Stent complications became less common as medical technology improved. Newer stents coated with medication, called drug-eluting stents, reduced the rate of stent complications to about 10 percent of patients who need the procedure for blocked blood vessels. Older metal stents without medication showed a complication rate of about 20 percent, mostly due to arteries narrowing again after stents were implanted. A 2010 study examining cranial stent complications showed 14.7 percent of patients suffered strokes within a month of the procedure, while only 5.8 percent of stroke victims exposed to other treatment options died.
Patients with atherosclerosis, a condition that develops when fatty substances accumulate in blood vessels, might receive stents through angioplasty procedures. During angioplasty, a small balloon device is threaded into an artery and inflated at the site of a blockage. This widens it for a small, meshed tube, or stent, which is left inside to keep the artery open. When coated stents first appeared on the market, more complications occurred. As surgeons became more experienced in using the devices, the number of stent complications began to decline.
One adverse effect of the procedure involves blood clots forming near the stent. This increases the risk of stroke or heart attack, but blood-thinning medication might prevent formation of clots. Bleeding might also occur at the spot when a catheter enters the body, usually the groin, arm, or wrist, but hemorrhaging rarely occurs.
Patients with kidney problems might experience stent complications from the dye used to guide a surgeon to a blocked blood vessel. They may suffer an allergic reaction to the dye or experience organ damage if kidney disorders exist. Medication to address this side effect might lower the risk.
Stent complications might occur if an artery is perforated during the procedure. This could cause internal bleeding, leading to serious health problems. The rate of complications from artery damage declines as doctors gain experience in angioplasty.
When analyzing stent complications from intracranial stents, researchers found higher risks of bleeding in patients with stents implanted into middle cerebral arteries. Blood clots leading to stroke developed within 30 days of angioplasty in some patients. Stents represent one form of treating blocked arteries in the brain or in carotid arteries in the neck that supply blood to the brain.