Recent advances in plastic stents: a comprehensive review

Cardiovascular diseases (CVD) are globally the number one cause of death reported by the World Health Organization. A relevant CVD is coronary artery disease (CAD) in which a layer of plaque is formed on the interior of the coronary arteries which limits the flow of oxygen-rich blood through the body and specifically to the heart. A well-known but invasive surgical technique to manage CAD is bypass surgery. A minimally invasive technique is the implantation of stents. Nowadays, the aim is to use biodegradable plastics as a stent material instead of metals. These plastic stents are to disappear after the blood vessel has healed. The biggest challenge is to match the mechanical requirements while still being deliverable and suitable to be inside human blood vessels for the total healing period. This challenge has encouraged a lot of scientists and engineers to find processing methods of the polymers to improve radial strength, while the polymer can still elongate, deform, and stretch under tensile stress during deployment without breaking the material. This review presents the current developments in plastic stent technology. It will finalize the current shortcomings and potential research areas. These areas include material and design objectives as well as on-demand manufacturing methods and long-term vessel and stent monitoring.