2018 Section 6 - Laryngology, Voice Disorders, and Bronchoesophalogy

S INCLAIR ET AL .

TABLE 1. Key comparisons between indirect mirror laryngoscopy and flexible transnasal fiber-optic laryngoscopy.

Indirect mirror laryngoscopy

Fiber-optic nasal endoscopy

Cost (purchase, sterilization, maintenance, repair) Quality of laryngeal view

Cheap

More expensive

Highly patient dependent, can afford excellent 3D view Slow learning curve requiring regular practice to proficiency

More consistent 2D view

Examination technique difficulty

Quick learning curve, proficiency obtained at 10 scopes Can avoid inducing gag reflex in most cases

Gag initiation

Gag reflex easy to initiate especially if inexperienced

Ability to circumvent secretions

Not possible Not possible

Usually possible

Assessment of swallow

Good

Assessment of vocal cord movement

Good, EBSLN palsy difficult to diagnose

Good, EBSLN assessment easier but still often difficult to diagnose

Assessment of gross lesions

Good

Good

Abbreviation: EBSLN, external branch superior laryngeal nerve.

sitting position, leaning forward if possible. The scope is inserted into the nasal cavity and may be directed into either the inferior meatus (between the inferior nasal tur- binate and floor of nose) or middle meatus (between the inferior and middle nasal turbinates) of the nose, depend- ing on patency. Mucosal contact, especially with the septum, should be kept to a minimum in order to avoid patient discomfort. Careful anterior rhinoscopy at the onset of the examination will enable the examiner to choose the more patent nasal passage and assess feasibil- ity of the examination especially as it relates to septal deviations, which can be limiting. The novice examiner may benefit from use of a laryngeal endoscopy simulator or the performance of at least 6 supervised examinations in order to improve efficacy and patient comfort. 19 Once inserted, the examiner must note normal and abnormal findings in the nasal cavity, nasopharynx, oro- pharynx, larynx, and hypopharynx. The integrity of nor- mal anatomy should be confirmed. Pathology in any of these areas should be recorded; either still photography or

video recording may be useful adjuncts in documentation and follow-up of findings. Anatomic and physiological function should be observed. In particular, palatal elevation, dynamic tension of the vocal cords on phona- tion, laryngeal elevation with phonation and swallowing, vocal cord mobility, laryngeal penetration and aspiration, subglottic patency, and presence of lesions or masses should be noted. In patients with thyroid disease, a main objective of the examination should be to detect any ipsi- lateral laryngeal nerve dysfunction or airway invasion. 20 In the postoperative patient, if superior or RLN dysfunc- tion is identified, side of involvement, vocal fold position, and contralateral compensation should be described. Doc- umentation of laryngeal function by the flexible trans- nasal technique preoperatively will allow for comparison to postoperative function and early detection and remedia- tion of any laryngeal nerve dysfunction through voice therapy and/or operative interventions. Dysfunction of the external branch of the superior laryngeal nerve is more difficult to diagnose and may

TABLE 2. Studies comparing ability of transcutaneous laryngeal ultrasound to accurately reflect vocal cord mobility compared to flexible transnasal laryngoscopy.

Total patients undergoing transcutaneous laryngeal ultrasound

Patients with vocal cords visualized by transcutaneous laryngeal ultrasound (%) Preoperative - 196 (96) Postoperative - 193 (95)

Outcomes compared to fiber-optic nasal endoscopy

Study

Wong et al 26

204

sensitivity – 93%, specificity – 98%,

PPV – 78%, NPV – 99%

Cheng et al 27

Phase 1–114 Phase 2–413 Group 1–100 Group 2–7

93 (82) 349 (84) 100 (100) 7 (100)

Phase 1 and 2 –sensitivity – 100% specificity – 100%

Sidhu et al 28

Group 1 – sensitivity – 67%, specificity – 97%, PPV – 57%, NPV – 97% Group 2 – sensitivity – 57%

Wang et al 29

705 (preoperative only) 510 (887 examinations)

613 (87)

Unable to report sensitivity – 100%, specificity – 98%, accuracy – 99%

Carneiro–Pla et al 30

688 (77) (range, 41–86)

Abbreviations: PPV, positive predictive value; NPV, negative predictive value.

HEAD & NECK—DOI 10.1002/HED JUNE 2016

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