Diagnostic Accuracy of Laryngeal Ultrasound for Evaluating Vocal Fold Movement Impairment in Children

PURPOSE

Vocal fold movement impairment (VFMI) secondary to recurrent laryngeal nerve (RLN) injury is a common source of morbidity after pediatric cervical, thoracic, and cardiac procedures. Flexible laryngoscopy (FL) is the gold standard to diagnose VFMI yet can be challenging to perform and/or risks possible clinical decompensation in some children and is an aerosolizing procedure. Laryngeal ultrasound (LUS) is a potential non-invasive alternative, but limited data exists in the pediatric surgical population regarding its efficacy. We aimed to investigate the diagnostic accuracy of LUS compared to FL in evaluating VFMI.

METHODS

A prospective, single-center, single-blinded (rater) cohort study was undertaken on perioperative pediatric patients at risk for RLN injury. Patients underwent FL and LUS. Cohen's kappa was used to determine chance-corrected agreement.

RESULTS

Between 2021 and 2023, 85 paired evaluations were performed with patients having a median (IQR) age of 10 (4, 42) months and weight of 7.5 (5.4, 13.4) kilograms. The prevalence of VFMI was 27.1%. Absolute agreement between evaluations was 98.8% (kappa 0.97, 95% CI: 0.91-1.00, P < 0.001). The sensitivity and specificity of LUS in detecting VFMI was 95.7% and 100%, yielding a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 98.4% (95% CI: 90-100%). Diagnostic accuracy was 98.8% (95% CI: 93-100%).

CONCLUSION

LUS is a highly accurate modality in evaluating VFMI in children. While FL remains the gold standard for diagnosis, LUS offers a low-risk screening modality for children at risk for VFMI such that only those with an abnormal LUS or presence of clinical symptoms discordant with LUS findings should undergo FL.

TYPE OF STUDY

Prospective, single-center, single blinded (rater), cohort study.

LEVEL OF EVIDENCE

Level II.

Support of deep learning to classify vocal fold images in flexible laryngoscopy

PURPOSE

To collect a dataset with adequate laryngoscopy images and identify the appearance of vocal folds and their lesions in flexible laryngoscopy images by objective deep learning models.

METHODS

We adopted a number of novel deep learning models to train and classify 4549 flexible laryngoscopy images as no vocal fold, normal vocal folds, and abnormal vocal folds. This could help these models recognize vocal folds and their lesions within these images. Ultimately, we made a comparison between the results of the state-of-the-art deep learning models, and another comparison of the results between the computer-aided classification system and ENT doctors.

RESULTS

This study exhibited the performance of the deep learning models by evaluating laryngoscopy images collected from 876 patients. The efficiency of the Xception model was higher and steadier than almost the rest of the models. The accuracy of no vocal fold, normal vocal folds, and vocal fold abnormalities on this model were 98.90 %, 97.36 %, and 96.26 %, respectively. Compared to our ENT doctors, the Xception model produced better results than a junior doctor and was near an expert.

CONCLUSION

Our results show that current deep learning models can classify vocal fold images well and effectively assist physicians in vocal fold identification and classification of normal or abnormal vocal folds.

Transnasal Flexible Laryngoscopy Using Different Topical Preparations and Methods of Application-A Randomized Study

BACKGROUND

The field of laryngology has grown exponentially since the advent of the transnasal flexible laryngoscopy. Flexible laryngoscopy when performed skillfully using the proper technique, facilitates a good view of the hidden areas of the larynx.

OBJECTIVE

To compare the effectiveness of the topical agents in providing a more comfortable experience for the patient, allowing the practitioner to advance the endoscope with less friction, pain and discomfort for the patient using 10% lidocaine spray, 2% lidocaine gel, 4% lidocaine with xylometazoline (1:1) soaked pledgets, or aqueous gel.

MATERIALS AND METHODS

A prospective randomized single-blinded clinical trial was conducted in a tertiary care teaching hospital in South India where 376 patients were recruited and allocated into four groups based on the topical preparation used. Following endoscopy, each subject filled a questionnaire grading their experience on a visual analogue scale. The clinician also then answered a questionnaire on aspects of the endoscopy performed.

RESULTS

The pain score and the ease of performing the procedure among the different groups were comparable. Those in the 10% lidocaine arm experienced significant burning sensation (P = 0.0001). The other variables such as throat pain (P = 0.783), gag reflex (P = 0.318), unpleasant taste (P = 0.092), globus (P = 0.190), swallowing difficulty after the procedure (P = 0.273), difficulty in breathing (P = 0.744) and willingness to have a repeat procedure (P = 0.883) were also comparable.

CONCLUSION

Aqueous gel can be used topically during a flexible nasopharyngolaryngoscopy instead of an anesthetic agent alone or one combined with a nasal decongestant.

A comparative study on the effects of flexible and rigid laryngoscopy techniques on intraocular pressure

OBJECTIVES

This study compared the impact of transoral rigid laryngoscopy (TORL) and transnasal flexible laryngoscopy (TNFL) methods on intraocular pressure (IOP).

METHODS

This study included 100 patients, with 50 patients undergoing a TORL, and 50 patients a TNFL. Before procedure IOP values were recorded by an ophthalmologist using Icare Pro tonometry, also immediately post procedure, and at the 15th, 30th and 60th minute after laryngoscopy.

RESULTS

Both groups were similar in terms of age, gender, mean body mass index (BMI), and pre-laryngoscopy IOP values. When the TNFL and TORL groups were compared, no significant differences were observed between pre-laryngoscopy, and 60^th minute IOP values (p = 0.891, p = 0.149, respectively). IOP values measured immediately after laryngoscopy, and at the 15th and 30th minute were significantly higher in the TORL group (p < 0.001, p < 0.001, p = 0.002, respectively).

CONCLUSIONS

We demonstrated higher IOP fluctuations in the TORL group, when compared to the TNFL group. For this reason, TNFL may be considered a safer method for evaluating laryngeal tissues in conditions that require lower IOP fluctuation as in glaucoma. However, further studies are required to clarify the exact effects of IOP fluctuations during TNFL and TORL in patients with glaucoma.

Is Office Laryngoscopy an Aerosol-Generating Procedure?

Objectives/Hypothesis

The aims of this work were 1) to investigate whether office laryngoscopy is an aerosol‐generating procedure with an optical particle sizer (OPS) during clinical simulation on healthy volunteers, and 2) to critically discuss methods for assessment of aerosolizing potentials in invasive interventions.

Study Design

Prospective quantification of aerosol and droplet generation during clinical simulation of rigid and flexible laryngoscopy.

Methods

Two healthy volunteers were recruited to undergo both flexible and rigid laryngoscopy. An OPS was used to quantify aerosols and droplets generated for four positive controls relative to ambient particles (speech, breathing, /e/ phonation, and /æ/ phonation) and for five test interventions relative to breathing and phonation (flexible laryngoscopy, flexible laryngoscopy with humming, flexible laryngoscopy with /e/ phonation, rigid laryngoscopy, and rigid laryngoscopy with /æ/ phonation). Particle counts in mean diameter size range from 0.3 to >10 μm were measured with OPS placed at 12 cm from the subject's nose/mouth.

Results

None of the laryngoscopy interventions (n = 10 each) generated aerosols above that produced by breathing or phonation. Breathing (n = 40, 1–3 μm, P = .016) and /æ/ phonation (n = 10, 1–3 μm, P = .022; 3–5 μm. P = .083; >5 μm, P = .012) were statistically significant producers of aerosols and droplets. Neither speech nor /e/ phonation (n = 10 each) were associated with statistically significant aerosols and droplet generation.

Conclusions

Using OPS to detect droplets and aerosols, we found that office laryngoscopy is likely not an aerosol‐generating procedure. Despite its prior use in otolaryngological literature, an OPS has intrinsic limitations. Our study should be complemented with more sophisticated methods of droplet distribution measurement.

Level of Evidence

3 Laryngoscope, 130:2637–2642, 2020

Dipping and rotating: two maneuvers to achieve maximum magnification during indirect transnasal laryngoscopy

Background

Since many years, office-based flexible transnasal laryngoscopy is a common routine procedure. The development of new technical equipment such as high-definition cameras and flexible tip-chip endoscopes nowadays allows for much more precise examination than a few years ago. In contrast to rigid laryngoscopy, it is possible to move the tip of the endoscope close to the vocal folds and to other structures of interest. Nevertheless, without professional handling of the equipment, one cannot benefit from the potential of the newest technology.

Method

Two easily performed and very helpful maneuvers in flexible endoscopy are described. The “dipping maneuver” enables a maximum magnification of the mucosal surfaces of the endolarynx as well as the examination of the subglottal region and the trachea by positioning the tip of the endoscope very close to the vocal folds or even in the upper trachea during long transnasal inspiration. During the “rotation laryngoscopy”, the tip of the endoscope is positioned in the posterior interarytenoid region by rotating the flexible endoscope by 180° and advancing it close to the glottis. This allows a close-up examination of the anterior commissure, the inferior aspect of the vocal folds and the inside of the Morgagni’s ventricle. Before performing transnasal flexible endoscopy, we routinely apply topical anesthesia sprayed intranasally.

Conclusion

The described techniques of flexible endoscopy are easily performed and allow a maximum magnification of the mucosal surfaces and otherwise not visible regions of the endolarynx.

Pediatric flexible laryngoscopy: Trends in diagnostic abilities throughout training

OBJECTIVES

Our objectives were to evaluate the ability of residents to diagnose pathology of the pediatric larynx on laryngoscopy, to trend this ability throughout training, to compare their skills to pediatric otolaryngologists, and to determine whether reviewing digitally captured videos in slow motion, as opposed to a live exam, enhanced diagnostic abilities. In addition, we identified pathologies and anatomical sub-sites that posed diagnostic challenges.

METHODS

Qualtrics was used to design and distribute an online test, which included 15 pediatric laryngoscopy videos. Participants selected a diagnosis for each video after (1) watching it once at full speed and (2) watching the video multiple times in slow motion. Anonymous responses were exported into excel for statistical analysis, including T-test, ANOVA, and descriptive statistics.

RESULTS

There were 21 total participants. Median scores for full speed versus slow motion video review were 47% and 60% respectively. When analyzed by training level, there was no significant difference in scores for full speed videos, but there was a significant difference across groups for slow motion review (p = 0.04). Post Graduate Year (PGY) 4 residents and pediatric otolaryngologists performed best with an average of 69% and 77% respectively. Base of tongue, subglottic, and laryngeal cleft lesions were the most difficult to diagnose. Motor, laryngeal, and vallecular pathologies were more accurately identified.

CONCLUSIONS

The ability to diagnose pathology on pediatric laryngoscopy tends to improve throughout residency training. Slow motion review enhances diagnostic skills. Laryngeal and vallecular pathologies are more easily diagnosed than base of tongue and subglottic lesions.

Transoral flexible laryngoscope biopsy: Safety and accuracy

Objective

To determine the accuracy of transoral flexible laryngoscope (TFL) biopsy and also to identify the safety as office based procedure in terms of complications.

Methods

This is a diagnostic study; the type of intervention is outpatient department based biopsy of laryngeal lesions. All patients seen in ENT outpatient department of Lyari General Hospital with suspicious lesions of Larynx were referred for Transoral Flexible Laryngoscopy Biopsy under local anesthesia. The specimens were sent for histopathology. The patients with benign pathology or carcinoma in situ were referred for direct laryngoscopy and biopsy. The sensitivity and specificity were calculated and the frequencies of complications were monitored to determine the complication rate.

Results

During the course of study a total of 47 patients underwent TFL biopsy in office settings. Out of these patients 16 patients were referred for direct laryngoscopy biopsy. The study population included 32 men and 15 women with ages ranging from 28 to 52 years and mean of (39 ± 6) years. Among 43 patients squamous cell carcinoma was the final diagnosis in 31 patients. In the rest of 12 patients’ dysplasia and benign lesion was the diagnosis in 9 and 3 patients respectively. These 12 patients underwent direct laryngoscopy biopsy and 10 of them diagnosed with invasive carcinoma rest had benign lesions. Hence the specificity was 75.6% and sensitivity was 100%. None of the patients developed any serious complication.

Conclusions

All patients with a suspicious lesion diagnosed by TFL biopsy as being benign or carcinoma in situ should have direct laryngoscopy for verification of the findings. But the results positive for carcinoma are reliable. In addition, this is a safe procedure.

Flexible Laryngoscopy in Management of Congenital Stridor

The incidence of congenital stridor is on rise due to improved neonate and infant survival rate. The gold standard investigation for evaluation of stridor is rigid laryngotracheobronchoscopy, but this is invasive and requires general anesthesia. Flexible fibreoptic laryngoscopy, a relatively simple and less invasive procedure can be done under topical anaesthesia for evaluation of stridor. In this study, we have presented our experience of flexible laryngoscopy in children with congenital stridor, their results and management. Laryngomalacia was the commonest cause of stridor accounting for 80% of cases. 15% (6) patients required tracheostomy for relieving airway obstruction and 22.5% (9) patients required a definitive surgical procedure for correcting the cause. Flexible laryngoscopy is safe and gives a comprehensive analysis of airway including its dynamic functions. We also recommend flexible laryngoscopy as a frontline investigation for evaluation of stridor.

Iatrogenic phenol injury: a case report and review of medication safety and labeling practices with flexible laryngoscopy

Medication errors can be reduced by following standards in patient identification and medication labeling. We present an investigation of a life-threatening event from medication error: A newborn that received intranasal phenol instead of topical anesthetic prior to flexible laryngoscopy. The patient required urgent intubation for respiratory distress and suffered chemical burns of the face, neck, and upper aerodigestive tract. The hospital course was prolonged and included intensive care, delayed oral feeding with enteral support, and the need for several endoscopies. Current standards of medication labeling are reviewed as well as evidence for and against using topical agents for flexible laryngoscopy.