Recent advances in central airway imaging

Differentiating tracheobronchial involvement in granulomatosis with polyangiitis and relapsing polychondritis on chest CT: a cohort study

Background

In patients with tracheobronchial involvement, the differential diagnosis between granulomatosis with polyangiitis (GPA) and relapsing polychondritis (RP) can be challenging. The aim of this study was to describe the characteristics of airway abnormalities on chest computed tomography (CT) in patients with GPA or RP and to determine whether specific imaging criteria could be used to differentiate them.

Methods

GPA and RP patients with tracheobronchial involvement referred to a national referral center from 2008 to 2020 were evaluated. Their chest CT images were reviewed by two radiologists who were blinded to the final diagnosis in order to analyze the characteristics of airway involvement. The association between imaging features and a diagnosis of GPA rather than RP was analyzed using a generalized linear regression model.

Results

Chest CTs from 26 GPA and 19 RP patients were analyzed. Involvement of the subglottic trachea (odds ratio for GPA=28.56 [95% CI: 3.17; 847.63]; P=0.001) and extensive airway involvement (odds ratio for GPA=0.02 [95% CI: 0.00; 0.43]; P=0.008) were the two independent CT features that differentiated GPA from RP in multivariate analysis. Tracheal thickening sparing the posterior membrane was significantly associated to RP (odds ratio for GPA=0.09 [95% CI: 0.02; 0.39]; P=0.003) but only in the univariate analysis and suffered from only moderate interobserver agreement (kappa=0.55). Tracheal calcifications were also associated with RP only in the univariate analysis (odds ratio for GPA=0.21 [95% CI: 0.05; 0.78]; P=0.045).

Conclusion

The presence of subglottic involvement and diffuse airway involvement are the two most relevant criteria in differentiating between GPA and RP on chest CT. Although generally considered to be a highly suggestive sign of RP, posterior tracheal membrane sparing is a nonspecific and an overly subjective sign.

• The presence of subglottic involvement is in favor of GPA.

• Extensive airway involvement is in favor of RP.

• Posterior tracheal membrane sparing is a nonspecific and an overly subjective sign.

Challenges and countermeasures of thoracic oncology in the epidemic of COVID-19

Since December, 2019, a 2019 novel coronavirus disease (COVID-19) infected by the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) emerged in Wuhan, Hubei province, and the epidemic situation has continued to spread globally. The epidemic spread of COVID-19 has brought great challenges to the clinical practice of thoracic oncology. Outpatient clinics need to strengthen the differential diagnosis of initial symptoms, pulmonary ground-glass opacity (GGO), consolidation, interstitial and/or interlobular septal thickening, and crazy paving appearance. In the routine of oncology, the differential diagnosis of adverse events from COVID-19 is also significant, including radiation pneumonitis, checkpoint inhibitor pneumonitis (CIP), neutropenic fever, and so on. During the epidemic, indications of transbronchial biopsy (TBB) and CT-guided percutaneous thoracic biopsy are strictly controlled. For patients who are planning to undergo biopsy operation, screening to exclude the possibility of COVID-19 should be carried out. For confirmed or suspected patients, three-level protection should be performed during the operation. Disinfection and isolation measures should be strictly carried out during the operation. At last, more attention to the protection of cancer patients and give priority to the treatment of infected cancer patients.

Postobstructive pneumonia in lung cancer

Postobstructive pneumonia can complicate lung cancer, particularly in more advanced stages of the disease, producing significant clinical decline and a poorer prognosis. It can lead to complications such as empyema, lung abscess and fistula formation. Postobstructive pneumonia can also be the first manifestation of an underlying malignancy. There are multiple challenges in the management of these patients. Recognition and treatment of this entity can be complex and includes the use of imaging, administration of broad-spectrum antibiotics to cover the wide variety of microorganisms involved and the use of different interventional modalities to relieve the obstruction. Existing literature on postobstructive pneumonia is scarce. In this article, we review the pathophysiology, different diagnostic methods and the therapeutic options to treat this condition. The utility and efficacy of the various modalities that are currently available in clinical practice to the interventional pulmonologist are described in some detail.

Techniques of endoscopic airway tumor treatment

Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors.

Integration of interventional bronchoscopy in the management of lung cancer

Tracheal or bronchial proximal stenoses occur as complications in 20-30% of lung cancers, resulting in a dramatic alteration in quality of life and poor prognosis. Bronchoscopic management of these obstructions is based on what are known as "thermal" techniques for intraluminal stenosis and/or placement of tracheal or bronchial prostheses for extrinsic compressions, leading to rapid symptom palliation in the vast majority of patients. This invasive treatment should only be used in cases of symptomatic obstructions and in the presence of viable bronchial tree and downstream parenchyma. This review aims to clarify 1) the available methods for assessing the characteristics of stenoses before treatment, 2) the various techniques available including their preferred indications, outcomes and complications, and 3) the integration of interventional bronchoscopy in the multidisciplinary management of proximal bronchial cancers and its synergistic effects with the other specific treatments (surgery, radiotherapy or chemotherapy).

Tracheobronchomalacia in pediatric patients with esophageal atresia: comparison of diagnostic laryngoscopy/bronchoscopy and dynamic airway multidetector computed tomography

PURPOSE

Diagnostic laryngoscopy and bronchoscopy (DLB) has been the traditional preoperative diagnostic modality for evaluating presence and severity of tracheobronchomalacia (TBM), and requires anesthesia. Alternatively, multidetector computed tomography (MDCT) is potentially a noninvasive modality that provides high-resolution, 3-dimensional (3D) imaging of the thorax providing preoperative guidance for pediatric surgeons. This study compares MDCT with intraoperative DLB in the assessment of TBM in symptomatic pediatric patients with esophageal atresia (EA).

METHODS

Following IRB approval all pediatric patients (≤18 years) who had EA and who underwent an MDCT study as a preoperative evaluation of TBM prior to aortopexy were retrospectively reviewed. Patients with incomplete reports on intraoperative DLB or MDCT studies were excluded. Two pediatric radiologists independently evaluated all MDCT studies in a blinded fashion. On both DLB and MDCT studies, TBM was scored as present or absent in five anatomic segments: upper, middle, and lower trachea, as well as right and left main stem bronchi. Operative reports including DLB findings were reviewed and compared to findings from MDCT study using the chance corrected kappa (κ) coefficient. Diagnostic accuracy of dynamic MDCT for detecting TBM was determined by sensitivity and specificity, and interobserver agreement between two radiology reviewers was measured by the kappa statistic.

RESULTS

The final study population included 18 patients (8 males and 10 females) with ages ranging from 1month to 11years (median: 7 months). Their presenting clinical symptoms included apneic spells (n=15, 83%) and failure to extubate (n=3, 17%). The overall diagnostic accuracy of dynamic airway MDCT compared to DLB was 91% (82/90 possible segments for TBM) with excellent overall agreement across all 5 anatomic segments (κ=0.82, p<0.001). The agreements for upper, mid, lower trachea, and right and left trachea were 89% (κ=0.73, p<0.001), 94% (κ=0.85, p<0.001), 89% (κ=0.76, p<0.001), 94% (κ=0.82, p<0.001), and 89% (κ=0.61, p=0.005); respectively. Interobserver agreement between two radiologists was excellent (κ=0.98, 95% confidence interval: 0.94-1.00, p<0.001) with only 1 disagreement between two radiologists that was found for the left main bronchus. Fifteen (83.3%) of the patients clinically improved after the aortopexy.

CONCLUSION

MDCT with 3D imaging is a highly accurate and reliable preoperative noninvasive imaging modality for evaluating TBM in pediatric patients with EA providing anatomic information consistent with and complimentary to bronchoscopy.

The "forgotten zone": acquired disorders of the trachea in adults

The upper airway is generally defined as the air passage segment that extends between the naso- or oropharynx and the carina. The longest segment of the upper airway—the trachea—begins at the inferior portion of the larynx and extends to the branch point of the main carina. The trachea has the potential to be a “forgotten zone” in differential diagnoses, as pathological processes involving this portion may not receive prominent clinical consideration in disorders presenting with respiratory symptoms and signs. Unlike the oropharynx, this anatomical area is beyond visualization on routine inspection; unlike the mediastinum and lung fields, it is a potential “blind spot” on initial, plain radiographic examination of the chest. Nonetheless, the adult trachea is affected by a number of primary disorders and is also a target organ of a variety of systemic diseases. This review will focus on both primary and systemic diseases involving the adult trachea with specific attention to their clinical manifestations and diagnostic hallmarks.

Advanced large airway CT imaging in children: evolution from axial to 4-D assessment

Continuing advances in multidetector computed tomography (MDCT) technology are revolutionizing the non-invasive evaluation of congenital and acquired large airway disorders in children. For example, the faster scanning time and increased anatomical coverage that are afforded by MDCT are especially beneficial to children. MDCT also provides high-quality multiplanar 2-dimensional (2-D), internal and external volume-rendering 3-dimensional (3-D), and dynamic 4-dimensional (4-D) imaging. These advances have enabled CT to become the primary non-invasive imaging modality of choice for the diagnosis, treatment planning, and follow-up evaluation of various large airway disorders in infants and children. It is thus essential for radiologists to be familiar with safe and effective techniques for performing MDCT and to be able to recognize the characteristic imaging appearances of large airway disorders affecting children.

Computed tomography measurements for airway stent insertion in malignant airway obstruction

BACKGROUND

Metallic airway stents for malignant airway obstruction are considered safe, yet are not without complications. This study reviews the role of computed tomography (CT) airway measurements for planning stent placement in malignant airway obstruction before the actual therapeutic procedure to avoid invasive diagnostic evaluation before the stent placement and to reduce complications.

METHODS

This study is a retrospective review of information from a stent order database and medical records of patients receiving stents for malignant airway obstruction at a university hospital over a 12-year period. CT scans were used to determine stent diameter by calculating mean diameters of healthy adjacent zones (proximal and distal), stent length (length of diseased airway), and location and number of potential stents. Results of CT planning before bronchoscopy were judged by complication rates.

RESULTS

Patient population consisted of 69 patients, 61.7±14.0 years old, 40 males, in whom 92 stents were inserted. The most frequent cause of airway obstructions was tracheobronchial cancer (32). All patients had nitinol stent placement; 66 stents were covered and 26 were uncovered. Follow-up time was 1 to 1067 days (median: 35 days). Complication rate was 10.1% and mainly involved the patients with tracheal obstruction (6). Complications included stent fractures (2), migration (2), granuloma (1), and infectious tracheitis (2). One early death within 24 hours after the procedure was not related to stent placement. Five patients required follow-up therapeutic bronchoscopy to treat the complications.

CONCLUSIONS

These results suggest that prestent planning by noninvasive method of obtaining CT scan provides optimal stent size and position, possibly avoiding a diagnostic bronchoscopy and reducing complications. Further prospective study is needed to confirm these results because of limitation of this study's design.

Multiplanar and two-dimensional imaging of central airway stenting with multidetector computed tomography

Background

Multidetector computed tomography (MDCT) provides guidance for primary screening of the central airways. The aim of our study was assessing the contribution of multidetector computed tomography- two dimensional reconstruction in the management of patients with tracheobronchial stenosis prior to the procedure and during a short follow up period of 3 months after the endobronchial treatment.

Methods

This is a retrospective study with data collected from an electronic database and from the medical records. Patients evaluated with MDCT and who had undergone a stenting procedure were included. A Philips RSGDT 07605 model MDCT was used, and slice thickness, 3 mm; overlap, 1.5 mm; matrix, 512x512; mass, 90 and kV, 120 were evaluated. The diameters of the airways 10 mm proximal and 10 mm distal to the obstruction were measured and the stent diameter (D) was determined from the average between D upper and D lower.

Results

Fifty-six patients, 14 (25%) women and 42 (75%) men, mean age 55.3 ± 13.2 years (range: 16-79 years), were assessed by MDCT and then treated with placement of an endobronchial stent. A computed tomography review was made with 6 detector Philips RSGDT 07605 multidetector computed tomography device. Endobronchial therapy was provided for the patients with endoluminal lesions. Stents were placed into the area of stenosis in patients with external compression after dilatation and debulking procedures had been carried out. In one patient the migration of a stent was detected during the follow up period by using MDCT.

Conclusions

MDCT helps to define stent size, length and type in patients who are suitable for endobronchial stinting. This is a non-invasive, reliable method that helps decisions about optimal stent size and position, thus reducing complications.

Clinical and Radiological Manifestations of Primary Tracheobronchial Tumours: A Single Centre Experience

Introduction: Tracheobronchial tumours usually cause an airway obstruction and secondary pulmonary infections. Although rare, they are an important differential diagnosis as they may mimic other conditions and diseases. This paper aims to analyse clinical, radiological and histological characteristics of the patients with tracheobronchial tumours diagnosed for a period of 7 years. Materials and Methods: In this retrospective, observational study, we carefully reviewed 65 patients who were diagnosed with tracheal and endobronchial tumours, and performed statistical analysis on the results. Results: Among these 65 patients (36 men and 29 women) with a mean age of 48.8 years (range, 15 to 75), 50 had malignant tumours while 15 had benign ones. The most common symptoms were cough, chest pain and haemoptysis. Cough was a more frequent symptom in patients with benign tumours (P <0.0014). Only 2 patients were asymptomatic. Tumours were predominantly localised in the large airways (46 in large bronchi and 2 in trachea). The most common radiological manifestation of malignant tumours was tumour mass (46%) followed by atelectasis. One third benign tumour caused atelectasis, while tumour mass and consolidation were found in 3 patients each. Computerised tomography revealed endoluminal tumour mass in 29.2% of the cases, which was more frequently found in benign than malignant tumours (47% vs 24%, respectively). On bronchoscopy, tumours were visible in 73% and 70% benign and malignant cases respectively. Conclusion: Tracheobronchial tumours should be ruled as a possible diagnosis in patients with cough, haemoptysis, dyspnoea and chest pain. The imaging techniques and histological examination of the tissue would subsequently lead to correct diagnosis and proper treatment can be administered. Key words: Bronchus, Computerised tomography, Trachea, Tumour, X-ray

320-detector CT imaging of the upper airway structure of patients with obstructive sleep apnea-hypopnea syndrome

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is one of the most common sleep disorders that have significant associated health costs. It is caused by recurrent occlusion of the upper airway during sleep. Recently, many researchers have provided evidence that patients with OSAHS tend to have a large tongue, a comparatively prolonged soft palate, and a narrow upper airway.There are many therapeutic methods for OSAHS, although determining the obstructive points is very important. Several methods to study the morphology of the upper airway in patients with OSAHS are available: acoustic reflection, fluoroscopy, endoscopic observation, and computed tomography (CT). After our hospital took the lead in the introduction the first 320-detector CT in East China, our team studied the morphology of the upper airway in patients with OSAHS using this 320-detector CT.From July 2010 to July 2011, the upper airway of 66 patients with OSAHS and 22 control subjects were scanned using a 320-detector CT scanner at the time of deep inspiration, deep expiration, normal respiration, and Müller maneuver. Cross-sectional areas of the upper airway at the nasopharyngeal, velopharyngeal, and tongue-pharyngeal levels were measured and compared. Mean velopharyngeal cross-sectional areas in OSAHS were less than those in the control group at the time of deep inspiration, deep expiration, normal respiration, and Müller maneuver (P < 0.05). Mean tongue-pharyngeal cross-sectional areas in OSAHS were less than those in the control group at the time of deep inspiration and Müller maneuver (P < 0.05).The results showed that velopharyngeal and tongue-pharyngeal areas could be the main obstructive regions for OSAHS and that the 320-detector CT scanner would be of great utility in identifying the location of the upper airway obstruction in patients with OSAHS, in exploring the pathogenesis of OSAHS, and in designing the appropriate treatment plan and surgical positioning.

Comparison of virtual bronchoscopy with fiberoptic bronchoscopy findings in patients exposed to sulfur mustard gas

BACKGROUND

Fiberoptic bronchoscopy (FB) is the best modality for evaluation of tracheobronchial endoluminal lesions. Virtual bronchoscopy (VB) with the aid of computed tomography (CT) makes it possible to reconstruct endoscopic-like visualization of major airways. Sulfur mustard (SM) used during the Iraq-Iran war affects respiratory tracts and can lead to tracheobronchial stenosis.

PURPOSE

To compare VB with FB in SM-exposed patients suspected for airway stenosis.

MATERIAL AND METHODS

Thirty-one patients were evaluated with CT and bronchoscopic studies about 15 years after chemical attacks. The median age of patients was 40 years. Spiral CT scans were obtained and data were transferred to a workstation to generate VB images of major airways. Less than one week after CT scan, FB was performed.

RESULTS

For the tracheal pathologies seen in FB, the sensitivity, specificity, and accuracy of VB was 90.9%, 95%, and 93.5% for tracheal stenosis, 40%, 96.2%, and 87.1% for vocal cord problems, 100%, 100%, and 100% for postoperative changes, and 100%, 96.7%, and 96.8% for intratracheal nodule. The inflammation of mucosal surface could not be assessed by VB. The bronchial pathologies seen in FB included eight cases of stenosis, and one case of nodule. Sensitivity, specificity, and accuracy of VB for detection of bronchial stenosis was 62.5%, 97.8% and 92.6%, respectively. Overall sensitivity, specificity and accuracy of VB in detecting tracheobronchial stenosis were 78.9%, 97.0%, and 92.9%, respectively.

CONCLUSION

Our study indicates that VB is an accurate method for evaluating stenoses, endoluminal nodules, and poststenotic areas within the tracheobronchial tree of SM-exposed victims. This complementary method could be helpful in revealing hidden post-stenotic lesions and also better depict the long tracheal strictures and their actual length.

Multidetector computed tomography of pediatric large airway diseases: state-of-the-art

Advances in multidetector computed tomography (MDCT) technology have given rise to improvements in the noninvasive and comprehensive assessment of the large airways in pediatric patients. Superb two-dimensional and three-dimensional reconstruction MDCT images have revolutionized the display of large airways and enhanced the ability to diagnose large airway diseases in children. The 320-MDCT scanner, which provides combined detailed anatomic and dynamic functional information assessment of the large airways, is promising for the assessment of dynamic large airway disease such as tracheobronchomalacia. This article discusses imaging techniques and clinical applications of MDCT for assessing large airway diseases in pediatric patients.

Update on multidetector computed tomography imaging of the airways

Recent advances in multidetector computed tomography (MDCT) technology have transformed the imaging evaluation of the trachea and bronchi. Multiplanar 2-dimensional and 3-dimensional volume reconstruction techniques, including external rendering and virtual bronchoscopy, can be generated in mere minutes, thereby complementing conventional axial CT imaging in the depiction of various central airway disease processes including airway stenoses, central airway neoplasms, and congenital airway disorders. Paired inspiratory and dynamic expiratory MDCT imaging, along with newer cine CT imaging methods, have enhanced the assessment of tracheobronchomalacia in both adults and the pediatric population. In addition, MDCT imaging plays an essential complementary role to conventional bronchoscopy, facilitating planning and guidance of bronchoscopic interventions, and providing a noninvasive method for postprocedural surveillance.

The role of interventional pulmonary procedures in the management of post-obstructive pneumonia

Post-obstructive pneumonia is the result of airway obstruction, commonly due to lung cancer. The majority of patients with lung cancer are non-operable and incurable at initial presentation. The clinical course of these patients is steadily downhill with complicating events such as post-obstructive pneumonia, respiratory failure, pleural effusion, and severe debilitation. Non-invasive conventional options for post-obstructive pneumonia include broad-spectrum antibiotics, combined with attempts at relieving the obstruction using radiation therapy. There is scant literature on the natural course of post-obstructive pneumonia, disease resolution, and optimal treatment. With the recent surge in technologic advances in interventional pulmonology, multiple airway recanalizaton options are now available. In this paper, we describe the causes of post-obstructive pneumonia, and the role of interventional pulmonary procedures in -establishing an open airway.

MDCT of trachea and main bronchi

Tracheobronchial imaging has undergone a major revolution since the advent of MDCT. The improved spatial and temporal resolution not only allows reformatting images that enhance the comprehension of disease before bronchoscopy or surgery, it has introduced newer techniques such as dynamic expiratory imaging to evaluate for tracheomalacia, which can be a subtle, but a confounding entity for patients and clinician alike. Tracheobronchial diseases can be arbitrarily divided into those that cause focal and diffuse narrowing and widening. Such groupings can help develop a practical approach in evaluating diseases of the central airways.

MDCT of trachea and main bronchi

Tracheobronchial imaging has undergone a major revolution. The improved spatial and temporal resolution has introduced newer techniques such as dynamic expiratory imaging to evaluate for tracheomalacia. This article describes these techniques.

Congenital airway lesions and lung disease

Structural upper and lower airway disorders and parenchymal disorders are uncommon in pediatric practice, but many pediatricians will encounter them and be responsible for the ongoing care of these patients. Pediatricians need to be cognizant of these diagnoses because, even though management of these disorders generally lacks an evidence base, existing principles of good care surrounding accurate diagnosis, classifications of severity, judicious use of investigations, medication, and surgical approaches are essential to good outcomes.

Recurrent severe lower respiratory tract infections in a child with abnormal tracheal morphology

Localized recurrent respiratory infections, leading to severe hypoxia in young children without immunological abnormalities or other risk factors, should raise the suspicion of airway structural abnormalities. In a 24-month-old boy, with recurrent severe post-viral wheezing and a history of RSV-induced bronchiolitis and gastro-esophageal reflux, fiberoptic bronchoscopy demonstrated an abnormal morphology of the distal portion of the trachea, ending in four openings. Computed tomography (CT) scans demonstrated the presence of a right tracheal bronchus and an anomalous upper lobar bronchus, originating at the level of the major carina.

[Clinico-radiological characteristics of bronchial carcinoid]

OBJECTIVES

To review clinical and radiological characteristics of a patients with bronchial carcinoid.

METHODS

In this retrospective study, we reviewed the clinical, pathological and imaging findings in 42 patients diagnosed with bronchial carcinoid during the seven years period.

RESULTS

There were 23 women and 19 men, with a mean age of 47 years (range from 15 to 75). Thirty patients had typical and 12 atypical bronchial carcinoid. Dominant symtoms were cough (46.7%) and 38%. Tumor was localized in 28 patients in the left, and 14 in the right lung. On radiographs carcinoid manifested as tumor shadow in 40.5%, nodule and atelectasis in 21.4% cases each respectively, pleural effusion and pneumonia in 7.1% each respectively and hyperinflation in 2.4% of the cases. Computerized tomography revealed endoluminal tumor in 30.9% patients.

CONCLUSION

Major imaging findings are central, tumor mass or nodule and obstruction signs like atelectasis. Diagnosis is confirmed by pathological examination of samples taken by bronchoscopy or surgery.

State of the art: interventional pulmonology

Interventional pulmonology (IP) provides comprehensive care to patients with structural airway disorders and pleural diseases. A growing armamentarium of diagnostic and therapeutic tools has expanded the interventional pulmonologist's ability to care for pulmonary patients with complex abnormalities, often in concert and close collaboration with physicians in other specialties, such as thoracic surgery. Innovative technologies promise to have an impact on diseases and clinical entities not traditionally treated by invasive pulmonary interventions, such as asthma, COPD, and the solitary pulmonary nodule. Training, credentialing, reimbursement, and scientific validation remain key necessities for the continued growth of IP, and require a concerted effort by chest physicians and their professional organizations.

Multiplanar reconstruction: a new method for the diagnosis of tracheobronchial rupture?

OBJECTIVE

To compare multiplanar reconstruction with operative techniques (bronchoscopy, surgery and/or autopsy) for the diagnosis of tracheobronchial rupture.

DESIGN

Prospective, observational study.

SETTING

Surgical intensive care unit.

PATIENTS AND PARTICIPANTS

Tracheobronchial rupture was suspected on clinical grounds and from radiological findings.

INTERVENTIONS

An initial helical computed tomography scan was performed on all patients meeting the inclusion criteria, and operative techniques were then performed. Multiplanar reconstructions were reformatted and reviewed by two independent radiologists.

MEASUREMENTS AND RESULTS

Twenty-four consecutive patients met the inclusion criteria. Tracheobronchial rupture was diagnosed in 13 patients by at least one operative technique. Multiplanar reconstructions were positive in 15 patients. The diagnostic sensitivity and specificity of multiplanar reconstructions were 100% (95%CI, 85-100) and 82% (95%CI, 64-82), respectively. The positive and negative predictive values were 87% (95%CI, 74-87) and 100% (95%CI, 78-100), respectively. For tracheobronchial rupture, the positive and negative likelihood ratios were 5.5 (95%CI, 2.35-5.5) and 0 (95%CI, 0-0.24), respectively. The Kappa coefficients were 0.83 (95%CI, 0.6-1.06) for agreement between operative techniques and multiplanar reconstruction, and 0.91 (95%CI, 0.59-0.91) for agreement between the two radiologists.

CONCLUSIONS

Multiplanar reconstruction appears to be a sensitive technique for the identification of tracheobronchial rupture because of its excellent negative likelihood ratio. In clinical practice, negative multiplanar reconstruction can exclude a diagnosis of tracheobronchial rupture, making bronchoscopy unnecessary. When multiplanar reconstruction is positive, tracheobronchial rupture should be confirmed by bronchoscopy.

DESCRIPTOR

Trauma.

A virtual bronchoscopic navigation system under X-ray fluoroscopy for transbronchial diagnosis of small peripheral pulmonary lesions

We had reported the utility of virtual bronchoscopic navigation system under CT-guidance for the diagnosis of small peripheral pulmonary lesions (PPLs). This study investigated the efficacy of virtual bronchoscopic navigation system for the diagnosis of small PPLs under X-ray fluoroscopy. We performed bronchoscopy with this system for 94 consecutive patients with 96 PPLs (< or =30mm in longest diameter; mean longest diameter, 16.2mm). A standard bronchoscope was used in 38 cases, and an ultrathin bronchoscope in 58 cases. Virtual bronchoscopic images were reconstructed from helical CT data. All the examinations were performed under X-ray fluoroscopy with virtual bronchoscopic navigation system, we referred both virtual bronchoscopic images and actual bronchoscopic images simultaneously to navigate the bronchoscopic pathway to the PPLs. Specimens for pathological examination were collected by transbronchial biopsy (TBB) and/or brushing. Virtual images accorded well with actual bronchoscopic images. The average total examination time was 24.1+/-7.4min (mean+/-S.D.). The overall diagnostic yields were 62.5% (60 of 96 PPLs), 71.1% (27 of 38 PPLs) with the standard bronchoscope, and 56.9% (33 of 58 PPLs) with the ultrathin bronchoscope. Diagnostic rates were 35%, 61.4% and 94.7% for lesions < or =10, 10-20, and >20mm, respectively. There were eight ground glass opacity (GGO) lesions confirmed only on CT scans; seven cases were pathologically diagnosed. All the examinations were performed safely with no complications. Bronchoscopy with virtual bronchoscopic navigation under X-ray fluoroscopy is useful for the diagnosis of small PPLs.

Tumoral and non-tumoral trachea stenoses: evaluation with three-dimensional CT and virtual bronchoscopy

BACKGROUND

We evaluated the ability of 3D-CT and virtual bronchoscopy to estimate trachea stenosis in comparison to conventional axial CT and fiberoptic bronchoscopy, with a view to assist thoracic surgeons in depicting the anatomical characteristics of tracheal strictures.

METHODS

Spiral CT was performed in 16 patients with suspected tracheal stenoses and in 5 normal subjects. Tracheal stenoses due to an endoluminal neoplasm were detected in 13 patients, whilst post-intubation tracheal stricture was observed in the other 3 patients. Multiplanar reformatting (MPR), volume rendering techniques (VRT) and virtual endoscopy (VE) for trachea evaluation were applied and findings were compared to axial CT and fiberoptic bronchoscopy. The accuracy of the procedure in describing the localization and degree of stenosis was tested by two radiologists in a blinded controlled trial.

RESULTS

The imaging modalities tested showed the same stenoses as the ones detected by flexible bronchoscopy and achieved accurate and non-invasive morphological characterization of the strictures, as well as additional information about the extraluminal extent of the disease. No statistically significant difference was observed between the bronchoscopic findings and the results of axial CT estimations (P = 1.0). No statistically significant differences were observed between bronchoscopic findings and the MPR, VRT and VE image evaluations (P = 0.705, 0.414 and 0.414 respectively).

CONCLUSION

CT and computed generated images may provide a high fidelity, noninvasive and reproducible evaluation of the trachea compared to bronchoscopy. They may play a role in assessment of airway patency distal to high-grade stenoses, and represent a reliable alternative method for patients not amenable to conventional bronchoscopy.

[Progressive primary tuberculosis with endobronchial involvement. Benefits of multislice helical computed tomography]

OBJECTIVES

To assess computed tomography (CT) imaging findings in progressive primary tuberculosis and to determine the use of the multislice images obtained.

PATIENTS AND METHODS

We report the case of a 37-day-old infant admitted to hospital because of persistent fever despite antimicrobial therapy. Thoracic X-ray and multislice helical CT (CT Light speed i1.6 GE) were performed with 3-dimensional and virtual endoscopy reconstructions.

RESULTS

CT showed mediastinal and hilar necrotic lymph nodes, pulmonary parenchymal involvement with miliary pattern, and multiple cavitated consolidations. Endobronchial involvement was clearly visualized by virtual endoscopy and was confirmed by fiberoptic bronchoscopy.

CONCLUSIONS

Virtual endoscopy is a new, less invasive alternative radiological technique to fiberoptic bronchoscopy that may influence the management of patients with tuberculosis with endobronchial involvement.

Tracheal stenosis diagnosed on pulmonary ventilation/perfusion scan

A 68-year-old woman, who had undergone coronary artery bypass surgery 5 months previously, was presented with cough, breathlessness and an elevated D-dimer. She was initially thought to have suffered a pulmonary embolus. A ventilation/perfusion scan demonstrated tracheal stenosis, which required dilation and endobronchial stent deployment. Tracheal stenosis is a well-recognised complication of endotracheal intubation; however, the onset of symptoms is often insidious and the diagnosis delayed.

Tracheomalacia and bronchomalacia in children: incidence and patient characteristics

OBJECTIVE

Congenital airway malacia is one of the few causes of irreversible airways obstruction in children, but the incidence in the general population is unknown. Severe airway malacia or malacia associated with specific syndromes is usually recognized and diagnosed early in infancy, but information about clinical features of children with primary malacia, often diagnosed only later in childhood, is scarce.

METHODS

We analyzed all flexible bronchoscopies performed between 1997 and 2004 in the Sophia Children's Hospital, summarized clinical features of children with primary airway malacia, estimated the incidence of primary airway malacia, and calculated the predictive value of a clinical diagnosis of airway malacia by pediatric pulmonologists.

RESULTS

In a total of 512 bronchoscopies, airway malacia was diagnosed in 160 children (94 males) at a median age of 4.0 years (range, 0 to 17 years). Airway malacia was classified as primary in 136 children and secondary in 24 children. The incidence of primary airway malacia was estimated to be at least 1 in 2,100. When pediatric pulmonologists expected to find airway malacia (based on symptoms, history, and lung function) prior to bronchoscopy, this was correct in 74% of the cases. In 52% of the airway malacia diagnoses, the diagnosis was not suspected prior to bronchoscopy. Presenting clinical features of children with airway malacia were variable and atypical, showing considerable overlap with features of allergic asthma. Peak expiratory flow was more reduced than FEV(1).

CONCLUSION

Primary airway malacia is not rare in the general population, with an estimated incidence of at least 1 in 2,100 children. Airway malacia is difficult to recognize based on clinical features that show overlap with those of more common pulmonary diseases. We recommend bronchoscopy in patients with impaired exercise tolerance, recurrent lower airways infection, and therapy-resistant, irreversible, and/or atypical asthma to rule out airway malacia.

Congenital absence of the right upper lobe bronchus with double segmental tracheal bronchi

A multidisciplinary approach revealed an absent right upper lobe bronchus and atretic bronchioles in a child with recurrent pulmonary infections. Use of a multidimensional computed tomographic scan and bronchoscopy clearly delineated the anatomical aberration. The child underwent an uncomplicated right upper anterior segmentectomy with an expedient recovery.

Endoscopic Removal of Metallic Airway Stents

BACKGROUND

Complications of metallic airway stents include granulation tissue formation, fracture of struts, migration, and mucous plugging. When these complications result in airway injury or obstruction, it may become necessary to remove the stent. There have been few reports detailing techniques and complications associated with endoscopic removal of metallic airway stents. We report our experience with endoscopic removal of 30 such stents over a 3-year period.

METHODS

We conducted a retrospective review of 25 patients who underwent endoscopic stent removal from March 2001 to April 2004. The patients ranged in age from 17 to 80 years (mean, 56.3 years). There were 10 male and 15 female patients. The stents had been placed for nonmalignant disease in 20 patients (80%) and malignant disease in 5 patients (20%). All procedures were done under general anesthesia with a rigid bronchoscope. Special attention was focused on the technique of stent removal and postoperative complications.

RESULTS

Thirty metallic airway stents were successfully removed from 25 consecutive patients over a 3-year period. The basic method of removal involved the steady application of traction to the stent with alligator forceps. In all cases, an instrument such as the barrel of the rigid bronchoscope or a Jackson dilator was employed to help separate the stent from the airway wall before removal was attempted. In some instances, the airway wall was pretreated with thermal energy prior to stent removal. Complications were as follows: retained stent pieces (n = 7), mucosal tear with bleeding (n = 4), re-obstruction requiring temporary silicone stent placement (n = 14), need for postoperative mechanical ventilation (n = 6), and tension pneumothorax (n = 1).

CONCLUSIONS

Although metallic stents may be safely removed endoscopically, complications are common and must be anticipated. Other investigators have described airway obstruction and death as a result of attempted stent removal. Placement and removal of metallic airway stents should only be performed at centers that are prepared to deal with the potentially life-threatening complications.

Multislice CT Evaluation of Airway Stents

Tracheobronchial stents are playing an increasing role in the palliative treatment of large airway obstruction due to a variety of conditions, including extrinsic compression, intraluminal disease, and malacia. Computed tomography (CT) plays an important role in aiding planning of stent placement and in detecting various stent complications. In this pictorial essay, we illustrate and review the role of multislice CT in the pre- and post-stent placement settings. A special emphasis is placed upon the characteristic CT appearance of specific stent complications and upon the role of CT multiplanar reformations and 3-dimensional (3-d) reconstruction techniques.

Tracheomalacia and Tracheobronchomalacia in Children and Adults

Tracheomalacia and tracheobronchomalacia are disorders that are encountered in both pediatric and adult medicine. Despite increasing recognition of these disease processes, there remains some uncertainty regarding their identification, causes, and treatment. This article is intended to be a comprehensive review of both the adult and pediatric forms of the diseases, and includes sections on the historical aspects of the disorders, and their classification, associated conditions, histopathology, and natural history. We also review the various modalities that are used for diagnosis as well as the state of the art of treatment, including airway stent placement and surgical intervention.

Central Airway Obstruction

Central airway obstruction is a problem facing all medical and surgical subspecialists caring for patients with chest diseases. The incidence of this disorder appears to be rising because of the epidemic of lung cancer; however, benign causes of central airway obstruction are being seen more frequently as well. The morbidity is significant and if left untreated, death from suffocation is a frequent outcome. Management of these patients is difficult, but therapeutic and diagnostic tools are now available that are beneficial to most patients and almost all airway obstruction can be relieved expeditiously. This review examines current approaches in the workup and treatment of patients suffering from airway impairment. Although large, randomized, comparative studies are not available, data show significant improvement in patient outcomes and quality of life with treatment of central airway obstruction. Clearly, more studies assessing the relative utility of specific airway interventions and their impact on morbidity and mortality are needed. Currently, the most comprehensive approach can be offered at centers with expertise in the management of complex airway disorders and availability of all endoscopic and surgical options.

Stenting at the Flow-limiting Segment in Tracheobronchial Stenosis due to Lung Cancer

Airway stenting at the wave-speed flow-limiting segment (the choke point) is assessed. We determined prospectively the precise location of the choke point using the flow-volume curve, endobronchial ultrasonography, ultrathin bronchoscopy, and three-dimensional computed tomography scan before and after stenting in 64 patients with extrincic compression due to lung cancer. We noted distinct flow-volume curve patterns specific to the type of stenosis. The tracheal stenosis group indicated fixed narrowing patterns with an expiratory plateau, bronchial stenosis group dynamic collapse patterns with an expiratory flow deterioration (choking), carinal stenosis group combined fixed and dynamic patterns, and extensive stenosis group complex patterns containing elements of all the former. After stenting, almost full-function patterns with significant improvement in PEF were observed in all groups (p < 0.01, p < 0.05, p < 0.001, p < 0.01, respectively). In patients with extensive stenosis, implantation of additional stents was required when the choke points were observed to have migrated to the areas of malacia with cartilage destruction by the tumor. Secondary stenting at migrated choke points resulted in a significant improvement in PEF over the initial stenting (p < 0.01). Stenting at the choke point improved expiratory flow limitation by increasing the cross-sectional area, supporting the weakened airway wall and relieving dyspnea.

Grading Airway Stenosis Down to the Segmental Level Using Virtual Bronchoscopy

OBJECTIVE

To assess the sensitivity of noninvasive virtual bronchoscopy based on multirow detector CT scanning in detecting and grading central and segmental airway stenosis using flexible bronchoscopic findings as the reference standard.

MATERIALS AND METHODS

In a blinded controlled trial, multirow detector CT virtual bronchoscopy and flexible bronchoscopy were used to search for and grade airway stenosis in 20 patients. CT scan data were obtained with a multirow detector CT scanner using 4 x 1 mm collimation. Flexible bronchoscopy findings were graded by a pulmonologist and served as the reference standard for 176 central airway regions (ie, trachea, main bronchi, and lobar bronchi) and 302 segmental airway regions. The extent of airway narrowing was categorized as grade 0 (no narrowing), grade 1 (< 50%), or grade 2 (> or =50%).

RESULTS

Flexible bronchoscopy revealed 30 stenoses in the central airways and 10 in the segmental airways. Virtual bronchoscopy detected 32 stenoses in the central airways (sensitivity, 90.0%; specificity, 96.6%; accuracy, 95.5%) and 22 in the segmental airways (sensitivity, 90.0%; specificity, 95.6%; accuracy, 95.5%). The number of false-positive findings was higher in the segmental airways (13 false-positive findings) than in the central airways (5 false-positive findings), which caused a lower positive predictive value for the segmental airways (40.9%) than for the central airways (84.4%). Flexible and virtual bronchoscopic gradings correlated better for central airway stenosis (r = 0.87) than for segmental airway stenosis (r = 0.61).

CONCLUSION

Although a high sensitivity was found for the detection of both central and segmental airway stenosis, the number of false-positive findings was higher for segmental airways. However, noninvasive multirow detector CT virtual bronchoscopy enables high-resolution endoluminal imaging of the airways down to the segmental bronchi.

Methodological Aspects of Bronchoscopic Lung Volume Reduction with a Proprietary System

Bronchoscopic lung volume reduction (BLVR) is emerging as a new technique to palliate symptoms in patients with severe emphysema. Several devices and techniques are being developed to occlude airways resulting in collapse and reduced lung volume. Here we present in detail the methodological aspects of one such interventional bronchoscopic approach.