Airway Stents

Indications for airway stenting

Approximately 30% of patients with lung cancer present with central airway obstruction, of whom 35% will die as a result of asphyxia, hemoptysis, and postobstructive pneumonia.¹¹ Airway stenting is a valuable adjunct to the other therapeutic bronchoscopic techniques, which not only results in rapid relief of symptoms and improved quality of life but also gives time for adjuvant chemoradiotherapy that might lead to prolonged survival.1, 11, 12, 13, 14 Chhajed and coworkers¹⁵ have demonstrated no

Types of stents

A variety of stents are available for application in the tracheobronchial tree, and the biomechanical properties depend on the materials used and how they are constructed (Box 3, Table 1). Stents are grouped into (1) tube stents which include Montgomery T-tube (Boston Medical Products, Boston, MA, USA), Dumon (Novatech, France), Polyflex (Boston Scientific, Natick, MA, USA), Noppen (Reynders Medical Supplies, Lennik, Belgium), and Hood (Hood Laboratories, Pembroke, MA, USA); (2) metal covered

Metallic stents

Metallic stents are gaining popularity because of their ease of insertion. They can be placed at an outpatient setting via flexible bronchoscopy and under local anesthesia.21, 22 They are categorized into 2 by the method of deployment: balloon expandable and self-expanding. A balloon-expandable stent consists of a stent balloon assembly and relies on the balloon to dilate it to its correct diameter at the target site. A self-expanding stent has a shape memory that enables it to assume its

Choice of stent

Besides the site, shape, and length of stenosis, presence or absence of malacia or fistula determine the choice of stent; the underlying cause of airway pathology is also an important consideration. Proper sizing of the stent (length and diameter) in relation to the dimensions of the trachea or bronchus is also important to avoid stent-related complications, such as migration, mucous plugging, granulation, and tumor ingrowth.

Tube stent placement requires specialized equipment, training, and

Stent insertion techniques

Before stent insertion, dilatation of the stricture to its optimal diameter should be attempted using a rigid bronchoscope, bougie, or balloon. Tumor tissue should be removed with either laser or electrocautery. The largest possible prosthesis should be selected, and even if it does not completely unfold, it can be opened with a balloon or forceps.

Special catheters and deployment systems have been developed for metal stents. The Palmaz and Strecker stents are mounted on balloon catheters. These

A novel treatment of tracheal malignancy with aortic allograft

Primary tracheal tumors can arise from the respiratory epithelium, salivary glands, and mesenchymal structure of the trachea. Primary tracheal tumors account for up to 0.4% of malignant diseases, with 2.6 new cases per million people every year.35, 36 In adults, 90% are malignant with squamous cell carcinoma, and adenoid cystic carcinoma accounts for two-thirds of these tumors.³⁶ The adult trachea measures 12 cm in length and is 1.5 to 2.5 cm wide. Depending on an individual's anatomic and

Summary

Airway stenting is a valuable adjunct to other therapeutic bronchoscopic techniques used for relieving central airway obstruction. Notwithstanding that various stents are available, each has its complications, and the search for the ideal stent continues. Moreover, clinical studies are required to identify patients who will derive the greatest benefit from stenting. Creation of biocompatible stents that can be customized and airway replacement using aortic allograft may offer promise in the