Coronary stents were first implanted in the late 1970s. The first ever stent was inserted in a human coronary artery in 1986 by Dr. Julio Palmaz. He invented the stent by shaping a wire mesh tube in order to hold open a blocked coronary artery.
The need for an innovation like the stent arose from the fact that coronary artery disease (CAD) is one of the leading causes of death worldwide, and one of the most common treatments for CAD is angioplasty, a procedure that uses a balloon catheter to open a blocked coronary artery. However, the problem with angioplasty alone is that the artery would often collapse or reclog after the procedure, which could lead to another heart attack or death. The stent was invented as a solution to this problem by holding the artery open and preventing restenosis (reclogging) after the angioplasty.
Over the last 40 years, the technology of coronary stents has evolved significantly. Early stents were made of metal alloy and were not coated with any medication. These stents had a high rate of restenosis, around 30%. To combat this, drug-eluting stents (DES) were invented. These stents have a coating that releases medication to prevent the formation of scar tissue inside the artery, thereby reducing the rate of restenosis. The first generation of DES had a drug coating called sirolimus, and later generations used other drugs like paclitaxel.
The advantages of coronary stents include: -Reduced risk of restenosis (reclogging) after angioplasty -Reduced need for repeat procedures -Reduced risk of death -Improved quality of life
The disadvantages of coronary stents include: -Risk of stent thrombosis (blood clot formation within the stent) -Risk of allergic reactions to the stent material or coating -Cost
In summary, the different types of material used in the manufacturing of coronary stents are: -bare metal stents (BMS) -drug-eluting stents (DES)
The history of stents can be summarized in a timeline as follows: -1986: The first coronary stent is implanted in a human coronary artery -1994: The first drug-eluting stent is implanted in a human coronary artery -2003: The FDA approves the use of drug-eluting stents in the United States