Multidetector computed tomography imaging planning for bronchoscopy stent and valve placement in the treatment of COPD, air leaks, and airway stenosis

Bronchoscopy using a flexible bronchoscope is considered a safe procedure and has been used for diagnosing and treating airway and parenchymal lung diseases. Bronchoscopic interventions in selected patients with emphysema, airway stenosis, and air leaks provide new treatment options. The application of multidetector computed tomography (MDCT) planning prior to bronchoscopy is comprehensively addressed. Using MDCT scan for pre-procedural planning, ensures precise navigation and device placement during bronchoscopy, ultimately improving patient outcomes. Radiological features can be correlated with bronchoscopy findings, linking MDCT images with direct bronchoscopy observations. This educational statement provides a comprehensive overview of the integration of computed tomography and bronchoscopy in managing different pulmonary conditions treated with endobronchial valve and airway stent placement, focusing on key aspects to enhance understanding and application in clinical practice. Emphasis is placed on their role in treating airway stenosis (AS), air leaks, and chronic obstructive pulmonary disease (COPD), highlighting the conditions under which these procedures are most beneficial. It explores how MDCT imaging contributes to the diagnosis and treatment planning of these conditions and the correct interpretation of MDCT image findings during follow-up after the procedure.

Advancements in airway stents: a comprehensive update

PURPOSE OF REVIEW

This review provides an overview of the evolving field of airway stenting (AS), highlighting its relevance in the management of central airway obstruction (CAO). It discusses recent advancements, including 3D-printed silicone stents (3DPSS), metallic stents, biodegradable stents (BS), and drug-eluting stents (DES), which are transforming clinical practice. The review underscores the ongoing challenges in patient selection, stent choice, and long-term management in the context of an evolving landscape.

RECENT FINDINGS

Innovations, particularly 3DPSS, have shown promise in providing patient-specific solutions. These stents offer improved symptom relief, enhanced quality of life, and lower complication rates, especially for complex airway diseases. The use of BS and DES is explored, raising prospects for future applications.

SUMMARY

The evolution of AS reflects a deepening understanding of airway obstructions. Recent innovations, such as 3DPSS, BS, and DES, show considerable promise in addressing the limitations of conventional stents. However, challenges related to complications, patient selection, and long-term management persist, demanding further research. Wide practice variations in the management of AS highlight the need for more clinical data and standardized guidelines. The search for the ideal stent continues, driven by the pursuit of better outcomes for patients with CAO.

Imaging of therapeutic airway interventions in thoracic oncology

Tracheobronchial obstruction, haemoptysis, and airway fistulas caused by airway involvement by primary or metastatic malignancies may result in dyspnoea, wheezing, stridor, hypoxaemia, and obstructive atelectasis or pneumonia, and can lead to life-threatening respiratory failure if untreated. Complex minimally invasive endobronchial interventions are being used increasingly to treat cancer patients with tracheobronchial conditions with curative or, most often, palliative intent, to improve symptoms and quality of life. The selection of the appropriate treatment strategy depends on multiple factors, including tumour characteristics, whether the lesion is predominately endobronchial, shows extrinsic compression, or a combination of both, the patient's clinical status, the urgency of the clinical scenario, physician expertise, and availability of tools. Pre-procedure multidetector computed tomography (MDCT) imaging can aid in the most appropriate selection of bronchoscopic treatment. Follow-up imaging is invaluable for the early recognition and management of any potential complication. This article reviews the most commonly used endobronchial procedures in the oncological setting and illustrates the role of MDCT in planning, assisting, and follow-up of endobronchial therapeutic procedures.

Airway stent current practices evaluation: Survey among French bronchoscopy practitioners

BACKGROUND

Airway stenting (AS) is performed for the treatment of benign or malignant central airway stenosis. In France, more than 30 centers practice AS. The aim of this survey was to evaluate the current practice around airway stenting among French bronchoscopy practitioners.

METHOD

We performed an online survey sent to the GELF group (Groupe d'Endoscopie de Langue Française) mailing list. The first part comprised 10 questions about the different attitudes before AS and the second part included 10 questions about the management after AS.

RESULTS

Thirty-six participants answered to the first part of the questionnaire and thirty-three to the second. There were some similarities, for example the absence of prophylactic antibiotic treatment before procedure (86%), use of saline nebulization, and removing or replacing the airway stent in case of persistent chest congestion or infection (73%). We also noted an important heterogeneity of the practices with several differences concerning systematic endoscopic control, bacteriological sampling before procedure (44%) and systematically AS replacement.

CONCLUSION

This survey shows that AS management in France varies between practitioners. Respondents agreed on a few points, but disagreed on several important aspects of the management. These results emphasize the need of expert recommendations to improve AS management.

Airway stents

Stents and tubes to maintain the patency of the airways are commonly used for malignant obstruction and are occasionally employed in benign disease. Malignant airway obstruction usually results from direct involvement of bronchogenic carcinoma, or by extension of carcinomas occurring in the esophagus or the thyroid. External compression from lymph nodes or metastatic disease from other organs can also cause central airway obstruction. Most malignant airway lesions are surgically inoperable due to advanced disease stage and require multimodality palliation, including stent placement. As with any other medical device, stents have significantly evolved over the last 50 years and deserve an in-depth understanding of their true capabilities and complications. Not every silicone stent is created equal and the same holds for metallic stents. Herein, we present an overview of the topic as well as some of the more practical and controversial issues surrounding airway stents. We also try to dispel the myths surrounding stent removal and their supposed use only in central airways. At the end, we come to the long-held conclusion that stents should not be used as first line treatment of choice, but after ruling out the possibility of curative surgical resection or repair.

Spectrum of Imaging Findings Following Bronchoscopic Intervention

Interventional pulmonology (IP) is a relatively new field that uses endoscopy and other technologies for both the diagnosis and treatment of pulmonary and thoracic conditions. IP is a continually developing field driven by clinical need as well as technological and therapeutic innovation. Developments in IP have increased both the efficacy and breadth of procedures that may be encountered by radiologists on periprocedural and postprocedural imaging. In this article, we will describe commonly performed IP procedures, with a focus on relevant imaging implications for radiologists.

Multidetector CT evaluation of airway stents: what the radiologist should know

Airway stents are increasingly used to treat symptomatic patients with obstructive tracheobronchial diseases who are not amenable to surgical resection or who have poor performance status, precluding them from resection. The most common conditions that are treated with tracheobronchial stents are primary lung cancer and metastatic disease. However, stents have also been used to treat patients with airway stenosis related to a variety of benign conditions, such as tracheobronchomalacia, relapsing polychondritis, postintubation tracheal stenosis, postoperative anastomotic stenosis, and granulomatous diseases. Additionally, airway stents can be used as a barrier method in the management of esophagorespiratory fistulas. Many types of stents are available from different manufacturers. Principally, they are classified as silicone; covered and uncovered metal; or hybrid, which are made of silicone and reinforced by metal rings. The advantages and disadvantages of each type of airway stent are carefully considered when choosing the most appropriate stent for each patient. Multidetector computed tomography plays an important role in determining the cause and assessing the location and extent of airway obstruction. Moreover, it is very accurate in its depiction of complications after airway stent placement.

Tracheobronchial stenting

Airway stenting can be a life-preserving intervention in patients with critical airway obstruction. It may be safely performed using flexible bronchoscopy under conscious sedation as a day-case procedure in selected patients, but a high incidence of complications limits its use to palliation of malignancy or bridging treatment in benign disease.

Novel use of a percutaneous endoscopic gastrostomy tube fastener for securing silicone tracheal stents in patients with benign proximal airway obstruction

BACKGROUND

Benign tracheal obstruction occurs for a variety of reasons. Bronchoscopic intervention includes silicone stent placement, which effectively maintains airway patency. Stent migration is a common complication, particularly when placed in the proximal trachea. We used a novel technique of securing tracheal stents with a percutaneous endoscopic gastrostomy tube fastener (PEG-TF) to prevent stent migration. The purpose of this study was to determine the feasibility of securing silicone stents in the proximal trachea with PEG-TF.

METHODS

Silicone stents were placed under general anesthesia by rigid bronchoscopy in 7 consecutive patients with inoperable benign proximal tracheal obstruction. PEG-TFs were placed under sterile conditions with direct bronchoscopic visualization. A needle was inserted through the anterior neck and silicone stent wall allowing stylet introduction of a T-fastener into the interior of the stent. The T-fastener was secured externally by a metal clamp and cotton pledget at the surface of the neck. Patients had routine outpatient follow-up and covered the external portion of the PEG-TF with a waterproof dressing when showering.

RESULTS

All 7 PEG-TFs were placed without complications. The PEG-TFs were left in for 1 to 25 weeks. Complications of the PEG-TF included localized cellulitis and suture breakage. No stent migration occurred while the fastener was in place. Two stents were removed within 2 weeks due to patient's difficulty tolerating the stent.

CONCLUSIONS

Securing silicone stents in the proximal trachea is feasible and may prevent stent migration, but further study and possible modification of the PEG-TF device are needed.

Multidetector CT and postprocessing in planning and assisting in minimally invasive bronchoscopic airway interventions

A widening spectrum of increasingly advanced bronchoscopic techniques is available for the diagnosis and treatment of various bronchopulmonary diseases. The evolution of computed tomography (CT)-multidetector CT in particular-has paralleled these advances. The resulting development of two-dimensional and three-dimensional (3D) postprocessing techniques has complemented axial CT interpretation in providing more anatomically familiar information to the pulmonologist. Two-dimensional techniques such as multiplanar recontructions and 3D techniques such as virtual bronchoscopy can provide accurate guidance for increasing yield in transbronchial needle aspiration and transbronchial biopsy of mediastinal and hilar lymph nodes. Sampling of lesions located deeper within the lung periphery via bronchoscopic pathways determined at virtual bronchoscopy are also increasingly feasible. CT fluoroscopy for real-time image-guided sampling is now widely available; electromagnetic navigation guidance is being used in select centers but is currently more costly. Minimally invasive bronchoscopic techniques for restoring airway patency in obstruction caused by both benign and malignant conditions include mechanical strategies such as airway stent insertion and ablative techniques such as electrocauterization and cryotherapy. Multidetector CT postprocessing techniques provide valuable information for planning and surveillance of these treatment methods. In particular, they optimize the evaluation of dynamic obstructive conditions such as tracheobronchomalacia, especially with the greater craniocaudal coverage now provided by wide-area detectors. Multidetector CT also provides planning information for bronchoscopic treatment of bronchopleural fistulas and bronchoscopic lung volume reduction for carefully selected patients with refractory emphysema.

An instant rare complication: a fractured metallic pyloric stent

Metallic pyloric stenting (also termed as metallic enteral stenting) performed endoscopically, stands as first-line treatment for malignant gastric outlet obstruction. With reported evidence, these self-expandable metallic stents (SEMS) re-enable oral food intake, preventing patients having to face invasive techniques such as surgical gastroenterostomy. We report a patient having received a covered pyloric SEMS insertion following a tumour growth causing stenosis in the gastric antropyloric region. After 3 weeks, the patient presented with a fracture of the pyloric SEMS, a rare complication, resulting in a second pyloric SEMS insertion.

Update on interventional bronchoscopy for the thoracic radiologist

Interventional bronchoscopy, together with other domains of interventional pulmonology, has experienced tremendous technological advances. Diagnostic applications include endobronchial ultrasound, which enables endoscopists to see through airway walls. White light videobronchoscopy, autofluorescence imaging, and narrow band imaging have enhanced the ability to detect early lung cancer at a preinvasive stage. Electromagnetic navigational bronchoscopy, ultrathin bronchoscopy, and virtual bronchoscopy increase the diagnostic yield of biopsy of small peripheral lung lesions. The options that are currently available for the relief of central airway obstruction are also numerous, with both flexible and rigid bronchoscopic applications. Stents, although dichotomized to silicone and metal, come in various sizes and shapes to suit the requirements of the pathology being treated. Ablative techniques are categorized into those with an immediate effect and those with a delayed effect. Laser, electrocautery, and argon plasma coagulation can immediately relieve obstruction and control hemoptysis, whereas cryosurgery, brachytherapy, and photodynamic therapy have established roles in subacute airway obstruction and in the treatment of early lung cancer. Microdebriders have recently been added to the armamentarium of modalities for mechanical debulking of tumor. Distal airway obstruction has also been targeted with bronchial thermoplasty treatment of refractory asthma and with bronchoscopic lung volume reduction for the management of severe emphysema. This array of new technology has fostered collaborative work with a wide range of other medical specialties to deliver safer, more effective, minimally invasive treatment.

Respiratory infections increase the risk of granulation tissue formation following airway stenting in patients with malignant airway obstruction

BACKGROUND

The most serious complications of airway stenting are long term, including infection and granulation tissue formation. However, to our knowledge, no studies have quantified the incidence rate of long-term complications for different stents.

METHODS

To compare the incidence of complications of different airway stents, we conducted a retrospective cohort study of all patients at our institution who had airway stenting for malignant airway obstruction from January 2005 to August 2010. Patients were excluded if more than one type of stent was in place at the same time. Complications recorded were lower respiratory tract infections, stent migration, granulation tissue, mucus plugging requiring intervention, tumor overgrowth, and stent fracture.

RESULTS

One hundred seventy-two patients with 195 stent procedures were included. Aero stents were associated with an increased risk of infection (hazard ratio [HR] = 1.98; 95% CI, 1.03-3.81; P = .041). Dumon silicone tube stents had an increased risk of migration (HR = 3.52; 95% CI, 1.41-8.82; P = .007). Silicone stents (HR = 3.32; 95% CI, 1.59-6.93; P = .001) and lower respiratory tract infections (HR = 5.69; 95% CI, 2.60-12.42; P < .001) increased the risk of granulation tissue. Lower respiratory tract infections were associated with decreased survival (HR = 1.57; 95% CI, 1.11-2.21; P = .011).

CONCLUSIONS

Significant differences exist among airway stents in terms of infection, migration, and granulation tissue formation. These complications, in turn, are associated with significant morbidity and mortality. Granulation tissue formation develops because of repetitive motion trauma and infection.

Multidetector CT evaluation of central airways stenoses: Comparison of virtual bronchoscopy, minimal-intensity projection, and multiplanar reformatted images

Aims:

To evaluate the diagnostic utility of virtual bronchoscopy, multiplanar reformatted images, and minimal-intensity projection in assessing airway stenoses.

Settings and Design:

It was a prospective study involving 150 patients with symptoms of major airway disease.

Materials and Methods:

Fifty-six patients were selected for analysis based on the detection of major airway lesions on fiber-optic bronchoscopy (FB) or routine axial images. Comparisons were made between axial images, virtual bronchoscopy (VB), minimal-intensity projection (minIP), and multiplanar reformatted (MPR) images using FB as the gold standard. Lesions were evaluated in terms of degree of airway narrowing, distance from carina, length of the narrowed segment and visualization of airway distal to the lesion.

Results:

MPR images had the highest degree of agreement with FB (Κ = 0.76) in the depiction of degree of narrowing. minIP had the least degree of agreement with FB (Κ = 0.51) in this regard. The distal visualization was best on MPR images (84.2%), followed by axial images (80.7%), whereas FB could visualize the lesions only in 45.4% of the cases. VB had the best agreement with FB in assessing the segment length (Κ = 0.62). Overall there were no statistically significant differences in the measurement of the distance from the carina in the axial, minIP, and MPR images. MPR images had the highest overall degree of confidence, namely, 70.17% (n = 40).

Conclusion:

Three-dimensional reconstruction techniques were found to improve lesion evaluation compared with axial images alone. The technique of MPR images was the most useful for lesion evaluation and provided additional information useful for surgical and airway interventions in tracheobronchial stenosis. minIP was useful in the overall depiction of airway anatomy.

Update in airway stents

PURPOSE OF REVIEW

Malignant central airway obstruction heavily impacts patients' quality of life and its management continues to be a challenge. The current article will review the use of airway stents in this population.

RECENT FINDINGS

Airway stenting is highly effective in palliating symptoms of airway obstruction. There are several types of stents available with different advantages and disadvantages depending mainly on the material they are made from. Clinical outcomes seem to be comparable between silicone and self-expanding metal stents. Self-expanding metal stents have proven to be efficient in recanalizing 'complex' central airway obstructions. Preliminary data show that a new self-expanding 'hybrid' stent appears to be effective and safe for malignant airway obstruction. Airway stent complications vary according to the type of stent and the type of obstruction. Multidetector computed tomography seems to be a valuable adjunct to bronchoscopy in detecting and characterizing stent complications. A clear definition of airway stent-related infection is urgently needed to provide adequate diagnosis and management of this complication. Metal stent fracture is less common in patients with malignant airway obstruction as compared with benign disease, and this could be partially explained by the decreased survival and shorter exposure to stent in the former population.

SUMMARY

Airway stents are of great help in palliating symptoms of malignant central airway obstruction. Unfortunately, there have been no recent striking advances in stent technology and the ideal stent has yet to be designed.

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.

Imaging-bronchoscopic correlations for interventional pulmonology

The improvements to patient care that can be achieved by combining advanced imaging techniques and bronchoscopy are considerable. In this regard, CT imaging often plays an indispensable role in both the selection of appropriate candidates tor therapy as well as the choice of optimal interventional techniques. However, it is apparent that alternate methods for evaluating the airways and lung including ultrasound and electromagnetic navigation will likely play an increasingly important diagnostic role, necessitating a thorough understanding of their advantages and limitations. Disease-specific applications for which imaging technologies, including CT and VB, are either currently routinely used or show the greatest promise are for suspected or diagnosed lung cancers, central and peripheral, and emphysema. It may be anticipated that with growing experience, the potential for additional indications of these remarkable technologies are likely to increase in the near future.

Palliative treatment of inoperable malignant tracheobronchial obstruction: temporary stenting combined with radiation therapy and/or chemotherapy

OBJECTIVE

The purpose of our study was to evaluate the clinical results of temporary stenting followed by radiation and/or chemotherapy in patients with inoperable malignant tracheobronchial strictures.

CONCLUSION

Temporary stenting combined with radiation therapy and/or chemotherapy may be clinically effective in the palliative treatment of patients with malignant tracheobronchial strictures. Stent placement may serve as an effective bridge to radiation and/or chemotherapy, allowing the latter to consolidate durable relief of obstructing symptoms by reducing tumor burden. Furthermore, our treatment strategy may increase patients' quality of life by reducing stent-related complications.

Imaging-bronchoscopic correlations for interventional pulmonology

The development and rapid advancement of both bronchoscopic, CT and ultrasound imaging technology has had considerable impact on the management of a wide variety of pulmonary diseases. The synergy between these newer imaging modalities and advanced interventional endoscopic procedures has led to a revolution in diagnostic and therapeutic options in patients with both central and peripheral airway disease. Given the broad clinical implications of these technological advances, only the most important areas of interventional pulmonology in which imaging has had a major impact will be selectively reviewed to highlight fundamental principles.