Interventional management of tracheobronchial strictures

Central airway squamous metaplasia following radiation therapy mimicking local tumour recurrence

Radiation therapy can result in injury to the lung parenchyma and central airways; the latter is less well documented in the literature. Here, we describe a 65-year-old Caucasian male, who developed focal endobronchial nodules and right main bronchial stenosis suggesting tumour recurrence, 32 months following curative intent concurrent chemoradiation therapy for Stage 3B squamous cell carcinoma of the lung. Computed tomography and positron emission tomography results are detailed. Flexible bronchoscopy with bronchial biopsies revealed squamous metaplasia rather than malignant tumour recurrence, with ongoing observation planned.

Clinical outcomes of self-expandable metallic stents for malignant obstructive atelectasis

Self-expandable metallic stents (SEMSs) have been widely used in the treatment of malignant central airway obstruction. However, few reports focus on the treatment of atelectasis and how to estimate the prior probability of success via SEMSs placement, This current study aimed to study the safety and effectiveness of SEMSs for the treatment of obstructive atelectasis, and the value of preoperative CT enhancement for ventilation of atelectasis via SEMSs placement. A total of 35 patients with obstructive atelectasis (29 male and 6 female) was included from February 2012 to March 2018. The procedures were performed under fluoroscopic guidance, and bronchoscopic laser resection was performed for severe restenosis cases after SEMSs placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. Thirty-eight SEMSs were successfully implanted in 34 patients, included 29 Y type tracheal stents, 4 small y stents, and 5 straight airway stents. After stenting, 26 cases showed full ventilation, and 3 cases were partially ventilated. The technical success and clinical success was 97.1% and 82.9%, respectively. A higher maximum enhancement CT value was found in patients with full ventilation. Mean follow-up time was 18.8 ± 4.0 months. Eight cases showed restenosis and received endoscopic laser resection, included 1 case underwent removal and 3 cases received second stenting. There were 2 cases of perioperative non-operative death, and 11 cases of post-discharge death (2 cardiac deaths and 9 malignant tumors). The survival rates of 3 months, 1 year and 2 years were 78.6%, 58.5% and 58.5%, respectively. In conclusion, SEMSs placement is safe and effective for obstructive atelectasis, and the preoperative CT enhancement played an important role in estimating the prior probability of success in the treatment of atelectasis via SEMSs placement.

A canine model of tracheal stenosis induced by cuffed endotracheal intubation

Postintubation tracheal stenosis is a complication of endotracheal intubation. The pathological mechanism and risk factors for endotracheal intubation-induced tracheal stenosis remain not fully understood. We aimed to establish an animal model and to investigate risk factors for postintubation tracheal stenosis. Beagles were intubated with 4 sized tubes (internal diameter 6.5 to 8.0 mm) and cuff pressures of 100 to 200 mmHg for 24 hr. The status of tracheal wall was evaluated by bronchoscopic and histological examinations. The model was successfully established by cuffed endotracheal intubation using an 8.0 mm tube and an intra-cuff pressure of 200 mmHg for 24 hr. When the intra-cuff pressures were kept constant, a larger sized tube would induce a larger tracheal wall pressure and more severe injury to the tracheal wall. The degree of tracheal stenosis ranged from 78% to 91% at 2 weeks postextubation. Histological examination demonstrated submucosal infiltration of inflammatory cells, hyperplasia of granulation tissue and collapse of tracheal cartilage. In summary, a novel animal model of tracheal stenosis was established by cuffed endotracheal intubation, whose histopathological feathers are similar to those of clinical cases of postintubation tracheal stenosis. Excessive cuff pressure and over-sized tube are the risk factors for postintubation tracheal stenosis.

Inhibitory Effect of β-Elemene on Human Airway Granulation Tissue in vivo and in vitro

BACKGROUND

Recurrent airway granulation hyperplasia and scar formation make airway stenosis a clinical challenge. Therefore, a new approach for the treatment of airway stenosis is necessary.

OBJECTIVE

To explore the inhibitory effect of β-elemene on the proliferation of fibroblasts and airway granulation.

METHODS

In vivo: (1) study of the effect of local β-elemene injection by bronchoscopy. (2) During bronchoscopy, granulation tissues both before and after treatment were obtained. HE staining was performed and the result compared. In vitro: (1) human airway primary fibroblasts were purified and characterized. (2) Fibroblasts were treated with β-elemene and normal saline (NS) and then examined by optical and electron microscopy. (3) Fibroblasts treated with β-elemene or NS were assessed for viability by tetrazolium salt assay. (4) Apoptotic rates were determined by flow cytometry.

RESULTS

In vivo: (1) after local injection of β- elemene, airway granulation tissue was reduced. (2) Granulation tissue was found to have less edema, and fibroblasts turned into mature fiber cells. In vitro: (1) human airway primary fibroblasts were successfully purified and cultured. (2) Compared with the control group, fibroblasts of the experimental group became clumped, the plasma granules were increased, and some fibroblasts lost their nucleus and organelles. (3) Compared with the control group, reduction of cell viability was detected with increased concentrations of β-elemene. (4) With increased concentrations of β-elemene, apoptotic rates of the fibroblasts were raised compared with the control group.

CONCLUSIONS

β-Elemene may induce apoptosis and necrosis of airway primary fibroblasts and inhibit the proliferation of fibroblasts and airway granulation. The results provide a new approach for the treatment of airway stenosis.

Covered airway stent placement for malignant tracheobronchial strictures in patients with an endotracheal tube

AIM

To evaluate the technical feasibility and safety of covered airway stent placement for malignant tracheobronchial strictures in patients with an endotracheal tube.

MATERIALS AND METHODS

Data regarding retrievable, expandable, metal stent placement under fluoroscopic guidance in 20 patients with an endotracheal tube inserted for malignant tracheobronchial strictures were retrospectively analysed. The clinical effectiveness was assessed using the following variables: technical and clinical success; procedure and stent-related complications; and duration of intubation following stent placement.

RESULTS

Stent placement was technically successful in all 20 patients (100%), and with 19 of the 20 patients (95%) showing symptomatic improvement within 5 days. The endotracheal tube could be removed during (n=7) or after (n=12) stent placement, and the mean duration of intubation following stent placement was 1.4 days (range 0-3 days). One patient could not have his endotracheal tube removed and he died 9 days following stent placement in an intubated state. There were no procedure-related complications. Stent-related complications in three patients included partial (n=2) and complete (n=1) stent migration, all of which were managed with placement of a second stent (n=2) or stent removal and placement of a second stent (n=1).

CONCLUSION

Covered airway stent placement under fluoroscopic guidance in patients with an endotracheal tube inserted for malignant tracheobronchial strictures, is both technically feasible and safe.

Tracheal Self-Expandable Metallic Stents: A Comparative Study of Three Different Stents in a Rabbit Model

INTRODUCTION

The objective of this study was to assess tracheal reactivity after the deployment of different self-expandable metal stents (SEMS).

MATERIAL AND METHODS

Forty female New Zealand rabbits were divided into four groups. Three groups received three different SEMS: steel (ST), nitinol (NiTi), or nitinol drug-eluting stent (DES); the fourth group was the control group (no stent). Stents were deployed percutaneously under fluoroscopic guidance. Animals were assessed by multi-slice, computed tomography (CT) scans, and tracheas were collected for anatomical pathology (AP) study. Data from CT and AP were statistically analyzed and correlated.

RESULTS

The DES group had the longest stenosis (20.51±14.08mm vs. 5.84±12.43 and 6.57±6.54mm in NiTi and ST, respectively, day 30; P<.05), and higher granuloma formation on CT (50% of cases). The NiTi group showed the lowest grade of stenosis (2.86±6.91% vs. 11.28±13.98 and 15.54±25.95% in DES and ST, respectively; P<.05). The AP study revealed that the ST group developed intense proliferative reactivity compared to the other groups. In the DES group, a destructive response was observed in 70% of the animals, while the NiTi was the least reactive stent. CT was more effective in detecting wall thickening (positive correlation of 68.9%; P<.001) than granuloma (not significant).

CONCLUSIONS

The ST group developed granulomas and significant stenosis. NiTi was the least reactive stent, while DES caused significant lesions that may be related to drug dosage. This type of DES stent is therefore not recommended for the treatment of tracheobronchial stenosis.

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.

Safety of outpatient airway dilation for adult laryngotracheal stenosis

OBJECTIVES

To evaluate the safety of outpatient airway dilation for adult patients with subglottic or tracheal stenosis.

METHODS

The records of patients treated with airway dilation between October 2003 and September 2013 were reviewed. Outcomes of patients who underwent dilation as inpatients versus outpatients were compared. Emergency room visits, readmissions, and 3 or more primary care physician visits within 30 days postoperatively were specifically evaluated. Postoperative hemorrhage, airway edema, recurrent laryngeal nerve paralysis, reintubation, tracheostomy, tracheal rupture, pneumomediastinum, pneumothorax, acute respiratory distress, or death were also reviewed.

RESULTS

One hundred fourteen dilations performed in 53 patients with airway stenosis were included. Outpatient dilation was performed in 93 (82%); 21 (18%) underwent the procedure in the inpatient setting. Complications were low among both inpatient and outpatient groups (10% vs 1%, P=.09). No complications occurred during the overnight stay of the inpatient group.

CONCLUSIONS

Outpatient airway dilation is a safe and feasible procedure. It can be routinely performed on an ambulatory basis.

Preliminary application of hybrid operation in the treatment of carotid artery stenosis in patients with complex ischemic cerebrovascular diseases

Along with the recent development of intraluminal interventional techniques and correlated imaging methods, one-stop hybrid operation has become a new focus in clinical settings. The aim of this study is to discuss the clinical significance of the one-stop hybrid endarterectomy surgery in the treatment of complex ischemic cerebrovascular diseases. In this study, clinical data from 10 patients with complex ischemic cerebrovascular diseases (including multi-vessel severe stenosis of the internal extracranial carotid artery, single vessel series stenosis of the internal extracranial carotid artery, in-stent restenosis, complete occlusion of the common carotid or the internal carotid artery) admitted to Beijing Xuanwu Hospital and Liaocheng Brain Hospital, were retrospectively analyzed. All enrolled subjects underwent three types of hybrid operations. The clinical efficacy of this surgery was subsequently assessed in this clinical trial. The results indicated that no related surgical complications were noted during the perioperative period. Intraoperative and postoperative imaging revealed no signs of vascular stenosis, the blood supply recovered, and clinical symptoms were alleviated. The follow-up lasted for 6 to 12 months. Imaging re-examination showed no evidence of re-stenosis and good blood circulation was present in the recanalized blood vessels. Favorable treatment efficacy was achieved. The intracranial blood supply was significantly improved postoperatively. In conclusion, one-stop hybrid operation plays an important role in treating complex stenosis cerebrovascular diseases.