Xu J, Ong HX, Traini D, Byrom M, Williamson J, Young PM
Drug Dev Ind Pharm 2019 Jan;45(1):1-10
Airway stents are commonly used in the management of patients suffering from central airway obstruction (CAO). CAO may occur directly from airway strictures, obstructing airway cancers, airway fistulas or tracheobronchomalacia, resulting from the weakening and dynamic collapse of the airway wall. Current airway stents are constructed from biocompatible medical-grade silicone or from a nickel-titanium (nitinol) alloy with fixed geometry. The stents are inserted via the mouth during a bronchoscopic procedure. Existing stents have many shortcomings including the development of obstructing granulation tissue in the weeks and months following placement, mucous build up within the stent, and cough. Furthermore, airway stents are expensive and, if improperly sized for a given airway, may be easily dislodged (stent migration). Currently, in Australia, it is estimated that approximately 12,000 patients will develop CAO annually, many of whom will require airway stenting intervention. Of all stenting procedures, the rate of failure is currently reported to be at 22%. With a growing incidence of lung cancer prevalence globally, the need for updating airway stent technology is now greater than ever and personalizing stents using 3D-printing technology may offer the best chance of addressing many of the current limitations in stent design. This review article will assess what represents the gold standard in stent manufacture with regards to treatment of tracheobronchial CAO, the challenges of current airway stents, and outlines the necessity and challenges of incorporating 3D-printing technology into personalizing airway stents today.