Question
What are the differences and similarities between a videonasendoscopy and videofluoroscopy in regards to velopharyngeal function, including equipment and procedures, views obtained, and type of data provided. Why would you choose one over the other?
Answer
Videofluoroscopy is a radiographic procedure that can be used to diagnose the cause of velopharyngeal dysfunction. This technique allows visualization of most aspects of the velopharyngeal portal during speech. One drawback is that the velopharyngeal port is a structure of three dimensions and volume. However, radiographic images are two-dimensional in nature. Therefore, to image a volume structure adequately, it must be examined in three mutually perpendicular planes. Therefore, videofluoroscopy is done through the use of several standard views (lateral, frontal or anterior-posterior (AP), and base views). Although videofluoroscopy used to be the "gold standard" for evaluation, it is not used as extensively as it once was. Some of the reasons include the following:
- The resolution or clarity of videofluoroscopy is not as good as nasopharyngoscopy. The image is somewhat fuzzy.
- A slight rotation of the head can affect apparent results and make a large opening essentially disappear.
- Small gaps cannot be seen because the beam sums all the parts. Therefore, touch closure anywhere along the plane will appear to be total closure.
- You can't see entire valve at once in order to determine the pattern of closure and shape of the opening. This is important for determination of the type of surgical correction that would be most effective.
- To view the pharyngeal walls, they have to be coated with barium. The barium is squirted into the nasopharynx through a catheter that goes through the nose. This is somewhat uncomfortable for the child and the barium leaves a burning sensation in the pharynx for about an hour after. (I know from personal experience in making teaching videos.)
- The procedure requires low dose radiation
Through nasopharyngoscopy, you can evaluated the entire velopharyngeal valve and see even very small velopharyngeal openings. Unlike with videofluoroscopy, you can also see the nasal surface of the velum and see evidence of an occult submucous cleft. The contribution of the adenoid pad or even irregular adenoids can be seen. Finally, this procedure allows the examiner to see the results of secondary surgery (pharyngeal flap, sphincter pharyngoplasty, etc.). This is done with excellent resolution and no radiation. It can be done for children as young as three with nasal spray and numbing medicine. Because of its ease of use, high resolution, and ability to see the entire sphincter, most centers now rely on nasopharyngoscopy as the primary or only evaluation method for velopharyngeal function.
Dr. Kummer is Senior Director of the Speech Pathology Department at Cincinnati Children's and Professor of Clinical Pediatrics at the University of Cincinnati Medical Center. She is the current Coordinator of ASHA's Division 5: Speech Science and Orofacial Anomalies and is an active member of the American Cleft Palate-Craniofacial Association. She does many lectures and seminars on a national and international level. She is the author of many professional articles and 11 book chapters. She is also the author of the text entitled Cleft Palate and Craniofacial Anomalies: The Effects on Speech and Resonance, Thomson Delmar Learning, 2001. She is an ASHA Fellow.