Possible side effects of having stents placed in blood vessels include infection, allergic reaction to the marker dye, kidney damage, irregular heartbeat, damage to the blood vessel from the insertion catheter and bleeding from the catheterization site, notes the National Heart, Lung, and Blood Institute. These problems are relatively rare and do not occur to everyone.
The process of inserting a stent is called percutaneous coronary intervention, or PCI, according to the National Heart, Lung, and Blood Institute. In addition to the problems listed above, PCI also sometimes causes excess tissue growth inside the treated area of the artery. This leads the artery to develop another blockage, or at least significant narrowing, in a condition called restenosis.
Drug-eluting stents are a solution that prevents the development of excess tissue, explains the National Heart, Lung, and Blood Institute. These stents have a medicine coating that keeps the tissue from growing. Applying radiation treatment to the tissue surrounding the stent is another way to prevent tissue growth. After threading a wire to the stent through a catheter, the doctor uses the wire to send radiation into the tissue and stop cellular growth around the stent. Another stent risk includes the formation of a clot at the stenting site in about 1 to 2 percent of patients. Clots potentially cause stroke, heart attack or other severe conditions. The risk is highest during the first several months after placement of the stent.