Describe the growth pattern and pathophysiology of cholesteatomas.

Manage recurrent and residual cholesteatomas, as well as those complicated by concurrent otitis media.

Identify the best candidates for canal-wall-intact and canal-wall-down mastoidectomy.

Name the most common microorganisms and predisposing factors involved in otitis externa.

Explain why revision stapedectomy should be attempted only in low-risk patients.

Cholesteatomas: Surgery and Recidivism
Robert Jackler, MD, Sewall Professor and Chair, Department of Otolaryngology–Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA

Varieties of recidivism: recurrence; residual disease

Pathophysiology: begins at eardrum; eventually penetrates and sometimes fills mastoid; residual material rarely left in mastoid; explore middle ear first; look further only if infectious disease of concern, or if area around semicircular canals penetrated; oval window niche, posterior tympanic recesses (facial recess, sinus tympani) most likely locations

Growth pattern: posterior epitympanic cholesteatomas most common, followed by posterior mesotympanic and anterior epitympanic

Posterior epitympanic: draws pouch in lateral to malleus head and incus body; carries it into mastoid through aditus ad antrum

Posterior mesotympanic: presentation may be subtle; comes up under diaphragm in posterior middle ear, into epitympanum, deep to ossicle heads, before penetrating mastoid; drilling down bridge may transmit vibratory energy into inner ear; two crescentic recesses span from round window to oval window, separated by facial nerve into lateral and medial side; sinus tympani may be shallow or deep to facial nerve; can be hard to reach; often not visible on endoscopy, but good management critical for avoiding residual cholesteatoma; facial recess approach—when used for cholesteatoma in lateral recess, can augment pneumatization pathway between middle ear and mastoid; diamond burr facilitates procedure; tympanic annulus usually closest structure; best approach to orient to incus, view lateral canal, and start drilling with diamond burr; find facial nerve and irrigate with gentle pressure; find stapes and chorda tympani; exposure of round window usually not necessary; if incus eroded, remove bony bridge to create confluent opening (enhances connection between middle ear and mastoid); important tip—facial nerve sits at base of ridge behind stapes and round window; part of pyramidal process can be removed; no sinus tympani approach; cholesteatoma can penetrate ventral to malleus head; canal-wall-down ear may harbor some residual material

Role of laser: helpful when removing granulation tissue from around stapes; when cholesteatoma wraps around stapes, speaker first removes as much as possible mechanically; scraping last remnant from stapes may result in hearing loss and tinnitus; laser can remove final bits with no vibratory energy; sometimes arch remains intact, with cholesteatoma meeting in obturator foramen and wrapping around footplate; speaker dissects arch with laser (involves some vibratory trauma); leaves anterior arch high as basis for prosthesis; intact chain with severely medially rotated umbo stuck to medial wall—use laser to foreshorten back several millimeters for better graft placement; intact chain with cholesteatoma engulfing malleus head and incus body—explore middle ear early to determine whether erosion present; use laser to remove long process if still present (place small amount of Gelfoam, since overshoot of concern)

Congenital cholesteatoma: detach drum from malleus for better view of anterior cholesteatoma; after cutting, difficult to reattach drum to tip of umbo; use of laser facilitates reattachment

Recurrent cholesteatoma: speaker usually leaves canal wall intact unless ear highly hypopneumatic; other indications include good epitympanic support, reliable or pediatric patient, and healthy opposite ear; canal wall taken down in 60% to 70% of cases; associated with low recurrence rate; hearing results same, whether wall left intact or taken down; speaker places full cartilage shields in ears at high risk for retraction; palisades technique—strips of cartilage placed across eardrum; indications for staging—concern over residual disease in oval window, sinus tympani, or facial recess; mucosal factors (bare or sparsely lined promontory); hemostasis recommended to stop bleeding; speaker uses monopolar cautery; use of Bovie keeps area dry and facilitates microsurgery

Cholesteatoma with Chronic Otitis Media
Lorne Parnes, MD, Associate Professor and Chief, Department of Otolaryngology, University of Western Ontario School of Medicine, London, ON

Components of cholesteatoma: cystic content—keratin debris; matrix—epithelial lining; perimatrix— granulation tissue in contact with bone; produces proteolytic enzymes that erode bone; natural history is progressive growth and bone destruction; may be congenital or acquired

Pathogenesis of acquired cholesteatoma: theories include—invagination (poor eustachian tube function produces negative middle-ear pressure and resulting retraction); basal cell hyperplasia; migration (cells enter middle ear through marginal perforation); squamous metaplasia in middle ear and mastoid

Management: medical (aural toilet, local care, good hygiene, follow-up); tympanostomy tubes for early retraction pockets (not always effective)

Surgery: transcanal atticotomy; Bondy modified radical procedure; debate now concerns canal-wall-down vs intact-wall mastoidectomy; priorities are “safe, dry hearing” ear

Realities of Canadian health care system: advantages—equal access to treatment; single payor; less fear of malpractice lawsuits; disadvantages—competition for scarce resources, eg, computed tomography, (CT), magnetic resonance imaging (MRI); patients often wait 12 mo for elective chronic ear surgery; influences speaker’s management of chronic ear

Intact-canal-wall procedure: goals are to preserve wall, and make more natural, self-cleaning ear that can be exposed to water; contraindications—only-hearing ear; labyrinthine fistula; requires second staged procedure (additional 6-12 mo wait in Canada); associated with high incidence of recidivism; as result, almost all of speaker’s cases are canal- wall-down procedures

Key points: goal is safe, dry, hearing ear; practice; know anatomy and attend temporal bone laboratory; “what you do in practice is what you do in the game”; always obtain preoperative CT, read it yourself, and have it in operating room; use facial nerve as key landmark; when taking canal wall down, lower facial ridge and perform generous meatoplasty (both ensure well-aerated mastoid cavity); remain flexible, and “expect the unexpected”; follow patients for life

Diseases of the External Auditory Canal
Samuel Selesnick, MD, Professor and Vice Chair, Department of Otorhinolaryngology, Weill-Cornell Medical College, and Attending Otorhinolaryngologist, New York-Presbyterian Hospital, New York, NY

Anatomy: medial two-thirds bone; outer third is cartilage, site of external canal appendages, including apopilosebaceous (cerumen-producing) units

Cerumen: bacteriostatic; hydrophobic barrier with acid cloak (normal pH of canal acidic); also contains immunoglobulins and lysozyme

Natural protection of middle, inner ear: anterior canal overhang at temporomandibular joint; tragus, antitragus; hair at verge can capture microscopic particles before they enter external auditory canal (EAC)

Otitis externa

Proinflammatory stage: loss of cerumen, violation of skin

Inflammatory stage: characterized by “itch-scratch cycle” (inoculation, leading to accumulation of debris; patient attempts to clean, scratching EAC, and leading to further inoculation)

Diagnosis: pain; erythema and edema in EAC; tenderness of EAC and tragus; absence of cerumen; otorrhea (may elicit scratching); thickening of EAC

Microbiology: in industry-sponsored study of >2000 ears, Pseudomonas aeruginosa most common, followed by Staphylococcus aureus and others; otomycosis—fungi found in 1.7% of patients (incidence higher in hot humid locations); Aspergillus niger—most common and resistant to usual topical treatments

Predisposing factors: use of cotton-tipped applicators; heat and humidity; skin maceration (leads to removal of cerumen, saturation of stratum corneum, intercellular edema, and occlusion of cerumen glands, leading to stasis); psoriasis; chronic dermatitis; history of radiation therapy; systemic illnesses (eg, diabetes); allergies

Management: clear debris frequently (microscope helpful); maintain pH of 3 to 4 with boric acid powder and/or acidic drops; drops often contain acid, antimicrobial agent, and steroid; antibiotics—Pseudomonas resistant to neomycin; Staphylococcus may be resistant to polymyxin; allergic reactions to neomycin common; quinolones (eg, ciprofloxacin and dexamethasone [Ciprodex], ofloxacin [Floxin Otic]) provide good antimicrobial coverage with no ototoxicity; fungal infections—topical treatments include low pH agents and astringents toxic to fungi; topical antifungals have low efficacy against Aspergillus but work for Candida (comprises only 20% of EAC pathogens); oral antifungals highly effective, but hepatotoxic; caveat—oral fluoroquinolones effective, but usually contraindicated in children (may damage epiphyseal plates); management pearls—have patients avoid trauma and hot humid environments (use hair dryer to dry ear; protect ears from water); apply topical steroids for dermatoses to prevent acute infection; follow irradiated patients closely; eliminate allergens; appropriate topical medications; difficult cases—patients who are immunosuppressed, infected with HIV, noncompliant or infected with unusual pathogens

Medial EAC fibrosis: most common etiologies chronic infection, surgery, and trauma; treatment—dilate and excise plug; meatoplasty, and mastoidectomy if necessary; problem may recur unless tissue replaced with flaps or grafts

EAC exostoses and osteomas: largest study conducted at House Ear Institute, Los Angeles, CA; 401 ears over 16 yr; indications for surgery include pain, recurrent otitis externa, significant conductive hearing loss, and recurrent cerumen impaction; surgery consisted of postauricular approach, canal incisions as medially as exostoses allowed, lifting skin off canal, “burrowing” into exostosis (keeping skin as intact as possible), and flicking off bony edge with curette; replace with patient’s own ear skin, split thickness skin graft when necessary; some surgeons operate on posterior wall at same time, but associated with higher risk for scar formation; transcanal osteotome technique also used, but associated with higher risk for complications such as perforation of tympanic membrane

Stapes Surgery: Handling Challenging Cases
Dr. Jackler

Mixed hearing loss: if patient will still need hearing aid after surgery, “it’s not worth the risk”

Surgical pearls: speaker usually takes transcanal approach, but uses postauricular approach for closure <5.5 mm; scissors recommended for cutting vascular strip; “never accept limited exposure”; strive for unhindered view of oval window and good view of facial nerve and junction of pyramid and tendon

Footplate variants: 2 main types are heavily fixed (obliterative) and lightly fixed (biscuit); biscuit—small flange underneath that hooks footplate in; blood pools peripherally; obliterative—more common; blood pools centrally

Procedure: obliterative—thin footplate by drilling, then open in usual way; biscuit—drilling mobilizes flange (impairs hearing); speaker drills on promontory side and “log-rolls it”; drill away promontory overhang if present; drill away small remaining edge for unhindered view

Facial nerve dehiscence: some facial nerves completely covered, but many have small opening on undersurface; do not place hook or reflect laser into opening; overhanging facial nerve may create pseudo-otosclerosis and cause conductive hearing loss; manage with hearing aid; if nerve narrows niche and overhangs, push it back with wire 0.5 mm longer than nerve, or with prosthesis; facial palsy—occurs (rarely) 7 to 10 days after surgery; some experts recommend acyclovir (speaker does not); may be transient

Mass pushing on stapes: do not biopsy; may be facial nerve schwannoma pushing on stapes arch; obtain image before proceeding

Incus problems: deficient long process—speaker creates groove with microdrill; sets wire in groove and attaches it to prosthesis; dislocated incus—if loose, replace it, let it reattach, and reschedule surgery; no useful incus—perform malleus-down technique; challenging (must raise pocket around umbo); difficult to measure accurately; put bend in long prosthesis and swing it down toward oval window, gradually straightening bend until correct angle achieved; persistent stapedial artery—prescribe hearing aid

Vestibular problems: endolymphatic hydrops—fluctuating, low-frequency hearing loss or vertigo; do not open oval window (swollen endolymphatic system increases risk); speaker makes opening with microdrill; use 24-gauge needle suction, thumb off hole; avoid fenestra vestibuli; do not penetrate plane; 45-mm hook essential; leave fragments that drop in oval window (speaker leaves mucosa on footplate); if laser does not work on stapes footplate surface, could be that footplate reflecting energy to undersurface of facial nerve (possibly resulting in facial nerve palsy), or elsewhere; induce minor bleeding so blood can absorb laser energy; speaker uses membrane only on large fenestra; perilymph fistulae—rare; when removed, round window grows back; if fistula present, create iatrogenic hemotympanum to promote healing

Revision stapes surgery: speaker not in favor of early re-exploration; margination of wire important; avoid bony reclosure of window; redrilling raises risk for sensory loss; speaker revises cases only if risk “relatively modest”; examples of low-risk cases—removing adhesions with laser; tightening loose wire; medium-risk cases—marginalized prosthesis and big fenestra; popped piston with thin membrane (speaker removes prosthesis and opens fenestra slightly); high-risk cases—removing long prostheses; redrilling bony window; patients with significant sensory loss

Anesthesia: speaker prefers local anesthesia for revisions; can get patient responses to wire movement

Informed consent: 90% better in primary surgery (1% deafness); in “all comers,” hearing improves after revision in 50% of patients and incidence of deafness 4%; justifies selection of lower-risk cases

Early postoperative sensory hearing loss: takes 4 to 6 wk for hearing to stabilize after stapedectomy; better not to perform hearing test too soon after procedure

Postoperative vertigo: usually resolves spontaneously

Pseudoconductive hearing loss: may signal canal dehiscence; intact reflexes clue that hearing loss not caused by otosclerosis; if hearing loss present since childhood, rule out malformation with CT; disruption of cochlear-vestibular malformation may induce leakage of cerebrospinal fluid (CSF; only first 30 µL is perilymph); managing CSF leak—put patient in Trendelenburg position; let fluid drain out; then put patient in reverse Trendelenburg position, and apply tissue sealant; stapedectomy contraindicated for abnormal inner ear

Suggested Reading

Bauchet St Martin M et al: High-frequency sensorineural hearing loss after stapedectomy. Otol Neurotol 29:447, 2008; House JW, Wilkinson EP: External auditory exostoses: evaluation and treatment. Otolaryngol Head Neck Surg 138:672, 2008; Makarem A, Linthicum FH: Cochlear otosclerosis and endolymph hydrops. Otol Neurotol 29:571, 2008; Massey BL et al: Stapedectomy in congenital stapes fixation: are hearing outcomes poorer? Otolaryngol Head Neck Surg 134:816, 2006; Rinaldo A et al: Immediate facial nerve palsy following stapedectomy. ORL J Otorhinolaryngol Related Spec 64:355, 2002; Roland PS, Stroman DW: Microbiology of acute otitis externa. Laryngoscope 112:1166, 2002; Rosenfeld RM et al: Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg 134:S4, 2006; Rosenfeld RM et al: Systematic review of topical antimicrobial therapy for acute otitis externa. Otolaryngol Head Neck Surg 134:S24, 2006; Salvinelli F et al: Delayed peripheral facial palsy in the stapes surgery: can it be prevented? Am J Otolaryngol 25:105, 2004; Sanna M et al: Canalplasty for severe external auditory meatus exostoses. J Laryngol Otol 118:607, 204; Selesnick S et al: Surgical treatment of acquired external auditory canal atresia. Am J Otol 19:123, 1998.