Videostroboscopy, Mirror, and Fiberoptic Laryngoscopy: Objective Comparisons
Dworkin, James Paul, Stachler, Robert J., Kewson, Danny T., Meleca, Robert J., Garfield, Ilene, Journal of Medical Speech - Language Pathology
This investigation represents a retrospective analysis of the degree to which rigid endoscope videolaryngostroboscopy either augmented or altered initial laryngeal examination findings and treatment recommendations obtained during mirror or fiberoptic laryngoscopy in 130 subjects. Results revealed that stroboscopy added important new information or actually influenced changes in the original diagnoses and treatment plans in more than 20% of the study population. These findings are discussed, and directions for future research are suggested, especially with respect to the value of videolaryngostroboscopy versus simpler and less expensive videolaryngoendoscopy.
In 1855, Manuel Garcia first reported use of a dental mirror for examining the laryngeal inlet (Mackinlay, 1908). Since then, there have been numerous technological advances that have enabled detailed study of both the anatomical and biome-chanical characteristics of the larynx previously not accomplished via indirect mirror laryngoscopy (ML) alone. Perhaps of greatest significance was the advent of both flexible and rigid fiberoptic endoscopes (Silberman, Wilf, & Tucker, 1976; Williams, Farquharson, & Anthony, 1975). Over the past two decades, the coupling of videostroboscopic and multichip camera equipment with these viewing instruments to enhance the images obtained has revolutionized the field of modern laryngology (Yoshida, 1977). Collectively, these instruments have improved the diagnostic reliability of in-office laryngoscopy, and they have facilitated scientific investigations of normal laryngeal anatomy and functioning as well as the pathophysiology of various vocal pathologies (Leonard et al., 2002).
Although ML continues to be routinely employed by most otolaryngologists because it is quick, inexpensive, and affords three-dimensional images of the larynx with accurate tissue coloration, this technique presents several limitations when detailed laryngeal appraisal is desired by the examiner. These include:
1. tendency for the mirror to induce a strong gag response,
2. insufficient illumination of the laryngeal inlet, particularly in those patients with aberrant cartilaginous or soft tissue anatomy,
3. minimal viewing window, and
4. inability to interface a camera for video documentation of findings both before and following required treatments.
Notwithstanding the increased costs associated with use of the aforementioned endoscopic equipment, otolaryngologists and speech-language pathologists (SLP) alike consider this expense differential necessary in order to compensate for or avoid the shortcomings of ML.
Gould (1983) reported that only 70% of MLs proved adequate for diagnoses of various laryngeal pathologies. Barker and Dort's (1991) results were less robust, revealing that only 52% of mirror examinations were reliable compared to an 83% success rate using rigid videolaryngostroboscopy (VLS) for 100 study subjects. Dellon, Hall, and Chretien (1975) contrasted results of flexible fiberoptic endoscopic laryngoscopy (FFL) and ML and demonstrated that the former technique not only augmented general observations of the larynx, but also induced alterations of the diagnostic conclusions in 40% of the cases studied. Sataloff, Spiegel, and Hawkshaw (1991) and Woo, Colton, Casper, and Brewer (1991) investigated the potential additive value of stroboscopy during laryngeal endoscopy. Results revealed that although inclusion of such quasi-slow-motion technology generally promoted diagnostic and treatment benefits when compared to other examination methods, these outcomes were highly variable.
The purpose of the current study was to increase the literature base on this subject. To achieve this objective, we analyzed our clinical experience with various laryngeal examination techniques relative to the extent to which VLS either confirmed, augmented, or actually changed the diagnoses of and treatment plans for patients with vocal pathologies initially evaluated via indirect ML, FFL, or both. …