Tympanoplasty is a surgical procedure to reconstruct a perforated tympanic membrane (eardrum) or the small bones of the middle ear. Eardrum perforation may result from chronic infection or, less commonly, from trauma to the eardrum. Mastoid exploration may or may not be combined with this operation.
The tympanic membrane(Ear Drum) of the ear is a three-layer structure. The outer and inner layers consist of epithelium cells. Perforations occur as a result of defects in the middle layer, which contains elastic collagen fibers. Small perforations usually heal spontaneously. However, if the defect is relatively large, or if there is a poor blood supply or an infection during the healing process, spontaneous repair may be hindered. Eardrums may also be perforated as a result of trauma, such as an object in the ear, a slap on the ear, or an explosion.
The purpose of tympanoplasty is to repair the perforated eardrum, and sometimes the middle ear bones (ossicles) that consist of the incus, malleus, and stapes. Tympanic membrane grafting may be required. If needed, grafts are usually taken from tragus or temporalis fascia
There are five basic types of tympanoplasty procedures:
and Type I tympanoplasty is called myringoplasty, and only involves the restoration of the perforated eardrum by grafting.
and Type II tympanoplasty is used for tympanic membrane perforations with erosion of the malleus. It involves grafting onto the incus or the remains of the malleus.
and Type III tympanoplasty is indicated for destruction of two ossicles, with the stapes still intact and mobile. It involves placing a graft onto the stapes, and providing protection for the assembly.
and Type IV tympanoplasty is used for ossicular destruction, which includes all or part of the stapes arch. It involves placing a graft onto or around a mobile stapes footplate.
and Type V tympanoplasty is used when the footplate of the stapes is fixed.
Depending on its type, Tympanoplasty can be performed under local or general anesthesia. In small perforations of the eardrum, Type I tympanoplasty can be easily performed under local anesthesia with intravenous sedation. An incision is made into the ear canal and the remaining eardrum is elevated away from the bony ear canal, and lifted forward. The surgeon uses an operating microscope to enlarge the view of the ear structures. If the perforation is very large or the hole is far forward and away from the view of the surgeon, it may be necessary to perform an incision behind the ear. This elevates the entire outer ear forward, providing access to the perforation. Once the hole is fully exposed, the perforated remnant is rotated forward, and the bones of hearing are inspected. If scar tissue is present, it is removed either with micro hooks or laser.
Tissue is then taken either from the back of the ear-Temporalis fascia graft, the tragus (small cartilaginous lobe of skin in front the ear).. The tissues are thinned and dried. An absorbable gelfoam sponge is placed under the eardrum to support the graft. The graft is then inserted underneath the remaining eardrum remnant, which is folded back onto the perforation to provide closure. Very thin sheeting is usually placed against the top of the graft to prevent it from sliding out of the ear when the patient sneezes.
The examining physician performs a complete physical with diagnostic testing of the ear, which includes an audiogram and history of the hearing loss, as well as any vertigo or facial weakness. A microscopic exam is also performed. Otoscopy is used to assess the mobility of the tympanic membrane and the malleus.
CT Scan is routinely performed before tympaoplasty.
Once the mastoid bandage is and drain, if any removed, the neat day, patient can go home.
Antibiotics are given, along with a mild pain reliever. After 10 days, the packing is removed and the ear is evaluated to see if the graft was successful. Water is kept away from the ear, and nose blowing is discouraged. If there are allegies or a cold, antibiotics and a decongestant are usually prescribed. Most patients can return to work after five or six days, or two to three weeks if they perform heavy physical labor. After three weeks, all packing is completely removed under the operating microscope. It is then determined whether or not the graft has fully taken.
Possible complications include failure of the graft to heal, causing recurrent eardrum perforation; narrowing (stenosis) of the ear canal; scarring or adhesions in the middle ear; perilymph fistula and hearing loss; erosion or extrusion of the prosthesis; dislocation of the prosthesis; and facial nerve injury. Other problems such as recurrence of cholesteatoma, may or may not result from the surgery.
Tinnitus (noises in the ear), particularly echo-type noises, may be present as a result of the perforation itself. Usually, with improvement in hearing and closure of the eardrum, the tinnitus resolves. In some cases, however, it may worsen after the operation. It is rare for the tinnitus to be permanent after surgery.
Tympanoplasty is successful in over 90% of cases. In most cases, the operation relieves pain and infection symptoms completely. Hearing loss is minor.