Self-expandable Airway Stents Research Articles

A Novel Self-Expandable, Radioactive Airway Stent Loaded with 125I Seeds: A Feasibility and Safety Study in Healthy Beagle Dog.

Airway stent placement is an effective treatment for the immediate palliation of malignant airway obstruction. However, restenosis caused by tumor ingrowth and/or overgrowth after stenting is common. The purpose of this study was to investigate the feasibility and safety of a novel self-expandable stent loaded with 125I seeds in healthy beagle dog. Under fluoroscopic guidance, forty-eight self-expandable airway stents loaded with 125I seeds were perorally placed in the main trachea of 48 healthy beagle dogs, who were randomly divided into four groups (Group A: 0.3mCi; Group B: 0.6mCi; Group C: 0.9mCi; Control group: 0mCi). The estimated radiation dose was calculated using the isotropic point source approximation. Radiological follow-up examinations and histopathological examinations of stented tracheal segments and their adjacent organs and tissues were performed at 2, 4, 8, and 16weeks following the stenting. All stents were successfully deployed in the targeted tracheal segment in the beagle dogs without procedure-related complications. Tracheal stenosis became severe gradually in all the four groups, which was not associated with the radioactivity of 125I seeds (p>0.05). The tracheal injury scores increased along with the higher dose of radioactive seeds which reached peak at 8weeks and then turned back slightly at 16weeks. The adjacent tissue did not show pathohistological changes under microscope, while mild and reversible ultrastructure changes were showed under electronic microscope. This study demonstrates that it is feasible and safe to insert this novel self-expandable airway stent loaded with 125I seeds in healthy beagle dog.

Mediastinal Migration of Self-Expanding Bronchial Stents in the Management of Malignant Bronchoesophageal Fistula

Airway stents are commonly used to palliate malignant central airway obstruction and tracheo-/bronchoesophageal fistulas. Despite their efficacy in immediately relieving airway obstruction, they can be associated with a variety of complications. We report the case of a 44-year-old woman with a malignant bronchoesophageal fistula treated initially with a self-expanding silicone mesh stent in the left main bronchus followed 2 weeks later by an esophageal stent. Shortly afterward, she presented with chest pain, worsening cough, and breathlessness. A CT scan of the chest revealed the airway stent in the contralateral mediastinum perforating the right main bronchus. We discuss her subsequent management and complications associated with self-expanding airway stents in this setting.

EFFECTIVE TAMPONADE OF MASSIVE HEMOPTYSIS FROM A CAVITARY LUNG CANCER VIA EMERGENT ENDOBRONCHIAL DEPLOYMENT OF COVERED, SELF-EXPANDING STENTS

INTRODUCTION:Massive hemorrhage from a lung tumor may lead to exsanguination and asphyxiation. Management often includes localization of the bleeding with subsequent vascular embolization. To protect the contralateral lung, patients may be selectively intubated or ventilated with a double lumen endotracheal tube, but these measures offer only temporary relief. We present a case in which emergent deployment of self-expanding airway stents produced a successful tamponade of massive hemorrhage from a lung tumor, allowing time for follow-up palliative therapy.

Long-term safety and tolerance of silicone and self-expandable airway stents: an experimental study

Background. A variety of respiratory stents are currently available, but the ideal airway prosthesis seems far from being recognized. The objective of this study was to verify safety and long-term effect on the bronchial wall of three different types of airway stents.Methods. Twelve healthy adult sheep were divided in three groups, scheduled to receive: (1) bare self-expandable metallic stents (Gianturco); (2) silicone stents (Dumon); and (3) covered self-expandable synthetic stents (Polyflex). Insertions were performed through a rigid bronchoscope under general anesthesia. Chest roentgenogram was performed 1 and 6 months after surgery, and flexible bronchoscopy after 6 months. Twelve months postoperatively, the animals were killed and a postmortem examination was carried out.Results. All Polyflex stents migrated during the observation period; one late migration was observed in the Dumon group. Microscopic study showed: (1) Gianturco stents: full-thickness perforation of the bronchial wall covered by a thick layer of a chronic inflammatory infiltrate. Infection by Candida at the bottom of some ulcerations; (2) Dumon stents: mild bronchial inflammation (squamous metaplasia, submucosal inflammatory infiltrates; granuloma-like infiltrates). In case of displacement, no significant changes of the previously stented bronchus occurred; and (3) Polyflex stents: no changes of the previously stented bronchi.Conclusions. Gianturco stents proved unsafe in the long term, owing to the risk of severe airway wall damage. The Polyflex stent is well tolerated but presents a high migration rate. Silicone stents show several limitations but appear to be well tolerated by the host mucosa.