prior to tympanoplasty or myringoplasty, unless evaluating for cholesteatoma and/or concurrent mastoid disease
2.
Magnetic resonance imaging (MRI): Not routinely necessary prior to tympanoplasty or myringoplasty; however, should be included if patient complains of chronic imbalance or vertigo or for evaluation of asymmetric sensorineural hearing loss

Indications

1.
Repair of tympanic membrane (TM) perforation to lift water restrictions
2.
Prevention of recurrent otorrhea and/or recurrent ear infections
3.
Attempt to improve hearing

Contraindications

1.
Extreme caution must be exercised if planning to operate on an only-hearing ear. Unless significant active disease exists, despite maximal medical therapy, aural amplification should be recommended.
2.
Avoid operating on an ear with an active vestibulopathy.

Preoperative Preparation

1.
An attempt should be made to achieve a dry ear prior to surgery with otic drops and/or systemic antibiotics.
2.
Preoperative medical clearance prior to anesthesia is recommended for all patients.
3.
Preoperative testing (laboratory tests, electrocardiogram, chest radiograph) per hospital guidelines
4.
Informed consent
- a.
  Risks: Worsening of hearing or complete hearing loss, vertigo, temporary or permanent changes in taste due to disruption of the chorda tympani nerve, facial paresis or paralysis, infection, failure of the graft to heal causing persistent or recurrent perforation, and/or numbness of the superior auricle if undergoing a postauricular approach
5.
Review of all previous otologic operative reports
- a.
  Reminder: After several procedures, local tissue for grafting may not be readily available and alternative sources should be considered, such as perichondrium, periosteum, or even tissue from the contralateral ear.
6.
Determine if the patient will be compliant and return for postoperative care.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here