Videostroboscopy

Number: 0305

Policy

Aetna considers videostroboscopy medically necessary as a diagnostic procedure for detection of vocal cord pathology (e.g., polyps, invasive carcinoma, and vocal cord paralysis) in members who have received both a mirror-image and an endoscopic examination, and in whom no abnormal function or clinical pathology has been found with these tests, despite persistent symptoms.

Aetna considers videostroboscopy experimental and investigational for all other indications because its effectiveness for indications other than the one listed above has not been established.

Background

The cover and body of the vocal cord have different densities and therefore different mechanical properties.  The stiff underlying body is comprised of the vocalis muscle of the vocal cord and the deep lamina propria, and is responsible for the transverse movement of the cord.  The loose cover consists of the overlying mucosa and the superficial lamina propria, and vibrates primarily in the vertical direction and forms the traveling mucosal wave.  Ordinarily, the vibrating movements of the vocal cords are too rapid to be seen by the unaided eye.  One method of getting a clear view is by means of videostroboscopy.

Evaluation of the larynx by videostroboscopy is usually performed using a stroboscopic unit coupled with a Wolf rigid laryngoscope and a video recorder.  If patients exhibit extreme gagging, the transoral approach is replaced by the transnasal approach using a flexible fiberoptic laryngoscope.  For the latter procedure, local anesthesia is topically applied to the nasal, pharyngeal, and laryngeal mucosa of the patient before the fiberscope is inserted transnasally into the larynx.  The procedure requires the patient to cause the vocal cords to vibrate by speaking or singing during the evaluation: therefore, the procedure can not be performed on aphonic patients, patients who are unable to hold steady phonation for at least 2 to 3 seconds, and persons with a high degree of breathy voice and incomplete glottic closure.

Videostroboscopy provides detection of vibratory asymmetries, structural abnormalities, small masses, submucosal scars and other conditions that might not be visible under continuous light.  It produces not only valuable information concerning the motion of the normal vocal cord movements.  In contrast, stroboscopic examination revealed that half of the same patients had reduced mobility.  Studies have suggested that stroboscopic examinations might be the most useful technique in the early detection of invasive cancers of the vocal cords.  A careful videostroboscopic examination can differentiate, to a certain extent, epithelial hyperplasia and dysplasia from invasive carcinoma of the vocal cords.  Videostroboscopy is also useful for evaluating patients with vocal cord paralysis.

Mehta and Hillman (2012) summarized recent technological advancements and insight into the role of stroboscopy in laryngeal imaging.  Although stroboscopic technology has not undergone major technological improvements, recent clarifications have been made to the application of stroboscopic principles to video-based laryngeal imaging.  Also recent advances in coupling stroboscopy with high-definition video cameras provide higher spatial resolution of vocal fold vibratory function during phonation.  Studies indicated that the inter-rater reliability of visual stroboscopic assessment varies depending on the laryngeal feature being rated and that only a subset of features may be needed to be representative of an entire assessment.  High-speed videoendoscopy (HSV) judgments have been shown to be more sensitive than stroboscopy for evaluating vocal fold phase asymmetry, pointing to the future potential of complementing stroboscopy with alternative imaging modalities in hybrid systems.  The authors concluded that laryngeal videostroboscopy alone continues to be the modality of choice for imaging vocal fold vibration, but technological advancements in HSV and associated research findings are driving increased interest in the clinical adoption of HSV to complement videostroboscopic assessment

Mendelsohn et al (2013) stated that although high-speed imaging (HSI) has been identified as a valuable tool in phonatory biomechanics research, to-date, there have only been a selected number of reports investigating the clinical utility of HSI.  These researchers examined the role of HSI in the diagnosis of the dysphonic patient.  The video files from 28 consecutive dysphonic patients with concurrently acquired videostroboscopy and HSI were retrospectively collected.  Stroboscopy video files were edited to include vibratory motion only.  Videos were then anonymously and randomly presented to 4 academic laryngologists.  Experts were asked to assign a single best diagnosis for each video file.  Assigned diagnoses were then compared with treatment diagnoses conferred based on medical history, phonatory evaluation, laryngeal examination, and response to treatment.  Inter-rater analysis for the 4 laryngologists demonstrated significant and meaningful correlations for the diagnoses of polyps, cysts, nodules, and normal examination using stroboscopy (kappa > 0.40, p < 0.001).  The experts demonstrated significant and meaningful correlations for the diagnoses of polyps, presbyphonia, and normal examination using HSI (kappa > 0.40, p < 0.001).  Combined intra-rater analysis performed by comparing single rater's diagnosis for single patient across both modalities resulted in poor correlation without statistical significance (kappa = 0.30, p = 0.07).  Both stroboscopy- and HSI-assigned diagnoses matched the treatment diagnoses at equal predicted frequencies (32.3 %), as demonstrated through multi-variate logistic regression analysis (p < 0.001).  The authors concluded that overall HSI did not improve the diagnostic accuracy above stroboscopy alone.  Moreover, they stated that although specific laryngeal states such as presbyphonia may be better diagnosed with HSI, further studies are needed to define HSI's precise role in the clinical setting.

Assessment of Non-Invasive Vocal Cord Lesions (Cysts, Nodules, and Polyps):

Mehlum and colleagues (2015) stated that correct assessment of patients with a glottic lesion is crucial for ensuring proper treatment in cases of cancer or pre-malignancy and for avoiding unnecessary surgery.  For years, videostroboscopy (VS) has been the gold standard for assessing such lesions, but diagnostic difficulties have been described.  These researchers estimated the diagnostic accuracy of VS in differentiating early glottic cancer from non-invasive lesions by conducting a systematic review and meta-analysis of published studies.  PubMed and Embase databases were searched without restrictions on publication date.  A systematic review and subsequent meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement.  These investigators systematically searched the literature for publications on stroboscopic diagnosis of cancer or pre-malignant lesions on the vocal cords.  All retrieved studies were reviewed and qualitatively assessed.  The pooled sensitivity and specificity of VS were calculated, and bubble and summary receiver operating characteristics plots were created.  A meta-analysis was conducted on 5 studies with a total of 307 patients.  The sensitivities of VS within the single studies ranged from 86 % to 100 % and specificities ranged from 7 % to 93 %.  The meta-analysis showed that the sensitivity of the combined results was 0.96 (95 % confidence interval [CI]: 0.89 to 0.98), and the specificity was 0.65 (95 % CI: 0.21 to 0.93).  The authors concluded that VS is able to identify almost all patients with cancer, but only approximately 2/3 of patients with non-invasive lesions are correctly identified as not having cancer.  They stated that further research concerning assessment of patients with vocal cord lesions is needed.

CPT Codes / HCPCS Codes / ICD-10 Codes
Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":
ICD-10 codes will become effective as of October 1, 2015 :
CPT codes covered if selection criteria are met:
31579	Laryngoscopy, flexible or rigid fiberoptic, with stroboscopy
Other CPT codes related to the CPB:
31505	Laryngoscopy, indirect: diagnostic (separate procedure)
31520	Laryngoscopy, direct, with or without tracheoscopy; diagnostic, newborn
31525	diagnostic, except newborn
31526	diagnostic, with operating microscope or telescope
ICD-10 codes covered if selection criteria are met (not all-inclusive):
C32.0 - C32.2	Malignant neoplasm of glottis, supraglottis, and subglottis [vocal cords]
C78.39	Secondary malignant neoplasm of other respiratory organs [invasive carcinoma vocal cords]
D02.0	Carcinoma in situ of larynx [vocal cords]
D14.1	Benign neoplasm of larynx [vocal cord]
D38.0	Neoplasm of uncertain behavior of larynx [vocal cords]
D49.1	Neoplasms of unspecified behavior of respiratory system [vocal cords]
J38.00 - J38.7	Diseases of vocal cords and larynx, not elsewhere classified

The above policy is based on the following references:

1. Bless DM, Hirano M, Feder RJ. Videostroboscopic evaluation of the larynx. ENT Journal. 1987;66(7):289-296.
2. Sercarz JA, Berke GS, Ming Y, et al. Videostroboscopy of human vocal fold paralysis. Ann Otol Rhinol Laryngol. 1992;101(7):567-577.
3. Sataloff RT, Spiegel JR, Hawkshaw MJ. Strobovideolaryngoscopy: Results and clinical value. Ann Otol Rhinol Laryngol. 1991;100(9 Pt 1):725-727.
4. Casiano RR, Zaveri V, Lundy DS. Efficacy of videostroboscopy in the diagnosis of voice disorders. Otolaryngol Head Neck Surg. 1992;107(1):95-100.
5. Yanagisawa K, Yanagisawa E. Techniques of endoscopic imaging of the larynx. Curr Opin Otolaryngol Head Neck Surg. 1996;4:147-153.
6. Omori K, Kacker A, Slavit DH, Blaugrund SM. Quantitative videostroboscopic measurement of glottal gap and vocal function: An analysis of thyroplasty type I. Ann Otol Rhinol Laryngol. 1996;105(4):280-285.
7. Shohet JA, Courey MS, Scott MA, Ossoff RH. Value of videostroboscopic parameters in differentiating true vocal fold cysts from polyps. Laryngoscope. 1996;106(1 Pt 1):19-26.
8. Remacle M. The contribution of videostroboscopy in daily ENT practice. Acta Otorhinolaryngol Belg. 1996;50(4):265-281.
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10. Rosen CA, Murry T. Diagnostic laryngeal endoscopy. Otolaryngol Clin North Am. 2000;33(4):751-758.
11. Dejonckere PH, Bradley P, Clemente P, et al. A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Committee on Phoniatrics of the European Laryngological Society (ELS). Eur Arch Otorhinolaryngol. 2001;258(2):77-82.
12. Schneider B, Wendler J, Seidner W. The relevance of stroboscopy in functional dysphonias(1). Folia Phoniatr Logop. 2002;54(1):44-54.
13. Rihkanen H, Reijonen P, Lehikoinen-Soderlund S, Lauri ER. Videostroboscopic assessment of unilateral vocal fold paralysis after augmentation with autologous fascia. Eur Arch Otorhinolaryngol. 2004;261(4):177-183.
14. Hartl DM, Hans S, Crevier Buchman L, et al. Dysphonia: Current methods of evaluation. Ann Otolaryngol Chir Cervicofac. 2005;122(4):163-172.
15. Singh A, Kazi R, Venkitaraman R, et al. Does flexible videostroboscopy compare with rigid videostroboscopy in the assessment of the neoglottis? A preliminary report. Clin Otolaryngol. 2008;33(1):60-63.
16. Grøntved AM, Faber CE, Jakobsen J. Assessment of thyroplasty for vocal fold paralysis. Ugeskr Laeger. 2009;171(3):117-121.
17. Kazi R, Rhys-Evans P, Nutting CM, Harrington KJ. The great debate: Stroboscopy vs high-speed imaging for assessment of alaryngeal phonation. J Cancer Res Ther. 2009;5(2):121-123.
18. Verikas A, Uloza V, Bacauskiene M, et al. Advances in laryngeal imaging. Eur Arch Otorhinolaryngol. 2009;266(10):1509-1520.
19. Bryson PC. Stroboscopy. eMedicine Surgery. New York, NY: Medscape: Updated April 30, 2012.
20. Nospes S, Kuhr K, Napiontek U, Keilmann A. Stroboscopy findings: A comparison of flexible CCD-videostroboscopy and rigid stroboscopy. Laryngorhinootologie. 2011;90(4):218-223.
21. Mehta DD, Hillman RE. Current role of stroboscopy in laryngeal imaging. Curr Opin Otolaryngol Head Neck Surg. 2012;20(6):429-436.
22. Mendelsohn AH, Remacle M, Courey MS, et al. The diagnostic role of high-speed vocal fold vibratory imaging. J Voice. 2013;27(5):627-631.
23. Shinghal T, Low A, Russell L, et al. High-speed video or video stroboscopy in adolescents: Which sheds more light? Otolaryngol Head Neck Surg. 2014;151(6):1041-1045.
24. El-Demerdash A, Fawaz SA, Sabri SM, et al. Sensitivity and specificity of stroboscopy in preoperative differentiation of dysplasia from early invasive glottic carcinoma. Eur Arch Otorhinolaryngol. 2015;272(5):1189-1193.
25. Mehlum CS, Rosenberg T, Groentved AM, et al. Can videostroboscopy predict early glottic cancer? A systematic review and meta-analysis. Laryngoscope. 2015 Nov 3 [Epub ahead of print].