Stroboscopy in Detection of Laryngeal Dysplasia Effectiveness and Limitations

Value of high-speed videoendoscopy as an auxiliary tool in differentiation of benign and malignant unilateral vocal lesions

PURPOSE

The study aimed to assess the relevance of objective vibratory parameters derived from high-speed videolaryngoscopy (HSV) as a supporting tool, to assist clinicians in establishing the initial diagnosis of benign and malignant glottal organic lesions.

METHODS

The HSV examinations were conducted in 175 subjects: 50 normophonic, 85 subjects with benign vocal fold lesions, and 40 with early glottic cancer; organic lesions were confirmed by histopathologic examination. The parameters, derived from HSV kymography: amplitude, symmetry, and glottal dynamic characteristics, were compared statistically between the groups with the following ROC analysis.

RESULTS

Among 14 calculated parameters, 10 differed significantly between the groups. Four of them, the average resultant amplitude of the involved vocal fold (AmpInvolvedAvg), average amplitude asymmetry for the whole glottis and its middle third part (AmplAsymAvg; AmplAsymAvg_2/3), and absolute average phase difference (AbsPhaseDiffAvg), showed significant differences between benign and malignant lesions. Amplitude values were decreasing, while asymmetry and phase difference values were increasing with the risk of malignancy. In ROC analysis, the highest AUC was observed for AmpAsymAvg (0.719; p < 0.0001), and next in order was AmpInvolvedAvg (0.70; p = 0.0002).

CONCLUSION

The golden standard in the diagnosis of organic lesions of glottis remains clinical examination with videolaryngoscopy, confirmed by histopathological examination. Our results showed that measurements of amplitude, asymmetry, and phase of vibrations in malignant vocal fold masses deteriorate significantly in comparison to benign vocal lesions. High-speed videolaryngoscopy could aid their preliminary differentiation noninvasively before histopathological examination; however, further research on larger groups is needed.

In Vivo Automatic and Quantitative Measurement of Adult Human Larynx and Vocal Fold Images

INTRODUCTION

Qualitative laryngoscopy belongs to a diagnostic routine. Nevertheless, quantitative morphometric measurements of laryngeal structures remain challenging. This study aimed to introduce a special laser projection device that can facilitate computer-assisted digitalized analysis and provide important quantitative information for diagnostics and treatment planning.

MATERIALS AND METHODS

The laryngeal images were captured with our device, which contained two parallel laser beams in order to provide the scaling reference. The maximum length of the vocal fold during respiration and vibration (phonation), vocal width at midpoint, total fold area, maximum cross-sectional area of the glottic space, and maximum vocal fold angle were determined and calculated. These parameters were analyzed and compared on the basis of age, sex, body height, body weight and body mass index.

RESULTS

A total of 87 subjects were enrolled in this study, comprising 39 males and 48 females. The age range for all subjects was 21 to 80 years old. The maximum value of the glottic area and vocal angle showed no significant gender difference. Both the respiration and vibration vocal fold length was significantly longer in males than in females. The vocal width revealed no gender difference, but the fold area during both respiration and phonation was significantly larger in men than in women. As for the respiration-to-vibration ratio of the vocal length, there was a trend, but without statistical significance (P = 0.06), toward a higher length compression ratio in men than in women. Meanwhile, age was found to have a strong relationship with vocal width during phonation. The width of vibration vocal fold decreased with aging significantly.

CONCLUSION

Our innovative module can provide reference parameters, which makes it possible to directly estimate the objective absolute values of relevant laryngeal structures. Our non-invasive approach can be used during routine laryngoscopy and the findings easily documented. In future, we can extend its clinical application to measure subtle laryngeal or hypopharyngeal changes, which are difficult to objectively quantify.

Multivariate Analysis of Vocal Fold Vibrations in Normal Speakers Using High-Speed Digital Imaging

INTRODUCTION

Little is known about the normal variations in vocal fold vibrations. We conducted a prospective study on normal subjects using high-speed digital imaging (HSDI) to elucidate key parameters regarding age/gender-related normal variations.

METHODS

Forty-six healthy adult volunteers were divided into young (aged ≤35 years) male, young female, elderly (aged ≥65 years) male, and elderly female subgroups. HSDI data of sustained phonation of /i/ at a comfortable pitch and loudness were obtained, and vibratory parameters were calculated using the visual-perceptual rating, laryngotopography, digital kymography, and glottal area waveform. Multivariate analysis was then performed on these parameters to clarify the subgroup-specific key parameters.

RESULTS

Four key parameters were identified from a total of 83: one from visual perceptual rating and three from laryngotopography. Subgroup analyses showed that posterior-to-anterior longitudinal phase difference (PD) and high fundamental frequency (F₀) were specific to young female participants. A low F₀ was specific to young male participants. Large anterior-to-posterior longitudinal PD and its left-right difference were specific to elderly male participants. There were no key parameters for elderly female participants.

CONCLUSIONS

Methods that can assess F₀ and longitudinal PD, such as visual-perceptual rating and laryngotopography, were effective in the evaluation of normal vocal fold vibrations and their variations.

Pathology-Related Influences on the VEM: Three Years' Experience since Implementation of a New Parameter in Phoniatric Voice Diagnostics

The vocal extent measure (VEM) represents a new diagnostic tool to express vocal capacity by quantifying the dynamic performance and frequency range of voice range profiles (VRPs). For VEM calculation, the VRP area is multiplied by the quotient of the theoretical perimeter of a circle with equal VRP area and the actual VRP perimeter. Since different diseases affect voice function to varying degrees, pathology-related influences on the VEM should be investigated more detailed in this retrospective study, three years after VEM implementation. Data was obtained in a standardized voice assessment comprising videolaryngostroboscopy, voice handicap index (VHI-9i), and acoustic-aerodynamic analysis with automatic calculation of VEM and dysphonia severity index (DSI). The complete dataset comprised 1030 subjects, from which 994 adults (376 male, 618 female; 18-86 years) were analyzed more detailed. The VEM differed significantly between pathology subgroups (p < 0.001) and correlated with the corresponding DSI values. Regarding VHI-9i, the VEM reflected the subjective impairment better than the DSI. We conclude that the VEM proved to be a comprehensible and easy-to-use interval-scaled parameter for objective VRP evaluation in all pathology subgroups. As expected, exclusive consideration of the measured pathology-related influences on the VEM does not allow conclusions regarding the specific underlying diagnosis.

Laryngeal Leukoplakia: State of the Art Review

Objective

This state-of-the-art article reviews the epidemiology, diagnosis, and management of vocal fold leukoplakia, with focus on recent advances. It focuses on the clinical challenges that otolaryngologists face balancing both oncological efficacy and functional outcomes in leukoplakia and presents the current philosophies and techniques to consider when managing such patients.

Data Sources

PubMed/MEDLINE.

Review Methods

We conducted a detailed review of publications related to vocal cord and laryngeal leukoplakia, dysplasia, hyperkeratosis, leukoplakia endoscopy, and leukoplakia management focusing specifically on oncologic outcomes, voice preservation, current and emerging diagnosis, and management techniques.

Conclusions

There has been a paradigm shift away from performing “vocal cord stripping” procedures that can cause irreversible hoarseness toward voice preservation surgery while achieving comparable oncologic control. Surgical technical and instrumental developments have been designed to maximally treat superficial disease while preserving underling vibratory mucosa. Recent improvements in histopathological grading systems and advances in biomarker classification may allow for improved oncologic risk stratification. Furthermore, improvements in endoscopic imaging capabilities and contact endoscopy are currently being studied for their potential diagnostic significance.

Implications for Practice

To optimally manage vocal fold leukoplakia, the otolaryngologist should become familiar with the oncologic implications of the disease and the importance of obtaining pathologic diagnosis to rule out malignancy. In addition, the surgeon should maintain surgical techniques and knowledge of available instruments and lasers that can assist in surgical management while prioritizing the preservation of vibratory tissue and voice quality. Finally, the surgeon and the patient should understand the clinical importance of routine endoscopic surveillance.

European Laryngological Society position paper on laryngeal dysplasia Part II: diagnosis, treatment, and follow-up

PURPOSE OF REVIEW

To give an overview of the current knowledge regarding the diagnosis, treatment, and follow-up of laryngeal dysplasia (LD) and to highlight the contributions of recent literature. The diagnosis of LD largely relies on endoscopic procedures and on histopathology. Diagnostic efficiency of endoscopy may be improved using videolaryngostroboscopy (VLS) and bioendoscopic tools such as Narrow Band Imaging (NBI) or Storz Professional Image Enhancement System (SPIES). Current histological classifications are not powerful enough to clearly predict the risk to carcinoma evolution and technical issues such as sampling error, variation in epithelial thickness and inflammation hamper pathological examination. Almost all dysplasia grading systems are effective in different ways. The 2017 World Health Organization (WHO) system should prove to be an improvement as it is slightly more reproducible and easier for the non-specialist pathologist to apply. To optimize treatment decisions, surgeons should know how their pathologist grades samples and preferably audit their transformation rates locally. Whether carcinoma in situ should be used as part of such classification remains contentious and pathologists should agree with their clinicians whether they find this additional grade useful in treatment decisions. Recently, different studies have defined the possible utility of different biomarkers in risk classification. The main treatment modality for LD is represented by transoral laser microsurgery. Radiotherapy may be indicated in specific circumstances such as multiple recurrence or wide-field lesions. Medical treatment currently does not have a significant role in the management of LD. Follow-up for patients treated with LD is a fundamental part of their care and investigations may be supported by the same techniques used during diagnosis (VLS and NBI/SPIES).

Laryngeal Mid-Cord Erythroleukoplakias: How to Modulate the Transoral CO2 Laser Excisional Biopsy

Background: The endoscopic appearance of glottic erythroleukoplakias is non-predictive of their histopathology, potentially ranging from keratosis to invasive squamous cell carcinoma (SCC). The aim of this study was to assess a comprehensive workup for the one-step diagnosis and treatment of mid-cord erythroleukoplakias, using CO₂ laser excisional biopsy. Methods: We evaluated 147 untreated patients affected by 155 mid-cord erythroleukoplakias submitted to excisional biopsy by subepithelial (Type I) or subligamental cordectomy (Type II), across two academic institutions. Patients were evaluated by preoperative videolaryngostroboscopy, pre- and intraoperative videoendoscopy with biologic endoscopy (narrow band imaging, NBI, or the Storz professional image enhancement system, SPIES), either with or without intraoperative saline infusion into the Reinke’s space. Adequacy of treatment was the primary outcome. Results: The histopathologic diagnosis was keratosis in 26 (17%) cases, squamous intraepithelial neoplasia (SIN1-2) in 47 (30%), carcinoma in situ in 21 (14%), and SCC in 61 (39%) patients. The adequacy of treatment across the entire cohort was 89%. The intraoperative saline infusion procedure, facing not clearly suspicious lesions, raised the adequacy of treatment from 60% to 90% (p = 0.006). Conclusions: Excisional biopsy by Type I–II cordectomies, after a comprehensive diagnostic workup, should be accepted as an adequate and cost-effective treatment of unilateral mid-cord glottic erythroleukoplakias.

Outcome Analysis of Microlaryngeal Surgery for Benign Lesions of Vocal Cord Using Videostroboscopy and Voice Handicap Index

Benign vocal cord mass lesions are common causes of dysphonia which are often surgically correctable. They include lesions like vocal polyps, vocal cysts, vocal nodules and Reinke's edema. A prospective study of 30 patients was carried out at SMS medical college and hospital between April 2014 to November 2015 after institutional ethical committee clearance. The purpose of our study was to evaluate outcome of microlaryngeal surgery for benign lesions of vocal cord using videostroboscopy and voice handicap index. All cases between the age group 15-60 years with clinical evidence of benign lesions of vocal cord were included in study. Preoperative amplitude, mucosal wave, glottic closure was seen by videostroboscopy and subjective assessment of severity of handicap in voice was assessed by set of questionnaire using voice handicap index (Jacobson et al. in Am J Speech Lang Pathol 6: 66-70, 1997). Postoperative follow up was done at 3rd week and 10th week, and outcome of microlaryngeal surgery was assessed using videostroboscope and voice handicap index. At the end of study data was compiled systemically and analysed using paired 't' test and Chi square test. Our study observed statistically significant improvement in amplitude and mucosal wave and glottic closure. Subjective improvement in perception of severity of handicap in voice was analysed by voice handicap index which shows statistically significant data. Overall our study conclude microlaryngeal surgery as an effective way for improvement in speech parameters, that can be assessed by use of videostroboscopy and voice handicap index.

Value of pre- and intraoperative diagnostic methods in suspected glottic neoplasia

PURPOSE

To evaluate the individual and combined ability of videostroboscopy (VS), high-speed digital imaging (HSDI), enhanced endoscopy (EE) and saline infusion (SI) to predict neoplasia, defined as glottic precursor lesion (GPL) or T1a glottic cancer, in patients suspected for glottic neoplasia.

METHODS

A nationwide prospective cohort study of patients treated by cordectomy for suspected GPL or T1a glottic cancer from August 1st 2016 to October 31st 2018 was conducted in the five Danish University Departments of Head and Neck surgery. Sensitivity, specificity, negative and positive predictive values, and area under Receiver Operating Curves (AUC-ROC) were calculated with 95% confidence intervals with respect to the histological diagnosis. Logistic regression with an imputation model for missing data was applied.

RESULTS

261 patients aged 34-91 years participated; 79 (30.3%) with non-neoplasia (i.e., inflammation, papilloma, hyperkeratosis) and 182 (69.7%) neoplasia, hereof 95 (36.4%) with GPL and 87 (33.3%) with T1a glottic cancer. Data from 188 VS, 60 HSDI, 100 preoperative EE, 209 intraoperative EE, and 234 SI were analyzed. In the complete case analysis the AUC-ROC of each diagnostic test was low, but increased when the tests were combined and especially if the combination included EE. However, multinomial logistic regression with imputation showed significant association (p < 0.05) only between age, male gender, and perpendicular vasculature in intraoperative EE, and the endpoint neoplasia.

CONCLUSIONS

Intraoperative EE was the most accurate diagnostic method in detecting neoplasia. The prediction ability of methods applied preoperatively was more limited, but improved when test modalities were combined.

Clinical and surgical implications of intraoperative optical coherence tomography imaging for benign pediatric vocal fold lesions

INTRODUCTION

Benign vocal disorders in children include an extensive list of abnormalities creating a variety of debilitating levels of dysphonia. Precise delineation of the benign lesion type and margins may have significant public health implications in children. An innovative technology such as optical coherence tomography (OCT) is being explored to delineate pediatric benign laryngeal lesions. An accurate assessment of the subepithelial morphology may help towards tailoring more personalized therapeutic treatments. This study was established to highlight key morphological and optical features of benign pediatric laryngeal lesions using intraoperative OCT and to suggest clinical implications that arise from such optical imaging.

METHODS AND MATERIALS

This in vivo study was performed at Massachusetts Eye and Ear Infirmary. Intraoperative imaging was performed on twenty-five pediatric patients ranging from 1 year to 16 years of age presenting hoarseness. Three-dimensional OCT images of benign laryngeal lesions or a subsite of the lesion were acquired.

RESULTS

High-resolution OCT images of 25 patients with benign laryngeal lesions such as nodules, cysts, Reinke's edema, vocalis sulcus, and papilloma revealed distinct and specific morphological differences with normal tissue. Nodules show a symmetrical superficial remodeling of the vocal fold epithelial layer and the basement membrane. Cysts have oval-like shape and are either superficial or deeply located in the lamina propria. Sulcus vocalis OCT imaging allows characterizing if the lesion is shallow or deep according to Ford's classification system. Reinke's edema of the mucosa can be observed and quantified, which may lead to suspicion on the underlying social and medical conditions. Finally, the ability to assess margins and depth of invasion of papilloma lesions is demonstrated, raising the possibility to use OCT with angiolytic lasers for patient-tailored treatments.

CONCLUSIONS

OCT imaging of benign pediatric vocal lesions is promising as it could improve preoperative decision-making and possibly peroperative imaging-guidance for patient-tailored treatments. An assessment of the optical contrast between healthy and abnormal tissue may help towards a more qualitative and quantitative approach to current standard care, especially when diagnosis remains unclear.

Parameters and Scales Used to Assess and Report Findings From Stroboscopy: A Systematic Review

OBJECTIVE

Laryngeal endoscopy with stroboscopy, a critical component of the assessment of voice disorders, is rarely used as a treatment outcome measure in the scientific literature. We hypothesized that this is because of the lack of a widely used standardized, validated, and reliable method to assess and report laryngeal anatomy and physiology, and undertook a systematic literature review to determine the extent of the inconsistencies of the parameters and scales used in voice treatment outcome studies.

STUDY DESIGN

Systematic literature review.

METHODS

We searched PubMed, Ovid, and Cochrane for studies where laryngeal endoscopy with stroboscopy was used as a treatment outcome measure with search terms representing "stroboscopy" and "treatment" guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards.

RESULTS

In the 62 included articles, we identified 141 terms representing 49 different parameters, which were further classified into 20 broad categories. The six most common parameters were magnitude of glottal gap, mucosal wave amplitude, location or shape of glottal gap, regularity of vibration, phase symmetry, and presence and size of specific lesions. Parameters were assessed on scales ranging from binary to 100 points. The number of scales used for each parameter varied from 1 to 24, with an average of four different scales per parameter.

CONCLUSIONS

There is a lack of agreement in the scientific literature regarding which parameters should be assessed to measure voice treatment outcomes and which terms and scales should be used for each parameter. This greatly diminishes comparison and clinical implementation of the results of treatment outcomes research in voice disorders. We highlight a previously published tool and recommend it for future use in research and clinical settings.

Using Innovative Acoustic Analysis to Predict the Postoperative Outcomes of Unilateral Vocal Fold Paralysis

Objective. Autologous fat injection laryngoplasty is ineffective for some patients with iatrogenic vocal fold paralysis, and additional laryngeal framework surgery is often required. An acoustically measurable outcome predictor for lipoinjection laryngoplasty would assist phonosurgeons in formulating treatment strategies. Methods. Seventeen thyroid surgery patients with unilateral vocal fold paralysis participated in this study. All subjects underwent lipoinjection laryngoplasty to treat postsurgery vocal hoarseness. After treatment, patients were assigned to success and failure groups on the basis of voice improvement. Linear prediction analysis was used to construct a new voice quality indicator, the number of irregular peaks (NIrrP). It compared with the measures used in the Multi-Dimensional Voice Program (MDVP), such as jitter (frequency perturbation) and shimmer (perturbation of amplitude). Results. By comparing the [i] vowel produced by patients before the lipoinjection laryngoplasty (AUC = 0.98, 95% CI = 0.78–0.99), NIrrP was shown to be a more accurate predictor of long-term surgical outcomes than jitter (AUC = 0.73, 95% CI = 0.47–0.91) and shimmer (AUC = 0.63, 95% CI = 0.37–0.85), as identified by the receiver operating characteristic curve. Conclusions. NIrrP measured using the LP model could be a more accurate outcome predictor than the parameters used in the MDVP.

Prognostic Relevance of Mucosal Waves in Patients With Unilateral Vocal Fold Paralysis

OBJECTIVES

To analyze the prognostic relevance of mucosal waves (MWs) for recovery of unilateral vocal fold paralysis (UVP).

METHODS

The charts and stroboscopic examinations of 100 consecutive patients with a complete UVP were reviewed retrospectively. All had a minimal (estimated <3 mm) mucosal gap on stroboscopy. A positive or negative MW on the paralyzed vocal fold was associated with complete recovery to full adduction and abduction. All patients were followed for at least 12 months.

RESULTS

Causes of the paralysis were iatrogenic/traumatic (n = 82), malignancy associated (n = 10), and idiopathic (n = 8). In patients with positive MW at diagnosis (n = 80), the chance of recovery of unilateral vocal fold paralysis was 91.25%, whereas the chance of recovery with a negative mucosal wave (n = 20) was only 10%.

CONCLUSION

Positive MWs in stroboscopy are a predictor for recovery of (iatrogenic/traumatic) unilateral vocal fold paralysis and should be used in routine diagnostic assessment.

A Preliminary Quantitative Comparison of Vibratory Amplitude Using Rigid and Flexible Stroboscopic Assessment

STUDY OBJECTIVE

The purpose of this study was to establish preliminary, quantitative data on amplitude of vibration during stroboscopic assessment in healthy speakers with normal voice characteristics. Amplitude of vocal fold vibration is a core physiological parameter used in diagnosing voice disorders, yet quantitative data are lacking to guide the determination of what constitutes normal vibratory amplitude.

METHODS/STUDY DESIGN

Eleven participants were assessed during sustained vowel production using rigid and flexible endoscopy with stroboscopy. Still images were extracted from digital recordings of a sustained /i/ produced at a comfortable pitch and loudness, with F0 controlled so that levels were within ±15% of each participant's comfortable mean level as determined from connected speech. Glottal width (GW), true vocal fold (TVF) length, and TVF width were measured from still frames representing the maximum open phase of the vibratory cycle. To control for anatomic and magnification differences across participants, GW was normalized to TVF length. GW as a ratio of TVF width was also computed for comparison with prior studies.

RESULTS

Mean values and standard deviations were computed for the normalized measures. Paired t tests showed no significant differences between rigid and flexible endoscopy methods. Interrater and intrarater reliability values for raw measurements were found to be high (0.89-0.99).

CONCLUSIONS

These preliminary quantitative data may be helpful in determining normality or abnormality of vocal fold vibration. Results indicate that quantified amplitude of vibration is similar between endoscopic methods, a clinically relevant finding for individuals performing and interpreting stroboscopic assessments.

Quantification of Vocal Fold Vibration in Various Laryngeal Disorders Using High-Speed Digital Imaging

OBJECTIVE

To quantify vibratory characteristics of various laryngeal disorders seen by high-speed digital imaging (HSDI).

METHODS

HSDI was performed on 78 patients with various laryngeal disorders (20 with polyp, 16 with carcinoma, 13 with leukoplakia, 6 with vocal fold nodule, and 33 with others) and 29 vocally healthy subjects. Obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography, digital kymography, and glottal area waveform.

RESULTS

Overall, patients with laryngeal pathologies showed greater asymmetry in amplitude, mucosal wave and phase, smaller mucosal wave, and poorer glottal closure than vocally healthy subjects. Furthermore, disease-specific vibratory disturbances that generally agreed with the findings in the literature were quantified: comparing polyp with nodule, differences were noted in longitudinal phase difference, amplitude, and mucosal wave. In comparison with leukoplakia and cancer, nonvibrating area was more frequently noted in cancer.

CONCLUSIONS

The HSDI analysis of various voice disorders using multiple methods can help phonosurgeons to properly diagnose various laryngeal pathologies and to estimate the degree of their vocal disturbances.