Tympanic Troubles: Management of the Eardrum

Educational Objectives

The goal of this program is to improve the medical and surgical management of the tympanic membrane. After hear­ing and assimilating this program, the clinician will be better able to:

1.   Recognize conditions for which intratympanic therapy would be appropriate and effective treatment.

2.   Distinguish the various causes of vertigo and recommend appropriate therapy.

3.   Administer intratympanic gentamicin therapy in patients with Meniere’s disease.

4.   Describe minimally invasive fat graft myringoplasty for tympanic perforations.

5.   Provide appropriate postoperative and follow-up care for patients who have had fat graft myringoplasty.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the plan­ning committee to disclose relevant financial relationships within the past 12 months that might create any personal con­flicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, Drs. Marzo and Josephson and the planning committee reported nothing to disclose.

Acknowledgments

Dr. Marzo was recorded at Innovations in Otolaryngology, held March 14, 2009, in Maywood, IL, presented by the Loyola University Chicago Stritch School of Medicine, and sponsored by the Stritch School of Medicine Department of Otolaryn­gology-Head and Neck Surgery and Division of Continuing Medical Education. Dr. Josephson was recorded at 8th Annual Otolaryngology Symposium, held April 29 to May 2, 2009, in Ponte Vedra Beach, FL, presented by the New York Head & Neck Institute, and sponsored by St. Luke’s and Roosevelt Hospitals Center for Head and Neck Oncology and University Hospital of Columbia University College of Physicians and Surgeons. The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

Intratympanic Therapy

Sam J. Marzo, MD, Professor and Residency Program Director, Department of Otolaryngology  —  Head and Neck Surgery, Loyola University Health System, Maywood, IL

Anatomy: external ear  —  pinna (auricle), external auditory canal, and tympanic membrane; all squamous epithe­lium; middle ear  —  contains ossicular chain (malleus, incus, and stapes); air-containing space connected to mastoid and Eustachian tube (drainage tube); inner ear  —  2 components, ie, balance component (3 canals plus utricle and saccule) and cochlea; balance canals indicate angular acceleration, utricle and saccule indicate vertical accelera­tion; canals keep eyes focused during reading, walking, and other activities; nerves in internal auditory canal  —  superior and inferior vestibular nerves; facial nerve; cochlear nerve

Types of hearing loss: conductive hearing loss  —  caused by anything that prevents sound from being conducted to inner ear (eg, wax, tympanic perforation, fixation or erosion of ossicular chain); frequently corrected surgically; sensorineural hearing loss (SNHL)  —  occurs in or medial to cochlea; caused by, eg, acoustic neuromas that com­press eighth cranial nerve; idiopathic sudden hearing loss may be SNHL

Intratympanic therapy: delivery of small amounts of medication through ear canal into middle ear for absorption into inner ear via round and oval windows; benefits  —  results in higher concentrations of medication in inner ear than with oral administration; minimizes systemic side effects

Causes of sudden hearing loss: most causes idiopathic and probably viral; 50% of patients have viral prodrome; vascu­lar etiology possible; autoimmune etiology  —  rare; patient presents with rapidly progressing hearing loss in one ear, followed by other ear; usually responds to oral or intratympanic steroids; if no response, offer cochlear implanta­tion; be aware of potential narcotic abuse-induced hearing loss in patients referred for autoimmune etiologies; infectious  —  acute and chronic otitis media; proteins enter inner ear and cause damage to hair cells; trauma  —fractures of temporal bone or skull base; postsurgical complications (eg, after stapes surgery); neoplastic  —eg, acoustic neuroma

History and physical examination: patient frequently attributes hearing loss to wax build-up and uses softening agent; may see clinician and be prescribed decongestant or antibiotic; referral to specialist may come >1 mo after onset, at which point patient deaf in ear; consider sudden hearing loss medical emergency, and refer immediately for audiometry and steroid therapy; patient may have ringing in ear, and/or dizziness in addition to hearing loss; check duration and severity of hearing loss and presence or absence of drainage (can suggest history of otitis media or surgery); tinnitus; vertigo; audiometry  —>20 dB normal; important metrics pure tone and speech discrimination scores; auditory brainstem response (ABR) may not be helpful in patient with severe hearing loss; magnetic reso­nance imaging (MRI) advisable in cases of sudden severe hearing loss

Treatment of sudden hearing loss: oral prednisone 1 mg/kg per day, tapering over 2 wk; ideally, should begin at first office visit; obtain MRI to look for acoustic neuroma; offer patient intratympanic steroid therapy (should result in substantial hearing improvement); intratympanic steroid given every week or every 2 wk

Steroid injections: previous methods  —  formerly, pump and catheter implanted for continuous delivery; pump and catheter companies both out of business now; next approach was insertion of small sponge (eg, MicroWick) onto which patient would place drops; high rate of complications (eg, tympanic membrane perforations); current method  —  in-office injection of solumedrol or dexamethasone (eg, Decadron) with 1- to 2-wk follow-up; 2 to 3 in­jections usually offered; efficacy  —  if patient presents for first time >6 wk after hearing loss, therapy will not be ef­fective; »66% chance of measurable hearing improvement (not necessarily complete resolution) if patient treated early; hearing aid may then be helpful; complication rates  —  4% to 5% with MicroWick; no complications with steroid injections

Vertigo: 30% of population have dizziness by age 65 yr; cause located in inner ear in »70% of cases; history critical in patients with suspected vertigo (physical examination and tests almost always normal); defined as illusion of spinning or movement of self or surroundings; usually secondary to dysfunction of inner ear (semicircular ca­nals, utricle, saccule, vestibular nerve, or vestibular nuclei in brainstem); unilateral low-frequency hearing loss, ringing in ear, dizziness accompanied by pressure in ear, and nausea and vomiting likely Meniere’s disease; many elderly patients experience dizziness due to hypertension, coronary artery disease, and prescribed medications

Causes: benign paroxysmal positional vertigo (BPPV)  —characterized by dizziness or spinning upon rolling in bed; treated effectively with exercises in office and physical therapy; labyrinthitis  —  infection (usually viral) in inner ear; can cause sudden hearing loss, vertigo, nausea, vomiting, and ringing; treated with oral and sometimes intratympanic steroids; vertigo usually improves and does not recur; recurrent vertigo and persistent hearing loss may indicate Meniere’s disease; perilymphatic fistula  — leakage of fluid from cochlea into middle ear; rare in ab­sence of trauma; dizziness with headache, especially in women aged 20 to 40 yr, likely migraine; although rare, hearing loss can accompany migraine

Intratympanic gentamicin therapy: used for patients with Meniere’s disease unresponsive to first-line treatments; gentamicin can cause ototoxicity; causes selected slow vestibular ablation; toxic to hair cells in cochlea and balance canals; more selective for vestibular hair cells than for cochlear hair cells; small amounts of gentamicin can quiet or deaden hyperactive hair cells in vestibular system; decreases fluid production in inner ear, thus decreasing fre­quency and severity of attacks; administration  —  apply anesthetic to tympanic membrane; (speaker uses lidocaine and prilocaine; Eutectic Mixture of Local Anesthetics [EMLA]); after 15 to 20 min, suction off anesthetic; inject buffered gentamicin; patient should lie flat for 20 to 30 min; explain to patient that although drug starts working im­mediately, effect (eg, lightheadedness) not felt until 4 to 5 days after application; should inject »0.5 mL via tubercu­lin syringe with 25 gauge spinal needle; injection through inserted tube not advised (forms meniscus in tube and not adequately delivered); follow up at 1 mo; re-treat if Meniere’s attacks continue; treatment failures  —  reconsider Meniere’s diagnosis, or offer alternative treatment (eg, vestibular nerve section or endolymphatic sac surgery in pa­tients with good hearing; labyrinthectomy in patients with poor hearing); mechanism of action  —  decreases produc­tion of endolymph; has direct toxic effect on vestibular hair cells; some patients may experience hearing loss (usually high frequency); potential side effects  —  tympanic membrane perforation; SNHL (treat with oral or intra­tympanic steroid); transient imbalance and gait difficulty (significant in patients with balance problems before treat­ment; consider alternative therapy); results  —»92% control of vertigo (1-5 injections, average 3); SNHL in »8%

Considerations: importance of nurse’s role  —  review procedure with patients; premedicating patient with acetamin­ophen or ibuprofen before solumedrol injection; informed consent important; make sure injection in correct ear (gentamicin may damage healthy ear)

Supplies: EMLA cream  —  injecting cream inefficient; speaker prefers sterile swab (eg, Calgiswab) dipped in cream; myringotomy knife; right-angle hook; cup forceps

Patient care and logistics: advise patient to keep ear free of water (can use cotton ball with petroleum jelly); activity restrictions  —  caution patients undergoing gentamicin treatment to avoid climbing ladders and be careful climbing stairs; follow-up  —  1 mo for intratympanic gentamicin therapy; 1 to 2 wk for intratympanic steroids; bleeding rare; patients may taste drops when applied; infection rare; provide patient with contact telephone numbers; patient should lie on side for 20 to 30 min after intratympanic injection; because patient must occupy room for extended period, best to schedule intratympanic injections toward end of clinic workday or at lunchtime; put Meniere’s pa­tients on specific diet; meclizine helpful for dizziness; no driving; avoid heavy lifting; keeping diary helpful for Meniere’s patients to determine when true attack occurs

Questions and answers: evolution of intratympanic therapy  —began with inserted pumps; MicroWick; single injec­tions with solumedrol and/or dexamethasone; warn patient that solumedrol burns (remedication with analgesic helpful); literature inconclusive on optimal dosage of dexamethasone (speaker currently uses 4 mg/mL); mixing in­jected drugs with anesthetic  —  not advised; temporarily paralyzes labyrinth, causing acute vertigo; ensuring deliv­ery of drug to inner ear  —  patient must lie flat with ear facing upward; medicine will drip out upon standing, but some amount absorbed into ear; previously injected drug found in inner ear during labyrinthectomy portion of acoustic neuroma surgery; oxycodone overuse and hearing loss  —effect depends on dose and duration of drug use; ask patients with sudden bilateral hearing loss about narcotics; routine dosages and durations do not cause hearing loss; low-frequency hearing loss  —  if unilateral, use MRI to check for acoustic neuroma; perilymphatic fistula rare; dexamethasone dosage  —middle ear holds 0.3 to 0.4 mL

Pediatric Tympanoplasty Simplified:
Fat Graft Myringoplasty

Gary D. Josephson, MD, Associate Professor, Mayo Clinic College of Medicine, and Chief, Division of Pe­diatric Otolaryngology  —  Head and Neck Surgery, Nemours Children’s Clinic, Jacksonville, FL

Background: literature indicates 70% to 80% success rate for temporalis fascia grafting in children; some physicians refuse to perform pediatric tympanoplasty until child reaches 7 or 8 yr of age, due to Eustachian tube development; history  —  split and full thickness skin and vein used in past; »60% success rate; vein presented technical problems, eg, difficulty bedding graft; Ringenberg (1962)  —  earlobe fat successfully used in myringoplasty for 3 mm by 4 mm dry perforation; graft placed lateral to tympanic membrane and held in place by 3 strips of adhesive material; mid­dle ear canal not packed; results  —  graft 70% covered with epithelium at 3 wk; tympanic membrane mobile on pneumatic otoscopy and completely epithelialized at 6 wk; studies comparing fat from earlobe, buttock, and abdo­men found earlobe fat more compact, fibrous, stronger, and gives more support to mucosa; in 1978, Ringenberg re­ported »80% success rate in 65 patients; 76% success rate reported in 1988; higher success rates subsequently reported, although studies may be flawed

Speaker’s experience and technique: larger perforations more problematic than smaller ones; however, procedure noninvasive and failure not harmful to patient, compared with traditional tympanoplasty; if procedure fails, patient still candidate for traditional approach; done under general anesthesia; encourage anesthesiologist to use laryngeal mask airway (LMA); table turned 180°; excavation of graft  —  local injection into earlobe of 1% lidocaine with epi­nephrine; clean ear thoroughly; incision made on back surface of earlobe to avoid visible scar; avoid areas with cur­rent or previous piercing; avoid buttonholing skin; removal of multiple pieces of earlobe fat acceptable if original piece too small; close with 5-0 fast-absorbing gut suture; apply liquid adhesive (eg, Mastisol) and adhesive strips (eg, Steri-Strip); application of graft  —  ensure proper rimming of perforation to remove squamous material; lift re­maining squamous tissue off fibrous layer of tympanic membrane; scratch bottom of eardrum to facilitate epitheli­alization; pack middle ear with antibiotic and steroid impregnated material; after insertion, ensure all edges of perforation touching graft; successful graft will be nearly large enough to pop out (prevent by applying packing [eg, Gelfoam] on lateral side)

Postoperative considerations: antibiotics; pain rare, but give acetaminophen with codeine as precaution; advise against heavy lifting, straining and nose-blowing; follow up at 7 to 10 days after procedure; remove adhesive strips; check for purulence; second follow-up 5 to 6 wk later; eardrum visible at this point; most or all of packing dis­solved; should see good epithelialization and movement of tympanic membrane on pneumatic otoscopy; hearing test useful only after »3 mo; failure  —  persisting or recurrent tympanic perforation; hole may be smaller; graft may heal but with retraction pocket; tube then necessary for Eustachian dysfunction

Conclusion: fat graft myringoplasty excellent first choice for tympanic perforation; easy quick operation; pain mini­mal; waiting until child older perhaps unnecessary

Suggested Readings

Battaglia A et al: Combination therapy (intratympanic dexamethasone + high-dose prednisone taper) for the treat­ment of idiopathic sudden sensorineural hearing loss. Otol Neurotol 29:453, 2008; Halim A et al: Pediatric myringo­plasty: postaural versus transmeatal approach. Int J Pediatr Otorhinolaryngol 73:1580, 2009; Hamid M et al: Issues, indications, and controversies regarding intratympanic steroid perfusion. Curr Opin Otolaryngol Head Neck Surg 16:434, 2008; Landsberg R et al: Fat graft myringoplasty: results of a long-term follow-up. J Otolaryngol 35:44, 2006; Lee HS et al: Results of intratympanic dexamethasone injection as salvage treatment in idiopathic sudden hearing loss. J Otolaryngol Head Neck Surg 37:263, 2008; Lin AC et al: Pediatric tympanoplasty: factors affecting success. Curr Opin Otolaryngol Head Neck Surg 16:64, 2008; Nguyen KD et al: Vestibular function and vertigo con­trol after intratympanic gentamicin for Ménière's disease. Audiol Neurootol 14:361, 2009; Ringenberg JC: Fat graft tympanoplasty. Laryngoscope 72:188, 1962; Salt AN et al: Dependence of hearing changes on the dose of intratym­panically applied gentamicin: a meta-analysis using mathematical simulations of clinical drug delivery protocols. La­ryngoscope 118:1793, 2008; Uyar Y et al: Tympanoplasty in pediatric patients. Int J Pediatr Otorhinolaryngol 70:1805, 2006; Wasson JD et al: Myringoplasty: impact of perforation size on closure and audiological improve­ment. J Laryngol Otol 123:973, 2009.