Tracheobronchoplasty for severe tracheobronchomalacia: a prospective outcome analysis

Excessive Dynamic Airway Collapse: Large Airway Function During Exercise

Large airway collapse on expiration is an increasingly recognized cause of airway centric symptoms. The 2 primary conditions are tracheobronchomalacia and excessive dynamic airway collapse, the latter a common comorbidity in those with underlying lung disease. The exertional dyspnea associated with these conditions is complex and exercise intolerance is a key clinical feature, despite the fact that the precise relationship is not fully understood. Forced expiratory maneuvers during supine bronchoscopy or imaging studies are used to evaluate these conditions. However, it may be relevant to characterize large airway function during occasions when patients present their symptoms.

Preoperative Workup of Patients With Excessive Central Airway Collapse: Does Stent Evaluation Serve a Role?

BACKGROUND

Tracheobronchoplasty (TBP) is a definitive anatomic intervention for patients with severe symptomatic expiratory central airway collapse. Although stent evaluations have been described for surgical workup, current literature does not address if improvement during stent evaluation is sustained after TBP. We compared health-related quality of life (HRQOL) and functional status responses after airway stenting to those post-TBP.

METHODS

A retrospective review was performed in patients with severe expiratory central airway collapse who underwent stent evaluation followed by TBP from January 2004 to December 2019. Baseline, poststent, 3- and 12-month postoperative HRQOL scores, and functional status were analyzed with statistical tests as appropriate.

RESULTS

One hundred twenty patients underwent a stent evaluation and TBP. Baseline and stent evaluation measurements were compared with statistically and clinically significant differences in the Cough Quality-of-life Questionnaire (CQLQ) (55 vs. 68, P <0.01), Modified Medical Research Council (mMRC) 0 to 2 (90% vs. 47%, P <0.01), 6-minute walk test (6MWT) (1301 ft vs. 1138 ft, P <0.01). Improvements in the HRQOL and functional status were maintained from stent evaluation to 3 months postoperatively [CQLQ 55 vs. 54, P =0.63; mMRC 0 to 2 (87% vs. 84%), P =0.39; 6MWT 1350 ft vs. 1314 ft, P =0.33], and 12 months postoperatively [CQLQ 54 vs. 54, P =0.91; mMRC 0 to 2 (95% vs. 86%), P =0.74; 6MWT 1409 ft vs. 1328 ft, P =0.13]. The magnitude of change between the data was not significantly different between the stent evaluation, 3-, and 12 months postoperative. Predicted forced expiratory volume in 1-second measurements at baseline, after stent placement, 3 months, and 12 months post-TBP were 74%, 79%, 73%, and 73%, respectively, and not clinically significant.

CONCLUSIONS

Improvement after stent evaluation and the magnitude of improvement may be predictive of postoperative outcomes up to 1 year after surgery.

Tracheobronchomalacia: an unusual cause of debilitating dyspnoea and its surgical management

Tracheobronchomalacia (TBM) is a progressive weakening of the airways, leading to collapse and dyspnoea. TBM can be misdiagnosed when multiple chronic conditions accompany it. Tracheobronchoplasty (TBP) is indicated for severe symptomatic TBM, diagnosed by bronchoscopy and CT thorax. We report the case of a patient who underwent tracheal resection and reconstruction for continuing dyspnoea post argon therapy, TBP and a failure to tolerate extracorporeal membrane oxygenation-assisted Y-stent insertion. Relevant background history includes asthma, sleep apnoea, reflux, cardiomyopathy and a high body mass index. Bronchoscopy postreconstruction showed patent airways. Airway reconstruction was a viable management option for this patient's TBM. TBP is a treatment option for TBM. In this case, tracheal resection was required to sustain benefit. In addition, surveillance bronchoscopies will be carried out every year.

Quantitative CT Scan Imaging of the Airways for Diagnosis and Management of Lung Disease

CT scan imaging provides high-resolution images of the lungs in patients with chronic respiratory diseases. Extensive research over the last several decades has focused on developing novel quantitative CT scan airway measurements that reflect abnormal airway structure. Despite many observational studies demonstrating that associations between CT scan airway measurements and clinically important outcomes such as morbidity, mortality, and lung function decline, few quantitative CT scan measurements are applied in clinical practice. This article provides an overview of the relevant methodologic considerations for implementing quantitative CT scan airway analyses and provides a review of the scientific literature involving quantitative CT scan airway measurements used in clinical or randomized trials and observational studies of humans. We also discuss emerging evidence for the clinical usefulness of quantitative CT scan imaging of the airways and discuss what is required to bridge the gap between research and clinical application. CT scan airway measurements continue to improve our understanding of disease pathophysiologic features, diagnosis, and outcomes. However, a literature review revealed a need for studies evaluating clinical benefit when quantitative CT scan imaging is applied in the clinical setting. Technical standards for quantitative CT scan imaging of the airways and high-quality evidence of clinical benefit from management guided by quantitative CT scan imaging of the airways are required.

[Interventionnal bronchoscopy for the treatment of tracheobronchomalacia]

Tracheobronchomalacia is usually characterized by more than 50% expiratory narrowing in diameter of the trachea and the bronchi. The expiratory collapse includes two entities: (1) the TBM related to the weakness of the cartilaginous rings, and (2) the Excessive Dynamic Airway Collapse (EDAC) due to the excessive bulging of the posterior membrane. Patients have nonspecific respiratory symptoms like dyspnea and cough. Diagnosis is confirmed by dynamic tests: flexible bronchoscopy and/or computed tomographic scan of the chest. There are different forms of tracheobronchomalacia in adults: primary (genetic, idiopathic) or secondary to trauma, tracheotomy, intubation, surgery, transplantation, emphysema, infection, inflammation, chronic bronchitis, extrinsic compression; or undiagnosed in childhood vascular rings. Some management algorithms have been proposed, but no specific recommendation was established. Only symptomatic patients should be treated. Medical treatments and noninvasive positive pressure ventilation should be the first line therapy, after evaluation of various quality measures (functional status, performance status, dyspnea and quality of life scores). If symptoms persist, therapeutic bronchoscopy permits: (1) patient's selection by stent trial to determine whether patient benefit for surgical airway stabilization; (2) malacic airways stenting in patients who are not surgical candidates, improving QOL despite a high complication rate; (3) the management of stent-related complication (obstruction, plugging, migration granuloma); (4) alternative therapeutics like thermo-ablative solution. Lasty, the development of new types of stents would reduce the complication rates. These different options remained discussed.

Thermoablative Techniques to Treat Excessive Central Airway Collapse

Excessive central airway collapse (ECAC) is a condition characterized by the excessive narrowing of the trachea and mainstem bronchi during expiration, which can be caused by Tracheobronchomalacia (TBM) or Excessive Dynamic Airway Collapse (EDAC). The initial standard of care for central airway collapse is to address any underlying conditions such as asthma, COPD, and gastro-esophageal reflux. In severe cases, when medical treatment fails, a stent-trial is offered to determine if surgical correction is a viable option, and tracheobronchoplasty is suggested as a definitive treatment approach. Thermoablative bronchoscopic treatments, such as Argon plasma coagulation (APC) and laser techniques (potassium-titanyl-phosphate [KTP], holmium and yttrium aluminum pevroskyte [YAP]) are a promising alternative to traditional surgery. However, further research is needed to assess their safety and effectiveness in humans before being widely used.

Interventional pulmonology techniques in lung transplantation

Lung transplantation is a key therapeutic option for several end-stage lung diseases. Interventional pulmonology techniques, mostly bronchoscopy, play a key role throughout the whole path of lung transplantation, from donor evaluation to diagnosis and management of post-transplant complications. We carried out a non-systematic, narrative literature review aimed at describing the main indications, contraindications, performance characteristics and safety profile of interventional pulmonology techniques in the context of lung transplantation. We highlighted the role of bronchoscopy during donor evaluation and described the debated role of surveillance bronchoscopy (with bronchoalveolar lavage and transbronchial biopsy) to detect early rejection, infections and airways complications. The conventional (transbronchial forceps biopsy) and the new techniques (i.e. cryobiopsy, biopsy molecular assessment, probe-based confocal laser endomicroscopy) can detect and grade rejection. Several endoscopic techniques (e.g. balloon dilations, stent placement, ablative techniques) are employed in the management of airways complications (ischemia and necrosis, dehiscence, stenosis and malacia). First line pleural interventions (i.e. thoracentesis, chest tube insertion, indwelling pleural catheters) may be useful in the context of early and late pleural complications occurring after lung transplantation. High quality studies are advocated to define endoscopic standard protocols and thus help improving long-term prognostic outcomes of lung transplant recipients.

Tracheobronchoplasty yields long-term anatomy, function, and quality of life improvement for patients with severe excessive central airway collapse

OBJECTIVES

This study examines the long-term anatomic and clinical effects of tracheobronchoplasty in severe excessive central airway collapse.

METHODS

Included patients underwent tracheobronchoplasty for excessive central airway collapse (2002-2016). The cross-sectional area of main airways on dynamic airway computed tomography was measured before and after tracheobronchoplasty. Expiratory collapse was calculated as the difference between inspiratory and expiratory cross-sectional area divided by inspiratory cross-sectional area ×100. The primary outcome was improvement in the percentage of expiratory collapse in years 1, 2, and 5 post-tracheobronchoplasty. Secondary outcomes included mean response profile for the 6-minute walk test, Cough-Specific Quality of Life Questionnaire, Karnofsky Performance Status score, and St George Respiratory Questionnaire. Repeated-measures analysis of variance was used for statistical analyses.

RESULTS

The cohort included 61 patients with complete radiological follow-up at years 1, 2, and 5 post-tracheobronchoplasty. A significant linear decrease in the percentage of expiratory collapsibility of the central airways after tracheobronchoplasty was present. Anatomic repair durability was preserved 5 years after tracheobronchoplasty, with decrease in percentage of expiratory airway collapse up to 40% and 30% at years 1 and 2, respectively. The St George Respiratory Questionnaire (74.7 vs 41.8%, P < .001) and Cough-Specific Quality of Life Questionnaire (78 vs 47, P < .001) demonstrated significant improvement at year 5 compared with baseline. Similar results were observed in the 6-minute walk test (1079 vs 1268 ft, P < .001) and Karnofsky score (57 vs 82, P < .001).

CONCLUSIONS

Tracheobronchoplasty has durable effects on airway anatomy, functional status, and quality of life in carefully selected patients with severe excessive central airway collapse.

Stent Evaluation for Expiratory Central Airway Collapse: Does the Type of Stent Really Matter?

BACKGROUND

Careful selection of patients with expiratory central airway collapse (ECAC) that may benefit from tracheobronchoplasty (TBP) can be aided by a short-term airway stent evaluation. This can be performed with either silicone Y-stents (SYSs) or uncovered self-expanding metallic airway-stents (USEMAS). No direct comparison has been made between these 2 stent types.

METHODS

This was a small retrospective review of consecutive patients that underwent a stent evaluation. A propensity score was used to match patients in the USEMAS and SYS groups. Outcomes included complications, changes in the health-related quality-of-life (HR-QoL), and changes in exercise capacity. Baseline measurements were compared with those obtained during stent evaluation and after TBP.

RESULTS

Forty-two patients with severe ECAC underwent USEMAS placement, while 18 patients had an SYS placed. Propensity score matching resulted in 13 matched SYS and USEMAS pairs. The SYS group had an increased rate of mucus plugging (38.5% vs. 0%, P <0.047). Although not statically significant, a clinical improvement was observed in HR-QoL and exercise capacity in the USEMAS group during stent placement. In patients who underwent TBP, both USEMAS and SYS groups had a statistically significant change in the Modified Medical Research Council Dyspnea Scale during stent evaluation and after TBP.

CONCLUSION

In patients with severe ECAC, short-term evaluation with airway stents appears to be safe and improves respiratory symptoms, HR-QoL, and exercise capacity. The use of USEMAS led to a lower complication rate, a greater improvement in HR-QoL and exercise capacity, and appeared to better predict how the patients would respond to TBP.

Tracheobronchomalacia and Excessive Dynamic Airway Collapse: Current Concepts and Future Directions

Tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC) are airway abnormalities that share a common feature of expiratory narrowing but are distinct pathophysiologic entities. Both entities are collectively referred to as expiratory central airway collapse (ECAC). The malacia or weakness of cartilage that supports the tracheobronchial tree may occur only in the trachea (ie, tracheomalacia), in both the trachea and bronchi (TBM), or only in the bronchi (bronchomalacia). On the other hand, EDAC refers to excessive anterior bowing of the posterior membrane into the airway lumen with intact cartilage. Clinical diagnosis is often confounded by comorbidities including asthma, chronic obstructive pulmonary disease, obesity, hypoventilation syndrome, and gastroesophageal reflux disease. Additional challenges include the underrecognition of ECAC at imaging; the interchangeable use of the terms TBM and EDAC in the literature, which leads to confusion; and the lack of clear guidelines for diagnosis and treatment. The use of CT is growing for evaluation of the morphology of the airway, tracheobronchial collapsibility, and extrinsic disease processes that can narrow the trachea. MRI is an alternative tool, although it is not as widely available and is not used as frequently for this indication as is CT. Together, these tools not only enable diagnosis, but also provide a road map to clinicians and surgeons for planning treatment. In addition, CT datasets can be used for 3D printing of personalized medical devices such as stents and splints. An invited commentary by Brixey is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Current practices in the management of central airway obstruction

PURPOSE OF REVIEW

Airway obstruction continues to cause substantial pulmonary morbidity and mortality. We present a review of classic, current, and evolving management techniques, highlighting recently published studies on the topic. Recommendations have historically been primarily based on anecdotal experience, case reports, and retrospective studies, but more solid evidence has emerged in the last decade.

RECENT FINDINGS

Novel endobronchial stents are being developed to mitigate the issues of stent migration, mucus plugging, fracture, and granulation tissue formation. Endobronchial drug delivery has become an active area of translational and clinical research, especially with regards to antineoplastic agents used for malignant airway stenosis. Even classic or updated techniques such as spray cryotherapy, injections of mitomycin-c, and balloon dilation have recently been examined in methodologically sound studies. Finally, recently published data have confirmed that patient breathlessness and quality of life improve significantly with therapeutic airway interventions. A multimodal and multidisciplinary approach to patient care is key to achieving the best outcomes.

SUMMARY

The treatment of central airway stenosis is often multimodal and should focus on patient-centric factors, taking into account risks and benefits of the procedure, operator, and center expertise, and always occur in the context of a multidisciplinary approach. Evidence-based clinical research is increasingly driving patient management.

Airway complications in lung transplantation

Airway complications (ACs) after lung transplantation remain an important source of morbidity and mortality despite significant advances in the surgical technics, leading to increased cost, and decrease quality of life. The incidences of ACs after lung transplantation range from 2% to 33%, even though most transplant centers have reported rates in the range of 7% to 8%. However, the reported rate of ACs has been inconsistent as a result of a lack of standardized airway definitions and grading protocols before the recent 2018 International Society for Heart and Lung Transplantation (ISHLT) proposed consensus guidelines on ACs after lung transplantation. The ACs include stenosis, perioperative and postoperative bronchial infections, bronchial necrosis and dehiscence, excess granulation tissue, and tracheobronchomalacia (TBM). Anastomosis infection, necrosis, or dehiscence typically develops within the first month after lung transplantation. The most frequent AC after lung transplantation is bronchial stenosis. Several risk factors have been proposed to the development of ACs after lung transplantation, including surgical anastomosis techniques, hypoperfusion, infections, donor and recipient factors, immunosuppression agents, and organ preservation. ACs might be prevented by early recognition of the airway pathology, using advance medical management, and interventional bronchoscopy procedures. Balloon bronchoplasty, cryotherapy, laser photo resection, electrocautery, high-dose endobronchial brachytherapy, and bronchial stents placement are the most frequent interventional bronchoscopic procedures utilized for the management of ACs.

Detection and diagnosis of large airway collapse: a systematic review

Large airway collapse (LAC) is a frequently encountered clinical problem, caused by tracheobronchomalacia +/− excessive dynamic airway collapse, yet there are currently no universally accepted diagnostic criteria. We systematically reviewed studies reporting a diagnostic approach to LAC in healthy adults and patients, to compare diagnostic modalities and criteria used. Electronic databases were searched for relevant studies between 1989 and 2019. Studies that reported a diagnostic approach using computed tomography (CT), magnetic resonance imaging or flexible fibreoptic bronchoscopy were included. Random effects meta-analyses were performed to estimate the prevalence of LAC in healthy subjects and in patients with chronic obstructive airway diseases. We included 41 studies, describing 10 071 subjects (47% female) with a mean±sd age of 59±9 years. Most studies (n=35) reported CT findings, and only three studies reported bronchoscopic findings. The most reported diagnostic criterion was a ≥50% reduction in tracheal or main bronchi calibre at end-expiration on dynamic expiratory CT. Meta-analyses of relevant studies found that 17% (95% CI: 0–61%) of healthy subjects and 27% (95% CI: 11–46%) of patients with chronic airways disease were classified as having LAC, using this threshold. The most reported approach to diagnose LAC utilises CT diagnostics, and at a threshold used by most clinicians (i.e., ≥50%) may classify a considerable proportion of healthy individuals as being abnormal and having LAC in a quarter of patients with chronic airways disease. Future work should focus on establishing more precise diagnostic criteria for LAC, relating this to relevant physiological and disease sequelae.

CT is mostly used to diagnose LAC, and at a threshold used by most clinicians (i.e. ≥50%) that would classify a large proportion of healthy individuals as being abnormal and LAC in a quarter of patients with chronic airway diseaseshttps://bit.ly/3izAuSk

Argon Plasma Coagulation (APC) for the Treatment of Excessive Dynamic Airway Collapse (EDAC): An Animal Pilot Study

BACKGROUND

Surgical stabilization of the airway through tracheobronchoplasty (TBP) is the current treatment modality for patients with severe symptomatic excessive dynamic airway collapse. However, TBP is associated with increased morbidity and mortality. Bronchoscopic treatment of the posterior membrane using argon plasma coagulation (APC) may be a safer alternative to TBP in highly selected patients. This study aimed to evaluate the effect of APC in the tracheobronchial tree of a sheep animal model.

PATIENTS AND METHODS

Two adult sheep were used for this study. Under flexible bronchoscopy, the posterior tracheal membrane was treated with precise APC using different power settings. Chest computed tomography was done at 2 days and bronchoscopy was performed at 30 days following initial procedure, before euthanasia. The airways were assessed for the presence of treatment-related histopathologic changes along with expression of genes associated with fibrosis.

RESULTS

There was no perioperative or postoperative morbidity or mortality. Chest computed tomography showed no signs of pneumomediastinum or pneumothorax. Flexible bronchoscopy showed adequate tracheobronchial tissue healing process, independent of the power settings used. Histologic changes demonstrated an increased extent of fibroblastic collagen deposition in the treated posterior membrane when higher power settings were used. In a similar manner, APC treatment managed to activate fibrosis-associated gene transcription factors, with higher settings achieving a higher level of expression.

CONCLUSION

APC at high-power settings achieved higher levels of fibroblast collagen deposition at the posterior membrane and higher expression of fibrosis-associated gene transcription factors, when compared with lower settings.

Recurrent Lower Respiratory Tract Infections Due to Mounier-Kuhn Syndrome

Mounier-Kuhn syndrome (MKS) is a rare disorder characterized by recurrent lower respiratory tract infections and bronchiectasis due to dilation of the trachea and bronchi. Diagnosis is made based on clinical suspicion along with radiographic evidence of tracheobronchomegaly. Mucolytic agents and chest physiotherapy have been shown to offer symptomatic improvement, and definitive surgical treatment is reserved for those with persistent symptoms. Herein, we report a case of MKS in a 72-year-old woman with bronchiectasis and recurrent multidrug-resistant lower respiratory tract infections.

Thermoablative Techniques for Excessive Central Airway Collapse: An Ex Vivo Pilot Study on Sheep Tracheal Tissue

BACKGROUND

Tracheobronchoplasty is the definitive treatment for patients with symptomatic excessive central airway collapse. This procedure is associated with high morbidity and mortality rates. Bronchoscopic techniques are an appealing alternative with less morbidity and the ability to apply it in nonsurgical patients. Although thermoablative methods have been proposed as treatment options to induce fibrosis of the posterior tracheobronchial wall, no studies have compared direct histologic effects of such methods. This study compared the effects of electrocautery, radiofrequency ablation, potassium titanyl phosphate laser, and argon plasma coagulation (APC) in the tracheobronchial tree in an ex vivo animal model.

METHODS

Four adult sheep cadavers were used for this study. Under flexible bronchoscopy, the posterior tracheal membrane was treated using different power settings on 4 devices. The airways were assessed for the presence of treatment-related histopathologic changes.

RESULTS

Histologic changes observed were that of acute thermal injury including: surface epithelium ablation, collagen fiber condensation, smooth muscle cytoplasm condensation, and chondrocyte pyknosis. No distinct histologic differences in the treated areas among different modalities and treatment effects were observed. APC at higher power settings was the only modality that produced consistent and homogenous thermal injury effects across all tissue layers with no evidence of complete erosion.

CONCLUSION

Although electrocautery, radiofrequency ablation, potassium titanyl phosphate laser, and APC all induce thermal injury of the airway wall, only APC at high power settings achieves this effect without complete tissue erosion, favoring potential regeneration and fibrosis. Live animal studies are now plausible.

Single-Lumen Endotracheal Tube and Bronchial Blocker for Airway Management During Tracheobronchoplasty for Tracheobronchomalacia: A Case Report

We present a case of a 69-year-old man who underwent tracheobronchoplasty for tracheobronchomalacia using a single-lumen endotracheal tube and a Y-shaped bronchial blocker for airway management. Tracheobronchoplasty is performed by sewing mesh to plicate the posterior, membranous wall of the distal trachea and main bronchi through a right posterolateral thoracotomy. The goals of airway management include continuous left-lung ventilation and lung protection from aspiration. Ideally, only conventional airway management tools are used. This case demonstrates that a single-lumen endotracheal tube with a bronchial blocker can be a straightforward strategy for airway management during tracheobronchoplasty.

Central Airway Collapse, an Underappreciated Cause of Respiratory Morbidity

Dyspnea, cough, sputum production, and recurrent respiratory infections are frequently encountered clinical concerns leading patients to seek medical care. It is not unusual for a well-defined etiology to remain elusive or for the therapeutics of a presumed etiology to be incompletely effective. Either scenario should prompt consideration of central airway pathology as a contributor to clinical manifestations. Over the past decade, recognition of dynamic central airway collapse during respiration associated with multiple respiratory symptoms has become more commonly appreciated. Expiratory central airway collapse may represent the answer to this diagnostic void. Expiratory central airway collapse is an underdiagnosed disorder that can coexist with and mimic asthma, chronic obstructive pulmonary disease, and bronchiectasis. Awareness of expiratory central airway collapse and its spectrum of symptoms is paramount to its recognition. This review includes clear definitions, diagnostics, and therapeutics for this challenging condition. We performed a narrative review through the PubMed (MEDLINE) database using the following MeSH terms: airway collapse, tracheobronchomalacia, tracheomalacia, and bronchomalacia. We include reports from systematic reviews, narrative reviews, clinical trials, and observational studies from 2005 to 2020. Two reviewers evaluated potential references. No systematic reviews were found. A total of 28 references were included into our review. Included studies report experience in the diagnosis and/or treatment of dynamic central airway collapse; case reports and non-English or non-Spanish studies were excluded. We describe the current diagnostic dilemma, highlighting the role of dynamic bronchoscopy and tracheobronchial stent trial; outline the complex therapeutic options (eg, tracheobronchoplasty); and present future directions and challenges.

Quality of life outcomes in tracheobronchomalacia surgery

Tracheobronchomalacia (TBM) is an obstructive airway disease characterized by laxity and redundancy of the posterior membrane of the main airways leading to dynamic airway collapse during exhalation. The gold standard for diagnosis is dynamic computed tomography (DCT) scan and dynamic flexible bronchoscopy (DFB). Patients with complete or near-complete collapse (>90% reduction in cross-sectional area) of the airway are possible candidates for surgical management. Central airway stabilization by tracheobronchoplasty (TBP) effectively corrects malacic airways and has demonstrated significant improvement in objective functional measures, which is often but not uniformly accompanied by equal improvement in health-related quality of life (HRQOL) metrics. This article reviews HRQOL instruments used to report outcomes after TBM surgery.

Tracheobronchomegaly, cough and recurrent chest infection: Mounier-Kuhn syndrome

A 49-year-old male ex-smoker was referred for recurrent chest infections requiring one course of antibiotics every winter, occurring over the last 20 years. Each episode is characterised by a productive cough with purulent sputum along with difficulty breathing, chest tightness and fatigue, but without haemoptysis. On some occasions, these symptoms were preceded by fever and rhinorrhoea. Each episode lasted ∼10 days and responded well to antibiotics. He had never been hospitalised for these infections, nor received a chest radiograph or sputum microbiology. He had been told that he developed episodes of pneumonia in his first year of life. Apart from these yearly infections, the patient was asymptomatic during the rest of the year.

Mounier-Kuhn Syndrome (MKS) is a rare disease characterised by recurrent chest infections, and dilation of the trachea and main bronchi, most likely to due to atrophy of elastic fibreshttps://bit.ly/3azhDjr

Upper airway wheezing: Inducible laryngeal obstruction vs. excessive dynamic airway collapse

There are multiple causes of dyspnea upon exertion in young, healthy patients to primarily include asthma and exercise-induced bronchospasm. Excessive dynamic airway collapse (EDAC) describes focal collapse of the trachea or main bronchi with maintained structural integrity of the cartilaginous rings. It is commonly associated with pulmonary disorders like bronchiectasis, chronic obstructive pulmonary disease and asthma. It is believed to result secondary to airway obstruction in these conditions. While uncommon in young, healthy adults, it has recently been found as a cause of dyspnea in this population. Inducible laryngeal obstruction (ILO) is an umbrella term that describes an induced, intermittent upper airway impediment. While ILO is found in 10% of young patients with exertional dyspnea, it is primarily inspiratory in nature due to paradoxical closure of the glottis or supraglottis. This report highlights the presentation of a United States Army soldier who after a deployment was given a diagnosis of asthma, later found to have ILO and was subsequently diagnosed with concurrent EDAC. We follow up with a literature review and discussion of symptomatology, diagnosis, exercise bronchoscopy, and treatment modalities for both EDAC and ILO.

Tracheobronchomalacia and Excessive Dynamic Airway Collapse

Tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC) are more frequently being recognized as the etiology of multiple types of respiratory complaints from chronic cough to exertional syncope to recurrent infections. Identification of these conditions requires a high suspicion, as well as a thorough history and physical examination. Dynamic computed tomography imaging and bronchoscopic evaluation are integral in achieving an accurate diagnosis. Once recognized, treatment ranges from addressing underlying contributing conditions to surgical stabilization of the airway. Referral to an institution familiar with the evaluation and treatment of TBM/EDAC is essential for the appropriate management of these conditions.

Circulatory Collapse due to Hyperinflation in a Patient with Tracheobronchomalacia: A Case Report and Brief Review

We present a case of repeated cardiac arrests derived from dynamic hyperinflation in a patient with severe tracheobronchomalacia. Mechanical ventilation led to auto-PEEP with hemodynamic impairment and pulseless electric activity. Adjusted ventilation settings, deep sedation, and muscle paralysis followed by acute stenting of the affected collapsing airways restored ventilation and prevented recurrent circulatory collapse. We briefly review the pathophysiology and treatment options in patients with dynamic hyperinflation.

Expiratory reactance abnormalities in patients with expiratory dynamic airway collapse: a new application of impulse oscillometry

Expiratory dynamic airways collapse (EDAC) is a condition that affects the central airways; it is not well characterised physiologically, with relatively few studies. We sought to characterise impulse oscillometry (IOS) features of EDAC in patients with normal spirometry. Expiratory data were hypothesised to be the most revealing. In addition, we compared IOS findings in chronic obstructive pulmonary disease (COPD) patients with and without EDAC.

EDAC was identified at bronchoscopy as 75–100% expiratory closure at the carina or bilateral main bronchi. Four patient groups were compared: controls with no EDAC and normal lung function; lone EDAC with normal lung function; COPD-only patients; and COPD patients with EDAC.

38 patients were studied. Mean IOS data z-scores for EDAC compared to controls showed significantly higher reactance (X) values including X at 5 Hz, resonance frequency and area under the reactance curve (A_X). EDAC showed significantly greater expiratory/inspiratory differences in all IOS data compared to controls. Stepwise logistic regression showed that resonant frequency best discriminated between EDAC and normal control, whereas classification and regression tree analysis found A_X ≥3.523 to be highly predictive for EDAC in cases with normal lung function (14 out of 15 cases, and none out of eight controls).

These data show a new utility of IOS: detecting EDAC in patients with normal lung function.

Central airway expiratory dynamic airway collapse can be “silent” on breathing tests, but impulse oscillometry can reveal ithttp://ow.ly/9oIb30lIOka

Frailty Characteristics Predict Respiratory Failure in Patients Undergoing Tracheobronchoplasty

BACKGROUND

Respiratory complications are the leading cause of morbidity in patients undergoing tracheobronchoplasty, yet risk stratification systems on this population are insufficient. We investigated the association between frailty and risk of major respiratory complications after tracheobronchoplasty.

METHODS

A retrospective review was made of 161 consecutive tracheobronchoplasties (October 2002 to September 2016). A frailty index was developed by the deficit-accumulation approach comprising 26 multidomain preoperative variables. The main outcome was a composite endpoint of major respiratory complications within 30 days of surgery. Odds ratio (OR) and 95% confidence interval (CI) were estimated using logistic regression.

RESULTS

The cohort consisted of 103 women (64%), median age of 58 years (interquartile range, 51 to 66) and median FI of 0.25 (interquartile range, 0.1 to 0.3). Forty-eight patients (30%) had respiratory complications, the most common being respiratory failure (n = 27, 16.8%) and pneumonia (n = 25, 15.5%). Severe frailty (frailty index ≥0.33) was strongly associated with major respiratory complications (73.8% versus 2.5%; OR 58.8, 95% CI: 9.6 to 358.3). The association with severe frailty appeared stronger for respiratory failure (47.6% versus 2.5%; OR 30, 95% CI: 4.7 to 189.9) than for pneumonia (40.5% versus 0%; OR 35.2. 95% CI: 2.0 to 599.8). Further adjustment for intraoperative crystalloid volume or forced expiratory volume in 1 second moderately attenuated the association between frailty with major respiratory complications (OR 17.4. 95% CI: 2.0 to 150.8), respiratory failure (OR 13.1, 95% CI: 1.7 to 95.8), and pneumonia (OR 20.1, 95% CI: 1.1 to 341.8).

CONCLUSIONS

Frailty, as indicated by frailty index, was associated with major respiratory complications, particularly respiratory failure after tracheobronchoplasty. Preoperative identification of frailty may help guide decision making for patients considering this effective, although arduous procedure.

ISHLT Consensus Statement on adult and pediatric airway complications after lung transplantation: Definitions, grading system, and therapeutics

Airway complications remain a major cause of morbidity and mortality after cardiothoracic transplantation. The reported incidence of airway ischemic complications varies widely, contributed to by the lack of a universally accepted grading system and standardized definitions. Furthermore, the majority of the existing classification systems fail to integrate the wide range of possible bronchial complications that may develop after lung transplant. Hence, a Working Group was created by the International Society for Heart and Lung Transplantation with the aim of elaborating a universal definition of adult and pediatric airway complications and grading system. One such area of focus is to understand the problem in the context of a more standardized consensus of classifying airway ischemia. This consensus definition will have major clinical, therapeutics, and research implications.

Exercise-associated Excessive Dynamic Airway Collapse in Military Personnel

RATIONALE

Evaluation of military personnel for exertional dyspnea can present a diagnostic challenge, given multiple unique factors that include wide variation in military deployment. Initial consideration is given to common disorders such as asthma, exercise-induced bronchospasm, and inducible laryngeal obstruction. Excessive dynamic airway collapse has not been reported previously as a cause of dyspnea in these individuals.

OBJECTIVES

To describe the clinical and imaging characteristics of military personnel with exertional dyspnea who were found to have excessive dynamic collapse of large airways during exercise.

METHODS

After deployment to Afghanistan or Iraq, 240 active U.S. military personnel underwent a standardized evaluation to determine the etiology of persistent dyspnea on exertion. Study procedures included full pulmonary function testing, impulse oscillometry, exhaled nitric oxide measurement, methacholine challenge testing, exercise laryngoscopy, cardiopulmonary exercise testing, and fiberoptic bronchoscopy. Imaging included high-resolution computed tomography with inspiratory and expiratory views. Selected individuals underwent further imaging with dynamic computed tomography.

MEASUREMENTS AND MAIN RESULTS

A total of five men and one woman were identified as having exercise-associated excessive dynamic airway collapse on the basis of the following criteria: (1) exertional dyspnea without resting symptoms, (2) focal expiratory wheezing during exercise, (3) functional collapse of the large airways during bronchoscopy, (4) expiratory computed tomographic imaging showing narrowing of a large airway, and (5) absence of underlying apparent pathology in small airways or pulmonary parenchyma. Identification of focal expiratory wheezing correlated with bronchoscopic and imaging findings.

CONCLUSIONS

Among 240 military personnel evaluated after presenting with postdeployment exertional dyspnea, a combination of symptoms, auscultatory findings, imaging, and visualization of the airways by bronchoscopy identified six individuals with excessive dynamic central airway collapse as the sole apparent cause of dyspnea. Exercise-associated excessive dynamic airway collapse should be considered in the differential diagnosis of exertional dyspnea.

[Characteristics of tidal breathing pulmonary function in children with tracheobronchomalacia]

OBJECTIVE

To investigate the characteristics of tidal breathing pulmonary function in children with tracheobronchomalacia (TBM).

METHODS

In this study, 30 children who were diagnosed with TBM using electronic bronchoscopy were enrolled in the observation group; 30 healthy children were recruited in the normal control group. For individuals in each group, the assessment of tidal breath pulmonary function was performed at diagnosis and 3, 6, 9, and 12 months after diagnosis.

RESULTS

There were no significant differences in tidal volume, inspiratory time, expiratory time, and inspiratory to expiratory ratio between the two groups (P>0.05). Compared with the control group, the observation group had a significantly higher respiratory rate and significantly lower ratio of time to peak tidal expiratory flow to total expiratory time (TPTEF/TE) and ratio of volume to peak tidal expiratory flow to total expiratory volume (VPTEF/VE). There was a time-dependent increase in TPTEF/TE and VPTEF/VE for TBM children from the time of initial diagnosis to 12 months after diagnosis.

CONCLUSIONS

Tidal breathing pulmonary function has characteristic changes in children with TBM. Tidal breathing pulmonary function tends to be recovered with increased age in children with TBM.

Airway stenting in excessive central airway collapse

In tracheobronchomalacia (TBM) and other disorders, weakened airway walls lead to expiratory central airway collapse (ECAC) and can cause symptoms of cough, dyspnea, retained secretions, and recurrent pulmonary infections. Diagnosis of severe ECAC is based on the presence of >90% expiratory airway collapse on dynamic computed tomography (CT) and/or bronchoscopy. We offer patients with severe ECAC a trial of airway stenting to determine whether splinting of the central airways leads to improvements in symptoms, quality of life, exercise capacity, or respiratory function. Patients who respond positively to airway stenting are considered for tracheobronchoplasty.

Recurrent dyspnea and wheezing- pulmonary function test and dynamic computed tomography may unfold the diagnosis of tracheobronchomalacia

Tracheomalacia patients often present with nonspecific symptoms like cough, wheezing and dyspnea. Tracheomalacia diagnosis is usually attributed to alternative common conditions such as asthma or chronic obstructive lung disease. Certain maneuvers, like forced expiration, or recumbent position may elicit subtle signs of tracheomalacia. Ordering novel pulmonary function testing in sitting upright and supine positions may provide additional clues to suspect tracheomalacia, which can be confirmed by either dynamic chest tomography or bronchoscopy.

Tracheobronchomalacia

The term tracheobronchomalacia refers to excessively compliant and collapsible central airways leading to symptoms. Although seen as a coexisting condition with various other pulmonary condition, it may cause symptoms by itself. The condition is often misdiagnosed as asthma, bronchitis or just chronic cough due to a lack of specific pathognomonic history and clinical findings. The investigation revolves around different modes of imaging, lung function testing and usually confirmed by flexible bronchoscopy. The treatment widely varies based on the cause, with most cases treated conservatively with non-invasive ventilation. Some may require surgery or stent placement. In this article, we aim to discuss the pathophysiology behind this condition and recognize the common symptoms and causes of tracheobronchomalacia. The article will highlight the diagnostic steps as well as therapeutic interventions based on the specific cause.

Teflon Injection into the Trachea Causes Predictable Fibroblastic Response and Collagen Deposition: A Pilot Study

BACKGROUND

Expiratory central airway collapse is an increasingly recognized abnormality of the central airways and may be present in as many as 22% of patients evaluated for chronic obstructive pulmonary disease and/or asthma. Many current treatment options require invasive procedures that have been shown to cause significant morbidity and mortality. To test the hypothesis that Teflon injection will induce sufficient fibroblast proliferation and collagen deposition, we evaluated the time course on the effect of Teflon injection in the posterior membranous trachea on the histopathology of the tracheobronchial tree.

METHODS

Six Yucatan Pigs were assigned to undergo general anesthesia and injection of 0.3 to 0.5 mL of sterile Teflon paste in 50% glycerin into the posterior membranous tracheal wall. A control pig received an equivalent volume of glycerin. Animals were euthanized in predefined intervals and tracheas were excised and examined under light microscopy for identifying fibroblast proliferation and collagen deposition.

RESULTS

Compared with the control pig, the Teflon injection site showed tissue reaction of fibrohistiocytic proliferation and subsequent collagen deposition in all animals. Furthermore, the increased fibroblast proliferation and collagen deposition were time dependent (P<0.01).

CONCLUSION

This pilot study demonstrates histopathologic changes in the trachea after Teflon injection, comprised of increased fibroblast activity and collagen deposition that could be of potential use in creating greater airway rigidity in patients with sever diffuse excessive dynamic airway collapse.

Digital light procession three-dimensional printing acrylate/collagen composite airway stent for tracheomalacia

Recently, more and more researchers have focused on airway stent applied in tracheomalacia. The airway stents for clinical application were usually manufactured in accordance with a fixed pattern, which were difficult to perfect match with children, especially infants. Digital light procession of light curing acrylate resin implantation showed higher accuracy and printing speed over traditional three-dimensional printing techniques. In this article, a novel personalized airway stent was developed by digital light procession three-dimensional printing and was modified by collagen I extracted from the fish scales. The morphology of the collagen-modified airway stent was examined by scanning electron microscopy, and the chemical structures were examined by attenuated total internal reflectance Fourier transform infrared spectroscopy. The biocompatibility of this synthetic acrylate/collagen composite airway stent was characterized by water contact angle test and cell culture. The results confirmed that the composite airway stent was hydrophilic and non-cytotoxic toward a cultured human bronchial epithelial cell line with good cell viability and show excellent physicochemical and biological properties. In conclusion, this study presented the three-dimensional printing composite acrylate and collagen airway stent may have potential in customized treatment for tracheomalacia.

Current concepts in severe adult tracheobronchomalacia: evaluation and treatment

There is increasing recognition of tracheobronchomalacia (TBM) in patients with respiratory complaints, though its true incidence in the adult population remains unknown. Most of these patients have an acquired form of severe diffuse TBM of unclear etiology. The mainstays of diagnosis are dynamic (inspiratory and expiratory) airway computed tomography (CT) scan and dynamic flexible bronchoscopy with forced expiratory maneuvers. While the prevailing definition of TBM is 50% reduction in cross-sectional area, a high proportion of healthy volunteers meet this threshold, thus this threshold fails to identify patients that might benefit from intervention. Therefore, we consider complete or near-complete collapse (>90% reduction in cross-sectional area) of the airway to be severe enough to warrant potential intervention. Surgical central airway stabilization by posterior mesh splinting (tracheobronchoplasty) effectively corrects malacic airways and has been shown to lead to significant improvement in symptoms, health-related quality of life, as well as functional and exercise capacity in carefully selected adults with severe diffuse TBM. A short-term stent trial clarifies a patient's candidacy for surgical intervention. Coordination of care between experienced interventional pulmonologists, radiologists, and thoracic surgeons is essential for optimal outcomes.

Laser tracheobronchoplasty: a novel technique for the treatment of symptomatic tracheobronchomalacia

The management of tracheobronchomalacia is a very challenging problem with few treatment options. This study aims to evaluate the outcomes of a novel surgical treatment for membranous tracheobronchomalacia. A consecutive series of patients with tracheobronchomalacia were treated with two to three holmium laser scarring surgeries of the hyperdynamic tracheal and bronchial walls for the purpose of stiffening them through fibrosis. Patients filled out a Dyspnea Index questionnaire before and after treatment. Ten patients were treated for their tracheobronchomalacia with a mean age of 54 years. Symptoms included severe dyspnea, dry cough, recurrent pulmonary infections, and respiratory failure. Fifty percent of patients presented with wheezing refractory to traditional treatment. Tracheobronchomalacia was associated with gastroesophageal reflux disease (n = 8), obstructive sleep apnea (n = 5), and tracheal stenosis (n = 3). Only 50 % of patients presented with morbid obesity. All cases showed significant improvement of their respiratory symptoms with a mean postoperative difference of 22.3 out of a maximum impairment score of 40 (P < 0.01) on the Dyspnea Index. The mean number of procedures was 2.3 per patient with the average laser energy delivered per procedure of 1600 J. Laser tracheobronchoplasty is a safe, easy to adopt, and effective technique for the treatment of membranous tracheobronchomalacia. It presents a simple alternative to the commonly used procedures like endoluminal stenting and open tracheobronchoplasty.

Tracheostomy Tube Placement: Early and Late Complications

Tracheostomy tube placement is a therapeutic procedure that has gained increased favor over the past decade. Upper airway obstructions, failure to liberate from the ventilator, and debilitating neurological conditions are only a few indications for tracheostomy tube placement. Tracheostomy tubes can be placed either surgically or percutaneously. A percutaneous approach offers fewer surgical site infections and postsurgical bleeding than a surgical approach. A surgical placement posses a lower risk of injury to the posterior tracheal wall and spontaneous decannulation is less common. Late complications of both approaches include stenosis, malacia, along with tracheoesophageal, tracheoinnominate, and tracheocutaneous fistulas. This review describes the indications and methods of placement of tracheostomy tubes along with early and late complications that may occur following placement.

Respiratory Conditions Associated with Tracheobronchomegaly (Mounier-Kuhn Syndrome): A Study of Seventeen Cases

BACKGROUND

Mounier-Kuhn syndrome (MKS) is a rare disorder characterized by enlargement of the trachea and main bronchi and associated with recurrent respiratory tract infections.

OBJECTIVE

This multicenter, retrospective study was carried out to describe respiratory conditions associated with tracheobronchomegaly.

METHODS

Nine institutions involved in the 'Groupe d'Endoscopie de Langue Française' (GELF) participated in this study. A standard form was used to record patient characteristics, treatments and follow-up from medical charts.

RESULTS

Seventeen patients, 53% male, aged 58 ± 18 years at diagnosis were included. Recurrent infections revealed MKS in 88% of cases. Main comorbid conditions were diffuse bronchiectasis in 88% of patients and tracheobronchomalacia in 67% of cases. The exacerbation rate was 1.5 exacerbations/patient/year. The main non-respiratory morbid condition was gastroesophageal reflux disease in 29% of cases. Interventional bronchoscopy was performed in seven patients (41%), consisting of laser (n = 2) and tracheal stenting (n = 5). Complications related to stents were observed in 80% of cases with a mean stent duration of 8 months. Four deaths, including three due to respiratory causes, occurred during follow-up.

CONCLUSIONS

This is the largest series of MKS reported in the literature, showing that bronchiectasis and tracheobronchomalacia are the main associated morbid conditions that constitute a challenge for treatment.

Is silicone stent insertion a clinically useful option for tracheobronchomalacia?

BACKGROUND/AIM

Tracheobronchomalacia (TBM) leads to the obstruction of expiratory airflow and interference with secretion clearance. Stabilization of the airway wall using a silicon stent or laser coagulation of the posterior wall may be treatment options. This study aimed to retrospectively analyze which interventional bronchoscopic method could be used to provide airway stabilization and gain control of symptoms and for whom this method could be used.

MATERIALS AND METHODS

Fifteen patients who had received treatment in our interventional pulmonology unit were analyzed. We analyzed the techniques used, stent duration, complications, and long-term treatment success retrospectively.

RESULTS

Stents were used in 10 patients: 4 patients had silicon Y-stents and 4 patients had silicon tracheal stents. Stents were removed due to early migration in 3 patients. In 5 of the 7 cases, the stent was removed due to frequent obstructions of the stent due to recurrent severe mucostasis. A suitable stent was not found for one patient who had an extremely enlarged trachea. Good clinical results were achieved in just two cases. The frequency of admissions to the emergency room and hospitalizations were diminished during the follow-up time in these two patients.

CONCLUSION

Silicon stents may be a good treatment option in selected patients with TBM and dynamic collapse. However, our patients were high-risk; thus, the criteria for candidates for bronchoscopic treatment should be carefully defined.

Tracheobronchomegaly associated with laryngo-tracheal amyloidosis: First case report

Tracheobronchomegaly (TBM) is a rare enlargement of the tracheal cartilage, also known as Mounier-Kuhn syndrome (MKS). Here, we describe an unusual case of acquired TBM in an adult, caused by amyloid regeneration and associated tracheal weakening, rather than by MKS. CT scan and fiberscopic examination of a 55-year-old woman suffering from severe dyspnea revealed TBM and subglottic stenosis, which was caused by deposition of amyloid tissue. We performed a tracheostomy and vaporized the subglottic stenosis with a CO2 laser, after which we installed a silicone T-tube. After the first operation, re-stenosis occurred, and the procedure was repeated; stenosis was subsequently cured and the dyspnea disappeared, after which the tracheostomy could be closed. This is the first report of adult TBM associated with amyloid deposition in the subglottis and trachea. This diagnosis is very difficult, as amyloid deposition in the trachea can have various clinical presentations.