Arterial stent procedures are performed using angioplasty. This is a minimally invasive procedure used to improve blood flow in the arteries and veins. During the procedure, imaging techniques are used to guide a catheter into the blocked artery or vein. The balloon is inflated to open the vessel, during which a small tube called a stent may be inserted.
Bare Stents
According to MayoClinic.com, bare metal stents are wire mesh tubes that contain no special coating and act simply as scaffolding to prop open blood vessels. The stent is placed after the vessel has been widened with an angioplasty balloon. The artery heals around the stent, holding it in position. Tissue grows around the stent during the healing process. Sometimes an overgrowth of tissue in the arterial lining will increase the risk that the artery will become blocked again.
Covered Stents
Drug-eluting stents, according to MayoClinic.com, are metal tubes that are coated with medication which is gradually released into the body to help prevent the overgrowth of scar tissue in the arterial lining. The medication helps the artery to remain open and smooth, ensuring good blood flow. These stents were developed to reduce the potential for scar tissue which leads to re-blockage in individuals who receive a bare metal stent.
Renal Vascular Hypertension
Renal vascular disease is one of the most common causes of hypertension that can be cured, but accounts for less than 2 percent of all cases, according to the Merck Manuals Online Medical Library. It is caused by a blockage in one or both of the main arteries, or any of their branches. This blockage affects the oxygen and nutrient transport to the kidney, and is likely to cause hypertension. Initial identification is often done with ultrasounds, magnetic resonance angiography or radionuclide imaging. Treatment is performed using angioplasty and potential stent placement.
Coronary Artery Disease
Coronary artery disease treatment commonly involves performing an arterial stent procedure in order to restore blood supply to the heart muscle when a blockage is found. According to a study published in 2007 in the "New England Journal of Medicine," drug-eluting stents were associated with an increased death rate compared to bare metal stents. Researchers evaluated 6,033 patients who were treated with drug-eluting stents and 13,738 treated with bare metal stents. The trend appeared after 6 months, when the risk of death climbed 0.5 percentage points higher.
Carotid Artery Disease
A carotid artery is found on both sides of the neck, and brings blood from the heart into the brain and face. This blood flow can become partially or totally blocked, reducing the blood supply to the brain and leading to a stroke, according to MedlinePlus. Two procedures are commonly used to treat this condition: endarterectomy and angioplasty with stent placement. During stent placement, a catheter is inserted through the groin and fed through the artery into the neck where the blockage is located. Using live X-ray, the surgeon passes a wire in a very small balloon to the area of the blockage. Once there, the balloon is inflated, pressing up against the wall of the artery and restoring proper blood flow to the brain. At this time a stent may also be placed which expands as the balloon is blown up.
References
- Mayo Clinic: Drug-Eluting Stents: Do they Increase Heart Attack Risk?
- Merck Manuals Online Medical Library: Renovascular Hypertension
- "New England Journal of Medicine"; Long-term Oucomes with Drug-Eluting Stents versus Bare Metal Stents in Sweden; Bo Lagerqvist, M.D., Ph.D.; February 2007
- MedlinePlus: Angioplasty and Stent Placement - Carotid Artery
