Flexible laryngoscopy: a comparison of fiber optic and distal chip technologies. Part 1: vocal fold masses

This study was designed to evaluate the usefulness of fiber optic (FO) and distal chip (DC) flexible imaging platforms in the diagnosis of true vocal fold pathology when compared to the gold standard rigid transoral laryngeal telescopic examination. The recorded strobovideolaryngoscopic examinations of 34 consecutive patients were evaluated retrospectively by five raters. All stroboscopy segments were evaluated by two laryngologists, an otolaryngologist, a laryngology fellow, and an otolaryngology resident. Seventeen patients were examined with a high-quality, large-diameter, FO flexible laryngoscope (FO group) and 17 random patients were examined with a DC flexible laryngoscope (DC group). Each patient was also examined using rigid laryngeal videostroboscopy at the same sitting. Examinations of three patients from each group were presented twice to monitor internal consistency. Diagnoses of intrinsic vocal fold pathology made with the flexible laryngoscopes were compared for accuracy to the diagnoses provided using the rigid laryngeal telescope. The ability to make clinical diagnoses via stroboscopy was statistically equivalent with FO technology and DC technology. Rigid examination provided more information than the flexible examination in 27% of the FO examinations and in 32% of the DC examinations. DC technology did not add diagnostic information to the examination when compared to a high-quality, large-diameter, FO endoscope. Rigid endoscopy provides superior images of the true vocal folds and is necessary for precise diagnosis in patients with true vocal fold pathology. Thus, the most cost-effective means of evaluation of voice disorders remains FO flexible endoscopy for dynamic voice assessment and the neurolaryngologic examination followed by rigid stroboscopy for evaluation of the vocal fold edge and mucosal wave. Strobovideolaryngoscopy using high-quality FO or DC flexible equipment should be reserved for patients who cannot tolerate transoral rigid examination, such as children and those with a very strong gag reflex.