Definition Renovascular hypertension is high blood pressure caused by the hardening and thickening of the arteries that supply blood to the kidney.
What is going on in the body? Arteries are tubes called blood vessels through which blood flows. Healthy arteries are smooth so that blood can flow through them easily. Over time, arteries become rough and fatty substances called plaque start to build up. This narrows the arteries, and blocks the normal flow of blood to the kidneys. The kidneys respond by releasing substances to increase the flow of blood. The kidneys also begin to retain salt and water. This will continue until normal blood flow resumes.
What are the signs and symptoms of the disease? Symptoms include:
very high blood pressure
headaches
mental status changes
high blood pressure that is hard to control, even with many types of drugs
high blood pressure that begins suddenly
high blood pressure that becomes low when taking an ACE inhibitor, or AII receptor blockers which are types of blood pressure medication
What are the causes and risks of the disease? These people have a greater risk of developing renovascular hypertension:
anyone with peripheral vascular disease, which is a condition that affects blood vessels, usually in the legs
smokers
anyone with diabetes, a disease in which the body cannot make insulin, so sugar builds up in the blood and
urine
How is the disease diagnosed? Diagnosis is made by looking at health records, and doing a physical examination and laboratory tests. Most people with this disease have very high blood pressure despite taking many drugs to control it. If they begin taking ACE inhibitors or AII receptor blockers, they often develop low blood pressure or kidney failure.
These tests are usually done:
ACE inhibitor-stimulated renography, which is an X-ray of the kidney and its blood system, taken after the patient is given an ACE-inhibitor such as captopril
duplex ultrasound
magnetic resonance arteriography (MRA) (special three-dimensional imaging using magnets). During this test, a group of pictures are taken of the arteries around the kidney. This information allows physicians to see the flow of blood to the kidneys and determine the location and amount of blood vessel blockage.
spiral CT renal angiogram which is a test like MRA except normal X-rays are used
renal arteriogram (x-ray test in which dye is injected into the artery to make sure it is not blocked or narrowed). This test is used if a doctor thinks a person has this disease, but the MRA wasn't clear, or if a doctor needs a clearer picture of the blocked arteries.
What are the treatments for the disease? Treatments include:
high blood pressure medication
angioplasty, which is a non-surgical procedure to unclog a blocked artery
stenting, a procedure that places a mesh tube into an artery to make it wider and hold it open for better blood flow
surgery
What happens after treatment for the disease? It is most important to bring the blood pressure down to a normal level and to control any kidney disease. Blockage in the arteries may recur, and angioplasty or stenting may have to be done again.
How is the disease monitored? Regular follow-up visits with the doctor will be needed to check blood pressure and kidney function.
Author: Crystal R. Martin, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 14/11/2004 Contributors Potential conflict of interest information for reviewers available on request
