#122 The Stent Surgery (English)


The Stent Surgery

A stent is a petite mesh tube that is used to cure narrow or weak arteries. Arteries are blood vessels that carry blood away from the heart to other parts of your body.


316 L Stainless Steel Plasticity

A stent is located in an artery as a part of a procedure called percutaneous coronary intervention (PCI), also widely known as coronary angioplasty. The rudimentary concept of this operation is to provide the support of the inner wall of the artery. This restores the blood flow through narrow or blocked arteries. Overall, the stent increases the size of the lumen of the artery creating moderate blood flow and pressure. Moreover, stents help prevent the arteries from bursting.

 There are many kinds of stents as they have manifold uses. Usually, the stents are made out of 316 L type stainless steel, but for the endovascular aneurysm repair in larger arteries, fabric stents (stent grafts) are used.



Aortic Stenting (right) and Coronary Stenting (left)

In the use of stent grafts, there is a fundamental distinction between coronary and aortic stenting. In coronary artery, the stent averts arterial recoiling and the collapse of the weak inner walls. On the other hand, in aorta, the stent encourages the recoiling and the collapsing of the aortic walls over the stent. 

In addition, the drug-eluting stents gradually release the medicine that is coated on the stents into the artery. The medicine hinders the reocclusion of the lumen of the artery.

The Procedure of Coronary Stenting

In the operation of the heart stent, firstly, the catheter with stent covered balloon is placed in the target location in the artery. Secondly, the ballon inflates to expand the stent and compress plaque layers. Thirdly, the stent expansion widens artery to restore blood flow. The balloon is deflated a d catheter is removed. The stent is fixed in place permanently and gradually enlarges the size of the lumen of the artery.



The Affect of Clopidogrel on Platelet Production

Unfortunately, as the stents surgery requires adding foreign objects in the body like the stent, it possesses various side effects. In fact, the immune system starts to produce vast amount of platelet at the site of the stent. The intake of aspirin and drugs like Clopidogrel is to prevent such phenomenon. Furthermore, the drug-eluting stents were developed to inhibit the accumulation of arterial tissue and the immune response at the stent site. However, these drug releasing stents trigger blood clotting. This is taken care by the anti-blood clotting drugs like Plavix. Nevertheless, this causes additional side effects.

Reference

http://www.nhlbi.nih.gov/health/health-topics/topics/stents
https://en.m.wikipedia.org/wiki/Stent
http://drsvenkatesan.com/tag/stent-graft/
http://www.buzzle.com/articles/what-is-a-heart-stent-operation.html

KSJ