Stents are expandable tubes that are used to treat patients with damaged or narrowed arteries. Since the 1970s, the optimum management of coronary heart disease has been a major focal point of research and development.
This condition is caused by plaque building up in the coronary arteries, which narrows and weakens these vessels. Usually made of metal mesh, coronary stents are often placed inside a narrowed artery in a procedure referred to as percutaneous coronary intervention (PCI) or angioplasty. Implantation of a stent helps ensure the vessel is kept open, improves blood flow to the heart muscles and decreases the likelihood of another blockage occurring.
Unlike other procedures such as coronary artery bypass surgery (CABS), PCI and stenting is considered minimally invasive because it does not require any major incisions. The patient is mildly sedated and given local anesthetic and the process usually takes around one hour, although it can take longer if several steps are required. Patients who have a stent implanted experience less pain and recover more quickly than patients who undergo CABG.
Originally stents were made of bare metal and although these devices prevented the artery from collapsing, they only modestly decreased the risk of the artery re-narrowing (restonosis) and around 25% of people treated with a bare metal stent for coronary artery disease, experienced restonosis within just six months. Researchers therefore started developing stents that were coated with agents that would prevent restenosis. These drug-eluting stents (DES) eventually became approved by the FDA and clinical trials have shown they significantly reduce the rate of restenosis. However the DES is not completely risk-free, as blood can form a clot inside the stent many years after it has been implanted. Referred to as “in-stent thrombosis”, this condition can be fatal and it is essential that patients who have a stent implanted during PCI take anti-clotting agents such as Effient, Plavix or Ticlid after the procedure.
Alternatives to PCI and DES
This procedure is similar to angioplasty, but the catheter has a laser tip that is used to open up the artery. Pulses of light beams then vaporize the build up of plaque.
This is also similar to angioplasty, but the catheter includes a shaver at its tip which rotates to cut away plaque.
Coronary artery bypass graft (CABG)
This is the most commonly performed but most invasive procedure for treating patients with an obstructed coronary artery. The procedure involves by-passing the blocked part of the artery by attaching a segment of blood vessel (graft) taken from another part of the body to the coronary artery, either side of the blocked or narrowed area. This can permanently restore the blood flow by redirecting the blood around the blockage and through the newly placed graft.
CABG is open heart surgery and involves making a large incision in the middle or side of the chest to open it up and expose the heart. The procedure can take up to six hours and patients need to stay in hospital for at least three days. Patient recovery time is around 4 to 6 weeks and most people can return to work within one or two months of the surgery.
This is an experimental procedure that involves skeletal muscles being taken from the abdomen or back and wrapped around the heart to provide extra muscle that is stimulated by a device to boost the organ’s pumping motion.
Here, the diseased and irreversibly damaged heart is removed and replaced with a donated healthy heart.
Port- Access Coronary Artery Bypass
This is an alternative to CABG where only small incisions or “ports” are made in the chest, through which instruments are passed to perform the bypass. The heart is stopped during the procedure and an oxygenator or “heart-lung” machine is used to pump blood. Arteries from the chest or veins from the leg are used to bypass the obstructed artery. The procedure is viewed using a monitor rather than directly, as in open heart procedures.