Tonsillectomy Mouth Gag-Assisted (McIvor) Fiberoptic

IntubationJames C. DuCanto, M.D.

Introduction

• A discussion of a new technique to assist fiberoptic intubation in the anesthetized patient

• This technique is an alternative to the “tongue hold” and “jaw thrust” commonly employed during fiberoptic intubation in an anesthetized patient

What is a McIvor Mouth Gag?

• An Instrument designed for creating oral and upper pharyngeal space, as well as for stabilization of patient’s head during tonsillectomy– Created by Dr McIvor to reduce incidence of

dental injury during tonsillectomy• Device stabilizes self on hard palate behind upper 2

incisors

My Inspiration for Use of the McIvor

• Concepts of Drs. Hsiu-chin Chou and Tzu-lang Wu (Inventor of the Wu-scope)– Mobility of the oral axis

and pharyngeal axis as well as the amount of space that can be created by a laryngoscope determine the ease of intubation by direct laryngoscopy

Limited mobility and limited space?

– Use an intubation technique that overcomes the problems of limited mobility

• A fiberoptic bronchoscope can see around corners

– Use an intubation technique that overcomes the problems of limited space

• A tonsil mouth gag opens the mouth and pharynx at the base of the tongue (well enough that the patient’s epiglottis is often visible once it is properly deployed)

Dr Wu’s solution to the problem of mobility and space

• Tubular blade that creates space, while the integral fiberoptic scope solves the problem of mobility

• 110 degree embodiment of the handle and blade. Fiber optic imaging and oral airway-shaped blade.

Our Solution to the problem of Mobility and Space

• Use our fiberoptic bronchoscope with a McIvor mouth gag

So what’s so great about the McIvor?

• It was designed as a tool to prevent dental injury during tonsillectomy and to facilitate the exposure of tonsils (structures at the back of the soft palate)– Device is deployed behind the front incisors

• Every hospital already has one!• Easy to use (with some practice)• It is a technique that uses direct visualization

during intubation

“Ethos” of direct visualization versus blind techniques

• Blind techniques are less favorable due to their lack of certainty that the airway has been secured properly

• Anesthesiologists generally agree that direct visualization of the vocal cords during intubation is the most favorable circumstance under which to perform an intubation

How do we prove this tool is useful?

• Let’s study it compared to the technique that is the most effective known technique for fiberoptic intubation (the “tongue hold”, (TH) and “jaw thrust” (JT)– Laryngoscopic view of TH and JT obtained on

anesthetized patient, then McIvor deployed, same information collected, intubation performed and rated for ease and speed

– Patient serves as their own control!

Larnygoscopic View

Clinical Example

• Morbidly Obese patient for laparoscopic surgery– 5’7”, 298 #– Mallampati 3– Prominent Teeth

• Easy fiberoptic intubation with McIvor!

How does this technique compare to the Fast-track (Intubating

LMA)?• Once again, this is a technique that uses

direct visualization--the Fast-track uses a blind technique for intubation– Fiberoptic intubation through the fast-track is

possible, but not by any means easy• Fiberoptic scopes 5 mm or larger in diameter are

required to lift aperture bar, occasionally elevation of the aperture bar is not possible even with these larger bronchoscopes

Our ultimate goal

• Have the McIvor recognized as a useful tool in the ASA Difficult Airway Algorithm (if we find it to be really useful, which I think we shall).