Expandable metallic stents in benign tracheobronchial obstruction

Placing covered self-expanding metal stents by suspension laryngoscope in benign tracheal stenosis

BACKGROUND

Tracheobronchial stent placement for malignant airway strictures has been proved to improve respiratory function, but experience for benign tracheobronchial stenoses is limited. The purpose of our study is to investigate the efficacy of covered expandable metallic stents, inserted through a suspension laryngoscope, treating tracheal stenosis following intubation or tracheostomy.

METHODS

From 2010 to 2018, 67 adult patients with the benign tracheal stenosis, underwent stent placement, using a suspension laryngoscope. According to the date of stent placement and stent caliber, these patients have been subdivided into two groups: Group 1 (from 2010 to 2013, stent caliber ranging from 16 to 20 mm) and Group 2 (from 2014 to 2018, stent caliber ranging from 18 to 22 mm). Complications, related reinterventions, and long-term prognosis were retrospectively evaluated.

RESULTS

Primary successful stent placement was achieved and symptoms were improved in all patients. Complications occurred in 27 (40.3%) cases. Among these, there were 14 (20.9%) cases with stent migration, 10 (14.93%) with granulation tissue formation and 3 (4.48%) with pneumonia. Stent migration in Group 1 was nearly 30% higher than that in Group 2 (P = 0.002). Five of the 8 patients who had placement of 16 mm stents had stent migration, more often than with 20 mm stents (P = 0.002). Ten patients' trachea had slight narrowing but without any symptoms. Six patients still had granulation tissue but without any growth at least two-year follow-up (2 patients whose stents were removed more than 1 year after placement). Even without tracheal narrowing and granulation tissue, 5 patients felt persistent shortness of breath. 92.5% of the patients reported to be satisfied with significant improvement in symptoms.

CONCLUSIONS

Patients with tracheal obstruction secondary to intubation or tracheostomy can benefit from tracheal stents. Placing 16 mm stents might lead to stent migration more easily than 20 mm stents. Tracheal stents placed by a suspension laryngoscope provide a reasonable alternative to open surgery for patients with benign tracheal stenosis or obstruction.

Coated expandable metal stents are effective irrespective of airway pathology

Background

Tracheobronchial stents are a treatment option for inoperable benign or malignant tracheobronchial stenosis (TBS) or postoperative bronchopleural fistulas (POBPF). The present study evaluated the outcomes of patients with TBS and POBPF who were treated by placement of recent generation, fully covered, self-expanding metallic stents (SEMS) and determined stent efficacy relative to airway pathology.

Methods

From January 2009 to January 2016, 68 patients with TBS or POBPF underwent rigid bronchoscopy, laser/mechanical debridement and placement of fully covered SEMS. Eighteen patients had benign stenosis, 38 had malignant stenosis, and 12 patients had POBPF.

Results

Seventy-four SEMS were successfully placed in 68 patients. There were no perioperative deaths. Stent-related complications occurred in 20 (29.4%) patients: granulation tissue formation [TBS group, 10.7% (n=6); POBPF group, 8.3% (n=1)]; stent fracture [TBS group, 5.4% (n=3); POBF group, 8.3% (n=1)], stent migration [TBS group, 7.1% (n=4); POBF group, 0% (n=0)], severe secretions not removable by flexible bronchoscopy [TBS group, 7.1% (n=4); POBF group, 8.3% (n=1)]. No stent migration was observed in the POBPF group. Four patients (7.1%) in the TBS group had stent migration requiring stent replacement. After stenting, all TBS patients had a Hugh-Jones classification score improvement ≥1 grade and 42 patients (75%) had an improvement ≥2 grades. Logistic regression analysis showed that the disease (stenosis vs. fistula) did not influence the occurrence of stent complications [OR 0.96, 95% confidence interval (CI): 0.71-1.13, P=0.13].

Conclusions

Fully covered SEMS are effective and provide a versatile treatment option for patients with inoperable TBS and POBPF.

Tracheobronchomalacia

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Successful removal of self-expanding metallic stent after deployment for tubercular bronchostenosis

The use of metallic stents is traditionally not recommended for benign tracheobronchial conditions. With advances in the field of interventional bronchoscopy, metal tracheobronchial stents have occasionally been used to treat benign disease. However, the removal of these stents from the airway is technically difficult. We are reporting the case of a young female subject who received a self-expanding metallic stent for alleviation of post-tubercular bronchostenosis, which was successfully removed after two months without complications. Metal stents can be used in benign tracheobronchial conditions but require meticulous follow-up to monitor complications. Experienced operators can remove them without major complications and this may be life-saving in emergencies. We are reporting this case for the rarity of such procedures in India.

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.

The Use of T-tube Cholangiocatheter Stents in the Treatment of Pediatric Tracheomalacia

Tracheomalacia is a common disorder in neonate and infants, which can lead to life-threatening airway occlusion, because of external pressure or intrinsic defect of tracheobroncial cartilage. Aortopexy and Stents are effective in relieving tracheomalacia in the latter patients. In this case we are to show how t-tube cholangiocatheter is effective and easy available in sever tracheomalacia neonates with intrinsic defect. It can be easily replaced and causes no infection, erosion, or sever complication in 9 months period.

Is there a correlation between right bronchus length and diameter with age?

OBJECTIVE

Right main bronchial anatomy knowledge is essential to guide endoscopic stent placement in modern era. The aim is to describe right bronchial anatomy, cross-area and its relation with the right pulmonary artery and patient's age.

METHODS

One hundred thirty four cadaveric specimens were studied after approval by the Research and Ethics Committee at the University of São Paulo Medical School and Medical Forensic Institute of São Paulo. All necropsies were performed in natura after 24 hours of death and patients with previous pulmonary disease were excluded. Landmarks to start measurement were the first tracheal ring, vertex of carina, first right bronchial ring, and right pulmonary artery area over the right main bronchus. After mobilization, the specimens were measured using a caliper and measurement of distances was recorded in centimeters at landmarks points. All the measures (distances, cross sectional area and planes) were performed by three independent observers and recorded as mean, standard error and ranges. Student t test was used to compare means and linear regression was applied to correlate the measurements.

RESULTS

From 134 specimens studied, 34 were excluded (10 with previous history of pulmonary diseases, surgery or deformities and 24 of female gender). Linear regression showed proportionality between tracheal length and right bronchus length; with the area at first tracheal ring and carina and also between the cross sectional area at these points. Linear regression analysis between tracheal length and age (R=0.593 P<0.005), right bronchus length and age (R=0.523, P<0.005), area of contact between right bronchus and right pulmonary artery and age (R=0.35, P<0.005).

CONCLUSIONS

We can conclude that large airways grow progressively with increasing age in male gender. There was a direct correlation between age and tracheal length; as has age and right bronchus length. There was a direct correlation between age and the area of the right bronchus covered by the right pulmonary artery.

Endoscopic therapies and stents for benign airway disorders: where are we, and where are we heading?

Benign strictures of the airway can be complex and challenging to manage. Although resection has the best long-term results, this is not always feasible, and there will be groups of patients who require additional therapy for failure after open operations or who are not surgical candidates and require endoluminal management. A number of stents are available; however, not all perform well for the longer duration that will be required for patients with benign compared with malignant strictures. For this reason, stenting should be considered a temporary solution or a last resort for patients with benign airway strictures. Combinational modalities hold promise; for example, radial laser incisions with dilatation and mitomycin C for tracheal stenosis. Many techniques, however, have been associated with failure, particularly for long strictures. Spray cryotherapy is a new technique that may have advantages over other treatments by modulating the healing response and resulting in improved healing and less refibrosis. A number of current and new therapies are reviewed in this article.

Successful Endobronchial stenting for bronchial compression from a massive thoracic aortic aneurysm

A case of bronchial occlusion caused by a thoracic aortic aneurysm and the relief of this obstruction by the implantation of expandable metallic stents is described. Stent deployment provided an immediate improvement in lung ventilation and chest radiograph appearances. Stent insertion was uncomplicated, but weaning from mechanical ventilation was unsuccessful and the patient died from a ventilator-associated pneumonia, unrelated to the procedure. Endobronchial stenting should be considered as a non-invasive therapy for the treatment of bronchial obstruction, with respiratory compromise, caused by a thoracic aortic aneurysm when vascular surgery is not an option. The medium to long term survival of this patient group is poor. This can be attributed to complications related to the stent and also to the poor performance status of these patients.

Do airway metallic stents for benign lesions confer too costly a benefit?

Background

The use of self-expanding metallic stents (SEMAS) in the treatment benign airway obstruction is controversial.

Methods

To evaluate the safety and efficacy of SEMAS for this indication, we conducted a 10-year retrospective review at our tertiary medical centre.

Results

Using flexible bronchoscopy, 82 SEMAS (67% Ultraflex, 33% Wallstent) were placed in 35 patients with inoperable lesions, many with significant medical comorbidities (88%). 68% of stents were tracheal, and 83% of patients showed immediate symptomatic improvement. Reversible complications developed in 9% of patients within 24 hrs of stent placement. Late complications (>24 hrs) occurred in 77% of patients, of which 37% were clinically significant or required an interventional procedure. These were mainly due to stent migration (12.2%), fracture (19.5%), or obstructive granulomas (24.4%). The overall granuloma rate of 57% was higher at tracheal sites (59%) than bronchial ones (34%), but not significantly different between Ultraflex and Wallstents. Nevertheless, Wallstents were associated with higher rates of bleeding (5% vs. 30%, p = 0.005) and migration (7% vs. 26%, p = 0.026). Of 10 SEMAS removed using flexible bronchoscopy, only one was associated with incomplete removal of fractured stent wire. Median survival was 3.6 ± 2.7 years.

Conclusion

Ill patients with inoperable lesions may be considered for treatment with SEMAS.

[Multidetector CT evaluation of airway metallic stents]

INTRODUCTION

Stenting is accepted in managing patients with inoperable obstruction of the upper airways. The choice of the type as well as the dimensions of stents are crucial as it impacts on the success of the procedure and potential complications which must be diagnosed non-invasively.

STATE OF THE ART

The goal of this review is to present our multidisciplinary experience using multidetector CT as a minimally invasive technique for detecting airway obstructions, for evaluating preoperatively local anatomic conditions useful to determinate the type and size of metallic stents to be used, and following non-invasively the stent in order to detect various complications.

CONCLUSIONS

MDCT acquisition should use thin slices as multiplanar reformations and 3D reconstructions play an essential complementary role to axial images in pre- and post-stent placement settings.

Tracheobronchomalacia and excessive dynamic airway collapse

Tracheobronchomalacia and excessive dynamic airway collapse are two separate forms of dynamic central airway obstruction that may or may not coexist. These entities are increasingly recognized as asthma and COPD imitators. The understanding of these disease processes, however, has been compromised over the years because of uncertainties regarding their definitions, pathogenesis and aetiology. To date, there is no standardized classification, diagnosis or management algorithm. In this article we comprehensively review the aetiology, morphopathology, physiology, diagnosis and treatment of these entities.

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.

Follow-up after stent insertion in the tracheobronchial tree: role of helical computed tomography in comparison with fiberoptic bronchoscopy

The aim of this study was to compare helical CT with fiberoptic bronchoscopy findings to appraise the medium-term results of proximal-airways stenting. Twenty-five patients with 28 endobronchial metallic stents inserted for local advanced malignancy ( n=13) or benign diseases ( n=12) underwent follow-up CT from 3 days to 50 months (mean 8 months). All studies were obtained using helical CT with subsequent multiplanar reformation and three-dimensional reconstruction including virtual bronchoscopy. The location, shape, and patency of stents and adjacent airway were assessed. The results of CT were compared with the results of fiberoptic bronchoscopy obtained with a mean delay of 2.5 days (SD 9 days) after CT scan. Twelve stents (43%) remained in their original position, patent and without deformity. Sixteen stents were associated with local complications: migration ( n=6); external compression with persistent stenosis ( n=4); local recurrence of malignancy ( n=4); fracture ( n=1); and non-congruence between the airway and the stent ( n=1). The CT demonstrated all the significant abnormalities demonstrated at fiberoptic bronchoscopy except two moderate stenoses (20%) related to granulomata at the origin of the stent. Ten of 14 stents inserted for benign conditions were without complications as compared with 2 of 14 in malignant conditions ( p=0.008). Computed tomography is an accurate noninvasive method for evaluating endobronchial stents. The CT is a useful technique for follow-up of patients who have undergone endobronchial stenting.

Wegener's granulomatosis presenting as necrosis of the left mainstem bronchus

A patient with pansinusitis, nasal septum necrosis, and saddle nose deformity showed necrosis of the left mainstem, upper, and lower bronchi, with complete loss of left lung perfusion and ventilation. Pneumonectomy was performed. Histological findings showed extensive necrotizing and granulomatous bronchial inflammation with vasculitis of the bronchial arteries and the pulmonary vein. Wegener's granulomatosis was diagnosed, despite a negative cytoplasmic pattern of antineutrophil cytoplasmic antibodies and the lack of renal involvement.

Benign tracheobronchial stenoses: changes in short-term and long-term pulmonary function testing after expandable metallic stent placement

PURPOSE

To determine the short- and long-term improvement in airflow dynamics in patients undergoing tracheobronchial stent placement for benign airway stenoses.

METHODS

Twenty-two patients underwent 34 tracheal and/or bronchial stent placement procedures for benign airway stenoses and had the results of pulmonary function tests available. Stent placement indications included bronchomalacia after lung transplantation (n = 11), postintubation stenoses (n = 6), relapsing polychondritis (n = 2), and 1 each of tracheomalacia, tracheal compression, and histoplasmosis. Six patients underwent more than one stent placement procedure (range: 2-7 procedures). The mean forced expiratory volume in one second (FEV(1) ), forced expiratory flow rate in the midportion of the forced vital capacity curve (FEF(25-75) ), forced vital capacity, and peak flow (PF) rate obtained before stent placement were compared with those immediately after stent placement and with those measurements most remote from stent placement using the paired two-tailed test.

RESULTS

All patients reported improved respiratory function immediately after stent placement. The mean FEV(1), FEF(25-75), and PF rate improved significantly (p < 0.001, p = 0.002, and p = 0.009, respectively) after stent placement. On long-term follow-up averaging 15 months after stent placement, these parameters declined despite patients' subjective sense of improvement. Segregating the population into transplant and nontransplant airway stenosis etiologies, however, FEF(25-75) and PF rate remained significantly improved (p = 0.045, p = 0.027, respectively), over the long term for the latter. FEV increased after subsequent stent placements for patients receiving multiple stents.

CONCLUSION

Stent placement for benign tracheobronchial stenoses provides significant immediate improvement in airflow dynamics. Long-term improvement in airflow obstruction may be expected, and additional stent placements may further improve pulmonary function.

Recent advances in central airway imaging

The purpose of this article is to familiarize chest physicians with recent advances in airway imaging, with an emphasis on the emerging role of two-dimensional reformatted and three-dimensional CT reconstructed images in the assessment of central airway disorders.

Multidisciplinary airway stent team: a comprehensive approach and protocol for tracheobronchial stent treatment

Tracheobronchial stents are being used with increasing frequency to treat major airway obstruction from both malignant and benign processes. Traditionally, stents have been placed via rigid bronchoscopy, flexible bronchoscopy, or fluoroscopy by members of various individual disciplines. We describe a novel multidisciplinary airway stent team (MAST) protocol for tracheobronchial stent placement and endoscopic management of major airway obstruction. A patient with symptoms of airway obstruction is generally first evaluated with a computed tomography scan and a videotaped flexible bronchoscopy. These studies are reviewed by the team otolaryngologist, pulmonologist, and interventional radiologist. A treatment plan, including the type and location of stents and the need for adjuvant therapies, is formulated. Stent placement is performed in the operating room under general anesthesia. Rigid bronchoscopy, with flexible bronchoscopy and fluoroscopy as needed, allows precise stent placement and the best use of various therapeutic methods. The MAST protocol combines the skills, knowledge, and unique therapeutic options of specialists from otolaryngology, pulmonology, and interventional radiology. This approach allows optimal stent placement and the use of other endobronchial therapies, including laser ablation, balloon dilation, photodynamic therapy, cryotherapy, and brachytherapy. A protocol with representative case reports is presented, along with a review and comparison of several of our most commonly used stents. Otolaryngologists who practice bronchoesophagoscopy, by virtue of their operative skill and knowledge of airway management, are well equipped to become leaders of MASTs and are encouraged to initiate MASTs at their institutions.

Relapsing polychondritis

Relapsing polychondritis is a rare inflammatory disease of unknown aetiology characterized by recurrent inflammation and destruction of cartilaginous structures and connective tissue. Current data provide increasing support for an autoimmune basis, but its cause remains unknown. Individuals of any race, gender, or age may be affected, but it is most commonly seen between the ages of 40 and 60 years. Although relapsing polychondritis occurs predominantly as a separately defined clinical complex, a significant number of patients may suffer from another underlying rheumatic and/or haematological disorder; vasculitic syndromes are the most commonly observed disorders associated with relapsing polychondritis. Common clinical features are auricular, nasal and respiratory tract chondritis with involvement of organs of special sense, such as the eyes and audiovestibular apparatus. Polyarthritis and vasculitic involvement are also common. Corticosteroids are still the agents of choice although several other anti-inflammatory drugs can be used in order to allow tapering of the steroid dose or to achieve a lower maintenance dose for refractory cases.

Endobronchial stenting for severe airway obstruction in relapsing polychondritis

Airway complications of relapsing polychondritis (RP), including tracheobronchial stenosis, can be fatal. This paper describes a life-saving technique (placement of multiple metallic endobronchial stents under conscious sedation) to prevent life-threatening airway closure in a 50-year-old woman with RP. Using fluoroscopic and bronchoscopic guidance, a tracheal stent and three endobronchial metallic stents were deployed in the central airways, with good functional outcome. There were no complications. In critical airway compromise caused by RP, the insertion of endobronchial stents can result in improved symptoms, pulmonary function, and a return to daily activities, without the use of tracheotomy and mechanical ventilation.