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Office Based Direct Videolaryngoscopy Using
a Zero Degree 4 mm Sinuscope

Authors:  Dr. Mubarak M Khan*, Dr. Sapna R. Parab** 
*Associate Professor, **Assistant Professor

Institution: Department Of Otorhinolaryngology, M.I.M.E.R. Medical College, Pune, India

Corresponding Author: 

Dr. Mubarak M Khan
Dept. Of Otorhinolaryngology, M.I.M.E.R. Medical College, Pune, INDIA –410507

Email: drmubarakkhan@yahoo.co.in , ent.khan@gmail.com

Abstract:

The authors describe an innovative office based procedure for direct visualization of the larynx with zero (0) degree 4 mm sinuscope.  It allows visualization of hidden areas of the larynx and hence overcomes the difficulties encountered with indirect mirror as well as rigid 70 and 90 degree laryngoscopic examination.

Aim:  To prove the efficacy and to assess the practical use of a zero degree 4 mm sinuscope in direct videolaryngoscopy for examining laryngopharyngeal disorders at Ear Nose Throat (ENT) Out Patient Department (OPD) level and documentation of these results.

Study Design:  Prospective analysis of direct videolaryngoscopies using zero degree 4 mm sinuscope (Karl Storz, Germany) performed at M.I.M.E.R. Medical College and Sushrut ENT Hospital, Talegaon-D, Pune, India, during the period of May 2008 to December 2009.

Materials and Methods:  All patients attending ENT OPD with predominant complaints of change of voice and foreign body sensation in throat were subjected for Direct Videolaryngoscopy by zero degree 4 mm Sinuscope.
955 patients were examined with our innovative technique.

Results:  The data of all patients has been analyzed and tabulated.  The success percentage of our technique in examining laryngopharyngeal disorders was found to be 98.01%

Conclusion:  Our technique is extremely useful for direct visualization of the larynx and pharynx and has been used as a routine office based procedure in our practice.  With further study, we believe that this technique will form the basis for further development of office based contact laryngoscopy and endoscopic laryngeal surgery.

 
Introduction:

Man’s curiosity to visualize the larynx dates back to before Garcia’s contribution to the field of laryngoscopy.  Benjamin Guy Babington, Ludwig Turck, Johann Czermak, Morell Mackenzie, Hans Kuhn, Robert Miller, Robert Macintosh, Adolf Kussmaul have all significantly contributed to laryngoscopy.1-4  

In 1890s, working with a tubed esophagoscope modified from a urethroscope, Kirstein noted that if the scope intended for the esophagus accidentally slipped into the larynx and trachea, an excellent view could be obtained.  Therefore, in 1895, Kirstein began developing a reproducible method to view the larynx directly.  Initially, Kirstein used a 25 cm tubed esophagoscope with the upper incisors serving as a fulcrum.  This allowed Kirstein to displace the base of the tongue and epiglottis anteriorly with the tip of the scope.  Kirstein’s practice of direct laryngoscopy was termed “Autoscopy.”   Historical accounts depict Kirstein performing “autoscopy” from in front of the patient with the patient leaning forward and from behind the patient with the neck flexed on the chest and the atlanto-occipital joint extended.  What is important is that Kirstein recognized that extreme extension of the neck was not required for the procedure and he reported that “the body must be placed in such a position that an imaginary continuation of laryngotracheal tube would fall within the opening of the mouth…"5

The telescopic rod lens system of the British optical physicist H.H. Hopkins of Reading University has been applied to endoscopy.  The greater magnification, depth and breadth of field are enhanced for detailed observation.  These telescopes have also been modified to view structures at various angles, i.e., 30, 70, 90,120 degree.5

Major contributions to the documentation and teaching of bronchoesophagology were made by Holinger with the Holinger-Brubaker camera.  This equipment provided unprecedented preoperative and post operative documentation.5  More recently compact robust high resolution digital video cameras permit simultaneous viewing by both the surgeon and patient.  Images can be captured and replayed, providing a highly useful technique for teaching and documentation.6

Indirect visualization of larynx in the out patient department can also be performed with 90 or 70 degree rigid laryngoscope.  These scopes have almost entirely replaced indirect mirror laryngoscopy.  Although excellent images are obtained using the 90 and 70 degree rigid laryngoscopes, they poses the same disadvantages as those encountered in indirect mirror laryngoscopy.

Kirstein’s experience with direct laryngoscopy made us to conceive the idea of rigid Videolaryngoscopy using a 0 degree 4 mm sinuscope.  In a study comparing rigid to mirror laryngoscopy, patients were found to tolerance the rigid rod lens significantly better than that of an indirect mirror(83% / 52%).7

We describe our technique of direct Vdeolaryngoscopy with a 0 degree 4 mm sinuscope.  Computerized video capture programs allow recording and documentation with high quality video i.e. MPEG2 at an affordable cost.

Hence the aim of this study is to prove the efficacy of using a zero degree 4 mm sinuscope in videolaryngoscopy for imaging larynx as an office based procedure.  Internet search with above key words in pubmed, MEDLINE, Medscape and Google scholar did not give the relevant results.  Hence we find it to be a unique technique.

Methods:

A total of 955 patients presenting to the ENT OPD of MIMER Medical College and Sushrut ENT Hospital, Talegaon-D, Pune, India.  The patients underwent Videolaryngoscopy using zero degree 4 mm sinuscope during May 2008 to December 2009. However, in 15 patients Videolaryngoscopy was abandoned due to hyperactive gag reflex, of which 6 patients allowed the Videolaryngoscopy the next day after proper counseling.  The remaining 9 patients did not follow-up for the repeat procedure.  In 10 patients, the Videolaryngoscopy was incomplete due to oral submucous fibrosis causing trismus.  These patients presented with symptoms of change of voice, cough, foreign body sensation in throat, heartburn and stridor.  Hence the number of patients examined successfully with our technique of Videolaryngoscopy was 936 out of 955.  The patients ranged from 11 to 68 years of age.  A detailed history was taken in all patients with special reference to drug allergy, gastritis, addictions like smoking and alcohol intake and past history of operative procedures and intubations.

All patients were verbally informed and explained about the procedure of videolaryngoscopy using a zero degree 4 mm sinuscope.  Written consent was obtained in all patients.

Procedure Of Videolaryngoscopy by zero degree 4 mm sinuscope, Pre requisites:

Video Laryngoscopy ProcedureOur technique of Videolaryngoscopy with 0 degree 4mm sinuscope is an ENT office procedure.  The patient is explained in detail about the procedure. The patient is made to sit comfortably on chair. ( same position as for routine ENT check up).  The base of tongue, posterior pharyngeal wall and inlet of larynx are anaesthetized with 10% lidocaine spray as done in flexible oesophagoscopy to prevent the gag reflex. Zero degree 4 mm sinuscope is connected to the light source and endoscopic camera so as to visualize the larynx and laryngopharynx on a TV monitor.  Subsequent recording of cases is done digitally in MPEG2 format. (Figure 1 - Picture to right)

The ENT surgeon stands in front of the patient. The patient's head is extended posteriorly over the neck so that the axis of the oral cavity and laryngeal will align and come into one plane.  With the help of a sterilized piece of gauze, the tongue is gently pulled outward and held with the surgeon's left hand.  The zero degree 4 mm sinuscope is held with the right hand and now advanced into the oral cavity along the left angle of mouth, using the upper left second molar as a fulcrum.  This avoids undue strain on the rod lens system of the sinuscope unlike the pressure when using the incisora as a fulcrum.  In addition, the decrease in working distance obtained by directing the sinuscope through the angle of the mouth gives direct view of the epiglottis (Figure 2).  Without touching anterior one third of the tongue, the endoscope is progressed inwards toward the base of tongue. Once the posterior pharyngeal wall is visualized, the head of the patient is tilted backwards and the sinuscope is given a downward inclination.  This allows the visualization of the epiglottis and laryngeal inlet (Figure 3).  The sinuscope further advanced downwards by displacing the epiglottis anteriorly with the scope's tip (Figure 4).

Eppiglottis Inlet of Larynx Beyond Epiglottis
Figure 2 Epiglottis Figure 3:  Inlet of Larynx Figure 4:  Beyond Epiglottis

This technique allows visualization of the false vocal cords, true vocal cords, anterior commissure, arytenoids, aryepiglottic folds and pyriform fossae (Figure 5).  The vocal cord mobility is assessed by asking the patient to say “ee” as in indirect mirror laryngoscopy (Figure 6).  The pyriform fossae can be visualized for any pathology by directing the tip of sinuscope on both sides (Figure 7).

Vocal Cords Phonation of 'ee' Left Pyriform Fossa
Figure 5:  Vocal Cords Figure 6:  Phonation of 'ee' Figure 7:  Left Pyriform Fossa

Vew of the hidden areas of the larynx like ventricle (Figure 8) and subglottis (Figure 9) can be obtained with good surface anesthesia of the true and false vocal cords.   Pediatric larynx can also be assessed in cooperative children (Figure 10).

Right Ventricle Subglottis Pediatric Layrnx
Figure 8:  Right Ventricle Figure 9:  Phonation of 'ee' Figure 10:  Pediatric Larynx

At the end of the procedure, the patient is advised to avoid liquids for 30 minutes due to loss of the gag reflex.  The whole procedure takes less than 10 minutes.  If an endoscopic camera is not available, then the larynx can be visualized by directly looking into the sinuscope.

Precautions:

Results

Our observations and diagnoses in 936 patients who underwent videolaryngoscopic examination with a zero degree sinuscope from May 2008 to December 2009 are tabulated and shown below.  The peak incidence of laryngeal disease was between 31 to 50 years of age.   Acute laryngitis, Puberphonia, Leukoplakia and Laryngeal Cancer was found to be more common in males.  Globus Pharyngis, Laryngopharngeal Reflux and Vocal Cord Nodules were found to be more common in females.  

Table 1:  Gender Distribution of Laryngeal Diisease

Table 2:  Age Gender Distribution of Laryngeal Disease 

Table 3:  Age Distribution of Laryngeal Disease 

Discussion:

Indirect laryngoscopy is an inexpensivet useful diagnostic office procedure but has pitfalls of often being unable to allow visualization of hidden areas of larynx, such as the anterior commissure, postero-inferior part of epiglottis, deep part of pyriform fossa, ventricle and subglottis.  It is not possible to prefrom in children and persons with hyperactive gag reflex.  Above all it is an indirect laryngeal visualization.

A zero degree 4mm sinuscope is available with every ENT surgeon for nasal endoscopy and functional endoscopic sinus surgery.  This zero degree 4 mm sinuscope can be used for direct laryngeal examination with little practice.  A digital recording facility allows for documentation and aids in ressident teaching.  Our technique of Videolaryngoscopy with a zero degree 4 mm sinuscope provided a direct visualization of the larynx and overcame the disadvantages of mirror laryngoscopy in out patient settings.

The total number of patients examined with our technique of Direct Videolaryngoscopy with a zero degree 4 mm sinuscope was 955.  However, in 15 patients Videolaryngoscopy was abandoned due to hyperactive gag reflex, of which 6 patients allowed the Videolaryngoscopy the next day after proper counseling, and the remaining 9 patients did not follow-up for the repeat procedure.  In 10 patients, the Videolaryngoscopy was incomplete due to oral submucous fibrosis causing trismus. Hence the number of patients examined successfully with our technique of Videolaryngoscopy was 936 out of 955.  The success percentage of our technique is 98.01%.

The patients ranged from 11 to 68 years of age.  Our youngest patient was 11 years of age and oldest was 68 years of age.  Most of our patients belonged to the 31 to 50 years age group (481 patients).  Our study group included 531 males and 405 females.  Office based laryngopharyngeal procedures such as removal of a fishbone and biopsies were done with an assistant holding the patient’s tongue and the surgeon holding the sinuscope in his left hand and a laryngeal forceps in the right hand.

The end on, direct visualization of all aspects of the endolarynx with a zero degree 4 mm sinuscope is definitely an advantage over a 70 and 90 degree rigid fiberoptic laryngoscope.  We believe that such direct and immediate contact of the tip of the sinuscope with the mucosa of larynx and pharynx in the out patient department could definitely form the basis for contact laryngoscopy as an office based procedure.  

The technique of direct visualization of the larynx, although technically difficult compared to using a 90 degree rigid laryngoscope, can be quickly mastered by the otolaryngologists.  It is not only a cost effective office procedure which allows direct visualization of larynx exploring hidden areas but is also a useful teaching aid and allows for documentation of the procedure with video recordings.

Advantages of our technique of direct videolaryngoscopy using zero degree sinuscope:

Over all, it is an extremely useful yet a simple office based procedure for laryngopharyngeal examination.  We have used 0 degree 4 mm sinuscope as a new tool in assessment of larynx.  We are stressing the extra future advantages which are possible with 0 degree 4 mm sinuscope.

Disadvantages:

Examples of Laryngeal Pathology:

Right Vocal Cord Polyp Vocal Cord Nodule Right Vocal Cord Palsy
Right Vocal Cord Polyp Vocal Cord Nodules Right Vocal Cord Palsy
     
Leukoplakia Phonation-gap Left Arytenoid Subluxation
Right Vocal Cord Leukoplakia Phonation Gap Left Arytenoid Subluxation
     
Post Cricoid Laryngeal Cancer  Left Vocal Cord Cancer Cancer of the Larynx and Pharynx 
Cancer of the Supraglottic and Post Cricoid Area Left Vocal Cord Carcinoma Laryngopharyngeal Cancer
     
Radiation Edema  Hematoma of Larynx  Fishbone of Larynx 
Radiation Edema  Hematoma of Larynx  Fish Bone in Hypopharynx 

Conclusion:

Videolaryngoscopy with a 0 degree 4 mm sinuscope is extremely cost effective, innovative and simple office based procedure to examine the various pathological conditions of larynx and laryngopharynx.  We think, in near future this technique could form basis for office based contact laryngoscopy and endoscopic laryngeal surgery with further study.  This procedure has replaced the traditional indirect mirror laryngoscopy and 70 and 90 degree rigid laryngoscopic examination in our ENT OPD setting.

 
References:

1)  Bailey B. Laryngoscopy and laryngoscopes- who’s first : The forefathers of
Laryngology. Laryngoscope 1996, 106 : 939-943.  View Abstract

2)  Bailey BJ. What's all the fuss about?: The Laryngoscope pages cause an international incident. Laryngoscope. 1996 Aug;106(8):925-7.  View Abstract

3)  Alberti PW. The history of laryngology: a centennial celebration. Otolaryngol Head Neck Surg. 1996 Mar;114(3):345-54.  View Abstract

4)  Weir N.  Otolaryngology: An illustrated history. London: Butterworth and
co.Ltd, 1990.

5) now JB, Wackym PA. Larynngoscopy.  Ballenger′s Otorhinolaryngology, Head and Neck surgery,  Seventeenth Edition, BC Decker Inc.  2009, 83:955-962 

6)  Kaplan MB, Ward DS, Berci G. A new video laryngoscope-an aid to intubation and teaching. J Clin Anesth. 2002 Dec;14(8):620-6.  View Abstract

7)  Barker M, Dort JC. Laryngeal examination: a comparison of mirror examination with a rigid lens system. J Otolaryngol. 1991 Apr;20(2):100-3.  View Abstract

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World Articles in Ear, Nose and Throat  www.waent.org                 Mar. 11, 2011              Vol 4-1

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