Advances in the management of major airway collapse: the use of airway stents

Management of post-operative ventilator dependency in an operated case of tetralogy of Fallot with absent pulmonary valve: a team approach involving cardiac surgeon, cardiologist, intensivist, and radiologist

Tetralogy of Fallot with absent pulmonary valve syndrome is commonly associated with trachea-bronchial anomalies, possibly due to airway compression caused by massively dilated pulmonary arteries secondary to severe pulmonary regurgitation. This airway obstruction may persist post-operatively also. We report a case of an infant who required a series of management strategies including bronchial stenting to manage his obstructive symptoms.

Anesthetic management of tracheal stent extraction using a double gum elastic bougie technique

Background

Tracheal stenosis is a life-threatening condition, and management of a patient with a risk of tracheal stenosis is challenging for anesthesiologists. In this report, we describe a method for airway management using two gum elastic bougie method when removing a tracheal stent via a tracheostomy orifice with a risk of airway restenosis.

Case presentation

A 71-year-old man had an enlarged squamous cell carcinoma of the lung invading the upper mediastinum that had caused severe stenosis of the trachea. Two months after diagnosis, a tracheal stent had been placed to maintain tracheal patency. One month after stent placement, acute respiratory failure was induced by upper airway obstruction caused by subglottic airway edema due to mechanical stimulation of the cranial end of the stent, and the patient was rescued by oral tracheal intubation. Tracheal stent extraction was scheduled to relieve the laryngeal edema. Since there was a risk of tracheal restenosis because of the possibility of accidental evulsion of the orally tracheal tube which intubated to secure an emergency airway and tracheal stent extraction, two gum elastic bougies were inserted through the oral tracheal tube and tracheostomy orifice to facilitate re-intubation. After extraction of the tracheal stent, airway openness was maintained and tracheostomy was completed without any complication.

Conclusion

Successful management of tracheal stent extraction was performed using a double gum elastic bougie technique.

Tracheobronchial stenting for airway malacia

Tracheobronchomalacia is a rare but clinically troublesome condition in paediatrics. The softening of the major airways - which can include some or all of the tracheobronchial tree can lead to symptoms ranging from the minor (harsh barking cough, recurrent chest infections) to severe respiratory difficulties including prolonged ventilator support and 'near death attacks'. The causes are broadly divided into intrinsic softening of the airway wall which is considered a primary defect (e.g. syndromes; post tracheo-oesophageal fistula repair; extreme prematurity) or secondary malacia due to external compression from vascular structures or cardiac components. These secondary changes can persist even when the external compression is relieved, for example, following the repair of a pulmonary artery sling or double aortic arch. For children with severe clinical symptoms attributed to malacia, consideration is given to possible surgical remedies such as an aortopexy for short limited areas of malacia, or long term positive pressure support with CPAP either by non invasive or tracheostomy interface. More recently the role of stenting in children is receiving attention, especially with the development of newer techniques such as bioabsorbable stents which buy time for a natural history of improvement in the malacia to occur. This paper reviews the stents available and discusses the pros and cons of stenting in paediatric airway malacia.

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.

Pediatric airway surgery

Pediatric airway surgery is a challenging field in pediatric surgery. Laryngotracheal stenosis has a variety of congenital and acquired conditions that require precise assessment and tailored treatment for each individual patient. About 90% of acquired conditions are represented by subglottic stenosis (SGS) resulting as a complication of tracheal intubation. Congenital tracheal stenosis (CTS) is a rare and life-threatening malformation, usually associated with complete tracheal rings along a variable length of the trachea. Tracheomalacia (TM) is a process characterized by flaccidity of the supporting tracheal cartilage, widening of the posterior membranous wall, and reduced anterior-posterior airway caliber. The clinical presentation can vary from almost asymptomatic patients to near fatal airway obstruction. There is considerable variation in both the morphologic subtypes and the prognosis of pediatric airway. The patients are divided into three clinical groups (mild, moderate, and severe). A further division was proposed according to the presence or absence of associated anomalies. The definitive diagnosis of pediatric airway was made by means of rigid bronchoscope and computed tomography scan with three-dimensional reconstruction (3D-CT). Rigid bronchoscopy and 3D-CT confirmed the diagnosis in all the cases. Other associated anomalies include congenital heart disease, vascular anomalies, and BPFM (maldevelopment of aerodigestive tract). After definitive diagnosis of pediatric airway lesions, surgical intervention should be considered. Surgical strategy was presented on each lesion.

Tracheal cartilage growth by intratracheal injection of basic fibroblast growth factor

BACKGROUND/PURPOSE

We have previously shown that intratracheal injection of slowly released (in gelatin) basic fibroblast growth factor (bFGF) significantly enlarged the tracheal lumen by a slight margin. This study aimed to investigate differences in tracheal cartilage growth by the intratracheal injection of bFGF doses in a rabbit model.

METHODS

Water (group 1; n=7; control) or 100μg (group 2; n=8) or 200μg (group 3; n=8) of bFGF dissolved in water was injected into the posterior wall of the cervical trachea of New Zealand white rabbits using a tracheoscope. All animals were sacrificed four weeks later.

RESULTS

The mean circumferences of cervical tracheas for groups 1, 2, and 3 were 18.8±0.83, 21.1±2.0, and 22.1±1.3mm, respectively. A significant difference was found between groups 1 and 2 (P=0.034) and groups 1 and 3 (P=0.004). The mean luminal areas of cervical tracheas for groups 1, 2, and 3 were 27.0±2.1, 32.2±4.8, and 36.3±4.6mm², respectively. A significant difference was found between groups 1 and 3 (P=0.001).

CONCLUSION

Intratracheal injection of bFGF in the dose range used significantly promoted the growth of tracheal cartilage in a rabbit model.

LEVELS OF EVIDENCE

Level II at treatment study (animal experiment).

Pediatric tracheomalacia

Tracheomalacia (TM) is defined as an increased collapsibility of the trachea due to structural anomalies of the tracheal cartilage and/or posterior membrane. Tracheomalacia has a wide range of etiologies but is most commonly present in children born with esophageal atresia and tracheal esophageal fistula. Clinical symptoms can range from minor expiratory stridor with typical barking cough to severe respiratory distress episodes to acute life-threatening events (ALTE). Although the majority of children have mild-to-moderate symptoms and will not need surgical intervention, some will need life-changing surgical treatment. This article examines the published pediatric literature on TM, discusses the details of clinical presentation, evaluation, diagnosis, and a variety of treatments.

Management of tracheobronchial obstruction in infants using metallic stents: long-term outcome

INTRODUCTION

Tracheobronchial obstruction, although uncommon in the pediatric age group, remains a challenging problem. We review the long-term outcome of endoscopic metallic stenting in infants with tracheobronchial obstruction.

MATERIALS AND METHODS

Medical records of all pediatric surgical patients who underwent tracheobronchial metallic stenting in our center were reviewed retrospectively from 1996 to 2014. Patients' demographic data, including etiology, associated anomalies and nature of obstruction were reviewed. Outcome measures include complications such as re-stenosis, granulation tissue, stent migration, fractured stent, maximal tracheal diameter achieved, weaning of ventilator and growth at interval follow-up.

RESULTS

Twelve balloon-expandable metallic stents were placed in the trachea (n = 10) and/or bronchi (n = 2) of 5 patients with a median age of 13 months (range 5-30 months). Etiology of the airway obstruction included congenital tracheal stenosis (n = 4), giant cervical and superior mediastinal lymphatic malformation with tracheobronchomalacia (n = 1). Seven complications were reported (3 patients developed granulation tissue, 2 patients had re-stenosis, 1 stent migrated, 1 stent fractured). All patients survived and were in good condition with a median follow-up of 16 years (range 11-18 years). Three patients weaned off ventilator and oxygen.

CONCLUSIONS

Endoscopic stenting with metallic stent has satisfactory long-term outcome in treating infants with tracheobronchial obstruction.

Tracheomalacia treatment using a large-diameter, custom-made airway stent in a case with mounier-kuhn syndrome

Mounier-Kuhn Syndrome (MKS) is a rare congenital disease that presents with abnormal enlargement in the central airways. In MKS, tracheomegaly is accompanied by difficulty in expelling recurrent lung infections and bronchiectasia. We presented a patient with MKS where commercially made stents were inadequate for stabilization and a custom-made, self-expandable metallic stent with a diameter of 28 mm and length of 100 mm was used. Chest pain that was thought to develop due to the stent and that disappeared after stent removal may be considered the main complication leading to stent removal. Continuous positive airway pressure therapy (CPAP) therapy was planned for the control of symptoms, which re-emerged after stent removal. This case is presented as an example that complications developing due to the stent as well as patient noncompliance may lead to stent removal, even when useful results are obtained from treatment of MKS.

Promotion of tracheal cartilage growth by intra-tracheal injection of basic fibroblast growth factor (b-FGF)

PURPOSE

Basic fibroblast growth factor (b-FGF) is a very effective growth factor that induces the proliferation of chondrocytes. This study aimed to investigate whether intra-tracheally-injected b-FGF solution promotes the growth of tracheal cartilage.

METHODS

Group 1: 500 μl of distilled water was injected at the posterior wall of the cervical trachea of New Zealand white rabbits by using a tracheoscope (n=5). Group 2: 100 μg/500 μl of b-FGF solution was injected at the posterior wall of the cervical trachea (n=5). Group 3: Biodegradable gelatin hydrogel microspheres incorporating 100 μg/500 μl of b-FGF solution were injected at the posterior wall of the cervical trachea (n=5). All animals were sacrificed 4 weeks later, and the outer diameter and luminal area of the cervical trachea at the site of b-FGF injection were measured.

RESULTS

The cervical tracheas in the two b-FGF injection groups were spindle-shaped and had a maximum diameter at the injection site. The median outer diameter of the cervical trachea in Groups 1, 2, and 3 was 7.3, 8.0, and 8.0mm, respectively, showing a significant difference among Groups 1, 2, and 3 (P=0.04). The median luminal area in Groups 1, 2, and 3 was 27.4, 29.4, and 32.1mm(2), respectively. The ad hoc test showed a marginally significant difference only between groups 1 and 3 (p=0.056).

CONCLUSION

Intra-tracheal injection of slowly released b-FGF enlarged the tracheal lumen.

Diagnosis and management of an elderly patient with severe tracheomalacia: A case report and review of the literature

Severe adult tracheomalacia is a dangerous disease that is difficult to manage, particularly at the time of airway infection, and has a high mortality rate. The present study reports the diagnosis and treatment of an elderly patient with severe adult tracheomalacia. In March 2012, the 59-year-old patient presented with progressive dyspnea to the Department of Respiratory Medicine, Taizhou People's Hospital (Jiangsu, China). Following admission, chest radiography revealed symptoms consistent with chronic obstructive pulmonary disease (COPD) and chest computed tomography (CT) demonstrated an evident stenosis of the tracheal lumen at the end of expiration. Bronchoscopy revealed a 91% reduction in the cross-sectional area of the tracheal lumen at the end of expiration. Following the final diagnosis, the patient was successfully treated with nasal continuous positive airway pressure (CPAP) combined with implantation of a temporary Chinese Li's metallic stent. These treatment methods appeared to be temporarily effective in alleviating the symptoms of the disease.

Prevalence of tracheobronchomalacia and excessive dynamic airway collapse in bronchial asthma of different severity

Background

Tracheobronchomalacia (TBM) is a pathologic condition in which softening of tracheal and bronchial cartilage causes the dynamic narrowing of transverse or sagittal diameters of tracheobronchial lumen; an excessive dynamic airway collapse (EDAC) may also be associated, with a substantial invagination of the posterior membrane of trachebronchial tree.

The aim of this study was to assess the prevalence of both TBM and EDAC in a population of asthmatics with different degrees of disease severity compared to a reference group of subjects without any bronchial obstruction.

Methods

A cohort of 202 asthmatics was investigated by means of a dynamic flexible videobronchoscopy: 74 mild persistent (MPA - age 18–68 ys; 35 males; mean FEV₁ = 88.6% pred. ± 8.3 sd); 63 moderate (MA - age 21–71 ys; 30 males; mean FEV₁ = 71.3% pred. ± 9.1 sd), 65 severe asthmatics (SA - age 33–70 ys; 25 males; mean FEV₁ = 48.5% pred. ± 7.6 sd), and 62 non obstructed subjects (NO - age 18–71 ys; 38 males; mean FEV₁ 98.6% pred. ± 2.7 sd). TBM and EDAC were classified according to FEMOS classification.

Results

TBM and EDAC were observed in only 1/62 subjects (both 1.61%) of NO group, while their prevalence was 2.70% and 6.75% in MPA group; 7.93% and 19.04% in MA group; 18.46% and 69.23% in SA group, respectively. The crude prevalence of thyroid disorders in the population was 12.9%. In particular, the prevalence of thyroid disorders was significantly higher in females than in men, but 54-fold higher in females than in men in the presence of EDAC.

Conclusions

1) The prevalence of both TBM and EDAC is directly related to age, gender (females), and asthma severity; 2) EDAC is much more frequent than TBM in all asthma patients; 3) both tracheal abnormalities proved to be more represented in asthmatics with thyroid disorders, and particularly in female asthmatics with EDAC.

Slow release of basic fibroblast growth factor (b-FGF) promotes growth of tracheal cartilage

PURPOSE

Tracheomalacia is a major cause of morbidity in conditions such as oesophageal atresia. However, symptoms usually improve with age. A more rapid growth of tracheal cartilage can be induced by basic-Fibroblast Growth Factor (b-FGF). This study aimed to investigate whether slow-release b-FGF could act as a novel treatment for tracheomalacia.

METHODS

Biodegradable gelatin hydrogel sheets incorporating 0.5, 5, or 50 μg/20 μl of b-FGF solution were inserted between the cervical trachea and esophagus of rats. No intervention was performed in rats in a control group. All animals were sacrificed 4 weeks later, and the luminal area of the cervical trachea and the thickness of the cartilage were measured.

RESULTS

The mean luminal areas in the control group and in the b-FGF groups were 3.1, 3.2, 3.8, and 2.6mm(2), respectively, and showed a peak area at 5 μg of b-FGF. A significant difference was seen only between the control group and the b-FGF 5 μg group (p<0.05). The mean thickness of the tracheal cartilage was 0.12, 0.13, 0.19, and 0.32 mm in the control and the b-FGF groups, respectively, and showed a dose-dependent increase, which was statistically significant between the b-FGF 5 μg or 50 μg groups and the control group (p<0.01).

CONCLUSION

This study showed that slow-release b-FGF enlarges the tracheal lumen and thickens the cartilage in a dose-dependent fashion.

Unmasking of tracheomalacia following short-term mechanical ventilation in a patient of adult respiratory distress syndrome

Patients with chronic obstructive pulmonary disease (COPD) are susceptible to airway malacia, which may be unmasked following mechanical ventilation or tracheostomy decannulation. Dynamic imaging of central airways, a non-invasive test as effective as bronchoscopy to diagnose airway malacia, has increased the recognition of this disorder. We describe a 70-year-old woman admitted with adult respiratory distress syndrome. She had cardiorespiratory arrest on admission, from which she was successfully resuscitated. She had obesity, hypertension, diabetes mellitus, recurrent ventricular tachycardia, sarcoidosis with interstitial lung disease and COPD. She received short-term (18 days) mechanical ventilation with tracheostomy and developed respiratory distress following tracheostomy decannulation.

Use of nitinol stents for end-stage tracheal collapse in dogs

OBJECTIVE

To report bronchoscopic placement of nitinol stents (Vet Stent-Trachea®) for improvement of end-stage clinical signs in dogs with tracheal collapse.

STUDY DESIGN

Case series.

SAMPLE POPULATION

Dogs (n = 18).

METHODS

Medical records (January 1, 2004-October 31, 2008) were searched for dogs with a diagnosis of tracheal collapse; 18 dogs met inclusion criteria. Tracheal diameter was compared before and after stent deployment. Stent dimensions were compared after stent deployment and at radiographic follow-up.

RESULTS

There was a significant difference in the minimum tracheal diameter when initial and post deployment tracheal diameters were compared (P = .003). Stent length was significantly shorter at follow-up when compared to post deployment measurements (P = .004). Owner assessment of outcome was available for all dogs with 11.1% mortality within 60 days. Complications were documented in 9 dogs.

CONCLUSIONS

Use of a nitinol stent (Vet Stent-Trachea®) in dogs with end-stage tracheal collapse is associated with a fair to good outcome despite significant temporal stent fore shortening after bronchoscopic placement.

Tracheobronchomalacia in children: review of diagnosis and definition

Tracheobronchomalacia is characterised by excessive airway collapsibility due to weakness of airway walls and supporting cartilage. The standard definition requires reduction in cross-sectional area of at least 50% on expiration. However, there is a paucity of information regarding the normal range of central airway collapse among children of varying ages, ethnicities and genders, with and without coexisting pulmonary disease. Consequently, the threshold for pathological collapse is considered somewhat arbitrary. Available methods for assessing the airway dynamically--bronchoscopy, radiography, cine fluoroscopy, bronchography, CT and MR--have issues with reliability, the need for intubation, radiation dose and contrast administration. In addition, there are varying means of eliciting the diagnosis. Forced expiratory manoeuvres have been employed but can exaggerate normal physiological changes. Furthermore, radiographic evidence of tracheal compression does not necessarily translate into physiological or functional significance. Given that the criteria used to make the diagnosis of tracheobronchomalacia are poorly validated, further studies with larger patient samples are required to define the threshold for pathological airway collapse.

Pulmonary function and long-term follow-up of children with tracheobronchomalacia

BACKGROUND

Primary tracheobronchomalacia (TBM) is a disease of the large airways. Long-term follow-up studies of TBM patients have not been reported. This study was undertaken to further elicit the natural history of this condition and the presence of concomitant reactive airways disease through clinical profiling and pulmonary function testing.

METHODS

Twenty-one children diagnosed with TBM by bronchoscopy between 1998 and 2001 in Queensland were recruited in 2008. Parents completed a questionnaire detailing their child's respiratory symptoms over the previous 12 months. Children then undertook pulmonary function and flow-volume loop classification. Mannitol bronchial provocation testing or post-bronchodilator spirometry was performed to assess for the confounding presence of reactive airways disease.

RESULTS

Data from 19 children (12 males) were able to be analyzed. The median age was 9.4 (range 7.6-14.3) years. 15 parents indicated their child's symptoms were unresolved. The mean FEV(1) was 81% predicted with 7 <80% predicted. This was significantly lower than the percent predicted population mean (P = 0.0005). Mean FEV(1) /FVC, FEF(25-75) , and PEF were also significantly reduced (P = < 0.0001). Four participants had a classical TBM flow-volume loop on analysis. One of 15 (6.7%) participants recorded a positive test for reactive airways disease.

CONCLUSIONS

Clinical symptom profiles and pulmonary function indicate persistent functional mechanical abnormalities of the large and small airways in TBM patients, and the absence of reactive airways disease.

Airway stenting and tracheobronchoplasty improve respiratory symptoms in Mounier-Kuhn syndrome

BACKGROUND

Mounier-Kuhn syndrome (MKS) is a condition characterized by tracheobronchomegaly resulting from the loss or atrophy of musculoelastic fibers within the airway wall. Concomitant tracheobronchomalacia is seen in most patients with MKS, often leading to significant respiratory compromise due to bronchiectasis, increased dead space, and impaired secretion clearance.

METHODS

We report a series of 12 patients with MKS and tracheobronchomalacia who were evaluated at our institution for significant respiratory problems. Stent trials were conducted in 10 patients, with seven proceeding to operative tracheobronchoplasty (TBP) and one continuing with long-term stent placement. One patient underwent TBP without prior stent placement. Of the remaining three patients, two had no improvement with trials of stent placement, and a stent could not be placed in the third because of a large tracheal diameter.

RESULTS

Compared with baseline values, clinically significant improvements in health-related quality-of-life measures and pulmonary function testing were seen in patients who underwent central airway stabilization (n = 9). Complications of both stent placement and TBP were generally mild. However, one death was reported in the surgical group secondary to an exacerbation of preexisting interstitial pneumonia.

CONCLUSIONS

An aggressive approach that targets central airway stabilization may improve outcomes for patients with MKS.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00550602; URL: www.clinicaltrials.gov.

Tracheobronchomalacia in infants and children: multidetector CT evaluation

Tracheobronchomalacia (TBM) is the most common congenital central airway anomaly, but it frequently goes unrecognized or is misdiagnosed as other respiratory conditions such as asthma. Recent advances in multidetector computed tomography (CT) have enhanced the ability to noninvasively diagnose TBM with the potential to reduce the morbidity and mortality associated with this condition. Precise indications are evolving but may include symptomatic pediatric patients with known risk factors for TBM and patients with otherwise unexplained impaired exercise tolerance; recurrent lower airways infection; and therapy-resistant, irreversible, and/or atypical asthma. With multidetector CT, radiologists can now perform objective and quantitative assessment of TBM with accuracy similar to that of bronchoscopy, the reference standard for diagnosing this condition. Multidetector CT enables a comprehensive evaluation of pediatric patients suspected of having TBM by facilitating accurate diagnosis, determining the extent and degree of disease, identifying predisposing conditions, and providing objective pre- and postoperative assessments. In this article, the authors present a step-by-step primer of multidetector CT imaging for evaluating infants and children with suspected TBM, including clinical indications, patient preparation, multidetector CT techniques and protocols, two- and three-dimensional processing of multidetector CT data, and image interpretation. The major aim of this article is to facilitate the reader's ability to successfully employ multidetector CT imaging protocols for evaluation of TBM in infants and children in daily clinical practice.

Tracheobronchoplasty for severe tracheobronchomalacia: a prospective outcome analysis

RATIONALE

Central airway stabilization with silicone stents can improve respiratory symptoms in patients with severe symptomatic tracheobronchomalacia (TBM) but is associated with a relatively high rate of complications. Surgery with posterior tracheobronchial splinting using a polypropylene mesh has also been used for this condition but to date has not been evaluated prospectively and objectively for patient outcomes.

OBJECTIVES

To evaluate the effect of surgical tracheobronchoplasty on symptoms, functional status, quality of life, lung function, and exercise capacity in patients with severe and symptomatic TBM.

METHODS

A prospective observational study in which baseline measurements were compared to those obtained 3 months after surgical tracheobronchoplasty.

MEASUREMENTS AND MAIN RESULTS

Of 104 referred patients to our complex airway center for severe TBM, 77 had baseline measurements. Of this group, 57 patients had severe malacia and underwent stent placement for central airway stabilization. Of those, 37 patients reported improvement in respiratory symptoms and 35 were considered for surgical tracheobronchoplasty. Two patients were excluded from surgery for medical reasons. Median age was 61 years (range, 39 to 83 years), 20 patients were men, 11 patients (31%) had COPD, 9 patients (26%) had asthma, and 4 patients (11%) had Mounier-Kuhn syndrome. Thirty-three patients (94%) presented with severe dyspnea, 26 patients (74%) with uncontrollable cough, and 18 patients (51%) reported recurrent pulmonary infections. Two patients (3%) presented with respiratory failure requiring mechanical ventilation. After surgery, quality of life scores improved in 25 of 31 patients (p < 0.0001), dyspnea scores improved in 19 of 26 patients (p = 0.007), functional status scores improved in 20 of 31 patients (p = 0.003), and mean exercise capacity improved in 10 patients (p = 0.012).

CONCLUSIONS

In experienced hands, surgical central airway stabilization with posterior tracheobronchial splinting using a polypropylene mesh improves respiratory symptoms, health-related quality of life, and functional status in highly selected patients with severe symptomatic TBM.

Airway stents in children

Airway obstruction in children is a rare, but difficult clinical problem, with no clear agreement on optimal therapeutic approach. Stenting of the airway has been used successfully in adults, and is an attractive alternative in children. Fundamental differences of pediatric compared to adult use include the benign nature of most stenoses, the narrow and soft airways of children, the required long-term tolerance and adaptation to growth. These differences may significantly alter the therapeutic balance, calling into question the precise role stents play in the treatment of airway obstruction in children. Stent placement can be technically demanding but is not exceedingly difficult. Experience is necessary to select the proper size and type of stent. Metal stents usually achieve airway patency and clinical improvement in the majority of cases, while this is less frequently the case with silicone stents. Some complications such as granulation and secretion retention seem to occur in most children after stent implantation. Unfortunately, severe complications including death have been reported in a significant proportion of children. Stent related mortality can be estimated at 12.9% from published data, but these include complication centered reports. The initial euphoria for airway stents in children has largely abated and most authors agree that they should only be employed in circumstances with no good alternatives. It is crucial that all surgical and medical alternatives are considered and the decision to place a stent is not made because other options are overlooked or not available locally. Stent use in a palliative setting has also been reported and is probably reasonable. Stents will only allow limited adaptation for the growth of pediatric airways by balloon dilatation. All metal stents should be considered as potentially permanent, and removal sometimes may only be possible through a surgical and sometimes risky approach.

Airway stabilization with silicone stents for treating adult tracheobronchomalacia: a prospective observational study

RATIONALE

It is postulated that in patients with severe tracheobronchomalacia (TBM), airway stabilization with stents may relieve symptoms.

OBJECTIVES

To evaluate the effect of silicone stents (tracheal, mainstem bronchus, or both) on symptoms, quality of life, lung function, and exercise capacity in these patients.

METHODS

A prospective observational study in which baseline measurements were compared to those obtained 10 to 14 days after stent placement.

MEASUREMENTS AND MAIN RESULTS

Of 75 referred patients, 58 had severe disease and underwent therapeutic rigid bronchoscopy with stent placement. Mean age was 69 years (range, 39 to 91 years), 34 were men, 33 had COPD, and 13 had asthma. Almost all patients (n = 57) had dyspnea as a sole symptom or in combination with cough and recurrent infections; four patients required mechanical ventilation for respiratory failure. In 45 of 58 patients, there was reported symptomatic improvement; quality of life scores improved in 19 of 27 patients (p = 0.002); dyspnea scores improved in 22 of 24 patients (p = 0.001); functional status scores improved in 18 of 26 patients (p = 0.002); and mean exercise capacity improved from baseline, although not significantly. The 49 complications included mainly 21 partial stent obstructions, 14 infections, and 10 stent migrations. Most patients with concomitant COPD also improved on most measures.

CONCLUSIONS

In the short term, airway stabilization with silicone stents in patients with severe TBM can improve respiratory symptoms, quality of life, and functional status. Coexisting COPD is not an absolute contraindication to a stenting trial in this population. Stenting is associated with a high number of short-term and long-term but generally reversible 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.

French experience of silicone tracheobronchial stenting in children

Silicone stents were inserted into the trachea or left main-stem bronchus in 14 children aged 2-69 months (median, 7 months). Indications were as follows: tracheomalacia or airway kinking (7 cases), vascular compression (5 cases), and surgically corrected congenital tracheal stenoses (2 cases). The best results were obtained in tracheomalacia. Overall, 6 cases out of 14 (43%) were considered successful, with a stent placement duration of 3-15 months (median, 7 months). Two cases were considered a technical success, although they were clinical failures. Five cases were considered failures primarily due to stent migration. A retrospective analysis of failures suggests that most of these could have been avoided by the use of larger stents. One patient died of stent obstruction. No wall erosion was observed, and the development of granulation tissue was infrequent. Endoscopic removal of the prostheses was uneventful. The biocompatibility of silicone stents appears to be better than what is reported for metal ones, although the stability of the former is less satisfactory. The present study shows the feasibility of silicone stent placement in infants. These stents should be considered as a possible therapeutic option in certain types of childhood airway disorders, although further studies are required.

Tracheobronchial intervention in children

Disorders of the major airways in children are often difficult to treat. Recent advances in interventional radiology are proving useful, for both assessment of the severity of the problem and treatment. Flexible bronchoscopy and bronchography are essential tools for diagnosis, intervention and follow-up. Echocardiography, computed tomography and magnetic resonance imaging may also be important for the evaluation of cardiovascular anomalies, which are often associated with airway obstruction. Surgery remains the first line of treatment for most congenital abnormalities of the airway and for cardiac anomalies that cause airway compression. Balloon dilatation and stenting are helpful in certain other conditions, as well as in children whose airway problem is not fully corrected by surgery. A multidisciplinary approach is required, with input from pediatric cardiothoracic surgeons, radiologists, radiographers, otolaryngologists, pulmonologists, anesthesiologists, intensivists, physiotherapists and liaison nurses.

Treatment of tracheal collapse with an intraluminal stent in a Miniature Horse

A 7-month-old miniature horse was referred for respiratory distress. Tracheal collapse at the level of the thoracic inlet was diagnosed. An intraluminal nitinol stent was placed with endoscopic guidance. Respiratory function was restored immediately after stent placement. The main complication observed during a 14-month follow-up period was growth of granulation tissue through the stent, which was controlled satisfactorily by electrocautery performed during endoscopy with the horse standing. Treatment of tracheal collapse with an intraluminal stent is an effective, practical, and minimally invasive procedure in miniature and young equids and ponies.

Management of synchronous subglottic stenosis and bronchial stenosis with a modified endotracheal tube

We present the case of a tracheostomy tube-dependent 6-month-old infant with synchronous airway lesions, including grade III subglottic stenosis and left main bronchomalacia with recurrence of granulation tissue and stenosis. Because the infant was at high risk for complications from the tracheostomy tube, decannulation was the desired outcome. The airway lesions were managed by single-stage laryngotracheal reconstruction and short-term stenting of the subglottis and left main bronchus. The greatest challenge was management of progressive stenosis caused by recurrence of granulation tissue in the left main bronchus. A novel modification of a soft silicone elastic endotracheal tube was devised to provide continued ventilation of both lungs while the corrected lesions healed. The role for this type of stent and the benefits and difficulties associated with its use are discussed.

Endoluminal stenting for tracheal stenosis

This prospective clinical study evaluates the role of endoluminal stents in the maintenance of a tracheal lumen after management of stenosis. Tracheal stenosis may be due to a variety of causes, and it is a significant health problem. Most patients either remain tracheostomized for prolonged periods of time or undergo several major surgical interventions. The most common sequel is restenosis at the site of repair either after augmentation or resection anastomosis. In this study, 16 patients with different pathologies causing tracheal stenosis or collapse are presented. All patients had the tracheal lumen re-established either endoscopically or by an open procedure. The stent was then placed to support the site of repair and prevent restenosis. A patent well-epithelialized lumen was achieved in 11 cases with a follow-up of 3-24 months. Complications were encountered in five cases: three misplaced stents, one tracheal erosion with a Dumon stent and one granulomatous obstruction. The technique, complications and follow-up of these patients are described with recommendations for the management of such patients.

Otorhinolaryngological problems occurring within the intensive care unit

OBJECTIVE

An overview of common otorhinolaryngological (ORL) problems and procedures in the intensive care unit (ICU) is presented.

FOCUS

Diagnostic, management, and treatment aspects of some conditions are discussed with emphasis on the potential difficulties encountered in the ICU. Approach recommendations are outlined as well as a list of required basic equipment.

CONCLUSIONS

Otorhinolaryngology should be included in intensive care continuing medical education programs.

Complications of Tracheobronchial Airway Stents

OBJECTIVE: Our goal was to identify and analyze airway stent complications and to devise approaches to manage stent complications.

STUDY DESIGN AND SETTING: We conducted a retrospective review of patients from a tertiary medical center.

METHODS: Twenty-eight airway stents were placed in 23 patients for benign (n = 15) and malignant (n = 13) tracheobronchial diseases. All patients were followed clinically for signs of complications.

RESULTS: Nine complications (8 in those with benign disease and 1 in a patient with malignant disease) were identified and included stent migration (n = 3), excessive granulation tissue (n = 2), stent fracture (n = 1), poor patient tolerance (n = 2), and inability to place (n = 1). Avoidance and management strategies for stent complications are introduced.

CONCLUSION: Tracheobronchial stents provide minimally invasive therapy for significant airway obstruction. Stent complications are more frequently encountered in the long-term treatment of benign conditions. Stents can be successfully removed endoscopically if complications arise, but the longer a metallic stent is in place, the more difficult it is to remove.

SIGNIFICANCE: As airway stent use increases, proper management will be required to avoid and manage complications. This is the first report to focus on stent complications and their management.