Authors describe the technique of office based rigid video laryngoscopy with 0° endoscope and compare with technique of 70° 4 mm videolaryngoscopy. (1) To compare and assess the efficacy of techniques of 0° and 70° office based video laryngoscopy for examining laryngopharyngeal disorders at Ear Nose Throat (ENT) Out Patient Department level. (2) To assess whether the degree of angle of the rigid endoscope makes any difference in the visualisation in videolaryngoscopy. Prospective non randomised double blinded study of direct videolaryngoscopies using 0° and 70° 4 mm rigid endoscope (Karl Storz, Germany) done at M.I.M.E.R. Medical College and Sushrut ENT Hospital, Talegaon-D, Pune, India, during the period of October to February . Patients with predominant complaints of change of voice and foreign body sensation in throat were subjected for Videolaryngoscopy by 0° and 70° 4 mm Endoscope. 375 patients were examined with both the techniques. After the end of the procedure, the patient preference or discomfort with any of the techniques was enquired. The unlabelled endoscopic recording of both techniques was visualised by the second author to compare and evaluate the 0° videolaryngoscopy with 70° in terms of extent of visualisation. The time taken for each technique was recorded. The data of all patients has been analysed in terms of patient and surgeon grading. On statistical analysis, both the techniques with 0° as well as 70° rigid endoscope videolaryngoscopy were found to be comparable. Our study concludes that both the endoscopes are equally efficient in comparable laryngeal visualization. Hence, the degree of angulation of the rigid endoscope makes no difference in videolaryngoscopy. With little practice, 0° videolaryngoscopy may be extended for routine use in laryngological examination.
Level of Evidence Level 4.
Keywords:
Laryngoscopy, 0°, 70° endoscope, Office procedure
Laryngoscopy or examination of the larynx is an essential part of the otolaryngologic examination. The 19th-century voice teacher Manuel Garcia was probably among the first to perform laryngoscopy in vivo [1]. Since introduction, the technique of indirect mirror laryngoscopy has been superseded by technologies that allow better visualization of the laryngeal structures through improved image resolution, improved light transfer, and greater patient comfort [2]. The first physician to directly visualise the larynx was the Berlin Laryngologist, Tobold [3, 4]. In the modern era of the endoscopy, the collaboration of Karl Storz and Harold Hopkins and the resulting in Hopkins rod telescope is a mainstay of otolaryngologic endoscopy. Indirect endoscopy through the rod-lens system provides not only excellent visualization but also stability of the light transmission system. In combination with 70 or 90 prisms, peroral laryngeal observations can be made in most patients [2].
Since last one decade, the senior author has been using the 0° rigid endoscope for laryngopharyngeal examination at office level as it gives end on direct visualisation of larynx and allows to look into the nooks and corners of larynx [5]. It is our opinion that the technique of 0° videolaryngoscopy is a useful technique for laryngeal examination with few additional advantages over 70°. This study was thus carried out to compare techniques of office based rigid video laryngoscopy with 0° and 70° endoscopes.
This study evaluates the videolaryngoscopy in 375 patients with 0° and 70° endoscopes in terms of the patient comfort, duration and the structures visualised. The completeness of the two techniques is assessed by viewing of the recordings of the two procedures by the second author. It was graded from 1 to 10 and was statistically analysed. The patient evaluation of the techniques was in terms of discomfort of the two procedures and their preference for any of the procedures. This was graded out of 10 for each of the procedure by the patient, 10 being the best and 0 being the least comfortable. This was documented and was statistically analysed.
The discomfort with the 0° and 70° videolaryngoscopy was experienced in 16 and 11 out of 375 which is 4.27 and 2.93% respectively. The mean scores of satisfaction with the 0° and 70° videolaryngoscopies was 7.36&#;±&#;0.13 and 8.01&#;±&#;0.49 respectively. The mean scores of the evaluation of the 2 techniques depending on the extent of the structures visualised was 8.89&#;±&#;0.23 and 9.02&#;±&#;0.14 respectively. With the exception of 2 patients with oral submucous fibrosis, in whom the 70° videolaryngoscopy fared better than 0°, the overall performance of 0° was comparable to the 70° videolaryngoscopy.
The mean time taken for the 0° and 70° videolaryngoscopy was 37.24&#;±&#;1.28 and 29.31&#;±&#;1.01 s respectively. On statistical analysis, there was no significant difference in the patient satisfaction level, laryngeal structures visualisation and time taken (p&#;<&#;0.001). Hence the two techniques are comparable in the parameters evaluated.
Laryngoscopy or laryngopharyngeal endoscopy can be performed with direct, rigid instrumentation or indirect instrumentation. Office-based laryngology is principally concerned with indirect laryngoscopy. Indirect endoscopy involves using mirrors, prisms, fiberoptic rods, or miniature chip cameras to bend or reflect the image of the pharynx and larynx back to the surgeon&#;s eye. Direct endoscopy, in contrast, is currently most commonly performed in the operating room under general anaesthesia. Indirect laryngoscopy allows the patient to maintain a relatively comfortable position while the examiner views the larynx and pharynx. This allows observations and procedures to be performed without general anaesthesia, and thus allows dynamic assessment of larynx and pharynx [2].
This is the first study to demonstrate the use of 0° office based laryngoscopy and compare with 70° videolaryngoscopy. We have been practicing this art of videolaryngoscopy since (last 13 years). Our previous non comparative study has been published [5]. Our technique of 0° videolaryngoscopy is an innovative one and in this study we attempt to demonstrate that in a single attempt examination of the larynx with a 4 mm zero endoscope with video monitoring was comparable to 70° in comfort, patient preference, and degree of laryngeal visualization.
The advantages of the 0° videolaryngoscopy [5]:
All the structures of the larynx are visualised with greater details as the endoscope can be kept very close to the structures without any trauma to the mucosal surfaces.
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Ventricle, subglottis, anterior commissure and tracheal rings are better seen. Hence the associated pathologies can be appreciated with greater precision.
In depth, close end on view of each and every structure with 70°, all structures seen in one view.
As the structures can be visualised from near, can form the basis of contact endoscopy at office level.
Can be used for office based procedures: foreign body removal and biopsy with the endoscope in the non- dominant hand and the laryngeal forceps in the dominant hand and the patient grasping his tongue with sterilised gauze piece.
It is very economical technique as the 0° endoscope is available with every otolaryngologist and is used in routine nasal and ear endoscopy.
The videolaryngoscopic recording can be used for future comparison, documentation, and to share the visualization in cases of referral and is a very good teaching aid.
The other methods of videolaryngoscopies with 90° and 30° rigid endoscopes have been reported [6, 7]. The study by Barker and Dort with a 10 mm, 90° rigid endoscope in reported a success rate of 83% in topically anesthetized larynx compared to 52% success with laryngeal mirror examination [6]. Barker and Dort [6] recommended that VRLE be utilized in all university teaching programs. They noted that video documentation improves post treatment follow up, but that there was no proof that its routine use improved patient treatment. Whereas, Dunklebarger, has reported, success rate of 83.7% with 30° rigid videolaryngoscopy [7].
At present, the Voice Subspecialty in most of the institutions utilize video archiving of all laryngeal examinations with either rigid endoscopy, utilizing primarily the 10-mm 90 endoscope or video flexible fiberoptic laryngoscopy or both, frequently complemented with stroboscopic evaluation [6].
In this non randomised double blinded study, we attempt to demonstrate the use of 0° videolaryngoscopy at office setup. Our study concludes that both the endoscopes were equally efficient in comparable laryngeal visualization. Though, learning the technique of 0° videolaryngoscopy requires effort, but definitely can be mastered with practice as any other art in clinical medicine. Hence it is evident that the degree of angulation of the rigid endoscope makes no difference in videolaryngoscopy. With little practice, 0° videolaryngoscopy use may be extended for routine use in the Out Patient Department. We believe that this technique may form the basis for further development of office based contact laryngoscopy and endoscopic laryngeal surgery with further study.
Conflict of interest
The authors declare that they have no conflict of interest.
We developed and tested a new, angled rigid endoscope as a tool for performing continuous visual monitoring during microsurgery. The shaft of the scope is angled 110 degrees at its midportion using a prism. We used the scope continuously in 30 cases including 15 pituitary tumours, 7 brain tumours, 7 cerebral aneurysms, and one hemifacial spasm. For pituitary tumours the tip of the scope was positioned in the sphenoid sinus or in the cavity formed by tumour removal; for cerebral aneurysms it was placed behind the parent artery or the aneurysmal neck. Image quality was acceptable for intraoperative monitoring. In no case did the neuroendoscope have a deleterious impact on th e proper function of the microscope or surgical instruments. This angled rigid scope was more effective for intraoperative monitoring than conventional straight scopes.