Inhalation of Carboxymethyl Chitosan Alleviates Posttraumatic Tracheal Fibrosis

OBJECTIVES

The present study was performed to determine whether the inhalation of carboxymethyl (CM)-chitosan can alleviate tracheal fibrosis in a rabbit model.

METHODS

We designed a rabbit model of tracheal stenosis involving electrocoagulation with a spherical electrode. Twenty New Zealand white rabbits were randomly divided into experimental and control groups (10 animals each). Tracheal damage was successfully established by electrocoagulation in all animals. The experimental group was given CM-chitosan (inhalation for 28 days), while the control group inhaled saline. The effects of CM-chitosan inhalation on tracheal fibrosis were analyzed. Laryngoscopy was performed to evaluate and grade tracheal granulation, while tracheal fibrosis was evaluated by histological examination. The effects of CM-chitosan inhalation on the tracheal mucosa were examined by scanning electron microscopy (SEM), and hydroxyproline content in tracheal scar tissue was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Laryngoscopy showed that the tracheal cross-sectional area was smaller in the experimental than control group. The amounts of loose connective tissue and damaged cartilage, as well as the severity of collagen and fibrosis, decreased following inhalation of CM-chitosan. According to the ELISA, the experimental group had low levels of hydroxyproline in the tracheal scar tissue.

CONCLUSION

The findings presented here showed that inhalation of CM-chitosan mitigated posttraumatic tracheal fibrosis in a rabbit model, thus suggesting a potential new treatment for tracheal stenosis.

Down-regulation of miR-21-5p by pirfenidone to inhibit fibroblast proliferation in the treatment of acquired tracheal stenosis

OBJECTIVE

Treatment options for acquired tracheal stenosis (ATS) are limited due to a series of pathophysiological changes including inflammation and cell proliferation. Micro ribonucleic acid-21-5p (miR-21-5p) may promote the excessive proliferation of fibroblasts. However, various types of fibrosis can be prevented with pirfenidone (PFD). Currently, the effect of PFD on miR-21-5p and its biological function has not been clarified. In this study, PFD was evaluated as a potential treatment for ATS by inducing fibroblast proliferation in lipopolysaccharide (LPS)-induced fibroblasts by targeting miR-21-5p.

METHODS

For 48 h, 1 g/ml LPS was used to generate fibroblasts in vitro, followed by the separation of cells into four groups: control, PFD, mimic, and mimic + PFD. The Cell Counting Kit-8 (CCK-8) technique was adopted to measure the proliferation of fibroblasts. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB) were used to measure the relative expressions of tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), drosophila mothers against decapentaplegic 7 (Smad7) and collagen type I alpha 1(COL1A1) messenger RNA (mRNA) and proteins, respectively.

RESULTS

(1) At 0, 24, 48, and 72 h, fibroblast growth was assessed using the CCK-8 method. Compared with the control group, the mimic group showed the highest fibroblast viability, and the PFD group showed the lowest fibroblast viability. However, fibroblast viability increased in the mimic + PFD group but decreased in the mimic one. (2) RT-qPCR and WB showed that the mimic group exhibited a significant up-regulation in the relative expressions of TNF-α, TGF-β1, and COL1A1 mRNA and proteins but a down-regulation in the relative expression of Smad7 mRNA and protein compared with the control one. In the PFD group, the results were the opposite. Nevertheless, the relative expressions of TNF-α, TGF-β1, and COL1A1 mRNA and proteins were increased, whereas that of Smad7 mRNA was decreased in the mimic + PFD group. The change was less in the mimic group.

CONCLUSION

PFD may have a preventive and curative effect on ATS by inhibiting fibroblast proliferation and the fibrotic process and possibly through down-regulating miR-21-5p and up-regulating Smad7 and its mediated fibrotic and inflammatory responses.

Use of Mitomycin-C in Laryngotracheal Stenosis: A Focused Clinical Review

BACKGROUND

Therapeutic options for managing laryngotracheal stenosis (LTS) are limited. Endoscopy is a minimally invasive approach to treating LTS, but carries a high risk of stenosis recurrence. Mitomycin C (MMC) is often used as an adjunct therapy to delay the time to symptomatic recurrence of LTS. This review synthesizes the current literature on the topic of MMC as an adjunct treatment strategy for LTS.

METHODS

A focused literature search was carried out from PubMed on June 12, 2022 using the terms "mitomycin c AND stenosis" in all fields with no date limitations. Evidence-based recommendations relevant to the clinical application of MMC as an adjunct therapy for LTS were formulated. Three questions were addressed: 1) efficacy of MMC, 2) single versus multiple application(s) of MMC, and 3) safety of MMC. The evidence rating and recommendation strength were guided by the GRADE system.

RESULTS

Twenty-nine studies were reviewed. The efficacy of MMC as an adjunct therapy for LTS varied across studies. Randomized controlled trials have not shown an outcome difference with MMC use, although methodologic flaws including underpowering were noted. A meta-analysis of observational studies with a comparator arm found the unadjusted probability of remaining symptom-free for > 1 year is greater with versus without MMC application (73% vs. 35%). Single versus multiple application(s) of MMC resulted in similar restenosis rates at long-term follow-up. Complications related to MMC use are rarely reported using conventional doses (0.4 mg/mL). Overall, the quality of evidence was low and the recommendation for intervention was weak.

CONCLUSION

The role for MMC as an adjunct therapy in LTS is uncertain. While safe in its application, the efficacy of MMC in reducing stenosis recurrence remains a matter of debate. Large, prospective studies are needed to inform future recommendations.

Sirolimus-eluting airway stent reduces profibrotic Th17 cells and inhibits laryngotracheal stenosis

Laryngotracheal stenosis (LTS) is pathologic fibrotic narrowing of the larynx and trachea characterized by hypermetabolic fibroblasts and CD4+ T cell-mediated inflammation. However, the role of CD4+ T cells in promoting LTS fibrosis is unknown. The mTOR signaling pathways have been shown to regulate the T cell phenotype. Here we investigated the influence of mTOR signaling in CD4+ T cells on LTS pathogenesis. In this study, human LTS specimens revealed a higher population of CD4+ T cells expressing the activated isoform of mTOR. In a murine LTS model, targeting mTOR with systemic sirolimus and a sirolimus-eluting airway stent reduced fibrosis and Th17 cells. Selective deletion of mTOR in CD4+ cells reduced Th17 cells and attenuated fibrosis, demonstrating CD4+ T cells' pathologic role in LTS. Multispectral immunofluorescence of human LTS revealed increased Th17 cells. In vitro, Th17 cells increased collagen-1 production by LTS fibroblasts, which was prevented with sirolimus pretreatment of Th17 cells. Collectively, mTOR signaling drove pathologic CD4+ T cell phenotypes in LTS, and targeting mTOR with sirolimus was effective at treating LTS through inhibition of profibrotic Th17 cells. Finally, sirolimus may be delivered locally with a drug-eluting stent, transforming clinical therapy for LTS.

IL-11 drives the phenotypic transformation of tracheal epithelial cells and fibroblasts to enhance abnormal repair after tracheal injury

Tracheal stenosis (TS) is a multifactorial and heterogeneous disease that can easily lead to respiratory failure and even death. Interleukin-11 (IL-11) has recently received increased attention as a fibrogenic factor, but its function in TS is uncertain. This study aimed to investigate the role of IL-11 in TS regulation based on clinical samples from patients with TS and a rat model of TS produced by nylon brush scraping. Using lentiviral vectors expressing shRNA (lentivirus-shRNA) targeting the IL-11 receptor (IL-11Rα), we lowered IL-11Rα levels in the rat trachea. Histological and immunostaining methods were used to evaluate the effects of IL-11Rα knockdown on tracheal injury, molecular phenotype, and fibrosis in TS rats. We show that IL-11 was significantly elevated in circulating serum and granulation tissue in patients with TS. In vitro, TGFβ1 dose-dependently stimulated IL-11 secretion from human tracheal epithelial cells (Beas-2b) and primary rat tracheal fibroblasts (PRTF). IL-11 transformed the epithelial cell phenotype to the mesenchymal cell phenotype by activating the β-catenin pathway. Furthermore, IL-11 activated the atypical ERK signaling pathway, stimulated fibroblasts proliferation, and transformed fibroblasts into alpha-smooth muscle actin (α-SMA) positive myofibroblasts. IL-11-neutralizing antibodies (IL-11NAb) or ERK inhibitors (U0126) inhibited IL-11 activity and downregulated fibrotic responses involving TGFβ/SMAD signaling. In vivo, IL-11Rα knockdown rats showed unobstructed tracheal lumen, relatively intact epithelial structure, and significantly reduced granulation tissue proliferation and collagen fiber deposition. Our findings confirm that IL-11 may be a target for future drug prevention and treatment of tracheal stenosis.

Comparison of Inhaled Drug Delivery in Patients With One- and Two-level Laryngotracheal Stenosis

OBJECTIVES/HYPOTHESIS

Laryngotracheal stenosis (LTS) is a functionally devastating condition with high respiratory morbidity and mortality. This preliminary study investigates airflow dynamics and stenotic drug delivery in patients with one- and two-level LTS.

STUDY DESIGN

A Computational Modeling Restropective Cohort Study.

METHODS

Computed tomography scans from seven LTS patients, five with one-level (three subglottic, two tracheal), and two with two-level (glottis + trachea, glottis + subglottis) were used to reconstruct patient-specific three-dimensional upper airway models. Airflow and orally inhaled drug particle transport were simulated using computational fluid dynamics modeling. Drug particle transport was simulated for 1-20 μm particles released into the mouth at velocities of 0 m/s, 1 m/s, 3 m/s, and 10 m/s for metered dose inhaler (MDI) and 0 m/s for dry powder inhaler (DPI) simulations. Airflow resistance and stenotic drug deposition in the patients' airway models were compared.

RESULTS

Overall, there was increased airflow resistance at stenotic sites in subjects with two-level versus one-level stenosis (0.136 Pa s/ml vs. 0.069 Pa s/ml averages). Subjects with two-level stenosis had greater particle deposition at sites of stenosis compared to subjects with one-level stenosis (average deposition 2.31% vs. 0.96%). One-level stenosis subjects, as well as one two-level stenosis subject, had the greatest deposition using MDI with a spacer (0 m/s): 2.59% and 4.34%, respectively. The second two-level stenosis subject had the greatest deposition using DPI (3.45%). Maximum deposition across all stenotic subtypes except one-level tracheal stenosis was achieved with particle sizes of 6-10 μm.

CONCLUSIONS

Our results suggest that patients with two-level LTS may experience a more constricted laryngotracheal airflow profile compared to patients with one-level LTS, which may enhance overall stenotic drug deposition.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:366-374, 2023.

Rapid and durable response to fifth-line lorlatinib plus olaparib in an ALK -rearranged, BRCA2-mutated metastatic lung adenocarcinoma patient with critical tracheal stenosis: a case report

Treatment options for heavily treated anaplastic lymphona kinase (ALK )-positive nonsmall cell lung cancer (NSCLC) patients, who typically bear-resistant mechanisms to ALK tyrosine kinase inhibitors (TKIs), are usually limited to chemotherapy, which elicits limited clinical benefit and may incur severe toxicity. It is clinically relevant to explore other revenues for these patients. poly (ADP-ribose) polymerase (PARP) inhibitors, such as olaparib are currently approved to treat BReast CAncer gene 1/2 ( BRCA1/2 )-mutated patients in a few tumor types. There have been a trial and two case reports of an olaparib-containing regimen in treating epidermal growth factor receptor (EGFR)-positive or driver-negative NSCLC. We report a case of a 27-year-old female nonsmoker diagnosed with ALK -rearranged metastatic lung adenocarcinoma. She was treated with alectinib and acquired ALK p.I1171N and p.V1180L mutations. Germline BRCA2 p.F2801fs was also identified. After sequential lines of ceritinib and chemotherapy, lorlatinib was chosen as the fourth-line therapy and maintained control for 6 months. Shortly after progression, the patient was admitted to the ICU due to critically severe stenosis caused by a tracheal mass and soon relieved by embolization and stenting. Afterward lorlatinib plus olaparib was started and elicited a rapid response within 1 month. The progression-free survival was 6 months as of the latest follow-up, with the best response of partial response. To the best of our knowledge, this case is the first to provide clinical evidence of antitumor activity of olaparib plus ALK TKI in ALK -positive, g BRCA -mutated metastatic NSCLC. Together with previous reports in EGFR -positive or driver-negative patients, our finding warrants further studies on PARP inhibition in BRCA1/2 -mutated NSCLC.

Orally Inhaled Drug Particle Transport in Computerized Models of Laryngotracheal Stenosis

OBJECTIVE

Adjuvant management for laryngotracheal stenosis (LTS) may involve inhaled corticosteroids, but metered dose inhalers are designed for pulmonary drug delivery. Comprehensive analyses of drug particle deposition efficiency for orally inhaled corticosteroids in the stenosis of LTS subjects are lacking.

STUDY DESIGN

Descriptive research.

SETTING

Academic medical center.

METHODS

Anatomically realistic 3-dimensional reconstructions of the upper airway were created from computed tomography images of 4 LTS subjects-2 subglottic stenosis and 2 tracheal stenosis subjects. Computational fluid dynamics modeling was used to simulate airflow and drug particle transport in each airway. Three inhalation pressures were simulated, 10 Pa, 25 Pa, and 40 Pa. Drug particle transport was simulated for 100 to 950 nanoparticles and 1 to 50 micron-particles. Particles were released into the airway to mimic varying inhaler conditions with and without a spacer chamber.

RESULTS

Based on smallest to largest cross-sectional area ratio, the laryngotracheal stenotic segment shrunk by 57% and 47%, respectively, for subglottic stenosis models and by 53% for both tracheal stenosis models. Airflow resistance at the stenotic segment was lower in subglottic stenosis models than in tracheal stenosis models: 0.001 to 0.011 Pa.s/mL vs 0.024 to 0.082 Pa.s/mL. Drug depositions for micron-particles and nanoparticles at stenosis were 0.06% to 2.48% and 0.10% to 2.60% for subglottic stenosis and tracheal stenosis models, respectively. Particle sizes with highest stenotic deposition were 6 to 20 µm for subglottic stenosis models and 1 to 10 µm for tracheal stenosis models.

CONCLUSION

This study suggests that at most, 2.60% of inhaled drug particles deposit at the stenosis. Particle size ranges with highest stenotic deposition may not represent typical sizes emitted by inhalers.

Fiberoptic Bronchoscopic Submucosal Injection of Mitomycin C for Recurrent Bening Tracheal Stenosis: A Case Series

BACKGROUND

Benign tracheal stenosis has emerged as a therapeutic challenge for physicians involved in the care of survivors of critical care units. Although the traditional mainstay of open surgical reconstructive treatment is still considered the gold standard, endoscopic therapies such as laser re-canalization, balloon dilation, or stenting are commonly practiced in invasive bronchology. Recurrent obstructing granulomas pose a challenge for bronchoscopists. Mitomycin C (MyC) is a cytotoxic agent that is isolated from Streptomyces caespitosus and acts by inhibiting DNA and RNA synthesis through alkylation and cross-linkages. Topical MyC is commonly used in indirect laryngoscopies for the treatment of granulation tissue in the trachea by using saturated pledgets.

OBJECTIVES

To describe fiberoptic bronchoscopic submucosal injection of MyC as a treatment for recurrent bening tracheal stenosis.

METHODS

The authors report their successful experience with submucosal intralesional injection of MyC in the management of recurrent obstructing granulomas/stenosis using the flexible fiberoptic bronchoscope in a series of 10 patients between 2005 and 2019.

RESULTS

The results suggest that intralesional injection of MyC using the flexible bronchoscope after the endoscopic treatment of the stenotic lesion may reduce the rate of subsequent formation of granulation tissue and scarring without side effects.

CONCLUSIONS

The efficacy of MyC injection should be studied prospectively.

Autoimmune Tracheal Cartilage Inflammation Responsive to Anti-TNF-α Therapy

Tracheal inflammation, or tracheitis, is a pathologic process that can occur secondary to a number of systemic inflammatory diseases, or it may be idiopathic in nature. Regardless of the underlying etiology, tracheitis can, in its most severe form, be life-threatening, thus making its treatment an area of interest. Our case is one of a 50-year-old man with a remote history of inflammatory bowel disease achieving clinical cure following surgical resection who presented with progressive dyspnea due to tracheal stenosis that was presumed secondary to an autoimmune and inflammatory etiology. His disease was initially refractory to recurrent surgical interventions. He ultimately achieved clinical improvement with a combination of methotrexate and the tumor necrosis factor alpha (TNF-α) inhibitor, adalimumab. While both clinical trials and standardized treatment guidelines are lacking in this domain, this case illustrates a potential role for TNF-α inhibitors in the treatment of inflammatory tracheitis, irrespective of the underlying etiology.

Targeting metabolic abnormalities to reverse fibrosis in iatrogenic laryngotracheal stenosis

OBJECTIVE

Management of laryngotracheal stenosis (LTS) remains primarily surgical, with a critical need to identify targets for adjuvant therapy. Laryngotracheal stenosis scar fibroblasts exhibit a profibrotic phenotype with distinct metabolic shifts, including an increased glycolysis/oxidative phosphorylation ratio. This study examines the effects of the glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) on collagen production, gene expression, proliferation, and metabolism of human LTS-derived fibroblasts in vitro.

METHOD

Paired normal and scar-derived fibroblasts isolated from subglottic and proximal tracheal tissue in patients with iatrogenic laryngotracheal stenosis (iLTS) were cultured. Proliferation rate, gene expression, protein production, and cellular metabolism were assessed in two conditions: 1) fibroblast growth medium, and 2) fibroblast growth medium with 1 × 10-4 M DON.

RESULTS

DON treatment reduced cellular proliferation rate (n = 7, P =  0.0150). Expression of genes collagen 1 and collagen 3 both were reduced (n = 7, P =  0.0102, 0.0143, respectively). Soluble collagen production decreased (n = 7, P =  0.0056). As measured by the rate of extracellular acidification, glycolysis and glycolytic capacity decreased (n = 7, P =  0.0082, 0.0003, respectively). adenosine triphosphate (ATP) production and basal respiration decreased (n = 7, P = 0.0045, 0.0258, respectively), determined by measuring the cellular rate of oxygen consumption.

CONCLUSION

The glutamine antagonist DON reverses profibrotic changes by inhibiting both glycolysis and oxidative phosphorylation in iLTS scar fibroblasts. In contrast to untreated iLTS scar fibroblasts, collagen gene expression, protein production, metabolic rate, and proliferation were significantly reduced. These results suggest DON and/or its derivatives as strong candidates for adjuvant therapy in the management of iatrogenic laryngotracheal stenosis. Enzymes involved in glutamine metabolism inhibited by DON offer targets for future investigation.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:E59-E67, 2018.

Laryngotracheal Stenosis Repair Using Cartilage-Derived Morphogenic Proteins: A Pilot Study

Objectives:

This pilot study evaluated the role of cartilage-derived morphogenic proteins (CDMPs) as promoters of cartilage growth and differentiation and as a possible alternative to autologous cartilage grafts in laryngotracheal reconstruction.

Methods:

In phase 1, 6 New Zealand rabbits underwent subperichondrial injection of CDMP-1, CDMP-2, or CDMP-3 in the right thyroid ala and normal saline solution in the left thyroid ala as controls. In phase 2, 14 rabbits underwent anterior cricoid split and interposition of a fibrillar collagen sponge saturated with normal saline solution, CDMP-2, or CDMP-3.

Results:

In both phases, saline solution failed to induce new cartilage or bone growth. Small foci of cartilage and/or bone formation were observed within the thyroid subperichondria of those rabbits injected with CDMP-2 or CDMP-3. In phase 2, a few small foci of new cartilage and/or bone formation were observed at the edges of the cricoid split with CDMP-2 and CDMP-3.

Conclusions:

A different carrier of CDMP, a change in dosage, or a combination of CDMPs might yield more significant neochondrification. The role of CDMPs as promoters of cartilage and differentiation could not be disqualified in this study and should be further investigated.

[Improved results of the trachea scar stenosis treatment by inclusion in the complex therapy of combined application diprospan and low-intensity infrared laser radiation]

The experience of treating 61 patients over the rumen of stenosis of the trachea was summarizes. To improve the results suggested inclusion complex diprospan treatment in combination with low intensity infrared laser radiation. The advantages of the proposed method of treatment of tracheal stenosis scarring are reduced severity of chronic inflammation, reducing the proliferation of granulation tissue.

A case of subglottic and diffuse tracheal stenoses appearing responsive to macrolide therapy

We present an atypical case of subglottic stenosis with diffuse tracheal stenoses in a child responsive only to steroid and azithromycin (AZI) therapy. A 12-year-old boy presented with acute biphasic stridor on the background of an 18-month history of progressive shortness of breath, decreased exercise tolerance and snoring. Subsequent laryngoscopy and bronchoscopy revealed granulation tissue in the subglottic area, two circumferential stenoses of the trachea and a number of fibrous bands at the carina and at the aperture if the right main bronchus were seen. A battery of serological and histological investigations did not reveal a specific aetiology. In the acute phase this patient only responded to steroid therapy. In the medium term, repeat laryngoscopies were performed with sharp division of stenotic bands and balloon dilatation. The patient's condition was unresponsive to non-steroidal anti-inflammatories, multiple first-line antibiotics, and surgical treatment of the tracheal lesions. However definitive treatment was found with the macrolide antibiotic AZI used for its anti-inflammatory properties. This highly unusual case of diffuse tracheal stenoses in a child proved to be a management challenge. Definitive treatment was found with the use of AZI. From our literature search this appears to be the first reported case of AZI successfully treating subglottic and tracheal stenoses.

[The application of the cryosurgical and lymphotropic technologies for the combined treatment of postintubation tracheal stenosis]

The combined treatment of 10 patients presenting with postintubation thracheal stenosis was carried out with the application of the cryosurgical and lymphotropic technologies. Cryogenic treatment of ciatrical stenosis was performed through the tracheostoma using a titanium nickelide cryoappliactor. The effect of the cryogenic treatment was enhanced by a lymphotropic mixture composed of diprospan and longidaza and administered retrosternally as a course of up to three injections once in a week. In the intervals between the injections and after the termination of the course, the patients were asked to inhale longidaza dissolved in a broncho- or mucolytic preparation through a nebulizer (up to 5 inhalations). All the treated patients reported the recovery of normal breathing through the natural airways.

[Hypothyroid goiter with tracheal compression in a child in Cote d'Ivoire]

The purpose of this report is to describe a case involving a primary form of hypothyroid goiter with tracheal compression discovered late in a four-year-old child. Slowing of height and weight gain and mental retardation was irreversible. The child was treated using L-thyroxin. Systematic screening for hypothyroidism during the neonatal period is recommended in developing countries.

Photodynamic Therapy for Airway Stenosis in Rabbit Models

BACKGROUND

Acquired airway stenosis in childhood is resistant to conventional treatment. We examined whether endoscope-assisted photodynamic therapy (PDT) is effective for airway stenosis in animal models of which the pathophysiologic progressions are similar to those of clinical cases showing rapid deterioration.

METHODS

Tracheal mucosa-scraped rabbits were administered IV porfimer sodium (Photofrin; Wyeth K.K., Tokyo, Japan) [2 mg/kg], and the tracheal lesions were irradiated with 630 nm of light emitted from a cylindrical diffuser tip via a transtracheal approach.

RESULTS

Rabbits without PDT (untreated animals) showed dense granulation tissue in the scraped lesion, resulting in airway stenosis complicated with respiratory stridor. PDT ameliorated the degree of airway stenosis (p = 0.008) and reduced respiratory stridor; rabbits that received PDT showed patchy granulation tissue that was only 20 to 30% of the volume of that seen in the untreated animals. Survival time of rabbits that received PDT was significantly prolonged compared with that of untreated animals (p = 0.03).

CONCLUSIONS

PDT was effective for airway stenosis in rabbit models. This suggests that PDT has the potential as a new therapeutic method for airway stenosis originating from granulation tissue.

Topical application of mitomycin C in the treatment of esophageal and tracheobronchial stricture: a report of 2 cases

We present 2 cases of successful treatment of recurrent anastomotic strictures using a topical application of mitomycin C. In the first case, a 4-year-old boy had a cervical cyst excised, which appeared to be an ectopic gastric mucosa. He consequently presented severe stenosis at the origin of the cervical esophagus that needed repeated balloon dilatations. The second case is about a 12-year-old girl who presented a traumatic complete rupture of the right mainstem bronchus managed by primary repair, with subsequent anastomotic stricture. Both patients were successfully managed with topical application of mitomycin C (1 mg/mL), and needed no more dilatations.

[Total idiopathic laryngotracheal stenosis. Treatment with mitomycin C]

This case report involves a 69-year-old woman who presented idiopathic laryngotracheal stenosis with total obstruction of the airway. Seven surgical procedures involving open field and endoscopy techniques had to be performed due to repeated re-obstructions. The novelty in this case is that success was finally obtained with the use of mitomycin C. The drug action is well known, but is interesting to report a case in which success was only obtained when we used mitomycin C.

The Efficacy of Mitomycin-C in the Treatment of Laryngotracheal Stenosis

OBJECTIVE

The purpose of this study is to evaluate whether the addition of topical mitomycin-C (MMC) application to the wound site after endoscopic treatment of laryngotracheal stenosis (LTS) resulted in measurable improvement in clinical outcomes.

STUDY DESIGN AND SETTING

A retrospective chart review of patients with LTS treated by the senior author over a 6-year period was performed. The treatment groups were stratified into two main categories: 1) endoscopic treatment alone and 2) endoscopic treatment + topical MMC. The "symptom-free" interval was determined (in months) for each subject using a two-tailed t test for statistical analysis of the control/study groups.

RESULTS

Sixty-seven procedures were performed in 36 patients with LTS with a mean of 1.86 surgical treatments per patient. The mean duration of the symptom-free interval after endoscopic treatment for LTS was 4.9 months in the endoscopic-only treatment group and 23.2 months in the endoscopic group receiving topical MMC. The symptom-free interval observed in the MMC group was significantly longer than the control subjects (P = 1 x 10).

CONCLUSIONS

The results of this study suggest that MMC is an effective adjuvant in the treatment of LTS. The results of this study provide strong supporting evidence that topical MMC is an effective adjuvant in the treatment of LTS.

Severe airway stenosis associated with Crohn's disease: case report

Background

Symptomatic respiratory tract involvement is not common in Crohn's disease. Upper-airway obstruction has been reported before in Crohn's disease and usually responds well to steroid treatment.

Case presentation

We report a case of a 32-year old patient with Crohn's disease who presented with progressively worsening dyspnea on exertion. Magnetic Resonance Imaging of the chest and bronchoscopy revealed severe tracheal stenosis and marked inflammation of tracheal mucosa. Histopathology of the lesion showed acute and chronic inflammation and extended ulceration of bronchial mucosa, without granulomas. Tracheal stenosis was attributed to Crohn's disease after exclusion of other possible causes and oral and inhaled steroids were administered. Despite steroid treatment, tracheal stenosis persisted and only mild symptomatic improvement was noted after 8 months of therapy. The patient subsequently underwent rigid bronchoscopy with successful dilatation and ablation of the stenosed areas and remission of her symptoms.

Conclusion

Respiratory involvement in Crohn's disease might be more common than appreciated. Interventional pulmonology techniques should be considered in cases of tracheal stenosis due to Crohn's disease refractory to steroid treatment.

Official Journal of the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc and the American Academy of Otolaryngic Allergy

OBJECTIVE

The management of laryngeal and tracheal stenosis remains a challenging problem despite advances in endoscopic surgical techniques. Scar formation and restenosis is the main cause of failure, and this study assesses the efficacy of two adjuvant treatments: endoscopic steroid injection and topical mitomycin C application. Study design and setting This is a retrospective cohort study comparing the efficacy of 3 endoscopic techniques: (1) carbon dioxide (CO(2)) laser incisions with bronchoscopic dilatation, (2) CO(2) laser with dilatation followed by steroid injection into the stenotic area, and (3) CO(2) laser with dilatation followed by topical application of mitomycin C. Included in the statistical analysis were 47 procedures performed by the senior investigator in a tertiary medical center between 1994 and 2001 based on their success or failure.

RESULTS

The percentages of successful outcomes in the study groups were 15%, 18.2%, and 75% with the CO(2) laser, CO(2) laser with steroid injection, and CO(2) laser with mitomycin C, respectively. Statistical comparisons reveal that the differences in outcomes were statistically significant (P < 0.05) between the mitomycin group and each of the other two treatment groups, whereas there was no statistically significant difference between the laser only and laser with steroid groups. There were no complications noted with the use of adjuvant medications.

CONCLUSION

These patient group results indicate a statistically significant increase, from <20% to 75%, in the success rate of endoscopic treatment of acquired upper airway stenosis when topical mitomycin C is added to the treatment regimen. No benefit has been demonstrated for using intraoperative local steroid injections as an adjunct to laser treatment. Clinical significance Mitomycin C appears to be an effective and safe adjuvant treatment in the endoscopic management of laryngeal and tracheal stenosis.

[Effect of the hyaluronic acid on tracheal healing. A canine experimental mode]

Several drugs have been used to modulate of the tracheal healing process in order to prevent tracheal stenosis. Hyaluronic acid (HA) is a modulator of the fibrogenesis. In this work we evaluate the effect in order the application of hyaluronic acid has on tracheal healing, after cervical tracheoplasty in dogs. A cervical tracheal resection and tracheoplasty was performed in 12 dogs and they were treated following surgery as follows: Group I (n = 6) Topical application of normal saline solution (0.9%) on the anastomosis site. Group II Topical application of hyaluronic acid on the trachea anastomosed. The animals were evaluated clinical, radiological and tracheoscopically during 4 weeks and were submitted to euthanasia. Macroscopic and microscopic examinations of the tracheal anastomotic healing were evaluated. Biochemical collagen quantification by the Woessner method was performed to evaluate the collagen development at the anastomotic site. All the animals survived the surgical procedure and the study time. No animal presented differences in clinical evaluation. Radiological and endoscopical findings both two showed more development of the tracheal stenosis in-group than in group II. The tracheoscopy and macroscopic studies showed major inflammation and development of fibrotic tissue with a firm consistency in the healing of the group I than in group II. Microscopic examination in group I showed severe fibrosis and inflammatory reaction. The group II presented deposits of a thin and organized collagen fibers and minimal inflammatory reaction. Biochemical collagen concentration was larger in-group I, however significantly. We conclude that the hyaluronic acid applied after cervical tracheoplasty in dogs reduces postsurgical tracheal stenosis and inflammation, as well as improve the quality of the tracheal healing.

Mitomycin Does Not Prevent Laryngotracheal Repeat Stenosis After Endoscopic Dilation Surgery: An Animal Study

OBJECTIVES/HYPOTHESIS

Conflicting data exist in the literature regarding the role of mitomycin in the prevention and treatment of laryngotracheal stenosis. The purpose of the study was to assess the value of mitomycin in preventing repeat stenosis after endoscopic dilation surgery of well-established stenoses.

STUDY DESIGN

Prospective controlled animal study.

METHODS

Laryngotracheal stenosis was induced in 16 dogs. After a period of 3 months the dogs underwent endoscopic dilation and were randomly divided into two groups. The control group received immediate topical application of normal saline. Dogs in the mitomycin group received immediate topical application of 0.5 mg mitomycin. The animals were then observed for 3 more months before euthanasia. The laryngeal lumens were measured endoscopically at baseline, before dilation, and before euthanasia. A comparison was made between the two study groups by means of the Wilcoxon rank-sum test for change in the percentage of stenosis attained by the endoscopic dilation.

RESULTS

Nine dogs were included in the control group, and seven in the mitomycin group. Group comparison for initial occlusion before endoscopic dilation using Wilcoxon rank-sum test showed no difference between the two groups (z = 0.16 [P =.87]). Three months after endoscopic dilation, no difference was observed between the two groups regarding the change in the percentage of occlusion (z = -0.21 [P =.83]).

CONCLUSION

Mitomycin exerts a benefit equal to that of normal saline when applied to a well-established laryngotracheal stenosis in dogs and does not prevent repeat stenosis after endoscopic dilation surgery.

[Airway manifestations of relapsing polychondritis: treatment with cyclophosphamide and placement of bronchial stents]

We report the case of a 41-year-old female patient with relapsing polychondritis and severe respiratory involvement. The patient presented with acute respiratory failure requiring endotracheal intubation. Bronchoscopy revealed tracheal collapse and inflammatory stenoses with dynamic collapse of the major airways. We describe a multidisciplinary therapeutic approach, consisting of immunosuppressive treatment, bronchoscopic placement of self-expandable stents into the collapsing bronchi, and tracheotomy. In addition, we report the effectiveness of oral cyclophosphamide for treatment of relapsing polychondritis with severe respiratory involvement after failure of other immunosuppressive agents. The problem of severe respiratory complications in patients with relapsing polychondritis and the need for a multidisciplinary approach is discussed.

The role of mitomycin in the prevention and treatment of scar formation in the pediatric aerodigestive tract: friend or foe?

OBJECTIVE

To evaluate the role of mitomycin in the prevention and treatment of scar formation in the pediatric aerodigestive tract.

DESIGN

Prospective study; institutional review board-approved clinical trial.

SETTING

Tertiary care pediatric medical center.

PATIENTS

Fifteen patients; choanal atresia in 5 patients, airway stenosis in 8 patients, hypopharyngeal stenosis in 1 patient, and esophageal stenosis in 1 patient.

OUTCOME

The efficacy and safety of mitomycin in the prevention of scar formation.

INTERVENTION

All patients underwent surgical repair of the stenotic area, followed by topical application of mitomycin (1 mL of 0.4 mg/mL) for 4 minutes.

RESULTS

Ten patients (67%) showed major improvement, 4 patients (27%) showed minor improvement, and 1 patient (7%) showed no improvement.

CONCLUSION

Topical application of mitomycin can play an effective role in the prevention and treatment of scar formation in the aerodigestive tract.

Comparison of 5-aminolaevulinic acid and porphyrin photosensitization for photodynamic therapy of malignant bronchial stenosis: a clinical pilot study

BACKGROUND AND OBJECTIVES

Photosan, a mixture of porphyrin oligomers as sensitizer for photodynamic therapy (PDT), carry the risk of prolonged photosensitivity of the skin. New sensitizer such as 5-aminolaevulinic acid (ALA) with low rates of skin phototoxicity appear to be promising alternatives. The aim of this study was to evaluate the efficacy of ALA compared to Photosan for PDT in malignant tracheo-bronchial stenosis. Reduction of tumor stenosis, increase in quality of life, and phototoxicity were considered as primary objectives. Improvement in clinical symptoms due to reduction of tumor stenosis, for example hemotysis, dyspnea, and poststenotic pneumonia were considered as secondary objectives.

PATIENTS AND METHODS

After diagnostic work-up, photosensitization was done in 16 patients with ALA (60 mg/kg BW, oral, 6-8 hours prior to PDT) and in 24 patients with Photosan (2 mg/kg BW, i.v., 48 hours before PDT). The light dose was calculated as 100 J/cm(2) tumor length. Light at 630 nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 absolute atmospheric pressure.

RESULTS

Stenosis diameter and Karnofsky performance status showed a significant improvement in favor of the Photosan-group, P = 0.00073 and 0.00015, respectively. In both groups no sunburn occurred due to phototoxicity of the sensitizer.

CONCLUSION

Despite the limitations of a non-randomized study, photosensitization with Photosan seems to be more effective in PDT of malignant tracheo-bronchial stenosis compared to ALA.

Beclomethasone diproprionate inhalation as a treatment for post-intubation tracheal stenosis

A 67-year-old man was intubated for one week and suffered from wheeze and dyspnoea three months after the extubation. Bronchoscopy revealed tracheal stenosis by a web, which subsequent biopsy showed to be granulation tissue. The stenosis was removed by laser therapy but the stenosis soon returned. As cardiac function was poor, beclomethasone diproprionate (BDP) inhalation therapy (1200 micrograms daily) was started and proved successful. Discontinuation of inhalation therapy resulted in restenosis. Steroid inhalation therapy may be able to control post-intubation tracheal stenosis caused by granulation tissue.

[Clinical analysis of 19 cases of scleroma respiratorium treated surgically]

Nineteen patients with scleroma respiratorium treated surgically were studied retrospectively. The results suggested that the surgical operation combined with antibiotic therapy were beneficial to the curtive effect of the patients in the granulomatous stage with nasal or pharyngeal obstruction or nasal sinuses involvement due to the serious proliferation of the lesions; tracheotomy should be considered in the patients with laryngeal obstruction up to the second degree or above; plastic operations were necessary for the patients with cicatrical stenosis or imperforation remained of the nasal cavity, pharynx, larynx or trachea.

Sonographic imaging of the trachea

We evaluated the feasibility of ultrasonography for imaging of the trachea and its effectiveness in the diagnosis and follow-up of patients with tracheal stenosis due to various diseases. Twenty normal volunteers and six adult patients with tracheal stenosis were included in the study group. Subjects were examined with ultrasonography in a supine position with the neck hyperextended or in a sitting position. At the level of the thyroid isthmus, the anterior tracheal wall thicknesses imaged by ultrasonography were 1.54 +/- 0.22 mm (mean +/- SD) and 1.22 +/- 0.18 mm for normal male and female volunteers, respectively. Ultrasonography could reveal the intrinsic tracheal wall lesions and extrinsic lesions compressing the trachea in patients with tracheal stenosis. These ultrasonographic images correlated with CT images. In conclusion, ultrasonography may be useful in imaging of the trachea.

Severe inflammatory upper airway stenosis in ulcerative colitis

Severe upper airway stenosis was diagnosed in a 23 year old woman who presented with hoarseness, cough and dyspnoea 8 yrs after initial diagnosis of ulcerative colitis. The respiratory symptoms worsened over the next few months, the patient eventually developing dysphagia and ultimately severe upper airway obstruction. The narrowest site was the glottis, which was severely stenosed by inflammatory swellings. Systemic corticosteroids led to rapid clinical improvement and restoration of normal airway patency within a few months. Ulcerative colitis is frequently associated with extraintestinal inflammatory manifestations. In the respiratory tract these usually take the form of chronic bronchitis, which occasionally develops into bronchiectasis. This case confirms that the inflammation can also involve the larynx and large airways.

The management of subglottic stenosis in patients with Wegener's granulomatosis

Wegener's granulomatosis (WG) is a multisystem inflammatory disease characterized by vasculitis, granuloma formation, and necrosis. Among 158 patients treated at the National Institutes of Health during the past 24 years, 145 (92%) had an otolaryngologic manifestation of their disease and 25 (16%) had subglottic stenosis (SGS). SGS varied from asymptomatic to life-threatening. Sixteen (80%) of 20 patients with fixed SGS required surgical intervention, including manual dilations, carbon-dioxide laser resections, and laryngotracheoplasty (LTP). LTP was performed with and without microvascular reconstruction. Thirteen of the patients required tracheostomy and all 13 were ultimately decannulated. Five patients who repeatedly failed dilations and/or endoscopic laser surgery underwent LTP. Since 1987, two patients have undergone LTP with microvascular free flaps. Both patients were subsequently decannulated. The authors' experience demonstrates that management of SGS in WG is complex, requiring individualized frequent multimodality interventions to achieve satisfactory results. Microvascular laryngotracheal reconstruction should be considered in the surgical armamentarium for patients with persistent stenoses.

Effect of corticosteroids on post-intubation tracheal stenosis

A 57 year old patient presented with progressive tracheal stenosis two months after intubation. An intraluminal polypoid lesion was found at the site of the cuff of the endotracheal tube. It disappeared within five days of treatment with inhaled beclomethasone. Further improvement of forced expiratory and inspiratory flow occurred after systemic corticosteroid treatment, with resolution of peritracheal oedema. Topical and systemic corticosteroids may be useful in the management of early post-intubation tracheal stenosis.

Subglottic stenosis in newborns after mechanical ventilation

Mechanical ventilation in the neonatal period is sometimes followed by difficulty in removal of the endotracheal tube although the patient does not need further respiratory support. This problem results from subglottic stenosis consequent on prolonged use of endotracheal tubes. We found this complication in 5 patients among 854 newborns who required artificial respiration. A further patient was admitted from another hospital because of extubation problems. Our clinical diagnosis was confirmed by endoscopy. Drug therapy with steroids and anti-inflammatory agents was tried in all six patients and was successful in two. In four patients conservative management failed and laser surgery was performed; three of these infants required tracheostomy. In two decannulation has already been performed at the age of 2 1/2 years.

IN CONCLUSION

five of six patients were treated successfully, and one 3-year-old patient is still being treated. In the light of reports from other authors, this approach can be recommended for the management of acquired subglottic stenosis.

Wegener's granulomatosis of the subglottis and the upper portion of the trachea

A relatively little-known complication of Wegener's granulomatosis is involvement of the subglottis and upper part of the trachea, which is illustrated in this report on 17 patients. Each of the patients had biopsy-proved Wegener's granulomatosis of the nose and paranasal sinuses. Some had concomitant involvement of the eye, kidney, lung and skin. Nine of the 17 patients required tracheotomy; 5 still require a tracheotomy tube, and 4 have had decannulation (1 had successful reconstructive surgery of the trachea). Medical treatment consisted of cyclophosphamide, with or without corticosteroids. All 17 are currently alive, the average follow-up having been 81 months. The otolaryngologist plays a key role in the detection and management of patients with Wegener's granulomatosis, particularly when the onset is a sudden progressive upper tracheal obstruction with airway symptoms that may overshadow the sometimes more subtle nasal manifestations.

Effects of surgery on airway mechanics in tracheal stenosis

12 patients suffering from severe extrathoracic tracheal stenosis mainly caused by long-term artificial ventilation were investigated by comparing their airway mechanics before and after tracheal sleeve resection and during long-term follow up. The investigations included body plethysmography, flow-volume relation, effect of bronchodilator, bronchial challenge and endoscopic estimation of the tracheal diameter. Tracheal sleeve resection in stenosis doubles the tracheal diameter from 5.9 to 11.0 mm. Resistance parameters and forced expiratory flow values reflected the significant improvement best. Airway structure remains stable during long-term follow-up, and effort-dependent parameters improve further. Compared to normal volunteers with artificially induced stenosis patients show a higher tolerability for airway narrowing. A tracheal diameter of 5 mm produces severe complaints and distinct functional distortions which are shown in specific airway resistance of 7.5 cm H2O X s, specific airway conductance of 0.02 cm H2O-1 X s-1 and FEV1 of 1 l X s-1. These values are absolute indications for resection. Tracheal stenosis after long-term artificial respiration can be influenced slightly by bronchodilator therapy. Nonspecific bronchial hyperreactivity is present, suggesting increased reagibility of the bronchial smooth muscles.

[Medical treatment of laryngotracheal stenosis (author's transl)]

The authors review the various types of treatment involving drugs and physical agents used for the non-surgical therapy of laryngotracheal stenosis. They emphasize three interesting propositions: the use of zinc sulphate, of lathyrogens and muscle relaxants, an extensive experimental study of which would be worthwhile in the particular context of laryngotracheal stenosis.

Therapy of iatrogenic subglottic stenosis: a steroid/antibiotic regimen

The authors have evaluated the efficacy of a medical regimen, consisting of systemic antibiotics and steroids, in the management of acute iatrogenic subglottic stenosis. The study consisted of the infliction of a standardized subglottic injury to three groups of five dogs: Group I animals were placed on prednisone 1 mg/kg/24 hours and potassium phenoxymethyl penicillin 50 mg/kg/24 hours from the day of the trauma. Group II were placed on a similar regimen from the eighth day after subglottic trauma. Group III received no medical therapy at all. Therapy was continued in treated Groups I and II for five weeks. At the end of the study the dogs were sacrificed and the final degree of subglottic stenosis evaluated, at which time the laryngotracheal complexes were submitted for pathological evaluation. A significant difference was found between the degree of stenosis attained in the three groups. The study suggests that the introduction of a steroid/antibiotic regimen has a beneficial effect in developing subglottic stenosis and that the timing of such therapy is of importance.

Pharmacotherapy in tracheal stenosis

From our experience in the treatment of immunological diseases with a tendency to the formation of granulomas, we conceived the idea of treating pharmacotherapeutically the scar-tissue formation in recurrent tracheal stenosis. We have combined two medicines with different modes of action, namely, klorokin and penicillamine. Two patients with recurrent tracheal stenosis have been treated with remarkable results. After several unsuccessful operations it has now been possible to decannulate both of them and enable them to regain a normal way of living.

Treatment of acquired subglottic stenosis

Four children, who had undergone major cardiac surgery, were treated for severe subglottic stenosis following prolonged endotracheal intubation and assisted respiration. Following removal of the endotracheal tube, all required tracheotomy after varying lengths of time. An adequate airway and good voice was obtained in each with injections of triamcinolone acetonide suspension combined with hyaluronidase, and gentle dilatations. This treatment greatly reduced the needed time of tracheotomy maintenance from that required with the previously recommended conservative management consisting of dilatations only. It also avoided the use of alloplastic stents which frequently resulted in a deformed larynx and poor voice.