Central Airway Obstruction

Endoscopic Removal of Uncovered Metallic Airway Stents

BACKGROUND

Self-expandable uncovered metallic stents (SEUMS) have been used in benign tracheobronchial stenosis. Stent complications may require risky removal due to SEUMS integration in the tracheobronchial wall. Our study aims to report techniques, including a novel one, and outcomes of SEUMS removal by rigid bronchoscopy.

METHODS

We studied a case series of 7 patients from a tertiary medical center, who underwent SEUMS removal from 2017 to 2022. SEUMS removals were performed through rigid bronchoscopy. We used a new technique with bronchoscopic hook scissors to gradually dissect the stent from the airway wall.

RESULTS

Nine SEUMS were removed from 7 patients. The mean duration of stenting was 7 years (5 to 12 y). Indications for stent removal included mostly recurrent pulmonary infections, obstructive granulation tissue, and stents' fractures. We used the usually described technique in the literature known as the "piecemeal fashion" without dissection in 4 SEUMS removals and a new dissection technique in 5 procedures. We reported one major intraoperative complication using the former technique in the form of tracheal tear with mediastinal breach, while we did not experience any major complications with the later one. One patient died 8 days after surgery from respiratory failure.

CONCLUSION

Dissection and "piecemeal fashion techniques" can be used to remove SEUMS by rigid bronchoscopy even after long-term stenting. SEUMS removal is a very risky procedure and must be performed by a trained operator. Patients should be aware of possible severe complications.

Cytomegalovirus tracheobronchitis mimicking lung cancer progression in a patient with lung adenocarcinoma: A case report

Cytomegalovirus (CMV) commonly infects immunocompromised individuals, such as cancer patients. We present a case involving a 60-year-old male with Stage 3A lung adenocarcinoma and chronic obstructive pulmonary disease (COPD) diagnosed with CMV tracheobronchitis, initially suspected as cancer progression. Treatment with ganciclovir led to partial improvement in symptoms of shortness of breath and cough, as well as bronchoscopic findings. However, due to ganciclovir-induced neutropenia, the therapy was switched to foscarnet. Distinguishing between cancer progression and infectious tracheobronchitis through physical examination and chest CT scans remains challenging. In lung cancer patients presenting with airway and bronchial narrowing along with ulcerative mucosal lesions, CMV infection should be considered. A bronchoscopic biopsy is crucial for accurate diagnosis and determining the appropriate treatment in these patients.

Characteristics of lung resistance and elastance associated with tracheal stenosis and intrapulmonary airway narrowing in ex vivo sheep lungs

BACKGROUND

Understanding the characteristics of pulmonary resistance and elastance in relation to the location of airway narrowing, e.g., tracheal stenosis vs. intrapulmonary airway obstruction, will help us understand lung function characteristics and mechanisms related to different airway diseases.

METHODS

In this study, we used ex vivo sheep lungs as a model to measure lung resistance and elastance across a range of transpulmonary pressures (5-30 cmH2O) and ventilation frequencies (0.125-2 Hz). We established two tracheal stenosis models by inserting plastic tubes into the tracheas, representing mild (71.8% lumen area reduction) and severe (92.1%) obstructions. For intrapulmonary airway obstruction, we induced airway narrowing by challenging the lung with acetylcholine (ACh).

RESULTS

We found a pattern change in the lung resistance and apparent lung elastance as functions of ventilation frequency that depended on the transpulmonary pressure (or lung volume). At a transpulmonary pressure of 10 cmH2O, lung resistance increased with ventilation frequency in severe tracheal stenosis, whereas in ACh-induced airway narrowing the opposite occurred. Furthermore, apparent lung elastance at 10 cmH2O decreased with increasing ventilation frequency in severe tracheal stenosis whereas in ACh-induced airway narrowing the opposite occurred. Flow-volume analysis revealed that the flow amplitude was much sensitive to ventilation frequency in tracheal stenosis than it was in ACh induced airway constriction.

CONCLUSIONS

Results from this study suggest that lung resistance and apparent elastance measured at 10 cmH2O over the frequency range of 0.125-2 Hz can differentiate tracheal stenosis vs. intrapulmonary airway narrowing in ex vivo sheep lungs.

Usefulness of net retrieval devices for central airway obstruction caused by blood clots during extracorporeal membrane oxygenation: Case series

RATIONALE

Extracorporeal membrane oxygenation (ECMO) is the last trump card for severe respiratory failure. The main complications of ECMO are bleeding and thrombosis, both of which can be life-threatening. Large blood clots can cause central airway obstruction (CAO) during ECMO, and CAO should be removed as soon as possible because of asphyxiation. However, there is no comprehensive reports on its frequency and management. The purpose of this study is to share therapeutic experiences for rare and serious conditions and provide valuable insights.

PATIENT CONCERNS

We report 3 patients placed on ECMO for severe respiratory failure.

DIAGNOSIS

CAO due to large blood clots occurred during ECMO in all 3 patients.

INTERVENTIONS

Large blood clots were removed using flexible bronchoscopy, grasping forceps, and net retrieval devices in all 3 patients.

OUTCOMES

In all 3 patients, large blood clots were removed multiple times during ECMO. The patients' respiratory conditions improved and they were eventually weaned off the ECMO.

LESSONS

CAO due to large blood clots during ECMO is rare. The frequency of CAO requiring bronchoscopic removal was estimated to be approximately 1,5%. When this occurs, clots should be removed as soon as possible. Net retrieval devices are useful tools for the collection of large blood clots.

Management of Central Airway Obstruction: An American College of Chest Physicians Clinical Practice Guideline

BACKGROUND

Central airway obstruction (CAO), seen in a variety of malignant and non-malignant airway disorders, is associated with a poor prognosis. The management of CAO is dependent on provider training and local resources, which may make the clinical approach and outcomes highly variable. We reviewed the current literature and provided evidence-based recommendations for the management of CAO.

METHODS

A multidisciplinary expert panel developed key questions using the PICO (Patient, Intervention, Comparator, and Outcomes) format and conducted a systematic literature search using MEDLINE (PubMed) and the Cochrane Library. The panel screened references for inclusion and used vetted evaluation tools to assess the quality of included studies and extract data, and graded the level of evidence supporting each recommendation. A modified Delphi technique was used to reach consensus on recommendations.

RESULTS

A total of 9,688 abstracts were reviewed, 150 full-text articles were assessed, and 31 studies were included in the analysis. One good practice statement and 10 graded recommendations were developed. The overall certainty of evidence was very low.

CONCLUSIONS

Therapeutic bronchoscopy can improve the symptoms, quality of life, and survival of patients with malignant and non-malignant CAO. Multi-modality therapeutic options, including rigid bronchoscopy with general anesthesia, tumor/tissue debridement, ablation, dilation, and stent placement, should be utilized when appropriate. Therapeutic options and outcomes are dependent on the underlying etiology of CAO. A multidisciplinary approach and shared decision-making with the patient are strongly encouraged.

World Association for Bronchology and Interventional Pulmonology (WABIP) guidelines on airway stenting for malignant central airway obstruction

Malignant Central Airway Obstruction (MCAO) encompasses significant and symptomatic narrowing of the central airways that can occur due to primary lung cancer or metastatic disease. Therapeutic bronchoscopy is associated with high technical success and symptomatic relief and includes a wide range of airway interventions including airway stents. Published literature suggests that stenting practices vary significantly across the world primarily due to lack of guidance. This document aims to address this knowledge gap by addressing relevant questions related to airway stenting in MCAO. An international group of 17 experts from 17 institutions across 11 countries with experience in using airway stenting for MCAO was convened as part of this guideline statement through the World Association for Bronchology and Interventional Pulmonology (WABIP). We performed a literature and internet search for reports addressing six clinically relevant questions. This guideline statement, consisting of recommendations addressing these six PICO questions, was formulated by a systematic and rigorous process involving the evaluation of published evidence, augmented with expert experience when necessary. Panel members participated in the development of the final recommendations using the modified Delphi technique.

Epidemiology and Survival of Malignant Central Airway Obstruction in Lung Cancer Identified on Cross-Sectional Imaging

BACKGROUND

The prevalence of malignant central airway obstruction at diagnosis and its 5-year incidence are largely unknown, as are basic epidemiological data pertaining to this serious condition. To address these data limitations, we retrospectively collected data from the cohort of patients diagnosed with lung cancer at our institution in 2015 and followed cohort patients 5 years forward, until 2020.

METHODS

We reviewed index PET/CT or CT scans at the time of lung cancer diagnosis to identify the presence, subtype, and severity of malignant central airway obstruction as well as progression/development over the next 5 years.

RESULTS

The prevalence of malignant central airway obstruction affecting the airway lumen by 25% or greater was 17%, and its 5-year incidence of development was 8.2%. Notable associations from the multivariate analysis included a younger age and a stepwise increase in obstruction with increasing stage of disease. Squamous cell carcinoma and small-cell lung cancer were the 2 histologic subtypes with the strongest association with obstruction. The presence of malignant central airway obstruction either at time of diagnosis or on follow-up imaging was associated with significantly shortened survival (multivariate Cox proportional HR for MCAO=1.702, P<0.001).

CONCLUSION

This study provides the first systematic characterization of fundamental epidemiological data on malignant central airway obstructions at a tertiary cancer center in the United States. This data is important to inform research directions and funding efforts of this serious complication. It also serves as a baseline value against which to compare for future studies.

[Tracheobronchial involvement in relapsing polychondritis and differential diagnoses]

Relapsing polychondritis is a systemic auto-immune disease that mainly affects cartilage structures, progressing through inflammatory flare-ups between phases of remission and ultimately leading to deformation of the cartilages involved. In addition to characteristic damage of auricular or nasal cartilage, tracheobronchial and cardiac involvement are particularly severe, and can seriously alter the prognosis. Tracheobronchial lesions are assessed by means of a multimodal approach, including dynamic thoracic imaging, measurement of pulmonary function (with recent emphasis on pulse oscillometry), and mapping of tracheal lesions through flexible bronchoscopy. Diagnosis can be difficult in the absence of specific diagnostic tools, especially as there may exist a large number of differential diagnoses, particularly as regards inflammatory diseases. The prognosis has improved, due largely to upgraded interventional bronchoscopy techniques and the development of immunosuppressant drugs and targeted therapies, offering patients a number of treatment options.

Diagnostic and Therapeutic Role of Electrocautery Snare Use in Endobronchial Polypoid Lesions

INTRODUCTION

Electrocautery with a snare probe offers a tool for the treatment of endobronchial polyps. The aim of this study was to demonstrate the efficacy of the snare probe in patients undergoing rigid bronchoscopy due to central airway obstruction.

METHODS

This retrospective descriptive study included patients who underwent rigid bronchoscopy with an electrocautery snare probe for the diagnosis and/or treatment of endobronchial polyps in an interventional pulmonology unit.

RESULTS

The mean age of the 47 patients (38 men) with endobronchial polypoid lesions was 61.5 years. Six lesions (12.8%) were located in the trachea, 6 (12.8%) in the right main bronchus, 11 (23.4%) in the left main bronchus, and 24 (51.1%) in the lobar bronchi. Twenty-eight lesions (59.5%) were malignant. Prior to the procedure, 6 (12.8%) patients had grade 1 obstruction, 6 (12.8%) had grade 2 obstruction, 15 (31.9%) had grade 3 obstruction, and 20 (42.6%) had grade 4 obstruction. In terms of airway obstruction after the procedure, grade 1 was present in 46 (97.9%) patients and grade 2 was present in 1 (2.1%) patient. No major complication developed in 93.6% of the patients. During a mean follow-up period of 48 months, 85.1% of the patients did not experience recurrence.

CONCLUSION

Our results demonstrate that the snare probe can be used to effectively and reliably establish airway patency in patients with central airway obstruction due to endobronchial polypoid lesions.

Interventional bronchoscopy in lung cancer treatment

Interventional bronchoscopy has seen significant advancements in recent decades, particularly in the context of lung cancer. This method has expanded not only diagnostic capabilities but also therapeutic options. In this article, we will outline various therapeutic approaches employed through either a rigid or flexible bronchoscope in multimodal lung cancer treatment. A pivotal focus lies in addressing central airway obstruction resulting from cancer. We will delve into the treatment of initial malignant changes in central airways and explore the rapidly evolving domain of early peripheral malignant lesions, increasingly discovered incidentally or through lung cancer screening programmes. A successful interventional bronchoscopic procedure not only alleviates severe symptoms but also enhances the patient's functional status, paving the way for subsequent multimodal treatments and thereby extending the possibilities for survival. Interventional bronchoscopy proves effective in treating initial cancerous changes in patients unsuitable for surgical or other aggressive treatments due to accompanying diseases. The key advantage of interventional bronchoscopy lies in its minimal invasiveness, effectiveness and favourable safety profile.

Feasibility, Tolerability, and Effectiveness of Transbronchial Interventions in Elderly Patients With Malignant Central Airway Obstruction: A Retrospective Single-institution Study

BACKGROUND

In elderly patients with malignant central airway obstruction (MCAO), the treating physicians often hesitate to undertake transbronchial interventions (TBIs) as a palliative procedure in view of the advanced age of the patients.

METHODS

We conducted this retrospective study to evaluate the differences in the feasibility, tolerability, and effectiveness of TBIs between elderly (aged 75 years old or above; elderly group; n=27) and nonelderly (aged below 75 years old; nonelderly group; n=50) patients with MCAO. The primary endpoint was the incidence of complications during (within 24 hours) and after (>24 hours) TBIs.

RESULTS

The mean age of the patients was 81 years in the elderly group and 61 years in the nonelderly group. The complications encountered during/after TBI included endobronchial bleeding or hypoxemia requiring intubation occurring during the TBIs, and bacterial pneumonia, airway reocclusion, and stent migration occurring after the TBIs, although there was no difference in the frequency of complications during/after the TBIs between the elderly group and nonelderly group (26% vs. 30%, P =0.706). There was no difference in the percentage of patients in whom successful airway recanalization was achieved by TBI (93% vs. 80%, P =0.197), the percentage of patients who showed symptomatic improvement after the TBIs (67% vs. 76%, P =0.380) and the OS after the TBIs (6.1 vs. 7.3 months, P =0.704) between the 2 groups.

CONCLUSION

TBIs can be undertaken without hesitation as a palliative procedure in elderly patients with MCAO.

Correlation of Bronchoscopy and CT in Characterizing Malignant Central Airway Obstruction

BACKGROUND

Malignant Central Airway Obstruction (MCAO) presents a significant challenge in lung cancer management, with notable morbidity and mortality implications. While bronchoscopy is the established diagnostic standard for confirming MCAO and assessing obstruction subtype (intrinsic, extrinsic, mixed) and severity, Computed Tomography (CT) serves as an initial screening tool. However, the extent of agreement between CT and bronchoscopy findings for MCAO remains unclear.

METHODS

To assess the correlation between bronchoscopy and CT, we conducted a retrospective review of 108 patients at Roswell Park Comprehensive Cancer Center, analyzing CT and bronchoscopy results to document MCAO presence, severity, and subtype.

RESULTS

CT correctly identified MCAO in 99% of cases (107/108). Agreement regarding obstruction subtype (80.8%, Cohen's κ = 0.683, p < 0.001), and severity (65%, Quadratic κ = 0.657, p < 0.001) was moderate. CT tended to equally overestimate (7/19) and underestimate (7/19) the degree of obstruction. CT was also poor in identifying mucosal involvement in mixed MCAO.

CONCLUSIONS

CT demonstrates reasonable agreement with bronchoscopy in detecting obstruction. Nevertheless, when CT indicates a positive finding for MCAO, it is advisable to conduct bronchoscopy. This is because CT lacks reliability in determining the severity of obstruction and identifying the mucosal component of mixed disease.

Role of interventional bronchoscopy and chemotherapy in the treatment of patients with small-cell lung cancer: A case report

Most of the small-cell lung cancer patients are of the central type of lung cancer. Small-cell lung cancer often intrudes into the atmospheric tract and large blood vessels, thus causing severe tracheobronchial stenosis and superior vena cava syndrome. In addition, patients with malignant tumors, especially those with respiratory failure and severe hypoxia, can be complicated with thromboembolic diseases. We reported a 65-year-old woman with severe stenosis of the trachea, and right main bronchus complicated with acute respiratory failure was treated with bronchoscopy and stent implantation to improve the patient's dyspnea, thus successfully receiving chemotherapy and timely treatment. After chemotherapy, the tumor shrank and the stenosis of the trachea and right main bronchus improved. We removed the right main bronchus stent and the tracheal stent successively to improve the quality of life of the patients. We managed both the cancer and exacerbation-related factors to improve the patient's medical conditions so that the patient could receive timely and suitable treatment.

Tracheobronchial stents: an expanding prospect

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean-Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel-titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug-eluting and three-dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction.

Cryodebulking to Relieve Critical Airway Narrowing Due to a Central Airway Tumor at the Carina: A Case Report and Literature Review

Central airway tumors presenting as critical airway stenosis is a medical emergency. Employing a cryoprobe, we successfully debulked a central airway tumor, providing rapid relief to a patient who came to the emergency room with severe breathlessness, hemoptysis, and respiratory failure. The current report underscores the efficacy of cryodebulking as an immediate and minimally invasive technique and a compelling alternative to conventional heat-based therapies.

Left Main Bronchus Obstruction in a Patient with Small-cell Lung Cancer Successfully Treated with Venovenous Extracorporeal Membrane Oxygenation

Lung cancer can cause fatal central airway obstruction. Rapid airway clearance is necessary in some cases, but ventilator management may be insufficient to maintain oxygenation levels. Venovenous extracorporeal membrane oxygenation (VV-ECMO) may be an effective rescue therapy for respiratory failure, but its efficacy in treating tumor-related airway obstruction is unknown. We herein report a case of central airway obstruction and severe acute respiratory failure due to small-cell lung cancer successfully treated with VV-ECMO, bronchoscopic airway intervention, and chemotherapy. VV-ECMO can be an effective option for the treatment of central airway obstruction with acute respiratory failure due to lung cancer.

Challenges in diagnosis and management of central airway obstruction: Case series

Central airway obstruction often presents with respiratory symptoms identical to those of common respiratory diseases. Diagnosis of central airway obstruction is challenging in clinical practice, especially misdiagnosed as asthma or chronic obstructive pulmonary disease in case of "normal" chest X-ray. Here, we reported five central airway obstruction cases: the first and fourth cases misdiagnosed as asthma, the second masquerading as chronic obstructive pulmonary disease exacerbation, the third diagnosed incorrectly with non-resolving pneumonia, and the fifth misdiagnosed as chronic obstructive pulmonary disease. We then analyzed diagnostic clues potentially useful to differentiate central airway obstruction from asthma/chronic obstructive pulmonary disease. A multidisciplinary approach to manage central airway obstruction is essential, particularly selecting judiciously the method of respiratory support due to the high risk of completed airway collapse or obstruction during interventional period.

Spray Cryotherapy for Benign Large Airway Stenosis: A Multicenter Retrospective Cohort Study of Safety and Practice Patterns

BACKGROUND

Benign airway stenosis (BAS) represents a significant burden on patients, providers, and healthcare systems. Spray cryotherapy (SCT) has been proposed as an adjunctive treatment to reduce BAS recurrence. We sought to examine safety and practice variations of the latest SCT system when used for BAS.

METHODS

We conducted a retrospective multicenter cohort study in seven academic institutions within the Interventional Pulmonary Outcomes Group. All patients who underwent at least one SCT session with a diagnosis of BAS at the time of procedure at these institutions were included. Demographics, procedure characteristics, and adverse events were captured through each center's procedural database and electronic health record.

RESULTS

A total of 102 patients underwent 165 procedures involving SCT from 2013 to 2022. The most frequent etiology of BAS was iatrogenic (n = 36, 35%). In most cases, SCT was used prior to other standard BAS interventions (n = 125; 75%). The most frequent SCT actuation time per cycle was five seconds. Pneumothorax complicated four procedures, requiring tube thoracostomy in two. Significant post-SCT hypoxemia was noted in one case, with recovery by case conclusion and no long-term effects. There were no instances of air embolism, hemodynamic compromise, or procedural or in-hospital mortality.

CONCLUSION

SCT as an adjunctive treatment for BAS was associated with a low rate of complications in this retrospective multicenter cohort study. SCT-related procedural aspects varied widely in examined cases, including actuation duration, number of actuations, and timing of actuations relative to other interventions.

Outcomes of Holmium Laser, Cryoablation, and Budesonide Inhalation for Treating Severe Central Airway Stenosis in Infants

BACKGROUND

Central airway stenosis (CAS) in infants is characterized by dysphonia, dyspnea, cyanosis, repeated apnea, and infection. This case series study aimed to evaluate the safety and efficacy of holmium laser, cryoablation and budesonide inhalation in treating infants with severe CAS.

METHODS

This retrospective study reviewed medical records data of 28 infants with severe CAS who underwent holmium laser treatment with cryoablation and/or balloon dilatation and budesonide inhalation therapy at Shanghai Children's Medical Center between June 2014 and May 2020. Outcomes were defined as treatment success when the stenotic area was <25% for the normal age group with stable reopening diameter at one-year follow-up.

RESULTS

Patients' mean age was 12.8 ± 8.8 months and 17 (60%) were male. Sixteen cases had web-like stenosis and 12 had scar contracture stenosis. Among 16 patients with web-like stenosis, 8 (50%) underwent balloon dilation with cryotherapy and 8 (50%) underwent balloon dilation only; treatment success was achieved in 10 (62.5%) cases and after revised treatments in 5 (31.25%) cases. Among 12 patients with scar contracture stenosis, 6 (50%) underwent balloon dilation with cryotherapy, 4 (33.3%) underwent cryotherapy and 2 (16.7%) underwent balloon dilation only; treatment success was achieved in 3 (23.1%) cases and after 1-4 revised treatments in 8 (61.5%) cases. Symptoms of the 2 unsuccessful (7.1%) cases were relieved after tracheal stent insertion. Neither severe adverse events nor complications were observed during follow-up.

CONCLUSION

Holmium laser with cryoablation followed by budesonide inhalation therapy safely and effectively cleans stenotic tissues and maintains airway reopening. Balloon dilation after holmium laser is recommended for treating web-like stenosis.

Microinjection Molded Biopolymeric Airway Stent with Antibacterial and Anti-Hyperplastic Properties

Central airway stenosis is a condition that the diameter of the trachea or main bronchus shrinkage is caused by external compression or internal tissue hyperplasia, which can cause difficulty breathing, asphyxia, and even death. Airway stenting is an easy way to restore the patency of the central airway, but airway stents commonly used in clinical practice can lead to complications such as mucus plugging, bacterial infection, and granulation tissue hyperplasia. Moreover, the non-degradable characteristic makes it requires a second operation to remove, which has the potential to cause tissue damage. In this study, a biodegradable airway stent is fabricated by microinjection molding using the bioelastomer of poly (L-lactide-co-ε-caprolactone) as the matrix material. The airway stent has excellent mechanical properties and an appropriate degradation rate. The hydrophilic surface of the airway stent can inhibit mucus plugging. The loading of silver nanoparticles and cisplatin endows the stent with antibacterial and anti-hyperplastic functions. In vitro and in vivo experiments demonstrate that this study provides an antibacterial and anti-hyperplastic biodegradable airway stent with elastic properties to avoid secondary removal operation and reduce complications associated with mucus plugging, bacterial infection, and granulation tissue hyperplasia.

[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.

Clinical Outcomes of Bronchoscopic Cryotherapy for Central Airway Obstruction in Adults: An 11-Years' Experience of a Single Center

BACKGROUND

Although bronchoscopic cryotherapy (BC) is a pragmatic modality for recanalization of central airway obstruction (CAO), the risk of complications, such as bleeding, remains a concern. This study aimed to present the clinical outcomes of BC and evaluate the factors associated with its complications.

METHODS

In this retrospective study, we reviewed the medical records of patients who underwent BC for CAO at the Asan Medical Center, South Korea. Most sessions were conducted via flexible bronchoscopy under moderate sedation. A multivariate logistic regression analysis was used to identify the factors associated with the success rate and complications.

RESULTS

BC was performed in 262 sessions in 208 patients between January 2009 and December 2020. The most common cause of cryotherapy was recanalization of the endobronchial tumor related CAO (233/262, 88.9%). More than partial re-establishment of airway patency was achieved in 211 of 233 (90.6%) sessions. The success rate did not differ significantly in the multivariate logistic regression analysis. The most common complication was intrabronchial bleeding (78/233, 35.5%); however, severe bleeding occurred only in one case (0.4%). Univariate and multivariate logistic regression analyses revealed that diabetes mellitus (odds ratio [OR] = 2.820, P = 0.011), respiratory failure before BC (OR = 3.546, P = 0.028), and presence of distal airway atelectasis (OR = 0.417, P = 0.021) were independently associated with moderate to severe intrabronchial bleeding, while the histologic type of tumor was not related to bleeding. BC for CAO caused by blood clot or foreign body was successful in most cases, and there were no complications.

CONCLUSION

BC is an efficient and relatively safe intervention for patients with CAO. Our findings suggest that diabetes, respiratory failure before BC, and the absence of distal airway atelectasis may be risk factors of moderate to severe intrabronchial bleeding.

Tumor-Related Factors Affecting the Success of Interventional Bronchoscopy in Malignant Airway Obstructions

BACKGROUND

It is difficult to select patients who will benefit from endobronchial treatment (ET) in malignant central airway obstruction (MCAO). We aimed to determine the tumor-related factors that affect the success of MCAO treatment.

METHODS

ETs for MCAO between March 2019 and June 2021 were analyzed retrospectively. The relationships between the success of the procedure and the percentage of endoluminal obstruction, tumor size, and type of lesion were evaluated.

RESULTS

Totally, 220 ETs were administered to 205 patients. Treatment was significantly more successful for the patients with pure endobronchial lesions than those with mixed lesions. The success rate was significantly lower when the tumor size was greater than 54.5 mm and the degree of endoluminal stenosis exceeded 92%; the area under the curve was 0.734 (0.625-0.842; P=0.001) and 0.733 (0.597- 0.870; P=0.001), respectively. There was no difference in the procedural success between lung cancer and extrathoracic malignancies and tumor treatment before the procedure.

CONCLUSION

Mixed lesions, tumor size over 54.5 mm, and a degree of stenosis over 92% are risk factors for unsuccessful endoluminal obstruction procedures. These parameters should be considered when selecting patients for ET interventions.

A Multi-armed Unfurling Actuator for Airway Lumen Measurement

Objective measurement of the lumen area demands an intraoperative diagnostic tool to aid on-site decision-making. We present a compliant mechanism-based unfurling actuator assembly integrated with a shaft connected to a motorized encoder to translate torque from the user at the proximal end to the actuator at the distal end. The actuator assembly has flexible arms coiled inside a cylindrical casing that moves radially outward upon actuation. Leveraging 3D printing of flexible materials, the unfurling actuator's four-arm design enables patency measurements in circumferential tracheal stenosis of varying grades. The rotary encoder output is correlated with the radially outward movement of the unfurling arms to estimate the lumen diameter. The measurement stability is analyzed using process control charts; data distribution over ten iterations reveals nearly 100% of process data falls between ±3 sigma (Upper and Lower control limits). Comparing measurements from the tool with direct measurement (vernier caliper) and ImageJ analysis, one-way ANOVA for circular morphology yields no significant differences in diameter p = 0.974 and area measurements p = 0.975.Clinical Relevance- Central airway narrowing reduces the effective lumen area in the tracheal and bronchial segments. Grading the degree of narrowing is often based on a suspicion index. A quick but thorough assessment of the airway caliber is essential in emergent or planned intubation, whether congenital, iatrogenic, or idiopathic tracheal stenosis.

Bronchoscopy Findings during Percutaneous Dilation Tracheostomy: A Single Tertiary Medical Center Experience

Percutaneous dilation tracheostomy (PDT) is a common procedure in intensive care units. Bronchoscopy has been recommended to guide PDT to decrease complication rates, but no study has analyzed bronchoscopy outcomes during PDT. In this retrospective study, we analyzed bronchoscopy findings and clinical outcomes during PDT. We collected data on all patients who underwent PDT between May 2018 and February 2021. All PDT operations were guided by bronchoscopy, and we assessed the airway to the third order of the bronchi. Forty-one patients who underwent PDT were included in this study. The average duration of PDT was 102.8 ± 34.6 s, and the average duration of bronchoscopy was 49.8 ± 43.8 s. No complications related to bronchoscopy and no significant changes in gas exchange or ventilator parameters were noted after the procedure. Fifteen patients (36.6%) exhibited abnormal bronchoscopy findings, including two patients (13.3%) with intra-airway mass lesions and obvious airway obstruction. None of the patients with intra-airway masses could be liberated from mechanical ventilation. This study observed a non-negligibly high incidence of unexpected endotracheal or endobronchial masses in patients with chronic respiratory failure during PDT, and a high rate of weaning failure was noted in these patients. The completion of bronchoscopy during PDT may provide additional clinical benefits.

Endobronchial mucormycosis diagnosed by fiberoptic bronchoscopy

Introduction

Endobronchial mucormycosis is very rare with only few cases reported in the literature. Here, we report a rare presentation of pulmonary mucormycosis in a diabetic patient who presented with left lung collapse. Bronchoscopy revealed an endobronchial growth, mimicking a tumor, causing complete occlusion of the left main bronchus. Histopathology confirmed the diagnosis of invasive mucormycosis.

Case presentation

Male patient 35 years old with accidental discovered Diabetes Mellitus, complained of hoarseness of voice and dry irritating cough that didn't respond to antitussives and nonspecific treatment. CT chest was done and revealed left total lung collapse. Fiberoptic bronchoscopy was done and revealed total occlusion of the left main bronchus with whitish fungating glistening tissue from which biopsies were obtained. Histopathological examination was consistent with mucormycosis. A trial of medical treatment failed after which the patient was referred for surgical resection.

Conclusion

Successful treatment of mucormycosis requires early diagnosis; prompt administration of antifungal therapy, and surgical intervention when applicable. Aggressive surgical intervention to remove necrotic tissue is generally accepted as the therapeutic mainstay for endobronchial obstructing mucormycosis.

[Non-infectious respiratory emergencies in patients with cancer]

Patients with a solid tumor or hematologic malignancy are often addressed to emergency units for an acute respiratory complication associated with the underlying cancer or secondary to treatments. The current article is part of a thematic series: "Intensive care and emergencies in solid tumours and blood cancer patients" and will develop the following points: (1) malignant proximal airway obstruction and, more specifically, the role of therapeutic bronchoscopy; (2) superior vena cava syndrome by tumor compression and/or secondary to thrombosis (diagnosis, local and systemic treatments); (3) cancer-related pulmonary embolism (incidence, indications for low-molecular weight heparins and direct oral anticoagulants). Other respiratory emergencies will be dealt in the other articles of this series.

Digital light processing-based multi-material bioprinting: Processes, applications, and perspectives

In the past decade, three-dimensional (3D) printing technology based on digital light processing (DLP) has developed rapidly and shown application prospects in several fields such as pneumatic robotics, flexible electronics, and tissue engineering. In particular, DLP-based multi-material printing has been capable of constructing heterogeneous 3D structures with characteristic gradients. DLP 3D printing technology has a wide range of applications in the field of bioprinting due to its high precision and mild printing conditions, including functionalized artificial tissues, medical models, and bioreactors. This paper focuses on the development of DLP-based multi-material 3D printing technology and its applications in the field of bioprinting, followed by giving an outlook on future efforts on overcoming the challenges and obstacles of this promising technique.

One-Lung Ventilation during Rigid Bronchoscopy Using a Single-Lumen Endotracheal Tube: A Descriptive, Retrospective Single-Center Study

Using one-lung ventilation (OLV) through a single-lumen endotracheal tube (SLT) in the untreated lung during rigid bronchoscopy (RB) and jet ventilation, high oxygenation can be guaranteed, whilst procedures requiring thermal energy in the other lung are still able to be used. This pilot study aimed to examine the bronchoscopy-associated risks and feasibility of OLV using an SLT during RB in patients with malignant airway stenosis. All consecutive adult patients with endobronchial malignant lesions receiving OLV during RB from 1 January 2017 to 12 May 2021 were included. We assessed perioperative complications in 25 RBs requiring OLV. Bleeding grades 1, 2, and 3 complicated the procedure in two (8%), five (20%), and five (20%) patients, respectively. The median saturation of peripheral oxygen remained at 94% (p = 0.09), whilst the median oxygen supply did not increase significantly from 0 L/min to 2 L/min (p = 0.10) within three days after the bronchoscopy. The 30-day survival rate of the patients was 79.1% (95% CI 58.4-91.1%), all of whom reported an improvement in subjective well-being after the bronchoscopy. OLV using an SLT during RB could be a new treatment approach for endobronchial ablative procedures without increasing bronchoscopy-associated risks, allowing concurrent high-energy treatments.

Therapeutic and prophylactic effects of radiation therapy in the management of recurrent granulation tissue induced tracheal stenosis: a review on the role of Endobronchial brachytherapy and external beam radiation therapy

PURPOSE

Granulation tissue-induced tracheal stenosis (mainly secondary to intubation or lung transplantation) is one of the most common etiologies of benign airway obstructions. Recurrence rates after standard treatment options (surgical resection and/or endobronchial interventions) can inadvertently worsen the stricture through the stimulation of more granulation tissue generation (via increased fibroblast activity and roliferation). Low-dose radiotherapy could be a promising tool to prevent granulation tissue formation after surgery and/or endobronchial interventions regarding its established role in the treatment of keloids or hypertrophic scars, two benign diseases with similar a pathophysiology to tracheal stenosis. This study reviews case reports and small series that used endobronchial brachytherapy (EBBT) or external beam radiotherapy (EBRT) for the management of refractory granulation tissue-induced tracheal stenosis after surgery and/or endobronchial interventions.

METHODS AND MATERIALS

Case reports and series (published up to October 2022) that reported outcomes of patients with recurrent granulation tissue-induced tracheal stenosis (after surgery and/or endobronchial interventions) treated by EBBT or EBRT (in definitive or prophylactic settings) were eligible.

RESULTS

Sixteen studies (EBBT: nine studies including 69 patients, EBRT: seven studies including 32 patients) were reviewed. The pooled success rate across all studies was 74% and 97% for EBBT and EBRT, respectively.

CONCLUSIONS

Radiation therapy appears to be effective in the management of selected patients with recurrent/refractory tracheal stenosis. Response to this treatment is usually good, but further studies with a larger number of patients and long-term followup are necessary to determine the optimal technique, dose, and timing of radiation therapy, late complications, the durability of response, and criteria for patient selection.

Early extracorporeal membrane oxygenation as bridge for central airway obstruction patients caused by neck and chest tumors to emergency surgery

Central airway obstruction caused by neck and chest tumors is a very dangerous oncological emergency with high mortality. Unfortunately, there is few literature to discuss an effective way for this life-threating condition. Providing effective airway managements, adequate ventilation and emergency surgical interventions are very important. However, traditional airway managements and respiratory support has only limited effect. In our center, using extracorporeal membrane oxygenation (ECMO) as a novel approach to manage patient with central airway obstruction caused by neck and chest tumors has been adopted. We aimed to show the feasibility: using early ECMO to manage difficult airway, provide oxygenation and support surgical procedure for patients with critical airway stenosis caused by neck and chest tumors. We designed a single-center, small sample size retrospective study based on real-world. We identified 3 patients with central airway obstruction caused by neck and chest tumors. ECMO was used to ensure adequate ventilation to emergency surgery. Control group cannot be established. Because traditional manner very likely led to death of such patients. Details of clinical characteristics, ECMO, surgery and survival outcomes were recorded. Acute dyspnea and cyanosis were the most frequent symptoms. All patients (3/3) showed descending arterial partial pressure of oxygen (PaO₂). Computed tomography (CT) revealed severe central airway obstruction caused by neck and chest tumors in all cases (3/3). All patients (3/3) had definite difficult airway. All cases (3/3) received ECMO support and emergency surgical procedure. Venovenous ECMO was the common mode for all cases. 3 patients weaned off ECMO successfully without any ECMO-related complications. Mean duration of ECMO was 3 h (range: 1.5-4.5 h). Under ECMO support, difficult airway management and emergency surgical procedure were finished successfully for all cases (3/3). The mean ICU stay was 3.3 days (range: 1-7 days), and the mean general ward stay was 3.3 days (range: 2-4 days). Pathology demonstrated the tumor dignity for 3 patients including 2 malignant cases and 1 benign case. All patients (3/3) were discharged from hospital successfully. We showed that early ECMO initiation was a safe and feasible approach to manage difficult airway for patients with severe central airway obstruction caused by neck and chest tumors. Meanwhile, early ECMO initiation could ensure security for airway surgical procedure.

Airway and Hemodynamic Considerations for the Anesthetic Management of an Intraluminal Tracheal Plasmacytoma

Central airway obstruction due to tracheal tumors presents unique challenges to the anesthesiologist. We present the case of a 44-year-old male taken to the OR for biopsy and resection of an undiagnosed tracheal mass. Intraoperative management was complicated by bleeding and significant hemodynamic instability, necessitating rapid surgical and anesthetic intervention. This ultimately led to abortion of surgical resection. Pathologic examination revealed a primary tracheal plasmacytoma, a rare type of tracheal tumor. Here, we describe anesthetic and hemodynamic considerations for a tracheal plasmacytoma. We discuss the approach to airway management in variable intrathoracic tracheal obstruction and the unpredictability of tracheal tumors.

Features of post-obstructive pneumonia in advanced lung cancer patients, a large retrospective cohort

BACKGROUND

Post-obstructive pneumonia refers to an infection of the lung parenchyma distal to a bronchial obstruction. Previous experience-based studies reported a high prevalence of this infection among patients with a medical history of advanced lung neoplasia, up to 40-55%.

OBJECTIVES

The current study was designed to investigate the features of post-obstructive pneumonia in lung cancer, including its predictors and the discriminants for 30-day mortality.

METHOD

Data from medical records at the tertiary University centre, UZ Brussel, were collected retrospectively between January 2016 and January 2021. Patients affected by lung cancer stages III and IV were included. A multidisciplinary team, composed of a pulmonologist, an infectious disease specialist and a chest radiologist, identified patients affected by post-obstructive pneumonia.

RESULTS

A total of 408 patients were included, of which 46 (11%) were diagnosed with post-obstructive pneumonia. Multivariable logistic regression for predictors of disease onset found significant differences for squamous cell carcinoma (OR:2.46 p-value: .014) and hilar location of the tumour (OR:2.72 p-value: .021). However, no significant differences were identified with regards to age or comorbidities. Furthermore, 30-day mortality among post-obstructive pneumonia patients was 30%. Multivariable logistic regression for prediction of 30-day mortality found significant differences in CURB-65 score (OR:73.20 p-value: .001) and smoking status (OR:0.009 p-value: .015).

CONCLUSIONS

Within this cohort, the prevalence of post-obstructive pneumonia in advanced lung cancer patients was lower than previously reported. Squamous cell carcinoma and a hilar tumour location were two variables associated with disease development, independent of age and comorbidities. Furthermore, a higher CURB-65 score at post-obstructive pneumonia diagnosis was correlated with mortality.

[Bronchoscopic management of malignant central airway obstructions]

Up to 30% of lung cancer patients suffer from central airway obstruction, resulting in major deterioration in prognosis and quality of life. Interventional bronchoscopy combines a number of invasive techniques used during rigid bronchoscopy. It is designed to rapidly improve symptoms, primarily dyspnea. Applied according to very precise indications, this technique requires careful patient selection and needs to be incorporated into the multimodal oncological management in combination with systemic treatments, radiation therapy and surgery.

Severe Central Airway Obstruction Secondary to a Giant Endobronchial Hamartoma: A Case Report

Central airway obstruction refers to the occlusion of more than 50% of the trachea, main stem bronchi, or lobar bronchus. It can potentially become a life-threatening condition. Pulmonary hamartomas (PH) are rare tumors with an incidence of 0.25%, constituting about 8% of all benign lung neoplasms. Only 10% of PH occur endobronchially, while the remaining appear peripherally. We present the case of a women with an endobronchial hamartoma that required emergent resection by bronchoscopy. This is 44-year-old woman, with a history of an endobronchial mass on the right main stem bronchus (RMSB) without histopathological diagnosis or surgical management. She presented with a history of chronic cough and expectoration. Upon admission, a chest X-ray was performed, showing opacities of the right lung and amputations of the RMSB. Bronchoscopy was performed and a tumor-like mass that occludes the RMSB was found, with valve effect causing intermittent occlusion. In anesthetic induction, she presents severe airway obstruction and cardiorespiratory arrest. During resuscitation maneuvers, the lesion that was obstructing the light is seen and resection was performed with electrocautery and cryotherapy probes. Histopathological report described an endobronchial chondromesenchymal hamartoma, with no signs of malignancy. The control X-ray showed adequate re-expansion of the right lung. In conclusion, although endobronchial hamartoma has a low incidence and has a slow growth rate, it can manifest as severe airway obstruction. To achieve a complete resection of an endobronchial lesion, both rigid and/or flexible bronchoscopy plus multimodal interventions are recommended.

Management of malignancy-induced, life-threatening hypoxemic respiratory failure using a self-expanding Y stent

We present the case of a young woman transferred to our center with acute hypoxic respiratory failure due to an obstructing subcarinal mass. We review the management and rationale of this respiratory failure at different stages of her hospital course. We describe the approach and rationale in both the intensive care unit as well as the bronchoscopy suite. Finally, we discuss how the use of a novel hybrid Y stent effectively palliated her symptoms.

Respiratory Failure during BIS-Guided Sedation in a Patient with Relapsing Polychondritis: A Case Report

Relapsing polychondritis (RP) is a rare autoimmune disorder that causes inflammation and deterioration of cartilaginous structures such as the ears, nose, joints and laryngotracheobronchial tree. A 42-year-old man receiving treatment for RP underwent open reduction and internal fixation of a femur fracture under spinal anesthesia and with sedation by propofol and remifentanil. The level of sedation was monitored via a bispectral index (BIS), and maintained at between 60 and 80. At the end of the operation, he lost consciousness and displayed weak respiratory effort. During mask ventilation, the patient was judged to have respiratory failure due to high end-tidal CO₂ (EtCO₂) concentration and respiratory acidosis in an arterial-blood-gas analysis (ABGA). Ventilation through a properly inserted laryngeal-mask-airway or endotracheal intubation were impossible; instead, a surgical tracheotomy was performed. After recovering from respiratory failure with ventilatory support in the intensive care unit (ICU), he experienced the same symptoms three more times, requiring ventilatory support. He was discharged with bilevel positive-airway-pressure (BiPAP), after successful adaptation.

Successful extracorporeal membrane oxygenation in a patient with central airway obstruction due to an endotracheal mass

Extracorporeal membrane oxygenation (ECMO) assists blood circulation and gas exchange via a heart–lung machine. ECMO is used mainly in intensive care units as bridging therapy until heart and respiratory failure can be addressed or until transplantation can be performed. ECMO is sometimes used during surgery under general anaesthesia, depending on the patient’s underlying diseases and the nature of the operation. If the oxygen supply and carbon dioxide removal capacity are limited, venovenous (VV)-ECMO can be helpful. Here, we describe the use of VV-ECMO for surgical resection of an endotracheal mass through rigid bronchoscopy in a patient who developed decompensating dyspnoea due to central airway obstruction (CAO).

First-In-Human Computer-Optimized Endobronchial Ultrasound-Guided Interstitial Photodynamic Therapy for Patients With Extrabronchial or Endobronchial Obstructing Malignancies

Objective

Patients with inoperable extrabronchial or endobronchial tumors who are not candidates for curative radiotherapy have dire prognoses with no effective long-term treatment options. To reveal that our computer-optimized interstitial photodynamic therapy (I-PDT) is safe and potentially effective in the treatment of patients with inoperable extra or endobronchial malignancies inducing central airway obstructions.

Methods

High-spatial resolution computer simulations were used to personalize the light dose rate and dose for each tumor. Endobronchial ultrasound with a transbronchial needle was used to place the optical fibers within the tumor according to an individualized plan. The primary and secondary end points were safety and overall survival, respectively. An exploratory end point evaluated changes in immune markers.

Results

Eight patients received I-PDT with planning, and five of these received additional external beam PDT. Two additional patients received external beam PDT. The treatment was declared safe. Three of 10 patients are alive at 26.3, 12, and 8.3 months, respectively, after I-PDT. The treatments were able to deliver a prescribed light dose rate and dose to 87% to 100% and 18% to 92% of the tumor volumes, respectively. A marked increase in the proportion of monocytic myeloid-derived suppressor cells expressing programmed death-ligand 1 was measured in four of seven patients.

Conclusions

Image-guided light dosimetry for I-PDT with linear endobronchial ultrasound transbronchial needle is safe and potentially beneficial in increasing overall survival of patients. I-PDT has a positive effect on the immune response including an increase in the proportion of programmed death-ligand 1-expressing monocytic myeloid-derived suppressor cells.

A narrative review of new research progress regarding the use of airway stents in benign airway stenosis

INTRODUCTION

Benign airway stenosis is a severe disease that can result in death with improper treatment. Clinicians must know about airway stents to choose the best one in their daily practice.

AREAS COVERED

PubMed, Embase, and other electronic databases and websites were searched to identify relevant randomized controlled trials and meta-analyses. This review summarizes different types of airway stents and analyzes their advantages and disadvantages.

EXPERT OPINION

Increasing attention has been given to the indications and prognosis of benign airway stenosis treated with different airway stents. With more investigations and data, better alternatives to silicone stents could be developed in the future.

Self-Expandable Metal Stent in the Management of Malignant Airway Disorders

Background

Self-expanding metallic stent (SEMS) is a palliative therapy for patients with malignant central airway obstruction (CAO) or tracheoesophageal fistula (TEF). Despite this, many patients experience death shortly after SEMS placement.

Aims

We aimed to investigate the effect of SEMS on the palliative treatment between malignant CAO and malignant TEF patients and investigate the associated prognostic factors of the 3-month survival.

Methods

We performed a single-center, retrospective study of malignant CAO or TEF patients receiving SEMS placement. Clinical data were collected using the standardized data abstraction forms. Data were analyzed using SPSS 22.0. A two-sided P-value &lt;0.05 was statistically significant.

Results

106 malignant patients (82 CAO and 24 TEF) receiving SEMS placement were included. The body mass index (BMI), hemoglobin levels, and albumin levels in the malignant TEF group were lower than in the malignant CAO group (all P &lt; 0.05). The procalcitonin levels, C-reactive protein levels, and the proportion of inflammatory lesions were higher in the malignant TEF group than in the malignant CAO group (all P &lt; 0.05). The proportion of symptomatic improvement after the SEMS placement was 97.6% in the malignant CAO group, whereas 50.0% in the malignant TEF group, with a significant difference (P = 0.000). Three months after SEMS placement, the survival rate at was 67.0%, significantly lower in the malignant TEF group than in the malignant CAO group (45.8% vs. 73.2%, P = 0.013). Multivariate analysis revealed that BMI [odds ratio (OR) = 1.841, 95% certificated interval (CI) (1.155-2.935), P = 0.010] and neutrophil percentage [OR = 0.936, 95% CI (0.883–0.993), P = 0.027] were the independent risk factors for patients who survived three months after SEMS placement.

Conclusions

We observed symptom improvement in malignant CAO and TEF patients after SEMS placement. The survival rate in malignant TEF patients after SEMS placement was low, probably due to aspiration pneumonitis and malnutrition. Therefore, we recommend more aggressive treatment modalities in patients with malignant TEF, such as strong antibiotics, nutrition support, and strategic ventilation. More studies are needed to investigate the prognostic factors in patients with malignant airway disorders receiving SEMS placement.

Therapeutic bronchoscopy for malignant central airway obstruction: impact on quality of life and risk-benefit analysis

PURPOSE OF REVIEW

Malignant central airway obstruction (CAO) is a common complication in cancer and confers significant symptom burden and reduction in quality of life. Multiple bronchoscopic interventions exist for malignant CAO. In this review, we discuss the role of therapeutic bronchoscopy in the management of malignant CAO, emphasizing its impact on symptom control and quality of life while balancing the risks and benefits of intervention.

RECENT FINDINGS

Significant practice variations exist among practitioners of therapeutic bronchoscopy, and limited data exist to guide real-time clinical decision-making. Recent analyses demonstrate that therapeutic bronchoscopy is effective for symptoms associated with malignant CAO with infrequent complications. These studies also show that many of the improvements in symptoms and quality of life are sustained after intervention and are associated with improved overall survival in patients with malignant CAO. Recent data have also shown that the improvement in symptoms associated with therapeutic bronchoscopy may enable more definitive cancer treatment, further improving patient outcomes.

SUMMARY

Therapeutic bronchoscopy is safe and effective at improving patient-centered outcomes in malignant CAO. Research is ongoing to better understand its optimal role in this setting, refine decision-making regarding advanced bronchoscopic interventions, and further improve patient outcomes.

Selection of the access channel in bronchoscopic intervention

BACKGROUND

At present, bronchoscopic intervention has become an important treatment approach for central airway obstruction (CAO). Choosing an appropriate access channel for different patients during this operation has become a research focus.

METHODS

Data of bronchoscopic interventions in 201 patients with CAO in which one of endotracheal intubation, laryngeal mask, or rigid bronchoscope were used as the only access channel were retrospectively reviewed.

RESULTS

The total immediate effective rate was 94.1% (398/423), and the main complications related to the access channels included hypoxemia, elevated arterial partial pressure of carbon dioxide, arrhythmia, airway mucosa tear, glottic edema, vocal cord injury, tooth loss, massive bleeding, airway mucosal necrosis, and asphyxia. The incidence of complications was 16.8% (71/423). Glottic edema was the most common complication with an incidence of 7.8% (33/423) and accounted for 46.5% of all complications. Glottic edema only occurred in the laryngeal mask and rigid bronchoscope groups, and the incidence was significantly correlated with the operation time (p < 0.001). Massive bleeding related to the access channel remains the most serious complication.

CONCLUSIONS

Endotracheal intubation, laryngeal mask, and rigid bronchoscope each have their own advantages and disadvantages. The most appropriate access channel should depend on a comprehensive assessment of the patient.

Malignant Central Airway Obstruction: What's New?

Malignant central airway obstruction (MCAO) is a debilitating and life-limiting complication that occurs in an unfortunately large number of individuals with advanced intrathoracic cancer. Although the management of MCAO is multimodal and interdisciplinary, the task of providing patients with prompt palliation falls increasingly on the shoulders of interventional pulmonologists. While a variety of tools and techniques are available for the management of malignant obstructive lesions, advancements and evolution in this therapeutic venue have been somewhat sluggish and limited when compared with other branches of interventional pulmonary medicine (e.g., the early diagnosis of peripheral lung nodules). Indeed, one pragmatic, albeit somewhat uncharitable, reading of this article's title might suggest a wry smile and shug of the shoulders as to imply that relatively little has changed in recent years. That said, the spectrum of interventions for MCAO continues to expand, even if at a less impressive clip. Herein, we present on MCAO and its endoscopic and nonendoscopic management-that which is old, that which is new, and that which is still on the horizon.

Targeted delivery of inhalable drug particles in a patient-specific tracheobronchial tree with moderate COVID-19: A numerical study

The coronavirus disease 2019 (COVID-19) pandemic has led to severe social and economic disruption worldwide. Although currently no consent has been reached on a specific therapy that can treat COVID-19 effectively, several inhalation therapy strategies have been proposed to inhibit SARS-CoV-2 infection. These strategies include inhalations of antiviral drugs, anti-inflammatory drugs, and vaccines. To investigate how to enhance the therapeutic effect by increasing the delivery efficiency (DE) of the inhaled aerosolized drug particles, a patient-specific tracheobronchial (TB) tree from the trachea up to generation 6 (G6) with moderate COVID-19 symptoms was selected as a testbed for the in silico trials of targeted drug delivery to the lung regions with pneumonia alba, i.e., the severely affected lung segments (SALS). The 3D TB tree geometry was reconstructed from spiral computed tomography (CT) scanned images. The airflow field and particle trajectories were solved using a computational fluid dynamics (CFD) based Euler-Lagrange model at an inhalation flow rate of 15 L/min. Particle release maps, which record the deposition locations of the released particles, were obtained at the inlet according to the particle trajectories. Simulation results show that particles with different diameters have similar release maps for targeted delivery to SALS. Point-source aerosol release (PSAR) method can significantly enhance the DE into the SALS. A C++ program has been developed to optimize the location of the PSAR tube. The optimized simulations indicate that the PSAR approach can at least increase the DE of the SALS by a factor of 3.2× higher than conventional random-release drug-aerosol inhalation. The presence of the PSAR tube only leads to a 7.12% change in DE of the SALS. This enables the fast design of a patient-specific treatment for reginal lung diseases.

Microwave Ablation for Malignant Central Airway Obstruction: A Pilot Study

Background

Malignant central airway obstruction (CAO) is a debilitating complication of primary lung cancer and pulmonary metastases. Therapeutic bronchoscopy is used to palliate symptoms and/or bridge to further therapy. Microwave ablation (MWA) heats tissue by creating an electromagnetic field around an ablation device. We present a pilot study utilizing endobronchial MWA via flexible bronchoscopy as a novel modality for the management of malignant CAO.

Methods

Therapeutic bronchoscopy with a flexible MWA probe was performed in 8 cases. We reviewed tumor size, previous ablative techniques, number of applications, ablation time, amount of energy delivered, rate of successful recanalization, complications, and 30-day follow-up.

Results

Successful airway recanalization was achieved in all cases. No complications were noted. In 1 case, tumor in-growth within a silicone stent was ablated with no damage to the stent.

Discussion

Endobronchial MWA is a novel technique for tumor destruction while maintaining an airway axis. The oven effect and air gap around a tumor allow for safe and effective tissue devitalization and hemostasis without a thermal effect on structures surrounding the airway.

Central airway obstruction: is it time to move forward?

INTRODUCTION

Central airway obstruction (CAO) represents a pathological condition that can lead to airflow limitation of the trachea, main stem bronchi, bronchus intermedius or lobar bronchus.

MAIN BODY

It is a common clinical situation consensually considered under-diagnosed. Management of patients with CAO can be difficult and deciding on the best treatment approach represents a medical challenge. This work intends to review CAO classifications, causes, treatments and its therapeutic limitations, approaching benign and malign presentations. Three illustrative cases are further presented, supporting the clinical problem under review.

CONCLUSION

Management of CAO still remains a challenge. The available options are not always effective nor free from complications. A new generation of costume-tailored airway stents, associated with stem cell-based therapy, could be an option in specific clinical situations.