Renal artery stenosis is a disease where one or both of the arteries that lead to the kidneys is narrowed. Because blood carries nutrients to the kidneys, the narrowing forces the kidneys to work harder. If renal artery stenosis isn’t treated, it will most likely get progressively worse, which can result in hypertension and renal damage.
Most renal artery stenosis is caused by a build up of plaque in the blood vessel. This plaque is made up of the same type of material that blocks arteries to the heart, lungs or other organs. These materials include cholesterol and fats. The overall term for the condition is atherosclerosis. Indeed, people who have problems with the blockages in their arteries to other parts of the body typically have the same problem with the arteries to their kidneys.
RAS is dangerous because the kidneys help regulate blood pressure, and it’s hard for them to do this if they can’t work properly. Interestingly, when the arteries narrow the kidneys believe that the person’s blood pressure is too low. So, they stimulate the body to retain water and salt.
Like other forms of atherosclerosis, renal artery stenosis often has no symptoms. However, the person with the condition often has uncontrollably high blood pressure. They also seem to develop high blood pressure at a younger than usual age.
People who smoke, have diabetes, have high levels of LDL or “bad” cholesterol or abuse alcohol or drugs are at higher risk for renal artery stenosis. It’s also a risk of advancing age.
Sometimes RAS is genetic. Some women under 50 have a condition called fibromuscular dysplasia. This makes cells grow abnormally in the walls of the renal arteries and also narrows them or blocks them off.
Treating Renal Artery Stenosis
People who discover they have renal artery stenosis might take medication to help lower their blood pressure and reduce their cholesterol levels. Other people have angioplasty of the same type that’s used with a blocked artery to the heart. During surgery, a tiny balloon is inserted into the artery to the kidney. The balloon is then blown up to hold the vessel open. Sometimes a stent, a tiny, metal, tube-like cage, is inserted as well. Some people who have angioplasty will be able to stop taking their blood pressure or cholesterol medicine, but most people will have to keep taking their medication.