Visual Physical Examination

There are five essential components to the physical examination of the larynx.

1. Endoscopes to view the voice box around the corners of the nose and mouth.
   • Rigid laryngoscopy
   • Flexible laryngoscopy
2. Anesthesia to prevent gagging, sneezing, discomfort and obtain an ultra close view of the vocal folds.
   • Anesthesia for rigid endoscopy
   • Anesthesia for flexible endoscopy
3. Video camera to record the voice box
4. Lighting various lights show different details.
5. Video tape recorder a method to review the motion and structure of the vocal folds in high detail.

Rigid laryngoscopy

Anesthesia

Topical anesthesia such as lidocaine may be sprayed onto the soft palate, posterior pharynx and base of tongue. Some people can be examined without anesthesia, athough many cannot. I prefer a longer, more thorough exam, rather than a brief glimpse.

Instrumentation

Both 70 and 90 degree scopes are available. Though they can be looked through directly, an attached videocamera adds immeasurably to the information that can be obtained. Rigid scopes provide a clear, detailed view. Since the improvement of flexible endoscope optics recently (2003), I use the rigid scopes less. Their strong point is that holding the tongue out during the exam provides a wide open view of the laryngeal introitus and it is a clear and detailed view. When I suspect a surface lesion of the larynx, I find it useful. Photos and videos samples comparing rigid and flexible exams are available.

Flexible laryngoscopy

Anesthesia

Topical 4% lidocaine with a vasoconstrictor (oxymetazolone or phenylephrine) is sprayed into the nares. An oral topical anesthetic such as 4% lidocaine is sprayed onto the soft palate, posterior pharynx and base of tongue. Yes again, some people can be examined without anesthesia. See examples of a normal female during a flexible exam.

If close inspection of the larynx is anticipated 4% topical lidocaine may be dripped onto the epiglottis and laryngeal introitus. This is often done under direct visualization with the rigid endoscope to be sure the entire surface of the larynx is covered. Typically, the anesthetic is dripped into the larynx in several aliquots since the first drops cause significant gagging. A curved cannula such as the Abraham cannula is utilized to direct the anesthetic. The other option is to drip without visualizing the larynx and listen for the laryngeal gargle, the gargle sound produced when liquid is sitting on the phonating vocal folds.

Alternative methods include injecting (25 gauge needle) via the trans-cricothyroid membrane into the trachea. The needle is angled slightly downward and syringe aspirated to assure intraluminal placement. The ensuing cough blankets the larynx with topical anesthesia.

Patients with tracheostomy tubes may be anesthetized by placing a folded sponge over the tube and injecting through the sponge with a needle. Holding the hub of the syringe against the sponge not only spares the examiner a shower but directs the cough and anesthetic up through the larynx.

All of these methods allow for intimate inspection of the vocal cords and below the vocal cords.

Instrumentation

Flexible fiberoptic laryngoscopy used to provide (prior to 2003 for me, I used an Olympus ENF L-3.) less clarity than a rigid scope and in many cases a flexible endoscope might still remains complementary to the rigid exam, providing additional information. In 2003 however, I purchased a Pentax “Chip on the Tip” camera - a Pentax videoendoscope VNL-1170K connected to an EPK-1000 camera. It provides a great deal of additional functional information and spectacular, additional anatomic detail. You may compare photos with the various endoscopes below and on the normal vocal cord photos.

Below is a comparison in a single individual. It is not a perfect comparison as there are many variables. The picture on the left is taken with the Pentax chip camera and even though there was a little mucous on the scope, the photo is still quite clear. On the right, the photo was taken from a slightly different position, camera software smoothed the image to hide the pixelation, but the view is not as clear.

Chip scope camera	Fiberoptic scope
		Patient with leukoplakia and dysplasia

Olympus also produces a "chip scope", but it is not a full screen image, so I feel the Pentax is the superior endoscope camera combination. The Pentax scope is so good, that I no longer use the fiberoptic scope in the office and I am even using my rigid scope less often. I really only use a fiberoptic scope if that is the only device available, such as in some hospitals.

Types of anatomy and function seen with the flexible scope not available with rigid scope

• Palate closure
• Panoramic functional view of pharynx
• Swallowing evaluation
• Detailed view of anterior commissure even when epiglottis is overhanging
• Detailed view of anterior larynx when larynx is topically anesthetized and the flexible scope is placed in the posterior larynx and angled directly anteriorly.
• Laryngeal ventricles
• Subglottic view
• Tracheal view
• Mainstem bronchi view
• Transtracheal view of subglottis when tracheostome present.

Tip: If false folds are obstructing the view, have the patient perform inspiratory phonation - then it is almost impossible to constrict the supraglottis.

Video camera

I love my zoom lens camera for the rigid and the fiberoptic scopes, the Karl Storz telecam SL which is very helpful when looking for small lesions. Though adapters can be put on almost any camera, the very small medical cameras with the D-adapter common to so many medical endoscopes are easily held in one hand and provide exquisite detail and color. The zoom feature is particularly helpful for small lesions when using the rigid endoscope and even more helpful with the flexible scope. The flexible scope is smaller in diameter to fit through the nose rather than the mouth and this can present a very small image on the video monitor.

I mentioned the Pentax camera EPK-1000 which mates directly with their "chip scopes".

Light

Constant: Xenon light is my preferred light, but Halogen can be used. Both can usually be color balanced by the video recorder, but if not, different degrees of redness will be seen. Because the light is a constant illumination the vocal fold edges will be sharp during breathing but blurred during phonation. That is because typical video devices record at about 30 frames per second while the vocal folds during speech vibrate at about 100 cycles per second in men and about 200 cycles per second in women. The video cannot capture information that quickly. Then if someone is singing, vibrations can easily top 1000 cycles per second.

Strobe: Various devices have been devised to capture the motion of the vocal folds. Stroboscopy utilizes a technique or slight of hand to give the appearance of slow motion. Two methods are utilized. These special devices may flashes a light or shutter the camera at about 2 cycles per second different than the pitch of the voice. Therefore, it has a microphone to determine the pitch of the voice which triggers the light. This shuttering causes the video recording to appear to be in slow motion. While this apparent slow motion misses some information that an ultra high speed recording might catch, it does add significant detail to the visual examination of the vocal cords. I use and prefer the Kay Elemetrics strobe light. There are other alternatives, that at this point are not as refined as the Kay light, though perhaps less expensive.

High speed recording: High speed film has been utilized though it is very expensive. There are now digital video capture boards that can briefly capture high frame rates. See Kay Elemetrics. top

Video recording

This key component can be any type of tape recording. I have used VHS, S-VHS and betacam in the past. Currently I use and like the Sony DVCAM. This is a digital recording tape that runs at a higher speed than the consumer version miniDV, though the resolution is the same. I use the DSR-30 tape deck because it has a jog-shuttle which I find essential to review motion, especially ABduction and ADduction. Vocal movement is so fast that I usually get 2 to 4 frames of the motion at the video recorders rate of 29 frames per second. The DSR tape deck also has a firewire output that can dump the video directly to a computer (my Apple Mac’s all come with Firewire) which is how all the video, audio and photos were obtained for this web site. Without a recording of some type, the human eye misses too much essential information.