Tympanoplasty

Chronic suppurative otitis media (CSOM), characterized by repeated or prolonged episodes of acute otitis media lasting for more than 12 weeks, can cause damage to the tympanic membrane (TM) and result in a non-healing perforation. Worldwide, CSOM is the most common childhood infectious disease. Risk factors include upper respiratory tract infection, malnutrition, poor hygiene, family history, low birth weight, craniofacial anomalies, and being of Native American, Native Alaskan, or Aboriginal Australian ancestry. The symptoms of CSOM are otorrhoea that leaks into the external ear canal through the TM perforation and hearing loss. The hearing loss is typically a mild conductive loss (10 to 20dB), though this may be worse with large perforations. Additionally, ossicular chain erosion can occur in some cases, causing a more profound audiologic alteration (50 to 70dB). It is crucial to exclude the presence of cholesteatoma in such instances. Tympanic membrane perforations may present in either the pars tensa or pars flaccida (though the former is by far the most common). The perforation can be further described as marginal or central depending on the position relative to the annulus, as well as wet or dry (persistent otorrhoea or no active otorrhoea, respectively). A subtype of CSOM is CSOM with cholesteatoma. Cholesteatomas are most commonly an acquired disease process occurring within the middle ear. They consist of a sac of squamous epithelium, usually in the attic and originating at the pars falccida of the TM, which can extend beyond the TM, eroding bone and thereby causing ossicular chain destruction.  Signs and symptoms of cholesteatoma are similar to CSOM and include foul-smelling otorrhoea, hearing loss, TM perforation, and attic retraction. Please see the StatPearls article entitled "cholesteatoma." Tympanoplasty is the surgical procedure performed to repair a perforated TM, with or without reconstruction of the ossicles (ossiculoplasty), aiming to prevent reinfection and restore hearing ability. CSOM is the most common indication; large invasive cholesteatomas may require a mastoidectomy as well as reconstruction of the TM. The history of tympanoplasty began in the 1950s when Wullstein and Zollner popularized the technique of using overlay graft to reconstruct the perforated TM and restore the sound conduction apparatus of the middle ear. Since then, surgical approaches to tympanoplasty have been modified, as described herein. Tympanoplasty can be classified into five types, according to the Wullstein classification. Type I: repair of the TM alone; no middle ear abnormality. Type I tympanoplasty is synonymous with myringoplasty. Type II: repair of the TM and middle ear; the malleus is eroded. Tympanoplasty involves grafting the TM to the incus. Type III: repair of the TM onto the stapes head; the malleus and incus have a defect. Type IV: the TM is grafted to the stapes footplate, which is movable. Type V: repair involves the stapes footplate, which is fixed.