Renal Artery Stenosis (RAS)
Narrowing of one or both arteries of the kidney is a condition called renal
artery stenosis (RAS). The most common cause of RAS is atherosclerosis,
in which fatty materials are deposited along the arteries' interior
walls, restricting blood blow to the kidney. Lacking sufficient blood
supply triggers the kidney to "think" that the body's blood
pressure is too low, and it secretes a hormone called Renin, which causes
the body to retain salt and water, resulting in hypertension (high blood
pressure). Approximately 5% of people with high blood pressure can attribute
their condition to RAS. RAS can also cause progressive kidney failure
and pulmonary edema (fluid in the lungs).
Signs of Renal Artery Stenosis:
- Deterioration of kidney function
- Elevated blood pressure unresolved with oral medications
- Sudden worsening of hypertension previously well-controlled
The diagnosis of renal artery stenosis can be made using a combination of:
- Catheter Angiography
- Computed Tomographic (CT) Angiography
- Duplex ultrasound imaging
- Magnetic Resonance Angiography (MRA)
- Radionuclide renal scanning
Many lesions can be fixed using minimally invasive
- Other narrowings require more invasive surgical reconstruction for optimal results.
- Restoring normal blood flow to the kidneys may lower the blood pressure,
preserve renal function and decrease the risk of pulmonary edema.
Following stenting, 30-60% of patients experience improved blood pressure
control, often requiring fewer
medications. Renal function is improved in a smaller percentage of patients.