Intricate medical devices are required for interventional procedures performed today on the coronary arteries. The most common interventions involve angioplasty with or without subsequent stents and/or surgical coronary artery bypass grafting.
Angioplasty and Stents
Percutaneous transluminal coronary angioplasty is a procedure during which a balloon catheter is introduced into the narrowed portion of the coronary artery lumen and inflated to reopen the artery to allow the return of normal blood flow: some of the newer stents may also be used for the target delivery of drugs. Currently during such procedures, often a coronary stent is also placed such that restenosis of the artery is significantly delayed. A stent is a medical device made up of wire mesh that provides scaffolding to support the wall of the artery and keep its lumen open and free from the buildup of plaque. Balloon angioplasty and coronary stents have prevented numerous patients from having to undergo coronary artery bypass graft surgery, which can be more costly and painful. Additionally, such stents have been produced with a variety of drug coatings in further attempts to minimize or eliminate the possibility of restenosis: i.e., drug eluting stents.
Aides in Stent Delivery
While these drug eluting stents have been considered as a great advancement over the clinical use of angioplasty , it is generally considered that success rates could be even further improved via applying additional new techniques. For example, the STAR - Subintimal Tracking and Reentry - technique utilizes a small wire to dissect into the obstruction . Further, it has been proposed that radiofrequency signals can warn the user when the wire tip is too close to the vessel wall to prevent perforation and can be pulsed to facilitate passage through a coronary artery obstruction . Another approach employs pulses that face of the obstruction so to create a path into the obstruction . Finally, proteolytic enzymes can be applied so to digest parts of the obstruction and thus aid in the eventual mechanical passage of a guidewire .