The Value of Spirometry in Subglottic Stenosis

[Functional, Radiological and Endoscopic Diagnostic of Tracheal Diseases]

Diseases of the trachea are rare, while other diseases associated with shortness of breath and pulmonary symptoms are common, which is why the necessary diagnosis and therapy are regularly delayed. At the same time, diseases range from simple scarring stenosis to extensive tumour disease. Patients may be otherwise healthy, suffer from autoimmune disease, or have severe general illnesses, as in tracheotomised patients. Therefore, history and clinical examination provide very important clues to a disease of the trachea. Subsequent diagnostics should be ordered in a reasonable manner and lead to the correct diagnosis and subsequent therapy in a timely manner. Functional, radiological and endoscopic examinations, each with a special focus in experienced hands, avoid duplicate examinations or misinterpretations. Patients are grateful because diseases of the trachea - a central airway that cannot be bypassed - are experienced as life-threatening or at least as severely limiting the quality of life.

Spirometry in laryngotracheal stenosis: a systematic review and meta-analysis

PURPOSE

This study aimed to assess the changes in spirometry parameters or indices after relieving laryngotracheal stenosis (LTS) in adult patients.

METHODS

A systematic review and meta-analysis of studies from PubMed, Scopus, Web of Science, Cochrane Library, and EBSCO databases was conducted for assessing changes in spirometry values after endoscopic balloon dilatation of LTS in adults. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Relevant data, such as changes in mean spirometry values between preoperative and postoperative interventions, and findings of receiver operating characteristic curve analyses for predicting the need for surgical intervention, were extracted.

RESULTS

Ten studies including 330 patients overall met the inclusion criteria. Significant improvements were observed from preoperative to postoperative mean values of different spirometry parameters and indices. The overall mean differences in peak expiratory flow (ΔPEF), expiratory disproportion index (ΔEDI), and peak inspiratory flow (ΔPIF) were 2.26 L/s (95% CI 2.14-2.38), 27.94 s (95% CI 26.36-29.52), and 1.21 L/s (95% CI 0.95-1.47), respectively. ΔPEF and ΔPIF values increased, while ΔEDI decreased. In predicting the need for surgical intervention, EDI had the highest sensitivity (88%), and forced expiratory volume per second/forced vital capacity had the highest specificity (85%).

CONCLUSION

Spirometry is a valuable tool for assessing patients with LTS. PEF, EDI, and PIF were the most commonly reported spirometry parameters that significantly improved after airway stenosis was relieved.

Effect of Intralesional Steroid Injections Among Patients with Acquired Laryngotracheal Stenosis Undergoing Endoscopic Balloon Dilation Using Pulmonary Function Tests

Objectives: Laryngotracheal stenosis (LTS) is characterized by an abnormal decrease in the upper airway diameter. The pulmonary function test (PFT) is an effective adjunctive diagnostic tool for upper airway obstruction. LTS can be managed with either open surgery or less invasive endoscopic approaches, among which endoscopic balloon dilation is the main method; this may include concurrent intralesional steroid injection (ILSI), which has the potential of improving the outcomes. However, the effectiveness of ILSI is unclear. We aimed to compare the improvement in PFT parameters among patients with acquired LTS following endoscopic balloon dilation who received and did not receive ILSIs. We also compared the recurrence times and rates between the 2 patient cohorts. Methods: We retrospectively collected data regarding pre- and postoperative PFTs, as well as inter-dilation interval records, obtained between June 2015 and April 2020. Results: We included 34 patients with acquired etiologies. The most common cause of stenosis was intubation (52.9%), followed by trauma (29.4%). Further, 52.9% of the patients received ILSIs. Symptom recurrence was reported in 23 (67.6%) cases, with no significant between-group difference -0.1389 [95% confidence interval (CI): -0.4483, 0.1705]. The mean (standard deviation) duration of the first reintervention was 8.62 (8.00) and 7.38 (3.20) months among patients who did and did not receive ILSIs, respectively (mean difference -1.23, P = .614, 95% CI -6.30, 3.84). Conclusion: Our findings indicated that PFT parameters improved following endoscopic balloon dilation, with forced expiratory volume in 1 second being significantly higher with concurrent ILSI. However, there was no between-method difference in the treatment effectiveness. Additionally, the restenosis recurrence rate was consistent with that reported in the literature.

Treatment with adult glottic stenosis using CO2 laser surgery combined with self-made laryngeal dilator

BACKGROUND/AIMS/OBJECTIVES

To investigate the treatment for adult glottic stenosis using CO2 laser surgery combined with a self-made laryngeal dilator.

MATERIAL AND METHODS

A retrospective analysis was performed on 18 patients with glottic stenosis who were treated using CO2 laser surgery combined with a self-made laryngeal dilator in our hospital from January 2018 to December 2020.

RESULTS

4 cases were caused by trauma and one by laryngophthisis. Laryngeal stenosis occurred in 4 and 9 patients respectively after CO2 laser surgery and open partial laryngectomy. Of them, one patient underwent postoperative radiotherapy. All patients were treated through CO2 laser surgery combined with a self-made laryngeal dilator under general anesthesia. 3-6 months later, the dilator was removed. Inflammation, ulceration and granulation were observed surrounding the dilator. But these complications would be cured and respiration was not affected. Finally, four patients could not be extubated and the decannulation rate achieved 78%. All patients successfully decannulated could normally intake. 13 cases had good voice quality and only one patient pronounced hoarsely.

CONCLUSIONS AND SIGNIFICANCE

It is demonstrated that the application of CO2 laser surgery combined with a laryngeal self-made dilator is feasible and effective for the treatment with adult glottic stenosis.

Computational fluid dynamics model of laryngotracheal stenosis and correlation to pulmonary function measures

3D models of airway lumens were created from CT scans of 19 patients with laryngotracheal stenosis. Computational fluid dynamics (CFD) simulations were completed for each, and results were compared to measured peak inspiratory flow rate, grade of lumen constriction, and measures of airway geometry. Results demonstrate flow resistance and shear stress correlate with degree of lumen constriction and absolute cross-sectional area as well as flow rate. Flow recirculation depends on airway constriction but does not vary with flow rate. Resistance and wall shear stress did not correlate well with functional measures. Flow recirculation did differ between subjects with higher functional measures and subjects with lower functional measures. This analysis provides mathematical models to predict airway resistance, wall shear stress, and flow reversal according lumen constriction and inspiratory flow rate. It suggests aerodynamic factors such as flow recirculation play a role in differences in functional performance between patients with similar airway measures.

The Reliability of the Arabic Version of the Dyspnea Index Questionnaire for Upper Airway-Related Dyspnea

Objectives

This study aimed to translate the Dyspnea Index (DI) questionnaire into the Arabic language and determine whether this version is valid and reliable for Arabic-speaking patients with upper airway-related dyspnea.

Methods

A cross-sectional study was conducted at the King Saud University Medical City otolaryngology clinics in Riyadh, Saudi Arabia. The DI questionnaire was translated into Arabic and then back-translated into the English language. Inclusion criteria were preoperative patients presenting to the otolaryngology clinic with upper airway-related dyspnea between November and December 2020. The results of internal consistency and factor analysis among the items were compared to the original DI development results to assess the reliability of the questionnaire.

Results

Among a total of 57 recruited patients, 50 questionnaires were completed with an 88% response rate. The mean age of the included patients was 38 ±14 years. Women constituted 58% of the patients. The most common diagnosis was subglottic stenosis (72%). Principle component extraction in factor analysis revealed a single underlying factor for all the questions. Factor loading ranged from 0.69 to 0.85. Reliability statistics showed a high value of internal consistency among the items. The mean inter-item correlation was 0.58.

Conclusion

Based on our findings, the Arabic version of the DI questionnaire is a reliable instrument for evaluating upper airway dyspnea.

Subglottic stenosis masquerading as asthma in a young adult: an overlooked and delayed diagnosis

An otherwise fit young woman presented with a 10-year history of non-progressive wheeze and 'noisy breathing'. She had previously been diagnosed with teenage-onset asthma but had been unresponsive to inhaled corticosteroids and bronchodilators. A dysfunctional breathing disorder had been considered a possible diagnosis by several general practitioners, and there were no features to suggest systemic conditions. The patient had undergone an otherwise apparently uncomplicated intubation general anaesthetic for a gastroenterological investigation 13 years earlier. An outpatient flexible endoscopic examination of the upper aerodigestive tract demonstrated an isolated subglottic stenosis which was characterised by cross-sectional imaging. Microlaryngoscopy confirmed a smooth subglottic stenosis which was dilated using a minimally invasive balloon dilatation technique to good clinical effect.

Endoscopic management of idiopathic subglottic stenosis in pregnancy

Aims

To describe the use of laser, endoscopic balloon dilatation with jet ventilation anaesthesia in the treatment of pregnant women with idiopathic subglottic stenosis.

Materials and methods

This is a case review of pregnant women with idiopathic subglottic stenosis, presenting to a tertiary referral centre with worsening breathlessness. Data were extracted from patient case notes.

Results

Four women underwent surgical management of subglottic stenosis in pregnancy. One patient required two procedures during the course of their pregnancy due to restenosis. All women had improvement in symptoms post-operatively and went on to deliver healthy babies at term.

Conclusion

Endoscopic balloon dilatation of idiopathic subglottic stenosis is a safe and viable treatment option in pregnancy and should be offered as first-line treatment in symptomatic women.

The Value of Dyspnea and Spirometry in Detecting Relapse of Benign Tracheal Stenosis

BACKGROUND

Benign tracheal stenosis may relapse after management.

OBJECTIVES

This study aimed to assess the value of dyspnea and spirometry in detecting relapse of benign tracheal stenosis.

METHODS

Patients with benign tracheal stenosis were evaluated post-management, at regular follow-up and emergency visits, with the Medical Research Council (MRC) dyspnea scale, spirometry, and flexible bronchoscopy. Patient visits were categorized and compared, in terms of change in clinical and functional parameters, in 2 groups: visits with relapse (case group) and visits with no relapse (control group). The ability of the MRC dyspnea scale and spirometry to predict relapse was evaluated.

RESULTS

Thirty-five patients with benign tracheal stenosis were included. Mean follow-up duration was 3.2 years (standard deviation = 3.3). Spirometry data were analyzed from 43 relapse visits (23 patients) versus 90 nonrelapse visits. The MRC dyspnea score and most spirometric indices were associated with relapse. In the receiver operating characteristic analysis, forced expiratory volume in 1 s, forced expiratory flow when 25% of forced vital capacity has been expired, peak expiratory flow (PEF), and total peak flow were superior to the MRC dyspnea score in predicting relapse. Among spirometric indices, >10.8% of PEF reduction has been very sensitive and specific.

CONCLUSIONS

This study supports the role of dyspnea and spirometry in monitoring benign tracheal stenosis, with spirometry predicting relapse even in clinically stable patients. PEF being a very sensitive index has the additional advantage of being assessed by peak flow meter and could potentially be used for remote monitoring.

Pulmonary Function Tests May Better Predict Dyspnea-Severity in Patients with Subglottic Stenosis Compared to Clinician-Reported Stenosis

OBJECTIVE

Patients with subglottic stenosis (SGS) present with varied degree of breathing complaints. The dyspnea index (DI) is a 10-question patient-reported outcome measure designed to measure the severity of upper airway obstruction. We set out to determine whether pulmonary function tests or clinician-reported degree of stenosis best predicted DI scores.

METHODS

Thirty patients with SGS were retrospectively reviewed over a 6-year period. One visit from each patient was included. Data including peak expiratory flow rate (PEFR), body-mass index (BMI), clinician-reported degree of stenosis, and DI scores were reviewed. Multiple linear regression was performed to determine how degree of stenosis and PEFR % predicted the variation in DI score.

RESULTS

PEFR % better predicted DI scores compared to degree of stenosis (partial correlation -0.32 vs 0.17). After stepwise elimination, PEFR % remained in the regression and was significantly associated with DI scores (F[1, 29] = 9.38, P = .005). BMI did not demonstrate a linear relationship with DI scores and was not included in the regression (r = -.02). The PEFR % unstandardized coefficient was -0.25 (95% CI: -0.42 to -0.08, P = .005). The model predicts that a 4% increase in the PEFR % results in a 1-point decrease in the DI score (95% CI: -1.68 to -0.32).

CONCLUSION

This study suggests that pulmonary function tests may be a better in-office measure to substantiate the severity of symptoms in patients with SGS.

Bronchoscopic management as an alternative treatment in non-operable benign tracheal stenosis

BACKGROUND

Endoluminal therapy either by dilatation, scar tissue resection or stent insertion is an established treatment for non-malignant airway stenosis although the surgical approach is still considered the "gold standard." No clear consensus exists on the structured role of each modality.

AIMS

We aimed to investigate the role of bronchoscopic management in non-operable tracheal stenosis cases, evaluating the effectiveness and safety of each procedure based on a structured algorithmic approach.

PATIENTS AND METHODS

This prospective study was carried out on (40) consecutive patients diagnosed between March 2017 and March 2020 with tracheal stenosis not amenable to surgery. All strictures were first evaluated by flexible bronchoscopy and classified as simple or complex. Patients were treated following a standardised therapeutic algorithm approach based on published evidence and our own expertise.

RESULTS

The mean age of the study population was 45.25 ± 18.79; lesions were classified as simple (14) and complex (24), while two patients had mixed type stenosis. Long term success rate was 100% in simple stenosis and 87.5% in the complex ones. Stents were deployed in 24 cases, most of which were of the complex type and only two of the simple type. Post-procedural mild to moderate complications were detected overall in 70% of the patients. All complications were non-life threatening, mostly stent-related and were effectively managed.

CONCLUSION

We conclude that after accurate classification and a structured algorithmic approach, interventional bronchoscopic management may play a crucial role in the effective treatment of benign tracheal stenosis.

Effect of inhaled fluticasone propionate on laryngotracheal stenosis after balloon dilation: a randomized controlled trial

PURPOSE

Laryngotracheal stenosis describes various airflow compromising conditions leading to laryngeal and tracheal narrowing, including subglottic and tracheal stenosis. Direct laryngobronchoscopy is the diagnostic gold standard for laryngotracheal stenosis. This study aimed to explore the effect of inhaled fluticasone propionate as adjuvant medical therapy in patients with laryngotracheal stenosis after balloon dilation.

METHODS

This prospective randomized controlled trial was conducted from April 2019 to April 2020. Fourteen adults (≥ 18 years) with laryngotracheal stenosis consented to participate. All patients underwent endoscopic balloon dilation. Seven patients were treated with inhaled fluticasone propionate, and seven acted as controls. Detailed documentation of operative findings and pre- and post-balloon dilation spirometry measurements were recorded. Basic demographic data and operative details, including information about the percentage of laryngotracheal stenosis, distance of laryngotracheal stenosis from the vocal cords, the stenotic segment vertical length, and the largest endotracheal tube used before and after dilation were noted.

RESULTS

Spirometry measurements were obtained on 34 occasions (17 before and 17 after balloon dilation). The two groups were similar in spirometry values after treatment. Both groups had significantly improved on most spirometry values after balloon dilation.

CONCLUSION

We found that using inhaled steroids after balloon dilatation in patients with laryngotracheal stenosis had no benefit over non-user patients in spirometry parameters during the short postoperative follow-up. To confirm this outcome, we recommend a large-scale double-blind study with a longer follow-up period.

Reliability of peak expiratory flow percentage compared to endoscopic grading in subglottic stenosis

OBJECTIVE

To determine the reliability of pulmonary function testing compared to endoscopic grading in the assessment of subglottic stenosis.

METHODS

Consecutively treated patients with subglottic stenosis at a tertiary care specialty hospital from 2009 to 2019 were identified. Two fellowship-trained laryngologists and two otolaryngologists blinded to clinical history reviewed laryngo tracheoscopic examinations and assessed the degree of stenosis using the Cotton-Myer grading system (% stenosis). Nine full flow-volume loops were performed at the time of each exam.

RESULTS

The endoscopic images of 45 subjects were graded for degree of stenosis and the spirometry data were analyzed. The kappa values for Cotton-Myer grade overall was 0.37, grade I was -0.103, grade II was 0.052, and grade III was 0.045. The overall intraclass correlation of the physician grading of estimated percent obstruction (% stenosis) was 0.712 (P < .01) whereas the overall intraclass correlation for PEF% was 0.96 (P < .01). Within each Cotton-Myer grade, the intraclass correlation for % stenosis was 0.45 (P = .02) for grade I, 0.06 (P = .30) for grade II, and 0.16 (P = .03) for grade III. The intraclass correlation for PEF% for grade I was 0.97 (P < .01), grade II was 0.92 (P < .01), and grade III was 0.96 (P < .01).

CONCLUSION

Cotton-Myer grading and estimating percent obstruction (% stenosis) for adult subglottic stenosis showed poor reliability as an assessment tool compared to the excellent intraclass correlation seen with pulmonary function tests within each Cotton-Myer grade subgroup. We recommend pulmonary function testing, specifically PEF% because it is a normalized value, for the assessment and management of subglottic stenosis.

LEVEL OF EVIDENCE

4.

Predicting Need for Surgery in Recurrent Laryngotracheal Stenosis Using Changes in Spirometry

OBJECTIVES/HYPOTHESIS

We sought to identify changes that occur in spirometric values between surgical interventions in patients with recurrent laryngotracheal stenosis and assess the utility of tracking those changes in predicting the need to return to surgery.

METHODS

This is a retrospective, case-control study of laryngotracheal stenosis. Charts from a 10 year period were reviewed, and 80 patients were identified with recurrent laryngotracheal stenosis and serial spirometry. Recorded forced expiratory volume in 1 second (FEV₁ ), forced inspiratory volume in 1 second (FIV₁ ), peak expiratory flow (PEF), and peak inspiratory flow (PIF), and body mass index (BMI) were tabulated. Calculations were then performed to determine deviations in spirometric measurements from maximums. Comparing the patients who required intervention to those who did not, we used a regression analysis to generate a decision tree based on factors with the strongest predictive power. We then calculated receiver operating characteristic (ROC) curves for all calculated variables.

RESULTS

Deviations in PEF, PIF, and FIV₁ from each patient's maximums had strong predictive power in determining return to surgery. PIF was the only fixed measurement found to have a statistically significant role in predicting return to surgery. BMI did not play a role.

CONCLUSION

For each patient, the deviation from their overall spirometric maximums had the statistically strongest predictive power in determining need to return to surgery. This suggests the importance of the trends in spirometric measures for each individual, and implies these trends have greater import than fixed measures alone.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:2199-2203, 2021.

Utility of Spirometry Values for Evaluating Tracheal Stenosis Patients Before and After Balloon Dilation

OBJECTIVES

Tracheal stenosis is defined as a narrowing of the airway distal to the lower edge of the cricoid cartilage. It is initially diagnosed based on clinical presentation and then confirmed using direct laryngobronchoscopy. Other adjunctive diagnostic methods, including spirometry, have been proposed. This study aimed to evaluate the relationship between tracheal stenosis severity and pre- and post-balloon dilatation spirometry parameters in order to assess for significant changes in spirometry values and to evaluate for the effects of stenosis-associated factors on post-dilation spirometry values, including vertical length and grade of the stenosis, as well as the role of wound-modifying agents.

METHODS

This retrospective study included adults (>18 years of age) with isolated tracheal stenosis who underwent endoscopic balloon dilations at King Saud University Medical City from June 2015 to May 2019, with detailed documentation of operative findings and valid spirometry measurements pre- and post-balloon dilation. Basic demographic data and operative note details, including information about the percentage of tracheal stenosis, distance of tracheal stenosis from vocal cords, vertical length of stenotic segment, and use of wound-modifying agents (topical mitomycin C or triamcinolone injections), were extracted.

RESULTS

Fourteen patients with spirometry measurements obtained on 50 occasions (25 pre-balloon dilation and 25 post-balloon dilation) were included. Each 1-unit increase in the vertical length of the stenosis showed a statistically significant negative relationship (-1.47 L/s) with pre-balloon dilation peak expiratory flow (PEF; P = .034). Post-balloon dilation spirometric values showed statistically significant improvements for most variables.

CONCLUSIONS

The vertical length of an isolated tracheal stenosis can be predicted before surgical interventions using PEF values and may be a significant indicator of anticipated post-balloon dilation surgical success. Our study suggested that spirometry is a very useful technique for evaluating patients with tracheal stenosis due to its noninvasiveness, cost-effectiveness, with a good clinical value.

Endoscopic Preoperative Assessment, Classification of Stenosis, Decision-Making

Pediatric Laryngo-Tracheal Stenosis (LTS) comprises different conditions that require precise preoperative assessment and classification. According to the guidelines, the optimal diagnostic work-up of LTS patients relies both on a comprehensive anamnesis and on endoscopic and radiological assessments. All the causes of LTS result in an impairment in airflow, mucociliary clearance, phonation, and sometimes in swallowing disorders. The main goals of treatment are to maintain an adequate respiratory space and restore the Upper Aero-Digestive Tract (UADT) physiology. The first step when dealing with LTS patients is to properly assess their medical history. The main causes of pediatric LTS can be divided into two groups, i.e., congenital and acquired. The most common causes of congenital LTS are: laryngomalacia (60%), vocal fold paralysis (15-20%), subglottic stenosis (SGS) (10-15%), laryngeal webs and atresia (5%), subglottic hemangioma (1.5-3%), and others. On the other hand, 90% of acquired pediatric LTS cases are subsequent to post-intubation injuries. Other less frequent causes are: iatrogenic complications from endoscopic laryngeal interventions, benign tumors, caustic or thermal injuries, external blunt force injury or trauma, chronic inflammatory disorders, or idiopathic causes. Diagnostic work-up consists in a step-by-step investigation: awake and asleep transnasal fiberoptic laryngoscopy (TNFL), direct laryngoscopy with 0° and angled telescopes to investigate the type of stenosis (arytenoid mobility, craniocaudal extension, involved anatomical sites, and active or mature scar tissue), and broncho-esophagoscopy to rule out associated mediastinal malformations. To date there are several available classifications for each of the involved sites: Cohen's classification for anterior glottic stenosis, Bogdasarian's for posterior glottic stenosis (PGS) and Myer-Cotton's for subglottic stenosis, even though others are used in daily practice (Lano-Netterville, FLECS, etc.). The European Laryngological Society recently proposed a new classification which is applicable in all LTS cases. In this chapter we deal with preoperative assessment and staging, reviewing the most relevant classifications applicable in patients affected by LTS, conditio sine qua non in order to tailor the best treatment modality to each subject. We'll also detail the comprehensive radiological, endoscopic and functional assessment for the correct use of each staging classification.