Idiopathic subglottic stenosis: techniques and results

An Ovine Model Yields Histology and Gene Expression Changes Consistent with Laryngotracheal Stenosis

OBJECTIVES

Animal models for laryngotracheal stenosis (LTS) are critical to understand underlying mechanisms and study new therapies. Current animal models for LTS are limited by small airway sizes compared to human. The objective of this study was to develop and validate a novel, large animal ovine model for LTS.

METHODS

Sheep underwent either bleomycin-coated polypropylene brush injury to the subglottis (n = 6) or airway stent placement (n = 2) via suspension microlaryngoscopy. Laryngotracheal complexes were harvested 4 weeks following injury or stent placement. For the airway injury group, biopsies (n = 3 at each site) were collected of tracheal scar and distal normal regions, and analyzed for fibrotic gene expression. Lamina propria (LP) thickness was compared between injured and normal areas of trachea.

RESULTS

No mortality occurred in sheep undergoing airway injury or stent placement. There was no migration of tracheal stents. After protocol optimization, LP thickness was significantly increased in injured trachea (Sheep #3: 529.0 vs. 850.8 um; Sheep #4: 933.0 vs. 1693.2 um; Sheep #5: 743.7 vs. 1378.4 um; Sheep #6: 305.7 vs. 2257.6 um). A significant 62-fold, 20-fold, 16-fold, 16-fold, and 9-fold change of COL1, COL3, COL5, FN1, and TGFB1 was observed in injured scar specimen relative to unaffected airway, respectively.

CONCLUSION

An ovine LTS model produces histologic and transcriptional changes consistent with fibrosis seen in human LTS. Airway stent placement in this model is safe and feasible. This large airway model is a reliable and reproducible method to assess the efficacy of novel LTS therapies prior to clinical translation.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2024.

In-depth analysis of pre- and postoperative functional outcome parameters in patients receiving laryngotracheal surgery

OBJECTIVES

Surgical treatment for airway stenosis necessitates personalized techniques based on the stenosis location and length, leading to favourable surgical outcomes. However, there is limited literature on functional outcomes following laryngotracheal surgery with an adequate number of patients.

METHODS

We conducted a retrospective analysis of patients who underwent laryngotracheal surgery at the Department of Thoracic Surgery, Medical University of Vienna, from January 2017 to June 2021. The study included standardized functional assessments before and after surgery, encompassing spirometry, voice measurements, swallowing evaluation and subjective patient perception.

RESULTS

The study comprised 45 patients with an average age of 51.9 ± 15.9 years, of whom 89% were female, with idiopathic being the most common aetiology (67%). Procedures included standard cricotracheal resection in 11%, cricotracheal resection with dorsal mucosal flap in 49%, cricotracheal resection with dorsal mucosal flap and lateral cricoplasty in 24% and single-stage laryngotracheal reconstruction in 16%. There were no in-hospital mortalities or restenosis cases during the mean follow-up period of 20.8 ± 13.2 months. Swallowing function remained intact in all patients. Voice evaluations showed a decrease in fundamental vocal pitch [203 (81-290) Hz vs 150 (73-364) Hz, P < 0.001] and dynamic voice range (23.5 ± 5.8 semitones vs 17.8 ± 6.7 semitones, P < 0.001). However, no differences in voice volume were observed (60.0 ± 4.1 dB vs 60.2 ± 4.8 dB, P = 0.788). The overall predicted voice profile changed from R0B0H0 to R1B0H1.

CONCLUSIONS

Laryngotracheal surgery proves effective in fully restoring breathing capacity while preserving vocal function. Even in cases of high-grade and complex airway stenosis necessitating laryngotracheal reconstruction, favourable functional outcomes can be achieved.

New Insight into Laryngo-Tracheal Surgery: High-Flow Oxygen Therapy to Prevent Early Complications after Surgery

BACKGROUND

Early post-operative airway management after laryngo-tracheal surgery is crucial. Acute respiratory failure due to glottis' edema may occur, requiring reintubation. This can prolong ventilatory assistance, jeopardizing anastomosis. To date, only judicious steroid administration and fluid management are available to avoid more invasive procedures. High-flow oxygen therapy (HFOT) is a noninvasive O2 support method providing humidification, warmed air, and Positive End-Expiratory Pressure (AIRVO2). No data about HFOT use to prevent early complications after laryngo-tracheal surgery are reported in the literature.

METHODS

Between September 2020 and September 2022, 107 consecutive patients who underwent laryngo-tracheal surgery received HFOT (Group A). Data and long-term results were compared with those of 80 patients operated between September 2018 and August 2020 (Group B), when HFOT was not available. All patients were operated in a single center. No pre- or post-operative settings changed, except for HFOT introduction. We analyzed and compared the risk for "delayed" reintubation (unexpected reintubation within the first 24-48 h after extubating/laryngeal mask removal) in the two groups.

RESULTS

No patients reported HFOT-related adverse events. The control group (B) presented "delayed" reintubation in 37% (p = 0.027), intensive care unit admission in 67% (p = 0.005) and longer hospital stay (p = 0.001) compared to the HFOT group (A). The minor complications' rate was 3% in both group and overall mortality was 0%. Re-stenosis was described in 4.6% of the HFOT group, without a statistically significant difference (p = 0.7006).

CONCLUSIONS

Our study is the first to investigate HFOT use in patients undergoing laryngo-tracheal surgery, potentially representing a consistent innovation in the peri-operative management of these patients. With the limitation of a retrospective series, we would suggest HFOT use for preventing post-operative reintubation rate, possibly reducing ICU admissions and hospital stays.

Anesthetic Management of Unanticipated Subglottic Stenosis in a Patient Undergoing Coronary Artery Bypass Graft Surgery

A 62-year-old female presented for a scheduled coronary artery bypass graft (CABG) and was found to have an unexpected subglottic stenosis during routine intubation. The case was aborted and six days later, the patient underwent lasering of the stenotic subglottic region and airway balloon dilation. In this case report, causes of subglottic stenosis and surgical/anesthetic management of the condition are discussed. The management of subglottic stenosis in this patient was complicated by concurrent severe coronary artery disease (CAD) involving the left main coronary artery and timing of airway surgery relative to interventions for her CAD. In situations of undiagnosed subglottic stenosis, anesthesiologists should be familiar with airway management based on the location and severity of the stenosis. Close multidisciplinary team management is required for patients who have other complex comorbidities.

The Effect of an Increasing Subglottal Stenosis Constriction That Extends From the Vocal Folds to the Inferior Border of the Cricoid Cartilage

Acquired subglottal stenosis is an unpredicted complication that can occur in some patients who have undergone prolonged endotracheal intubation. It is a narrowing of the airway at the level of the cricoid cartilage that can restrict airflow and cause breathing difficulty. Stenosis is typically treated with endoscopic airway dilation, with some patients experiencing multiple recurrences. The study highlights the potential of computational fluid dynamics as a noninvasive method for monitoring subglottic stenosis, which can aid in early diagnosis and surgical planning. An anatomically accurate human laryngeal airway model was constructed from computerized tomography (CT) scans. The subglottis cross-sectional area was narrowed systematically using ≈10% decrements. A quadratic profile was used to interpolate the transformation of the airway geometry from its modified shape to the baseline geometry. The numerical results were validated by static pressure measurements conducted in a physical model. The results show that airway resistance follows a squared ratio that is inversely proportional to the size of the subglottal opening (R∝A-2). The study found that critical constriction occurs in the subglottal region at 70% stenosis (upper end of grade 2). Moreover, removing airway tissue below 40% stenosis during surgical intervention does not significantly decrease airway resistance.

The Subglottic Stenosis 6 Questionnaire: A Novel Quality-of-Life Survey Validated to Predict Need for Intervention in Patients With Idiopathic Subglottic Stenosis

BACKGROUND

Idiopathic subglottic stenosis (iSGS) is a recurrent, chronic disease defined by fibroinflammatory narrowing of the subglottic airway. A key challenge in treatment is monitoring disease progression, which may be debilitating and unpredictable in its timing.

RESEARCH QUESTION

Can the Subglottic Stenosis 6 (SGS-6) questionnaire be validated as a novel quality-of-life (QOL) instrument to monitor breathing, disease progression, and disease severity proactively in patients with iSGS?

STUDY DESIGN AND METHODS

Panel data from 51 patients with iSGS were collected from January 2012 through June 2022, representing 1,684 patient encounters including routine office visits and treatment encounters. Subjective QOL scores (including the novel SGS-6 and established RAND-36 and EuroQol Five Dimensions [EQ-5D] Visual Analog Scale) and objective pulmonary function test (PFT) results were collected at each visit. Subjective SGS-6 QOL scores were repeated within 1 week of initial reporting. Panel regression analyses were performed to assess the relationship between SGS-6 scores, PFT results, and a patient's need for intervention. Minimal clinically important differences (MCIDs) for SGS-6 and peak expiratory flow percentage (PEF%) were assessed using receiver operating characteristic (ROC) curve analysis and a patient's need for intervention as the external anchor.

RESULTS

Each one-point increase in SGS-6 score (of a maximum of 27) was associated with a 3.26% decrease in PEF%, a 1.93-point decrease in RAND-36 Physical Health composite score, a 1.27-point decrease in RAND-36 Mental Health composite score, and a 0.88-point decrease in EQ-5D Visual Analog Scale score. The intracorrelation coefficient for the SGS-6 composite score is 0.838 (95% CI, 0.770-0.888). Compared with patient baselines, SGS-6 scores were 4.66 points greater at the time of intervention with an MCID of 2.25 from a patient's baseline. The area under the ROC curve for SGS-6 and a patient's intervention point was 0.81.

INTERPRETATION

iSGS disease severity can be modeled using the SGS-6 questionnaire, offering physicians and patients a potentially new method of tracking disease progression and need for intervention remotely.

Long-Term Follow-up of 64 Patients With Idiopathic Subglottic Stenosis: Treatment Pathways, Outcomes, and Impact of Serial Intralesional Steroid Injections

OBJECTIVE

To describe treatment pathways and long-term outcomes in 64 patients with idiopathic subglottic stenosis (iSGS), including the impact of serial intralesional steroid injection (SILSI) on degree of stenosis, need for subsequent operation, and patient-reported outcome measures.

METHODS

Retrospective review of 64 female patients with iSGS undergoing varied management approaches, 57 of whom underwent SILSI as at least part of their care. Treatment pathways included SILSI only, endoscopic intervention followed by SILSI only, endoscopic interventions only, endoscopic intervention followed by SILSI followed by need for repeat endoscopic intervention, open surgery, and tracheotomy. Outcomes assessed included subjectively estimated percent airway stenosis, dyspnea index (DI), modified medical research council (MMRC) dyspnea scale, voice handicap index-10 (VHI-10), number of operative and office-based procedures performed, need for subsequent operative intervention, and inter-operative interval.

RESULTS

Treatment pathways included SILSI alone (n = 6), endoscopic intervention(s) followed by SILSI only (n = 31), SILSI followed by additional endoscopic or office-based procedures (n = 16), open surgery (n = 3), and tracheostomy (n = 4). 57 of 64 patients underwent SILSI as at least part of their treatment. Inter-operative interval was increased after starting SILSI. Of patients undergoing SILSI, those with more procedures or shorter inter-operative interval prior to SILSI were more likely to return to the operating room. Estimated stenosis, DI, MMRC, and VHI-10 decreased with SILSI. Stenosis was not correlated with DI, MMRC, or VHI-10, though DI was correlated with both MMRC and VHI-10 score.

CONCLUSION

Of 57 patients undergoing SILSI, 37 did not require further operative intervention. Improvements in inter-operative interval, dyspnea, and voice were observed across patients. Randomized trials to identify which patients may benefit most from SILSI are warranted.

Impact of Socioeconomic Demographics and Race on Laryngotracheal Stenosis Etiology and Outcomes

OBJECTIVE

Certain sociodemographic variables are known to result in health care disparities. This study investigates potential differences in outcomes for patients with laryngotracheal stenosis (LTS) based on racial backgrounds and socioeconomic variables including insurance status and English language-Proficiency.

METHODS

Patients with LTS from 2016 to 2021were identified by relevant ICD codes. Variables including race, age, gender, language preference and insurance status were collected from medical records. Risk factors for LTS including COPD, smoking history, diabetes, GERD, and BMI were obtained. Etiology of LTS was categorized as autoimmune, traumatic, iatrogenic, or idiopathic. Need for temporary tracheostomy and tracheostomy dependence were determined at last follow-up visit.

RESULTS

129 patients were included for review. 70% of Black patients had iatrogenic LTS, whereas 65% of the White patient cohort had autoimmune or idiopathic LTS. Black patients were more strongly associated with temporary tracheostomy and tracheostomy dependence compared to White patients. Public health insurance and co-morbid GERD were associated with tracheostomy dependence for White patients only.

CONCLUSION

This study identified a disproportionate representation of Black patients in the iatrogenic etiology of LTS. Although controlling for risk factors of LTS, this cohort had an increased need for temporary tracheostomy and tracheostomy dependence compared to White and Latinx cohorts. This finding merits further study.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:908-913, 2023.

Can the Remote Use of a Peak Flow Meter Predict Severity of Subglottic Stenosis and Surgical Timing?

OBJECTIVE

We aimed to assess the relationship between patient-performed and patient-reported peak flow meter (PFM) measurements with pulmonary function testing (PFT) and Dyspnea Index (DI) scores as a tool for monitoring Subglottic stenosis (SGS) disease progression remotely.

METHODS

Thirty-five SGS patients were prospectively enrolled. Patients were given PFMs to report serial measurements from home. DI scores and PFT were recorded at serial clinic visits. Data were analyzed to determine the correlation between PFM measurements and PFT data. Pre-operative and post-operative PFM measurements, PFT, and DI scores were analyzed for patients who underwent operative intervention. Receiver operating characteristic (ROC) curves were created for PFM measurements, PFT data, and DI scores to predict the likelihood of surgery.

RESULTS

PFM measurements had a "strong" correlation with the peak expiratory flow rate (PEFR), r = 0.78. Means of PEFR, PIFR, EDI, PFM measurements, and DI scores all significantly improved after the operative intervention (p ≤ 0.05). The area under the curve for ROC curves for DI scores, PFM measurements, and EDI were highest in our cohort with values of 0.896, 0.823, and 0.806, respectively.

CONCLUSION

In our SGS cohort, PFM measurements correlate strongly with PEFR measurements. PFM measurements can adequately demonstrate disease progression and predict the need for surgery in this patient population. Together, DI scores and PFM measurements may be a useful tool to remotely follow patients with SGS and inform timing of in-person assessments.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:628-633, 2023.

Idiopathic double tracheal stenosis mimicking asthma: a case report

Idiopathic tracheal stenosis (Idio-SS) is an extremely rare disease. Its diagnosis is of exclusion and could be misdiagnosed as asthma. Herein, we report the case of a 39-year-old woman who had been treated for asthma for several months. She has no history of endotracheal intubation or granulomatous disease. Flexible fiberoptic bronchoscopy and thoracic computed tomography revealed double tracheal stenosis. The patient had rigid bronchoscopy; the upper tracheal stenosis was dilated with insertion of a silicone airway stent at the level of the distal stenosis. The diagnosis of idiopathic stenoses was made according to the clinico-radiological features. Symptoms were completely relieved and no recurrence was observed after one year of follow-up. This case highlights the importance of clinical suspicion and early diagnosis of Idio-SS in patients with unexplained wheezing and dyspnea. It also illustrates the role of endoscopic procedures in this situation.

Anxiety and Depression in Patients With Idiopathic Subglottic Stenosis

OBJECTIVES

To characterize the presence and severity of anxiety and depression in patients with symptomatic idiopathic subglottic stenosis (ISGS). To determine the relationship between dyspnea severity and anxiety and depression symptom severity.

METHODS

Patients diagnosed with idiopathic subglottic stenosis and treated at Mayo Clinic Florida or Mayo Clinic Arizona retrospectively completed the PROMIS Depression, PROMIS Anxiety, PROMIS Dyspnea Functional Limitations, and Dyspnea Index questionnaires. Patients with dyspnea and without idiopathic subglottic stenosis were also asked to complete the questionnaires as a control group.

RESULTS

This explorative retrospective study includes 44 control patients and 46 ISGS patients. Unadjusted and adjusted group comparisons found no statistically significant difference in dyspnea index, depression, anxiety, nor dyspnea functional limitation scores. Relationships between dyspnea severity and anxiety and depression severity were significant and persistent in both groups. Anxiety and depression were positively correlated (r = 0.66). Dyspnea severity positively correlate with both anxiety and depression (anxiety r = 0.49, depression r = 0.32).

CONCLUSIONS

Patients with symptomatic idiopathic subglottic stenosis are not at an increased risk of having anxiety and depression when compared to other dyspneic patients. As dyspnea severity worsens, patients are more likely to experience anxiety and depression. These findings support the prior literature and suggest the presence of dyspnea may warrant appropriate psychological screening and treatment to optimize dyspneic patients' quality of life and symptom improvement.

Post-intubation tracheal stenosis in pediatric age group: single-center experiences of 24 years

BACKGROUND AND AIM

Post-intubation tracheal stenosis (PITS) is an iatrogenic injury that involves some patients. Given the importance of this issue and the referral of a significant number of children with tracheal stenosis to Masih Daneshvari Hospital in Tehran, Iran, the present study investigated tracheal stenosis following prolonged intubation in the pediatric age group.

METHODS

In this observational retrospective study, from 1994 to 2018, the medical records of all children under 14 years of age with a history of PITS were reviewed. Demographic and clinical characteristics including signs and symptoms, the underlying condition that leads to intubation, duration of intubation, type of stenosis, and the therapeutic approach, type of surgery, and follow-up were collected and analyzed using SPSS.

RESULTS

Among 161 patients with a mean age of 9.8 ± 4.2 years, 69% were male. The site of stenosis was limited to the trachea in 47% and others both trachea and subglottic area were involved. The most common cause of intubation was trauma. The most common symptoms were dyspnea and wheezing. Success rates of reconstruction were 93.75% in type I, 82.15% in type II, and 35.70% in type III. Among the 16 patients who underwent Type III surgery, decannulation was not performed in 11 patients. Traction in the anastomosis and complications were stated in 26 and 10% of the patients respectively, a mortality rate of 8.7% was also reported.

CONCLUSION

In the case of endotracheal intubation, PITS should be considered in the differential diagnosis of dyspnea in children as well as adults.

Case report: Idiopathic subglottic stenosis in a girl; successful treatment with macrolides

An 8-year-old girl presented with treatment-refractory cough and inspiratory stridor. Bronchoscopies showed progressive scarring leading to narrowing of the proximal trachea (Myer-Cotton Grade 2) and epithelial metaplasia of the tracheal and bronchial mucosa. After excluding other causes of congenital and acquired tracheal stenosis, an idiopathic subglottic tracheal stenosis (iSGS) was diagnosed. Because of the patient's young age, a judicious therapeutic approach seemed appropriate. Therapy with azithromycin, followed by roxithromycin, was started. Symptoms almost completely subsided, spirometry normalized, and endoscopic and histologic findings improved considerably. Therapy has been continued for more than 3 years with normal lung function values, and no compromise on physical activities and development. In instances of iSGS, therapy with macrolides is worth considering before more invasive procedures such as dilatation, laser, intralesional injections, or surgical resection are performed.

Serial Intralesional Steroid Injection for Subglottic Stenosis: Systemic Side Effects and Impact on Surgery-Free Interval

Objectives

In-office serial intralesional steroid injections (SILSIs) have become a commonly used treatment for subglottic stenosis. We characterized the impact of SILSIs on the time between operating room visits and incidence of glucocorticoid systemic side effects.

Study Design

Retrospective case series.

Setting

Academic tertiary care center.

Methods

All patients with subglottic stenosis receiving SILSIs at 1 institution from 2016 to 2020 were included. Surgery-free interval was compared using paired t tests. Side effect incidence was calculated with Kaplan-Meier methodology for visualization.

Results

Nineteen patients and 207 procedures were included. The majority of patients were White (95%) and female (95%) and had idiopathic subglottic stenosis (53%). Mean surgery-free interval for all patients was 8.7 months (95% CI, 5.6-11.8) before initiating SILSIs. Of 11 patients with calculable surgery-free interval, 10 experienced improvement, with a mean surgery-free interval increase of 4.6 months (95% CI, 2.4-6.7). Seven patients have not required surgery since initiation of SILSIs, with a mean follow-up time of 28 months (95% CI, 25-31). Noncutaneous systemic side effects occurred at a mean 3.2 months (95% CI, 2.4-4.0) from first injection and included Cushing’s syndrome, increased intraocular pressure, central serous chorioretinopathy, and new insulin requirement in the setting of diabetes.

Conclusions

Ninety-one percent of patients who initiated SILSIs and had a subsequent return to the operating room experienced a mean 4.6-month increase in surgery-free interval. Systemic side effects of glucocorticoids occurred in 32% of patients after initiating SILSIs. This should be considered in preprocedure counseling and side effect monitoring during treatment.

Quality and readability of online information on idiopathic subglottic stenosis

OBJECTIVE

Idiopathic subglottic stenosis (ISS) is a chronic condition characterized by disease recurrence and multiple surgeries. These frustrated patients may utilize the internet to research their condition. The aim of this study was to determine the quality and readability of online ISS information.

METHODS

"Idiopathic subglottic stenosis" was entered into Google. The first 50 websites that met inclusion criteria were extracted. The DISCERN instrument, Flesch Reading Ease Score (FRES), and Flesch-Kincaid Grade Level (FKGL) assessed the quality and readability, respectively. Means, SDs, Pearson correlation coefficients, and two-tailed Student's t-test were calculated.

RESULTS

The 50 websites consisted of 17 patient-targeted and 33 professional-targeted websites, plus 30 major and 20 minor websites. The overall DISCERN, FRES, and FKGL scores were 2.81 ± 0.99, 27.75 ± 15.27, and 13.65 ± 2.79, respectively (mean ± SD). Patient-targeted websites had significantly lower quality (DISCERN [P < .00]) but were easier to read (lower FKGL [P < .00], higher FRES [P < .00]) than professional-targeted websites. Minor websites had a significantly lower quality (DISCERN [P < 0.00]) but were easier to read (lower FKGL [P < .00], higher FRES [P < .00]) than major websites. There was a positive correlation between overall quality and difficulty in readability.

CONCLUSION

The quality of online ISS information was suboptimal. Resources were too difficult to comprehend and readability scores were above AMA and NIH recommendations. Improved online information is required to properly educate this patient population.

LEVEL OF EVIDENCE

Level 4.

Multi-disciplinary management of patients with benign airway strictures: A review

Histologically benign airway strictures are frequently misdiagnosed as asthma or COPD and may present with severe symptoms including respiratory failure. A clear understanding of pathophysiology and existing classification systems is needed to determine the appropriate treatment options and predict clinical course. Clinically significant airway strictures can involve the upper and central airways extending from the subglottis to the lobar airways. Optimal evaluation includes a proper history and physical examination, neck and chest computed tomography, pulmonary function testing, endoscopy and serology. Available treatments include medical therapy, endoscopic procedures and open surgery which are based on the stricture's extent, location, etiology, morphology, severity of airway narrowing and patient's functional status. The acuity of the process, patient's co-morbidities and operability at the time of evaluation determine the need for open surgical or endoscopic interventions. The optimal management of patients with benign airway strictures requires the availability, expertise and collaboration of otolaryngologists, thoracic surgeons and interventional pulmonologists. Multidisciplinary airway teams can facilitate accurate diagnosis, guide management and avoid unnecessary procedures that could potentially worsen the extent of the disease or clinical course. Implementation of a complex airway program including multidisciplinary clinics and conferences ensures that such collaboration leads to timely, patient-centered and evidence-based interventions. In this article we outline algorithms of care and illustrate therapeutic techniques based on published evidence.

Drug-Eluting Endotracheal Tubes for Preventing Bacterial Inflammation in Subglottic Stenosis

OBJECTIVES/HYPOTHESIS

Subglottic stenosis (SGS) results from dysregulated extracellular matrix deposition by laryngotracheal fibroblasts causing scar tissue formation following intubation. Recent work has highlighted a relationship between this inflammatory state and imbalances in the upper airway microbiome. Herein, we engineer novel drug-eluting endotracheal (ET) tubes to deliver a model antimicrobial peptide Lasioglossin-III (Lasio) for the local modulation of the microbiome during intubation.

STUDY DESIGN

Controlled in vitro study.

METHODS

ET tubes were coated with a water-in-oil (w/o) emulsion of Lasio in poly(d,l-lactide-co-glycolide) (PLGA) by dipping thrice. Peptide release was quantified over 2 weeks via fluorometric peptide assays. The antibacterial activity was tested against airway microbes (Staphylococcus epidermidis, Streptococcus pneumoniae, and pooled human microbiome samples) by placing Lasio/PLGA-coated tubes and appropriate controls in 48 well plates with diluted bacteria. Bacterial inhibition and tube adhesion were tested by measuring optical density and colony formation after tube culture, respectively. Biocompatibility was tested against laryngotracheal fibroblasts and lung epithelial cells.

RESULTS

We achieved a homogeneous coating of ET tubes with Lasio in a PLGA matrix that yields a prolonged, linear release over 1 week (typical timeframe before the ET tube is changed). We observed significant antibacterial activity against S. epidermidis, S. pneumoniae, and human microbiome samples, and prevention of bacterial adherence to the tube. Additionally, the released Lasio did not cause any cytotoxicity toward laryngotracheal fibroblasts or lung epithelial cells in vitro.

CONCLUSION

Overall, we demonstrate the design of an effective-eluting ET tube to modulate upper-airway bacterial infections during intubation which could be deployed to help prevent SGS.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Pregnancy-associated idiopathic laryngotracheal stenosis: presentation, management and results of surgical treatment

OBJECTIVES

Idiopathic laryngotracheal stenosis (ILTS) is an uncommon problem arising mostly in women. In some, it arises during or is exacerbated by pregnancy. Experience with management of patients with this rare association is limited. This study seeks to evaluate the management of patients with pregnancy-associated ILTS and compare outcomes to cases not associated with pregnancy.

METHODS

Retrospective review of 15 patients undergoing surgical treatment of pregnancy-associated ILTS from 1971 to 2013. Variables of interest and airway outcomes were compared to patients with non-pregnancy-associated ILTS.

RESULTS

Pregnancy-associated ILTS was observed in 15/263 (5.7%) patients. Symptoms developed during their first pregnancy. When compared to non-pregnancy patients, these patients were younger (37 vs 47 years; P = 0.0003), had more prior tracheostomies (26.7% vs 10.9%; P = 0.085) and had more preoperative airway dilatations (86.7% vs 57.7%; P = 0.030). All patients completed pregnancy without complications and ultimately underwent laryngotracheal resection. The expression of hormonal receptors in the surgical specimens was similar in both groups (oestrogen receptors: 100% vs 75% and progesterone receptors: 71.4% vs 72.1%, in pregnancy and non-pregnancy patients, respectively). Airway outcomes were good/excellent in 13 (86.7%) patients with pregnancy-associated ILTS and 225 (90.7%) patients without pregnancy association (P = 0.642), and did not change when adjusting for other risk factors.

CONCLUSIONS

Pregnancy-associated ILTS is rare. The pathophysiology is unclear, but appearance of symptoms during pregnancy may suggest hormonal factors. To minimize foetal risk, dilatation during pregnancy followed by laryngotracheal resection after delivery is the preferred treatment. Pregnancy association does not seem to affect outcomes with expected satisfactory results in most patients.

Impact of Adjuvant Medical Therapies on Surgical Outcomes in Idiopathic Subglottic Stenosis

OBJECTIVES/HYPOTHESIS

Adjuvant medications including proton pump inhibitors (PPI), antibiotics (trimethoprim/sulfamethoxazole [TMP-SMX]), and inhaled corticosteroids (ICS) may be prescribed for patients with idiopathic subglottic stenosis (iSGS). We describe medication use with endoscopic dilation (ED) or endoscopic resection with medical treatment (ERMT) and evaluate impact on outcomes.

STUDY DESIGN

International, prospective, 3-year multicenter cohort study of 810 patients with untreated, newly diagnosed, or previously treated iSGS.

METHODS

Post hoc secondary analysis of prospectively collected North American Airway Collaborative data on outcomes linked with adjuvant medication utilization. Primary outcome was time to recurrent operation, evaluated using Kaplan-Meier curves and Cox regression analysis. Secondary outcomes of change in peak expiratory flow (PEF) and clinical chronic obstructive pulmonary disease questionnaire (CCQ) score over 12 months were compared.

RESULTS

Sixty-one of 129 patients undergoing ED received PPI (47%), and 10/143 patients undergoing ED received ICS (7%). TMP-SMX was used by 87/115 patients (76%) undergoing EMRT. PPI use in the ED group did not affect time to recurrence (hazard ratio [HR] = 1.00, 95% confidence interval [CI]: 0.53-1.88; P = .99) or 12-month change in PEF (L/min) (median [interquartile range], 12.0 [10.7-12.2] vs. 8.7 [-5.1 to 24.9]; P = .59), but was associated with 12-month change in CCQ (-0.05 [-0.97 to 0.75] vs. -0.50 [-1.60 to 0.20]; P = .04). ICS did not affect outcome measures. TMP-SMX use in ERMT did not affect time to recurrence (HR = 0.842, 95% CI: 0.2345-3.023; P = .79), PEF at 12 months (75 [68-89] vs. 81 [68-89]; P = .92), or 12-month change in CCQ (0.20 [-1.05 to 0.47] vs. -0.30 [-1.00 to 0.10]; P = .45).

CONCLUSION

There is no standard practice for prescribing adjuvant medications. These data do not support that adjuvant medications prolong time to recurrence or increase PEF. Patients with iSGS and gastroesophageal reflux disease may experience some symptom benefit with PPI.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 2021.

Comparative Treatment Outcomes for Patients With Idiopathic Subglottic Stenosis

Question

What are the outcomes of the 3 most common surgical approaches for idiopathic subglottic stenosis (iSGS)?

Findings

In this cohort study of 810 patients with iSGS who underwent 1 of the 3 most common surgical treatments, 23% of patients underwent a recurrent surgical procedure during the 3-year study period, but recurrence differed by modality (cricotracheal resection, 1%; endoscopic resection with adjuvant medical therapy, 12%; and endoscopic dilation, 28%). Among successfully treated patients, those who underwent cricotracheal resection reported the highest quality of life but the greatest perioperative risk and worst long-term voice outcomes.

Meaning

These results show the feasibility of integrating an engaged rare disease community with a network of surgeons to facilitate rapid and nuanced treatment comparisons; findings may help inform treatment decision-making in iSGS.

Importance

Surgical treatment comparisons in rare diseases are difficult secondary to the geographic distribution of patients. Fortunately, emerging technologies offer promise to reduce these barriers for research.

Objective

To prospectively compare the outcomes of the 3 most common surgical approaches for idiopathic subglottic stenosis (iSGS), a rare airway disease.

Design, Setting, and Participants

In this international, prospective, 3-year multicenter cohort study, 810 patients with untreated, newly diagnosed, or previously treated iSGS were enrolled after undergoing a surgical procedure (endoscopic dilation [ED], endoscopic resection with adjuvant medical therapy [ERMT], or cricotracheal resection [CTR]). Patients were recruited from clinician practices in the North American Airway Collaborative and an online iSGS community on Facebook.

Main Outcomes and Measures

The primary end point was days from initial surgical procedure to recurrent surgical procedure. Secondary end points included quality of life using the Clinical COPD (chronic obstructive pulmonary disease) Questionnaire (CCQ), Voice Handicap Index-10 (VHI-10), Eating Assessment Test-10 (EAT-10), the 12-Item Short-Form Version 2 (SF-12v2), and postoperative complications.

Results

Of 810 patients in this cohort, 798 (98.5%) were female and 787 (97.2%) were white, with a median age of 50 years (interquartile range, 43-58 years). Index surgical procedures were ED (n = 603; 74.4%), ERMT (n = 121; 14.9%), and CTR (n = 86; 10.6%). Overall, 185 patients (22.8%) had a recurrent surgical procedure during the 3-year study, but recurrence differed by modality (CTR, 1 patient [1.2%]; ERMT, 15 [12.4%]; and ED, 169 [28.0%]). Weighted, propensity score–matched, Cox proportional hazards regression models showed ED was inferior to ERMT (hazard ratio [HR], 3.16; 95% CI, 1.8-5.5). Among successfully treated patients without recurrence, those treated with CTR had the best CCQ (0.75 points) and SF-12v2 (54 points) scores and worst VHI-10 score (13 points) 360 days after enrollment as well as the greatest perioperative risk.

Conclusions and Relevance

In this cohort study of 810 patients with iSGS, endoscopic dilation, the most popular surgical approach for iSGS, was associated with a higher recurrence rate compared with other procedures. Cricotracheal resection offered the most durable results but showed the greatest perioperative risk and the worst long-term voice outcomes. Endoscopic resection with medical therapy was associated with better disease control compared with ED and had minimal association with vocal function. These results may be used to inform individual patient treatment decision-making.

Voice-Related Quality of Life Is Associated with Postoperative Change in Subglottic Stenosis

OBJECTIVES

To characterize the impact of subglottic stenosis (SGS) on voice-related quality of life (V-RQOL) and quantify the effect of treatment on voice outcomes.

STUDY DESIGN

Case series.

METHODS

Retrospective review of SGS patients treated from 1996 to 2018 at a single institution to assess for 1) V-RQOL association with individual patient cumulative treatment number and 2) V-RQOL correlation with treatment type, time between treatments, and degree of stenosis. Analysis included both parametric and nonparametric statistical comparison across treatment types and multivariable and univariate linear regression.

RESULTS

Sixty-one patients, predominantly white (93%) and female (93%), were included. Etiology of SGS included idiopathic (61%), iatrogenic (16%), granulomatosis with polyangiitis (16%), and other (7%). The plurality of patients had four or more treatments (44%), with the remainder having one (28%), two (13%), or three treatments (15%). Analysis of change between pre- and postoperative V-RQOL scores was completed for 130 treatments. These included dilation with laser incision (52%), in-office injection (34%), dilation without division (8%), cricotracheal resection (1%), and all other treatment (8%). For every 10% improvement in airway caliber postoperatively, there was a 1.3-point improvement in calculated V-RQOL (r = 0.27, P = .02). After adjustment for treatment type, age, sex, and SGS etiology, this association held (beta = 1.5, P = .02). Change in V-RQOL was not associated with treatment type, treatment number, or time between treatments.

CONCLUSION

Patients with subglottic stenosis who have greater degree of change in airway caliber experience greater improvement in V-RQOL scores following treatment. V-RQOL scores are not associated with treatment type or time between individual treatments.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:360-365, 2021.

Superior Strategy in Benign Tracheal Stenosis Treatment: Surgery or Endoscopy?

INTRODUCTION

 Due to the variations in (laryngeal) tracheal stenosis (TS) patient groups, there is still no consensus on which patient should be treated with endoscopy or surgery. The aim of the present study was to generate an algorithm in the light of the related literature and the data obtained from a clinic where both endoscopic and surgical treatments are conducted.

METHOD

 A retrospective analysis was performed on the data of a total of 56 patients during 2013 to 2019. A total of 38 patients were subject to surgery with 31 as a first treatment option and 7 due to the unsatisfactory results of endoscopic treatments. Endoscopic approaches were tried on a total of 29 patients with 25 as initial treatment and 4 due to postsurgical recurrence.

RESULTS

 Symptomatic full control ratio was determined as 69% with endoscopic treatments, 89.5% in subglottic stenosis (SGS) surgery (n = 19), and 89.5% in trachea surgery (n = 19). However, success rates with no recurrence were determined, respectively, as 40.0, 36.4, and 36.4% for patients subject to dilatation, stent, or T tube treatment. Dilatation was observed to be successful in patients with stenotic segment lengths of less than 1.5 cm (p = 0.02). Failure rates increased in SGS (p = 0.03) and TS (p = 0.12) in the surgical group with increasing stenotic segment length. The presence of comorbidities was not effective on treatment success.

CONCLUSION

 Endoscopic methods are preferred in cases of web-like stenosis. Surgical methods should first be considered for other patients and endoscopic methods should be used on patients who are not suited for surgery or in cases of postsurgical recurrence.

Proteomic and Genomic Methylation Signatures of Idiopathic Subglottic Stenosis

OBJECTIVE

Idiopathic subglottic stenosis (iSGS) is a chronic inflammatory condition that causes dyspnea and affects middle-aged women of White race and non-Latino or Hispanic ethnicity. To better characterize its phenotype and pathogenesis, we assessed the proteomic and genomic methylation signatures of subglottic tissue collected from iSGS patients compared to controls.

STUDY DESIGN

Molecular analysis of clinical biospecimens.

METHODS

We collected subglottic tissue biopsies from 12 patients during direct laryngoscopy, immediately prior to surgical treatment of iSGS; as well as from 4 age-, sex-, and race/ethnicity-matched control patients undergoing other direct laryngoscopic procedures. We isolated protein and genomic DNA, acquired proteomic data using label-free quantitative mass spectrometry techniques, and acquired genome-wide methylation data using bisulfite conversion and a microarray platform. We compared molecular profiles across the iSGS and control groups, and with respect to clinical course in the iSGS group. Eight of the 12 iSGS patients underwent subsequent blood collection and plasma isolation for further assessment.

RESULTS

Proteomic analysis revealed 42 differentially abundant proteins in the iSGS biopsies compared to controls, inferring enrichment of biological pathways associated with early wound healing, innate immunity, matrix remodeling, and metabolism. Proteome-based hierarchical clustering organized patients into two iSGS and one control subgroups. Methylation analysis revealed five hypermethylated genes in the iSGS biopsies compared to controls, including the biotin recycling enzyme biotinidase (BTD). Follow-up analysis showed elevated plasma BTD activity in iSGS patients compared to both controls and published normative data.

CONCLUSION

iSGS exhibits distinct proteomic and genomic methylation signatures. These signatures expand current understanding of the iSGS phenotype, support the possibility of disease subgroups, and should inform the direction of future experimental studies.

LEVEL OF EVIDENCE

Not applicable Laryngoscope, 131:E540-E546, 2021.

Biodegradable electrospun patch containing cell adhesion or antimicrobial compounds for trachea repair in vivo

Difficulty breathing due to tracheal stenosis (i.e. narrowed airway) diminishes the quality of life and can potentially be life-threatening. Tracheal stenosis can be caused by congenital anomalies, external trauma, infection, intubation-related injury, and tumors. Common treatment methods for tracheal stenosis requiring surgical intervention include end-to-end anastomosis, slide tracheoplasty and/or laryngotracheal reconstruction. Although the current methods have demonstrated promise for treatment of tracheal stenosis, a clear need exists for the development of new biomaterials that can hold the trachea open after the stenosed region has been surgically opened, and that can support healing without the need to harvest autologous tissue from the patient. The current study therefore evaluated the use of electrospun nanofiber scaffolds encapsulating 3D-printed PCL rings to patch induced defects in rabbit tracheas. The nanofibers were a blend of polycaprolactone (PCL) and polylactide-co-caprolactone (PLCL), and encapsulated either the cell adhesion peptide, RGD, or antimicrobial compound, ceragenin-131 (CSA). Blank PCL/PLCL and PCL were employed as control groups. Electrospun patches were evaluated in a rabbit tracheal defect model for 12 weeks, which demonstrated re-epithelialization of the luminal side of the defect. No significant difference in lumen volume was observed for the PCL/PLCL patches compared to the uninjured positive control. Only the RGD group did not lead to a significant decrease in the minimum cross-sectional area compared to the uninjured positive control. CSA reduced bacteria growth in vitro, but did not add clear value in vivo. Adequate tissue in-growth into the patches and minimal tissue overgrowth was observed inside the patch material. Areas of future investigation include tuning the material degradation time to balance cell adhesion and structural integrity.

Endoscopic Treatment of Idiopathic Subglottic Stenosis: A Systematic Review

Purpose: To identify different endoscopic techniques for treatment of idiopathic subglottic stenosis (iSGS) and evaluate treatment results.

Methods: Embase and Cochrane Library were searched for publications on endoscopically treated iSGS. Identified interventions included procedures with cold knife, dilation (rigid or balloon), or laser (CO₂ or Nd:YAG), used in several combinations and supplemented with mitomycin C and/or corticosteroids. Primary endpoint was time interval between successive endoscopic procedures. Secondary endpoints were stenosis recurrence rate, total number of interventions per patient during follow-up, tracheotomy rate, and rate of open surgery.

Results: Eighty-six abstracts were reviewed and 15 series were included in the analysis. Mean sample size was 57 subjects (range 10–384, σ 90.84) and mean age was 47 years (range 36–54, σ 4.45). Time interval ranged from 2 to 21 months [weighted mean (WM): 12]. Rate of stenosis recurrence ranged from 40 to 100% (WM: 68%). Mean amount of interventions per patient varied between 1.8 and 8.3 (WM: 3.7). Tracheotomy rate varied between 0 and 26% (WM: 7%) and rate of open surgery varied between 0 and 27% (WM: 10%). Single modality CO₂ lasering showed highest rate of recurrence, highest amount of interventions, and shortest time interval. Combined techniques generated overall better outcomes.

Conclusions: A multitude of endoscopic techniques are being used for treating iSGS, all with a considerable recurrence rate. In this review, no superior modality could be identified. Consequently, endoscopic management could be considered a valuable primary treatment option for iSGS, but open surgery still plays an important role.

Multicentric study applying the european laryngological society classification of benign laryngotracheal stenosis in adults treated by tracheal or cricotracheal resection and anastomosis

OBJECTIVES/HYPOTHESIS

Introduction and widespread use of cricotracheal resection and anastomosis (CTRA) as routine treatment for high-grade benign laryngotracheal stenosis (LTS) led to the need for a new classification system that could accurately predict surgical outcomes by integrating crucial stenosis and patient-related information. In 2015, the European Laryngological Society (ELS) proposed a new classification for benign LTS. We retrospectively tested it in adults treated at three referral centers to assess its reliability in predicting surgical outcomes.

STUDY DESIGN

Retrospective cohort study.

METHODS

We included 166 adults treated by open tracheal resection and anastomosis (TRA) and CTRA procedures, restaged according to the ELS classification evaluating grade of stenosis (I-IV, Myer-Cotton), number of subsites involved, and presence of systemic comorbidities. We correlated these parameters with decannulation, number of retreatments, and complications.

RESULTS

Final decannulation was predicted by a proposed ELS score ≥ IIIb, history of previous treatment, and length of resection (P < .05). Decannulation was achieved in 99% of patients without and in 88% of patients with surgical complications (P < .01). The incidence of surgical complications was related to the proposed ELS score (P < .01); an ELS score < IIIb showed a lower complication rate compared to patients with a ≥ IIIb score (32.8% vs. 57.7%, P < .01). Additional treatment was required in 73 (44%) patients (mean = 2.7 ± 2.2, range = 1-11). ELS score ≥ IIIb, length of resection, and occurrence of surgical complications predicted the number of such treatments (P < .05, P < .05, and P < .001, respectively).

CONCLUSIONS

ELS classification of benign LTS is able to accurately predict success in adult TRA/CTRA procedures and may be helpful in choice of therapy and patient counseling.

LEVEL OF EVIDENCE

2b Laryngoscope, 130:1640-1645, 2020.