Heart blockage is local blocking or narrowing in the arterial network of the body by accumulated deposits of plaque, which is mostly bad cholesterol. Every artery in the body is a blood pipeline. These pipelines get blocked with accumulation of bad cholesterol, assimilated through food. At such times, a heart surgery using stents is carried out by doctors to open up the clogged pipelines and make blood flow possible again.
What are Heart Stents?
Stents are thin wire metal meshes of stainless steel that offer structural rigidity to keep the arteries (heart pipelines) open when they are surgically placed in the right position. They prop open the arteries to facilitate blood flow. These stents are used in angioplasty and bypass surgeries of the heart, as part of interventional cardiology. Heart stent surgery is a technological wonder that has helped prolong the life of countless heart disease victims.
Fabric stents are also used when the surgery involves large arteries. Biodegradable stents made up of organic materials like poly-l-lactic acid are slowly making their way out of successful clinical trials. These stents are designed to dissolve into arterial walls over time, preventing the thrombogenic (blood clotting) effects triggered by metallic stents.
Heart Surgery Using Stents: The Procedure in a Nutshell
Let's try and understand how this advanced surgical procedure is carried out in detail. When a cardiologist suspects blockage in blood circulation network or narrowing of arteries, he carries out an angiography procedure. This procedure is an X-ray imaging technique which provides a clear image of all the arteries. By observing the angiogram, the doctor can exactly ascertain and locate the presence of any heart blockage or narrowing of arteries. Intravascular ultrasound (IVUS) may also be used to assess the size and exact position of the blockage.
The angiography procedure is carried out by first inserting a very narrow guidance line through the femoral artery in the thigh, from where it is progressively inserted to the desired location. By desired location, we mean the part of the network that has to be imaged. Consequently, a catheter is inserted along the guidance line to that point and an x-ray opaque dye is inserted. The dye spreads with the blood flow in that local region. Then a detailed x-ray image is created and blockage if any, is spotted and marked. The catheter is removed, but the guidance line stays in the location. Then the catheter is reinserted inside, with a balloon attached to its tip to predilate the blockage site and restore the normal size of the artery.
After predilation, the angioplasty procedure continues. A balloon catheter is inserted, with a customized collapsed stent wrapped over it. When the catheter reaches the position of arterial blockage, the balloon is inflated and the stent gets expanded and placed firmly, keeping the artery open at that point. During the procedure, the surgeon may be guided by IVUS, to place the stent in the exact position. This is the conclusion of the angioplasty procedure. Sometimes multiple stents need to be inserted due to multiple blockages. The entire procedure may last for an hour or more, depending on the complexity of arterial blockage. Patients are generally are generally kept under observation for a night or two, before being discharged.
What are the Risks Associated With Heart Stents?
There are two kinds of stents. One type is a bare stent which is made up of 316 L type stainless steel. Heart stents being foreign objects for the body, they have certain associated side effects. They trigger an immune response from the body causing platelet accumulation at the stent site. This is taken care of, by lifelong intake of aspirin and intake of drugs likeClopidogrel for 6 months after the procedure. Still the scarring left by the stents does cause problems and in time, there may be renarrowing of the arteries at the operated site.
To prevent this, drug-coated or drug-eluting stents were developed that prevent the accumulation of arterial tissue over the stent and suppress immune response against it. Heart stent surgery using these drug-eluting stents is preferred now. However, this type has been known to cause blood clots in some case studies. About 1% to 2% people undergoing a drug-eluted stent surgery suffer from the growth of blood clots at the stent site. Hence the patient has to use blood thinning, anti-blood clotting drugs like Plavix for a prolonged period of time, which causes additional side effects. These effects include gastrointestinal bleeding and strokes in some cases. So stents are lifesavers but they also come with their share of risks.
The technology of stents is used sparingly and only in extreme situations where no other alternative is available. Heart blockage and stents are thus inextricably connected. As mentioned before, biodegradable stents have been introduced recently, that may prevent the clotting effects of metallic stents, but they are still in developmental stages.
Despite angioplasty and insertion of stents, statistics reveal a 10% to 20% chance the artery narrowing again (termed as restenosis), leading to a relapse of heart problems. There is the alternative of bypass surgery that could be opted for. However, it is preferred in cases of extreme narrowing of arteries or multiple blockages. Angioplasty with stent insertion remains the most preferred heart surgery option.
How Long Does a Heart Stent Last?
There is no fixed life of a stent. A lot depends on how your body responds to its presence, your medical dosage, diet, medical history and your lifestyle. They have been known to last for up to 15 years after which one may require a heart stent replacement. Stents for heart operation come with their share of risks. So, post surgery, regular monitoring of heart condition by a physician is advisable.
Though there are associated risks, stent technology has helped millions reclaim their lives. Care for your heart through regular exercise and a healthy diet. That may go a long way in preventing such extreme measures like heart surgeries to be required in the first place. However, the incidence of heart ailment is even found in regularly exercising men and women. The best we can do is keep our body in shape and eat right.
Disclaimer: This article is meant for reference purposes only. It is not intended to supplant the advice of a certified medical practitioner.