TRENDS IN TECHNIQUE
| COST-EFFECTIVE DIAGNOSIS OF ACOUSTIC NEUROMAS —Samuel H. Selesnick, MD, Professor and Vice
Chairman, Department of Otolaryngology, Weill Medical College of Cornell University, New York, NY
|
| Acoustic neuromas: slow-growing tumors; goal to diagnose when small so can effectively treat; incidence rare (5000
diagnosed in United States per year); cost of diagnosis low (magnetic resonance imaging [MRI], office visits, and audiogram);
cost of missing diagnosis (larger tumor and more complications) and cost to society must be factored into
bigger equation
|
| Diagnosis: characteristic clinical presentation and findings (do not correlate with tumor size); understanding of tumor
dates back 100 yr; Dr. Harvey Cushing—father of acoustic tumor understanding in United States (wrote monograph
that was foundation of understanding in early 20th century and still has some clinical implications); his differential diagnosis
included chronic otitis media, tabes dorsalis, and trigeminal neuralgia; symptom progression (4 yr before diagnosis)
included acoustic labyrinthine dysfunction, occipitofrontal pain, suboccipital discomfort, cranial neuropathies,
then hydrocephalus with large tumors; hydrocephalus onset of demise; patients typically diagnosed at this point; patients
treated or succumbed within 12 mo due to compression of brainstem; dysarthria and dysphasia not due to cranial
neuropathy, but to brainstem compression by large lesion; patients presented late; early 1990s study—130 patients; incidence
of subjective hearing loss relatively rare with small tumors, close to 100% with tumors >3 cm; tinnitus too
common and subjective to be useful diagnostically; dysequilibrium increases with time and tumor compression; vertigo
comes on early (sensory conflict and working vestibular fibers) and decreases when nerve fibers replaced by tumor; facial
hypesthesia directly dependent on fifth nerve compression (vulnerable to compression, but friendly to recovery after
tumor removal); facial nerve not as vulnerable to compression, but not forgiving after tumor removal; progression of
symptoms over 3.9 yr
|
| Stages: intracanalicular stage—hearing loss; tinnitus; vertigo; active symptom period; cisternal stage—quiescent
period; large amount of growth without relatively large increase in symptomatology; brainstem compressive stage—
fifth nerve symptoms (compression of trigeminal nerve); headache; increasing neurologic symptomatology; hydrocephalic
stage—fourth ventricle compression; sixth nerve symptoms; dysarthria; dysphasia
|
| Diagnostic tools: clinical acumen; audiogram—classic findings asymmetric, unilateral sensorineural hearing loss
(SNHL) and poor speech discrimination; possible to have acoustic neuroma with symmetric audiogram; differential diagnosis
for downsloping symmetric high-frequency bilateral SNHL includes presbycusis, metabolic causes, ototoxicity,
autoimmune disease, infection, or noise-induced hearing loss; study—audiologic presentation in 130 patients; majority
of tumors 1 to 3 cm; hearing assessment looking at speech reception threshold (SRT), speech discrimination scores, high-
frequency SNHL; normal was within 15 decibels (dB) of SRT between sides, within 12% of speech discrimination between
sides, 15 dB for high frequency; study showed patients with small tumors can have symmetric hearing, and 7%
of patients had entirely normal hearing; normal audiogram does not clear patient; in patients with medium and large tumors,
number with symmetric hearing loss does not change, but number with normal hearing does decrease; hearing
loss not necessarily subjective symptom for patients; patients may complain of unilateral tinnitus, unexplained vertigo,
or otologic/aural pressure; patient with normal audiogram and specific otologic complaint needs follow-up; computed
tomography (CT) with intravenous (IV) contrast—high false-negative rate; CT with air contrast—good at making
diagnosis, but very uncomfortable for patient; risk associated with test; auditory brainstem response (ABR)—false-
negative rate up to one third for small tumors; MRI—cost for scan, gadolinium, and reading $2500; gadolinium cost
$700 of $2500
|
| Less expensive ways to diagnose: algorithm—first step putting patient in high-, intermediate-, or low-probability
group; high probability (unilateral SNHL); low probability (subjective symptoms, eg, otologic/aural pressure and tinnitus
without any other findings); T2 fast spin echo MRI—advantage of not requiring gadolinium; scans region of internal
auditory canal; cerebrospinal fluid (CSF) bright; ability to see neural structures, eg, cochlear nerve, inferior
vestibular nerve; dark void represents mass lesion; problems include missing non-internal auditory canal-related diagnoses
(eg, multiple sclerosis); ABR testing—cost-effective and innovative; latency of waves I, III, and V measured,
and comparison made between side in question and normal-hearing side (looking at difference between latencies; 0.2
msec unacceptable variability); problem that latencies good, but can miss small (<1 cm) tumors; cochlear
electrophysiology—acoustic tumors put pressure on eighth nerve nonuniformly, desynchronizing and blocking conduction
of axons involved (depends on which axons and how many involved); axons from varying regions of cochlea
have different wave V latencies due to traveling wave delay (summation of overlapping wave forms can lead to phase
cancellation and alter ability to reliably look at amplitude of ABR); goal to develop stacked ABR done over 4 or 5 different
frequencies (frequencies have different latencies of wave V), lining up latencies to reliably add them up and see
value; lack of data on method; many companies that sell ABR equipment also sell software to modify ABR machines;
study of 47 patients, half of whom had acoustic tumors missed with standard ABR, but none missed with stacked ABR;
cost to modify machine low, compared to cost of MRI
|
| Conclusion: no perfect test to diagnose acoustic tumor; perfect test features include high sensitivity and specificity,
inex-pensive, fast and easy to perform, and noninvasive; macroeconomic costs of diagnosing acoustic tumors—cost
of diagnosis (special testing); follow-up physician visits; cost of treatment (increases with tumor size); cost to society
of unproductive citizen; medicolegal costs; philosophic decision—does wealth of society affect decision; question
whether better to spend money on, eg, childhood vaccinations, management of hypertension, mammograms; question
value placed on disability and loss of life when caused by rare disease; patients must be offered highest level of care,
but we live in real world with real financial constraints and need to find balance
|
| CSF LEAKS DURING FESS —Richard Lebowitz, MD, Assistant Professor of Otolaryngology, New York University
School of Medicine, New York
|
| General: breach in 3 layers (nasal mucosa, bone, and dura) required for CSF leak; majority of CSF leaks iatrogenic
(surgical); rate low, but number significant because of volume of cases; biggest problem delayed recognition; risk
for meningitis biggest problem with CSF rhinorrhea (10% per year with chronic or intermittent leaks); intraoperative
leak possible occurrence for anyone who does endoscopic sinus surgery (success rate and ease of repair
greater in this situation)
|
| Confirming CSF leak: not necessary with reasonable surgical field (not too bloody) because leak evident; intrathecal
fluorescein—used in repairing CSF leaks secondarily to help identify leak; risks (primarily seizures); not approved
by Food and Drug Administration (FDA) for intrathecal use; preoperative discussion with patient required about risks
and lack of approval by FDA, but benefit outweighs risk; halo sign—used to determine whether fluid coming out of
nose or ear actually contains CSF; sample put on filter paper and blood in center diffuses less than CSF, creating halo;
usually not necessary because leaks relatively evident
|
| Repairing leak: expose surrounding skull base, prepare and place graft (overlay vs underlay), pack, and place lumbar
drain (controversial); graft material—tissue available in surgical field; mucoperiosteum of middle turbinate (turbinate
resection during repair, so tissue available); mucoperichondrium of nasal septum (easily accessible; use contralateral
side to avoid blood in field; heals by secondary intention); AlloDerm (acellular dermis; frozen; keep in operating room
[OR]); medium thickness AlloDerm easy to work with; bone or cartilage easily harvested from nose; underlay
technique—more technically difficult (graft placed on intracranial side of skull base defect; cannot be performed in all
areas, eg, cribriform), but graft more secure as held in by pressure from brain above; bone and cartilage possible material
for large defect; however, cannot use mucosa; fascia or AlloDerm appropriate; overlay technique—simpler; graft
laid over skull base defect; prepare surrounding bone so not covered with mucosa and graft has bed on which to heal;
packing necessary to hold graft in place; bone or cartilage not recommended as graft material; packing—standard with
both techniques, but more so with overlay technique; Gelfoam over graft before gauze packing; lumbar drain—
controversial; studies of use, not in this setting of intraoperative leak but for endoscopic repair of CSF rhinorrhea, demonstrate
good long-term success rates and no difference with or without lumbar drain; intraoperative leaks complicated
by fact that patient not prepared to wake up with drain; neurosurgery or anesthesia must place; if avoiding drain does
not compromise success of repair, do not have it placed; success rate 95%
|
| Postoperative care: monitoring in postoperative unit acceptable if no significant amount of bleeding associated
with leak and not worried about intracranial injury and bleeding; obtain CT if concerned; preoperative antibiotics not
usually given for sinus surgery, but put patient on antibiotic (cefazolin [Ancef]) if packing used; activity limited to
lying in bed for first few days; increased activity, eg, bearing down (Valsalva) increases pressure and may cause repair
to fail, so limit activities (no bending, lifting [heavier than phone book], straining) for 2 wk until site has mucosalized
and healed; secondary repair—bed rest for 3 days, then ambulation; if no problems, patient can go home
on day 4 or 5, with limited activity
|
| NONSEDATED IN-OFFICE LARYNGEAL SURGERY —Stacey L. Halum, MD, Assistant Professor, Department of Otolaryngology,
Wake Forest University Baptist Medical Center, Winston-Salem, NC
|
| Advantages of office-based surgery: general anesthesia or IV sedation unnecessary, making overall risk to patient
less; postoperative recovery time eliminated; self-transportation to and from procedure possible; time and cost savings
for patient; operating time minimized (maximum 20 min)
|
| Laryngeal injections: botulinum toxin type A (Botox) injection—adductor spasmodic dysphonia; procedure done with
electromyography (EMG) guidance or flexible laryngoscopy guidance; tremor reduced in patients with significant tremor
component to adductor spasmodic dysphonia by transoral injections of interarytenoid (IA) muscle and EMG guidance for injection
of thyroarytenoid (TA) muscle; risk for aspiration, so do not use in patient with history of or potential for aspiration;
cidofovir injections—transcervical injections; reduce frequency of surgery; augmentation—can inject, eg, collagen, hydroxyapatite
|
| Transnasal esophagoscopy (TNE): review of 711 TNE procedures done at Wake Forest showed most common indication
esophageal screening for patients with reflux or dysphagia, and most common findings included reflux esophagitis,
hiatal hernia, and Barrett’s esophagus; TNE also used for foreign body screening and transesophageal puncture (TEP)
placement and confirmation; TNE in head and neck cancer— study of panendoscopy and biopsy in office vs OR
showed congruent findings in diagnosing cancer; useful in patients with early laryngeal cancer who do not want surgery;
can evaluate dysphagia in patients with head and neck cancer who had previous surgery or irradiation (screen for recurrence
of disease or stenosis); TEP failure—look to see if colonized with fungus or if obstruction present proximal to TEP
|
| Treatment of benign laryngotracheal lesions: anterior glottic papilloma—pulsed dye laser (PDL) good because
patients do not develop significant anterior glottic webs; laser used for treatment of polyps, polypoid corditis,
leukoplakia, granulomas, and papilloma, with encouraging results
|
| Tools: transnasal esophagoscope—60 cm long; 5.1-mm diameter; insufflation, irrigation, suction ports, and working
channel that can be used to instill lidocaine, pass biopsy cups, give injection through, or transmit laser fiber; working
flexible laryngoscope (in development)—length of regular flexible laryngoscope, but has many of features of TNE;
reduces dead space; possibly easier to manipulate; PDL—fiberoptic delivery; wavelength absorbed preferentially by
blood vessels; limited depth of penetration (decreased scarring and web formation); limited for bulky disease or making
cuts through tissue because of limited depth of penetration; new flexible CO2 laser—good power and hemostasis;
FDA approval pending
|
| Technique of office-based laser surgery: start with topical nasal anesthesia; administer lidocaine to supraglottis and
area of proposed laser treatment through scope (nebulized lidocaine for tracheal lesions); pass biopsy cups or go straight to
PDL
|
| Lesions treated in office:laryngeal granuloma—preliminary experience shows results similar to traditional surgical results;
leukoplakia—physician treated various forms of leukoplakia with PDL in OR and had 80% reduction in size of hyperkeratosis
in >70% of patients; similar results seen in clinic; polypoid corditis—patients with severe Reinke’s edema who do
not want to go to OR treated with PDL with promising results; surface of lesion blanched or tip of fiber poked through mucosa
of lesion to laser within Reinke’s space (appears more effective); PDL acts on blood supply, so delayed resolution of disease;
hemorrhagic polyp—improvement in voice in patient with PDL treatment; difference between PDL and new
flexible CO2 laser—difficult to treat bulky lesions with PDL; CO2 laser ablates bulky lesions
|
Educational Objectives
| The goal of this program is to provide the listener with information on cost-effective diagnosis of acoustic neuromas,
dealing with cerebrospinal fluid (CSF) leaks during functional endoscopic sinus surgery (FESS), and the role of office-
based laryngeal surgery. After hearing and assimilating this program, the clinician will be better able to:
|
 | 1. Review the stages of an acoustic neuroma.
|
| 2. Discuss the diagnostic tools available for acoustic neuromas.
|
| 3. Describe the process of repairing a CSF leak during FESS and the postoperative care necessary.
|
| 4. Explain the advantages of office-based laryngeal surgery.
|
| 5. Discuss types of procedures suitable for and tools useful in office-based laryngeal surgery.
|
Discussed on This Program
Botulinum toxin type A [Botox, Botox Cosmetic]
Cefazolin sodium [Ancef, Zolicef]
Cidofovir [Forvade (investigational), Vistide]
Collagen, human [CosmoDerm, CosmoPlast]
Hydroxyapatite, tricalcium phosphate ceramic, and fibrillar collagen [Collagraft]
Lidocaine HCl [several trade names]
Suggested Reading
Andrus JG, et al: Transnasal esophagoscopy: a high-yield diagnostic tool. Laryngoscope 115:993, 2005; Araujo
Filho BC, et al: Endoscopic repair of CSF rhinorrhea: experience of 44 cases. New Bras Otorrinolaringol 71, 472,
2005; Bozorg Grayeli A, et al: Conservative management versus surgery for small vestibular schwannomas. Acta
Otolaryngol, 125:1063, 2005; Don M, et al: The stacked AR: a sensitive and specific screening tool for detecting small
acoustic neuroma. Audiol Neurootol 10:274, 2005; Fleischer S, et al: Office-based laryngoscopic observations of recurrent
laryngeal nerve paresis and paralysis. Ann Otol Rhinol Laryngol 114:488, 2005; Kerr JT, et al: Cerebrospinal
fluid rhinorrhea: diagnosis and management. Otolaryngol Clin N orth Am 38:597, 2005; Kim AH, et al: Transient
evoked otoacoustic emissions pattern as a prognostic indicator for hearing preservation in acoustic neuroma surgery. Otol
Neurotol 27:372, 2006; Mirza S, et al: Sinonasal cerebrospinal fluid leaks: management of 97 patients over 10 years.
Laryngoscope 115:1774, 2005; Propp JM, et al: Descriptive epidemiology of vestibular schwannomas. Neuro-oncol
8:1, 2006; Sauvaget E, et al: Sudden sensorineural hearing loss as a revealing symptom of vestibular schwannoma.
Acta Otolaryngol 125:592, 2005; Shah RK, et al: Mid-frequency sensorineural haring loss: aetiology and prognosis. J
Laryngol Otol 119:529, 2005; Tabaee A, et al: The efficacy of computer assisted surgery in the endoscopic management
of cerebrospinal fluid rhinorrhea. Otolaryngol Head Neck Surg 133:936, 2005; Tosun F, et al: Analysis for different
surgical approaches for the treatment of cerebrospinal fluid rhinorrhea. Minim Invasive Neurosurg 48:355, 2005;
Tufarelli D, et al: Quality of life after acoustic neuroma surgery. Otol Neurotol 27:403, 2006; Woo P: Office-based
laryngeal procedures. Otolaryngol Clin North Am 39:111, 2006; Woodworth BA, et al: Endoscopic repair of frontal
sinus cerebrospinal fluid leaks. J Laryngol Otol 119:709, 2005.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the faculty reports
nothing to disclose.
Drs. Selesnick and Lebowitz were recorded at the Annual Clinic Day Combined Meeting of the Nassau Surgical Society
Inc. and Brooklyn & Long Island Chapter of the American College of Surgeons, held December 7, 2005, in Uniondale,
NY. Dr. Halum was recorded at the 25th Annual James A. Harrill Lecture, held April 22-23, 2005, in Winston-
Salem, NC, and sponsored by Wake Forest University School of Medicine, Bowman Gray Campus. The Audio-Digest
Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.
|
