Managing obstruction of the central airways

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.

Choice of bronchoscopic intervention working channel for benign central airway stenosis

The purpose of this study is to report our experiences over 12 years with bronchoscopic interventions in patients with benign central airway stenosis using three types of working channels (rigid bronchoscope, laryngeal mask, and endotracheal intubation), with a focus on their related advantages, disadvantages, and postoperative complications. We analyzed the clinical data from 273 patients with benign central airway stenosis who underwent a bronchoscopic intervention. The Wilcoxon rank-sum test was used to analyze the immediate results after the first bronchoscopic intervention, and the Chi-square test was used to analyze the correlation between glottic edema and operation time. The 273 patients underwent a total of 479 bronchoscopic interventions, with satisfactory results. The immediate effective rates of the first bronchoscopic intervention by rigid bronchoscope, laryngeal mask, and endotracheal intubation were 91.4%, 91.3%, and 85.2%, respectively. Postoperative complications related to the working channels included hoarseness, glottic edema, pharyngalgia, paresthesia pharynges, cough, and tooth loss. Glottic edema was the most serious complication, and it occurred in 37.7% (23/61) of the rigid bronchoscope group and 9.8% (32/326) in the laryngeal mask group. And the incidence rate was significantly correlated with the operation time (P < 0.01). Therefore, for patients with benign central airway stenosis, the best choice of working channel during an operation should be made by the operation procedure, lesion location, and pathology of the patients. Shortening the operation time was an important factor in preventing glottic edema.

Paclitaxel-eluting silicone airway stent for preventing granulation tissue growth and lung cancer relapse in central airway pathologies

BACKGROUND

Airway stents are used to treat obstructive central airway pathologies including palliation of lung cancer, but face challenges with granulation tissue growth. Paclitaxel is a chemotherapy drug that also suppresses growth of granulation tissue. Yet, side effects arise from administration with toxic solubilizers. By incorporating paclitaxel in silicone stents, delivery of paclitaxel can be localized, and side effects minimized.

METHODS

Paclitaxel was incorporated into Liquid Silicone Rubber (LSR) containing polydimethylsiloxane, either as a powder or solution, prior to curing. Drug release study was compared in vitro at 37°C over 10 days. Drug release was quantified using HPLC, and bronchial cell lines were grown on LSR to investigate drug cytotoxicity, and expression of inflammatory markers, specifically interleukin-6 and interleukin-8.

RESULTS

Release rate of paclitaxel incorporated into silicone rubber was consistent with the Korsmeyer and Weibull models (R² > 0.96). Paclitaxel exposure reduced IL-8 levels in cancer cell lines, whilst no cytotoxic effect was observed in all cell lines at treatment concentration levels (≤ 0.1% (w/v) paclitaxel in silicone).

CONCLUSIONS

Incorporating paclitaxel into a silicone matrix for future use in a tracheobronchial stent was investigated. Drug release from silicone was observed and is a promising avenue for future treatments of central airway pathologies.

A Concentric Tube Robot System for Rigid Bronchoscopy: A Feasibility Study on Central Airway Obstruction Removal

New robotic systems have recently emerged to assist with peripheral lung access, but a robotic system for rigid bronchoscopy has yet to be developed. We describe a new robotic system that can deliver thin robotic manipulators through the ports of standard rigid bronchoscopes. The manipulators bend and elongate to provide maneuverability of surgical tools at the endoscope tip, without endoscope motion. We describe an initial feasibility study on the use of this system to bronchoscopically treat a central airway obstruction (CAO). CAO is prevalent and can be life-threatening in patients with large tumors, and conventional rigid bronchoscopic treatments place patients at risk of complications including broken teeth, neck trauma and damage to oropharyngeal structures due to significant forces induced by bronchoscope tilting and manipulation. In this study, we used an ex vivo ovine airway model to demonstrate the ability of a physician using the robotic system to efficiently remove tissue and restore the airway. Pre- and post-operative CT scans showed that the robot was able to reduce the degree of airway obstruction stenosis from 75 to 14% on average for five CAO resections performed in an ex vivo animal model. Using cadaver experiments, we demonstrated the potential of the robotic system to substantially reduce the intraoperative forces applied to the patient's head and neck (from 80.6 to 4.1 N). These preliminary results illustrate that CAO removal is feasible with our new rigid bronchoscopy robot system, and that this approach has the potential to reduce forces applied to the patient due to bronchoscope angulation, and thereby reduce the risk of complications encountered during CAO surgery.

[Simplification and Validation of Leicester Cough Questionnaire in Mandarin-Chinese]

背景与目的

患者行肺部手术后常常出现咳嗽，目前尚缺乏专门评估术后咳嗽的工具。本研究对中文版莱斯特咳嗽问卷（Leicester Cough Questionnaire in Mandarin-Chinese, LCQ-MC）改良并进行验证，探讨其临床应用价值。

方法

2015年9月-2016年12月四川大学华西医院胸外科单个医疗组共250例行胸腔镜肺部手术的患者参与调查，其中121例患者完成LCQ-MC，129例患者完成简化LCQ-MC，并进行信度和效度检验。

结果

新问卷保留LCQ-MC的框架与评分方式，由生理、心理和社会3个维度，共12个条目构成。量表内容效度良好，内容效度指数达到0.83；与日间咳嗽症状积分对比标准效度高（r=-0.578, P＜0.001），与夜间咳嗽症状积分和健康调查简表总分（Chinese version of the Medical Outcome Study 36-item Short-Form Healthy Survey, SF-36）对比标准效度中等（r=-0.358, P=0.004; r=0.346, P=0.030），与医院焦虑与抑郁评分总分（Hospital Anxiety and Depression Scale, HADS）对比标准效度较弱（r=-0.241, P=0.046）；内部一致性良好，克朗巴赫α系数在0.71-0.84之间；1周后重测信度良好（n=30, r=0.81-0.95）。

结论

简化版中文版莱斯特咳嗽问卷有良好的信度和效度，可应用于临床。

Central airway obstruction caused by adenoid cystic carcinoma in pregnancy: a case report and review of the literature

Malignancy complicates one in a thousand pregnancies. The most frequently diagnosed of these are breast, cervical, melanoma, ovarian, and haematological neoplasms. Tumours of respiratory origin are very uncommon during pregnancy. We present a case of tracheal adenoid cystic carcinoma (ACC), a rare type of primary airway tumour, diagnosed in a pregnant woman. To our knowledge, this is the third reported case of tracheal ACC complicating pregnancy. We discuss potential barriers to timely diagnosis of malignancies during pregnancy and consider optimal management strategies, taking into account the potential harm to the mother and foetus in a field with a limited evidence base.

Noninvasive Ventilation as a Temporizing Measure in Critical Fixed Central Airway Obstruction: A Case Report

BACKGROUND

Critical central airway obstruction (CAO) requires emergent airway intervention, but current guidelines lack specific recommendations for airway management in the emergency department (ED) while awaiting rigid bronchoscopy. There are few reports of the use of noninvasive ventilation (NIV) in tracheomalacia, but its use as a temporizing treatment option in fixed, malignant CAO has not, to the best of our knowledge, been reported.

CASE REPORT

An 84-year-old woman presented to the ED in respiratory distress, too breathless to speak and using her accessory muscles of respiration, with bilateral rhonchi throughout the lung fields. Point-of-care arterial blood gas revealed severe hypercapnia, and NIV was initiated to treat a presumed bronchitis with hypercapnic respiratory failure. Chest radiography revealed a paratracheal mass with tracheal deviation and compression. A diagnosis of critical CAO was made. While arranging for rigid bronchoscopic stenting, the patient was kept on NIV to good effect. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Recommendations for emergent treatment of life-threatening, critical CAO before bronchoscopic intervention are not well established. Furthermore, reports of NIV use in CAO are rare. We suggest that emergency physicians consider NIV as a temporizing measure for critical CAO while awaiting availability of bronchoscopy.

The anesthesia of trachea and bronchus surgery

The trachea and bronchus surgery is generally performed due to stenosis, traumatic injury, foreign body and tumors. Preoperative evaluation and anesthesia management are very important issues because of higher mortality and morbidity rates. Patients may be asymptomatic, but airway difficulties, hypoxia, stridor, cough, hemoptysis are common conditions in these patient population. The collaboration between the surgeon and the anesthesiologist is very substantial and necessary. Anesthetic techniques include various applications such as one lung ventilation, fiberoptic intubation, jet ventilation, and apneic oxygenation, general anesthesia with or without neuromuscular blockade. In this review, anesthesia management of the trachea and bronchus surgery is evaluated in the light of new knowledge.

Critical airway obstruction: challenges in airway management and ventilation during therapeutic bronchoscopy

BACKGROUND

Endobronchial interventions are used to alleviate symptoms of airway stenosis. The ventilatory management may be challenging during these procedures, and may influence the choice of airway device. We report our experiences from 902 procedures.

METHODS

Patients undergoing interventional bronchoscopy procedures were consecutively registered from 1999 to 2012. Critical airway obstruction (CAO) was defined as stridor, tracheal diameter <5 mm, stenosis of both the main bronchi, or clots/tumor fragments occluding the trachea or both main bronchi. Choice of airway, ventilation strategy, and survival are reported. Results are presented as median (interquartile range), and P≤0.05 was considered significant.

RESULTS

A total of 561 patients underwent 902 interventional bronchoscopy procedures (mechanical debulking, laser resection, balloon dilatation, and stent placement). The procedures were performed using flexible bronchoscope through an endotracheal tube (68.2%) or laryngeal mask airway (10.4%), or by rigid bronchoscopy (9.3%). All patients were primarily ventilated by volume-controlled ventilation. CAO was classified in 60 procedures, with more frequent use of laryngeal mask airway (21.7%), and change of airway device in 20/60 procedures. The survival for patients with malignant disease with or without CAO was 100 and 182 days, respectively, with 90 days survival probability of 0.65 and 0.51 (P=0.14).

CONCLUSIONS

Bronchoscopic treatment in patients with CAO may require a change of ventilatory and airway strategy during the procedure. Despite various challenges in the management of patients with CAO, the short-term survival in these patients is comparable to that in patients without CAO.

Endotracheal Tube Management and Obstructed Airway

Thoracic surgery encompasses a wide array of surgical techniques, most of which require lung isolation for surgical exposure in the pleural cavity; this, in turn, demands an extensive knowledge of respiratory mechanics and modalities of airway control. Likewise, effective treatment of an acute central airway obstruction calls for a systematic approach using clear communication between teams and a comprehensive knowledge of available therapeutic modalities by the surgeon.

Endobronchial deposits of chronic lymphocytic leukemia - an unusual cause of central airway obstruction

A 66-year-old woman with a background of chronic lymphocytic leukemia (CLL) was admitted to the hospital on several occasions with recurrent episodes of community-acquired pneumonia. Computed tomography and bronchoscopy revealed multiple obstructing endobronchial polyps. Post-obstructive pneumonia together with immunoglobulin G deficiency was considered the most likely cause of these recurrent infections. Bronchoscopy was performed for removal of the critically obstructing lesions. Histopathology revealed replacement of bronchial mucosa with CLL deposits. Despite a brief window of infection-free survival following therapy, she remained susceptible to pneumonia with further hospital admissions and eventually died from her disease.

Metachronous tracheal squamous cell carcinoma treated with Nd: YAG laser

Tracheal squamous cell carcinoma detected early in a high-risk patient has been treated twice with local neodymium-yttrium aluminium garnet laser therapy with good result so far. Ongoing bronchoscopic monitoring continues.

Neodymium yttrium-aluminium-garnet laser resection significantly improves quality of life in patients with malignant central airway obstruction due to lung cancer

Neodymium yttrium-aluminium-garnet (Nd : YAG) laser resection is one of the mostly used interventional pulmonology techniques for urgent desobstruction of malignant central airway obstruction (CAO). The major aim of this trial was to evaluate potential influence of Nd : YAG laser resection on overall quality of life (QoL) in patients with central lung cancer. Patients with malignant CAO scheduled for Nd : YAG laser resection were prospectively recruited in the trial. All patients were given European Organization for Research and Treatment, Quality of Life questionnaire (EORTC QLQ-30 v.3) before the procedure and approximately 2 weeks after the treatment. There were 37 male and 10 female patients, average age 54 ± 10 years. Most common tumour type was adenocarcinoma diagnosed in 51% of patients. Majority of patients were diagnosed in stage IIIB (53.2%) and stage IV (25.5%). Most common Eastern Cooperative Oncology Group performance status was 1 (72.3%). Nd : YAG laser resection significantly improved (P<0.0001) QoL and overall health according to EORTC QLQ-30. However, in some of the questions dealing with nausea, vomiting, diarrhoea, constipation, family life, social activities and financial situation, we did not observe statistically significant improvement. Nd : YAG laser resection of malignant CAO significantly improves QoL and overall health in patients with lung cancer.

Endoscopic removal of a self-expanding metallic airway stent: A case report

Self-expanding metallic stents are sometimes placed for the management of obstructing airway lesions or conditions such as airway wall malacia or tracheal stenosis. However, endoscopic removal of these devices from the airway can pose extreme challenges for both clinical airway management as well as for the administration of general anesthesia. We report on a 61-year-old man with a complex cardiac history presenting for endoscopic stent removal necessitated by the formation of extensive granulation tissue. Comorbidities included a history of myocardial infarction, an ischemic cardiomyopathy with severe left heart failure (ejection fraction of 25%), mild right heart failure, 2+ tricuspid regurgitation status post tricuspid valve repair, and atrial fibrillation. An automatic external (wearable) cardiac defibrillator (Zoll Life Vest) was also in place. Induction of anesthesia was carried out using etomidate, with maintenance of anesthesia carried out with a propofol infusion (total intravenous anesthesia). Rocuronium was used for neuromuscular blockade. A size 4 iGel supraglottic airway and, later, rigid bronchoscopy formed the basis for airway management. Stable conditions were met through the 2-h procedure, and the patient recovered uneventfully. Our successful experience in this case leads us to propose further use of a supraglottic airway in conjunction with total intravenous anesthesia for these procedures.

Safety and effectiveness of microdebrider bronchoscopy for the management of central airway obstruction

BACKGROUND AND OBJECTIVE

Microdebrider bronchoscopy is a relatively new modality for the management of central airway obstruction (CAO) of both benign and malignant origin. Our objective was to describe our experience with this technique, with special attention to its safety and effectiveness.

METHODS

We retrospectively reviewed cases of therapeutic bronchoscopies using microdebrider for CAO from two institutions (M.D. Anderson Cancer Center and Michael E. Debakey VA Medical Center, Houston) from August 2008 through February 2012.

RESULTS

We identified 51 cases. Malignant CAO was detected in 36 cases (71%): non-small-cell lung cancer (n = 22), melanoma (n = 3), small-cell-lung cancer (n = 2), thyroid cancer (n = 2), esophageal carcinoma (n = 2), breast cancer (n = 2), and others (n = 3). Benign diseases included: papillomas (n = 8), granulation tissue (n = 3), and others (n = 4). Obstruction was purely endoluminal in 32 cases (63%). Pre-treatment obstruction was severe in 25 cases (49%), moderate in 20 cases (39%) and mild in 6 (12%). Lesions were located in the trachea (n = 23), main stem bronchi (n = 25), and bronchus intermedius (n = 8), with some patients having more than one lesion. After tumor debulking with microdebrider, the residual airway obstruction was insignificant (n = 27 cases; 53%), mild (n = 23 cases; 45%), and moderate (n = 1; 2%). No major complications were encountered, only 2 patients had mild adverse events: one case of pneumomediastinum, and one self-expandable stent damage requiring its removal. Two patients (4%) died within 30 days of causes unrelated to the procedure or the CAO.

CONCLUSIONS

Microdebrider bronchoscopy is a potentially safe and effective way to manage central airway obstruction of both malignant and benign origin.

Causes of death of patients with lung cancer

CONTEXT

The causes of death for patients with lung cancer are inadequately described.

OBJECTIVE

To categorize the immediate and contributing causes of death for patients with lung cancer.

DESIGN

The autopsies from 100 patients who died of lung cancer between 1990 and February 2011 were analyzed.

RESULTS

Tumor burden was judged the immediate cause of death in 30 cases, including 26 cases of extensive metastases and 4 cases with wholly or primarily lung tumor burden (causing respiratory failure). Infection was the immediate cause of death for 20 patients, including 8 with sepsis and 12 with pneumonia. Complications of metastatic disease were the immediate causes of death in 18 cases, including 6 cases of hemopericardium from pericardial metastases, 3 from myocardial metastases, 3 from liver metastases, and 3 from brain metastases. Other immediate causes of death were pulmonary hemorrhage (12 cases), pulmonary embolism (10 cases, 2 tumor emboli), and pulmonary diffuse alveolar damage (7 cases). From a functional (pathophysiologic) perspective, respiratory failure could be regarded as the immediate cause of death (or mechanism of death) in 38 cases, usually because of a combination of lung conditions, including emphysema, airway obstruction, pneumonia, hemorrhage, embolism, resection, and lung injury in addition to the tumor. For 94 of the 100 patients, there were contributing causes of death, with an average of 2.5 contributing causes and up to 6 contributing causes of death.

CONCLUSIONS

The numerous and complex ways lung cancer kills patients pose a challenge for efforts to extend and improve their lives.

Patient-related independent clinical risk factors for early complications following Nd: YAG laser resection of lung cancer

INTRODUCTION

Neodymium:yttrium aluminum garnet (Nd:YAG) laser resection is one of the most established interventional pulmonology techniques for immediate debulking of malignant central airway obstruction (CAO). The major aim of this study was to investigate the complication rate and identify clinical risk factors for complications in patients with advanced lung cancer.

METHODS

In the period from January 2006 to January 2011, data sufficient for analysis were identified in 464 patients. Nd:YAG laser resection due to malignant CAO was performed in all patients. The procedure was carried out in general anesthesia. Complications after laser resection were defined as severe hypoxemia, global respiratory failure, arrhythmia requiring treatment, hemoptysis, pneumothorax, pneumomediastinum, pulmonary edema, tracheoesophageal fistulae, and death. Risk factors were defined as acute myocardial infarction within 6 months before treatment, hypertension, chronic arrhythmia, chronic obstructive pulmonary disease (COPD), stabilized cardiomyopathy, previous external beam radiotherapy, previous chemotherapy, and previous interventional pulmonology treatment.

RESULTS

There was 76.1% male and 23.9% female patients in the study, 76.5% were current smokers, 17.2% former smokers, and 6.3% of nonsmokers. The majority of patients had squamous cell lung cancer (70%), small cell lung cancer was identified in 18.3%, adenocarcinoma in 3.4%, and metastases from lung primary in 8.2%. The overall complication rate was 8.4%. Statistically significant risk factors were age (P = 0.001), current smoking status (P = 0.012), arterial hypertension (P < 0.0001), chronic arrhythmia (P = 0.034), COPD (P < 0.0001), and stabilized cardiomyopathy (P < 0.0001). Independent clinical risk factors were age over 60 years (P = 0.026), arterial hypertension (P < 0.0001), and COPD (P < 0.0001).

CONCLUSION

Closer monitoring of patients with identified risk factors is advisable prior and immediately after laser resection. In order to avoid or minimize complications, special attention should be directed toward patients who are current smokers, over 60 years of age, with arterial hypertension or COPD.