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How to View the Supraglottic Structures

Gustav Killian, who created suspension laryngoscopy, prepares a bronchoscopy in this historic photo. Photo Repro, Universität Freiburg, Germany.

My wife really doesn’t enjoy going to historical sites with me. I’m one of those guys who reads every word and looks at every artifact. I could spend an hour at just one display. Combine my interest in history with my passion for airway management and writing this article was inevitable.

I’ve heard it said that tradition is the reason we use to explain a technique when we’ve forgotten the original rationale. History gives a view of our origins and an explanation of why we do the things we do. In regard to laryngoscopy, I’ve found that little has changed in centuries.

Indirect Laryngoscopy: Sun & Mirrors
Indirect viewing of the supraglottic structures has been described since the mid 18th century. And while it isn’t specifically documented, laryngoscopy with mirrors has likely existed since the first century A.D. The use of dental mirrors to examine the oral cavity was mentioned by Celsus at the end of the first century B.C., and such instruments were found in the remains of Pompeii, which was destroyed in 79 A.D.(1,2) In 1743, French obstetrician Andre Levret described using a variety of oral inspection devices.(3) Philipp Bozzini invented an endoscope of sorts, a series of tubes connected to a small candle lantern. He developed the device in 1804 and used it to inspect bodily openings. In 1807, he published a description of his device and his works, but the Vienna Faculty of Medicine effectively quashed his work by saying, “Only very small and unimportant parts of the body could be examined.”(4)

Benjamin G. Babington, a physician and epidemiologist, is generally regarded as the inventor of the laryngoscope because a description of the device was published in March 1829.(5,6) With the patient’s back to the sun, a hand mirror directed sunlight on to a modified dental mirror, which reflected light onto the supraglottic structures. A down-turned metal tongue depressor was attached to the dental mirror with a spring to displace the tongue and help create a larger viewing area.(7)

Over the next 25 years, a number of European physicians experimented with a variety of mirror devices to observe the supraglottic area, but it took a Spanish singer to truly exploit indirect laryngoscopy. Intrigued by the singing voice, Manual Garcia made extensive records on his observations of the laryngeal structures and their movements to produce sound. He presented Physiological Observations on the Human Voice to the Royal Society of London in 1854 and was eventually awarded an honorary degree in medicine.(8)

If you accept that early Romans used dental mirrors, practitioners used indirect laryngoscopy to look around the tongue for more than 1,800 years. Although advancements were made in technique, the basics never changed. Today’s video laryngoscopy uses a similar technique to view around the anatomy with a camera, monitor and lights rather than mirrors and sunlight.

The Next Step: Direct Laryngoscopy
Indirect laryngoscopy provided reasonable observation, but substantial diagnostic and surgical constraints remained. With advances in anesthesia, patients better tolerated instruments placed in their hypopharynx, and this paved the way for exploitation of direct laryngoscopy.

Adelbert von Tobold is credited with the first direct visualization of the larynx in 1864 using a tongue depressor and mirror for illumination.(9) His technique was repeated by various practitioners who all sought to improve the view. Just as today, airway pioneers were beset with the problems of displacing the anatomy and adequate illumination.(10,11) To this day, almost every development in direct laryngoscopy equipment and technique has been directed at overcoming these two adversities.

Early techniques consisted of using a tongue spatula (depressor) to displace the tongue and a handheld mirror to focus light into the patient’s mouth. Head-mounted mirrors soon replaced the handheld mirrors, and light sources ranged from sunlight to gas or electric lights. In some cases, physicians used carbide miners lamps to provide illumination. This open-flame light source was short-lived due to several untoward incidents involving newly developed, highly flammable inhaled anesthetic agents.

At the turn of the 20th century, a viewing tube replaced the flattened spoon-shaped tongue depressors. Imagine a hollow wooden or metal tube with an L-shaped handle at the proximal end. In most cases, the patient sat facing the physician. The practitioner inserted the tube into the patient’s mouth and pulled the handle to displace the tongue and mandible. I found a picture from 1910 that showed an attachment that applied pressure on the thyroid cartilage and displaced the larynx posteriorly as the mandible was drawn forward.(12) Hmmm, maybe external laryngeal manipulation isn’t such a new technique?

Have you ever heard of suspension laryngoscopy? I hadn’t either until I read the story about Gustav Killian’s tired arm. As the story goes, Killian took a medical artist to a cadaver lab to get drawings of the larynx in 1909. Killian inserted a laryngoscope and exposed the supraglottic anatomy for the artist. Apparently the artist was slow and Killian’s arm got tired. Being a resourceful inventor, Killian screwed metal rods to the dissection table and attached the rods to the laryngoscope suspending the cadaver’s head and maintaining a view for the artist.(13)

The next two great steps were light bulbs and batteries. These eliminated the need for mirrors and the inevitable negative interaction between open flames and flammable anesthetic agents. Bulbs on the distal tip of the laryngoscope blade enhanced illumination of the structures.

I’d like to tell you about the next great leap forward in direct laryngoscopy, but I really didn’t find any.(14,15) I offer my apologies to doctors Magill, Miller and MacIntosh. I ran a search on the U.S. Patent and Trademark Office website for “laryngoscope” and found 225 patent numbers issued for devices since 1925.(16) The vast majority of these patents had to do with blade shape or illumination; all trying to resolve the two issues that Tobold spoke of in 1864. EMS exhibit halls are filled with the new and improved. Some devices truly help; others not so much.

Look at what’s in your airway bag today. Is it really that much different than Babington’s tools? Let’s face it; we’re still using a metal stick and a light. Perhaps that’s our lot in life … or is it?

Check out a video with Charlie and Dr. Jack Pacey, the inventor of the GlideScope video laryngoscope system. They talk about how Pacey came up with the idea for the video laryngoscope and how he turned that idea into today’s GlideScope devices.

1. Celsus: Lib. vii, cap. xii, 1.
2. Manning WH: Review of ‘Roman Surgical Instruments and Other Minor Objects in the National Archaeological Museum of Naples,’ Greece & Rome (Second Series). 1996;43(2):222–223.
3. Garrison FH: An Introduction to the History of Medicine. W.B. Saunders: Philadelphia, 459, 1922.
4. Mackenzie M: Use of the Laryngoscope in Diseases of the Throat. Longmans, Green & Co.: London, 12–18, 1865.
5. Mackenzie M: Use of the Laryngoscope in Diseases of the Throat. Longmans, Green & Co.: London, 20–24, 1871.
6. Harrison D: Benjamin Guy Babington and his mirror. J Laryngol Otol. 1998;112(3):235–242.
7. Proceedings of Societies. London Medical Gazette 1829; 3: 555.
8. Jahn A & Blitzer A: A short history of laryngoscopy. Log Phon Vocol. 1996; 21:181–185.
9. Jahn A & Blitzer A: A short history of laryngoscopy. Log Phon Vocol. 1996; 21:183.
10. Tobold A. Chronic Diseases of the Larynx. W. Wood & Co: New York, 5, 1868.
11. The Practitioner: A Journal of Practical Medicine. 1896; 337:89.
12. Jahn A & Blitzer A: A short history of laryngoscopy. Log Phon Vocol. 1996; 21:184.
13. Jahn A & Blitzer A: A short history of laryngoscopy. Log Phon Vocol. 1996; 21:184.
14. Burkle CM, Zepeda FA, Bacon DR, et al: A historical perspective on the advances in laryngoscopy as a tool for the anesthesiologist. Anesthesiology. 2004;100(4):1003–1005.
15. Macintosh RR: A new laryngoscope. Lancet . 1:205, 1943.
16. United States Patent and Trademark Office. http://patft.uspto.gov/

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